inria · hal id: inria-00074021 submitted on 24 may 2006 hal is a multi-disciplinary open access...

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HAL Id: inria-00074021 https://hal.inria.fr/inria-00074021 Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination of sci- entific research documents, whether they are pub- lished or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L’archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d’enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Algorithms seminar, 1994-1995 Bruno Salvy To cite this version: Bruno Salvy. Algorithms seminar, 1994-1995. [Research Report] RR-2669, INRIA. 1995. inria- 00074021

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Page 1: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

HAL Id: inria-00074021https://hal.inria.fr/inria-00074021

Submitted on 24 May 2006

HAL is a multi-disciplinary open accessarchive for the deposit and dissemination of sci-entific research documents, whether they are pub-lished or not. The documents may come fromteaching and research institutions in France orabroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, estdestinée au dépôt et à la diffusion de documentsscientifiques de niveau recherche, publiés ou non,émanant des établissements d’enseignement et derecherche français ou étrangers, des laboratoirespublics ou privés.

Algorithms seminar, 1994-1995Bruno Salvy

To cite this version:Bruno Salvy. Algorithms seminar, 1994-1995. [Research Report] RR-2669, INRIA. 1995. �inria-00074021�

Page 2: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

ISS

N 0

249-

6399

appor t de r ech erch e

1994

�✂✁☎✄✝✆✞�✟✆✡✠✞✆☛✁✞☞✌✆✞�✂✍✎✁✏☞✒✑✔✓✎✕✗✖✡✕✌✘✞✙☎✕✌✖✞✘✞✙✡✕✗✕✌✁✚�✂✁☎✛✜✍✎✖✡✢✣☞✤✆✞�✂✥✒✠☎✕✗✕✦✆✧☞✡✠✏✆✡✍✎✢✣☞✌✆✞�✂✥✎✠✡✕

★ ✩✜✪✬✫✮✭✰✯✎✱✳✲✵✴ ✶ ✶✗✷✸✴ ✯✌✹✵✺✻✭✽✼✿✾❁❀❂❀✽❃❅❄✣✾❆❀❇❀✻❈

❉✌❊●❋■❍■❏❑✄▲☞✒✑◆▼✏❖◗P✞❘❙❯❚✝❱❳❲✂❙ ❋❨❊✡❩❭❬ ❱❪❙ ❍ ❲●❱❴❫❛❵ ❋ ❙

❜❞❝❅❡✦❢✌❢✌❣✍✒❬ ❲ ❏✐❤❨❊ ❙❦❥♠❧✐❧✐♥

♦✌✖✞✍✎♣q✖✏☞✒✢r✢r✕✗s

Page 3: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 4: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✁✄✂ ☎ ✆ ✝✟✞ ✠ ✡ ☛ ☛✌☞ ✡ ✝✎✍ � ✆ ✏

✑✓✒✔✒✖✕✘✗✙✑✓✒✔✒✛✚

✜✣✢✥✤✧✦✩★✫✪✭✬✯✮✱✰✳✲✴✱✵✷✶✹✸✻✺ ★✯✢✽✼

✾❀✿❂❁✱❃❅❄❇❆❉❈❊❃✆✹❋ ❙ ❩ ❙ ❩ ❙✱● ❱ ❍❉❍◆❊ ❍■❏ ❲✂❙ ❩✣❊ ❙✱■ ❊ ❙ ❩ ❙ ❍ ❲ ❲ ❋ ❙❏■ ❊✂❏■❬ ❙ ❙❯❚✝❱ ❍▲❑✐❩✣❏❊▼◆❍ ❩ ❙✱● ❱ ❍❉❍◆❊ ❚✝❙✱❖ ❏ ❲✂❙❯❚ ❲ ❏ ❲ ❋ ❙ ❍◆❍❉❍❊P❘◗✝❩ ❱ ❩❏❇▼❙❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ❩❙❍ ❍ ❚ ❊ ❙ P❯❍ ❲✂❙❯❚ ❲ ❏ ■❨❱ ❬ ❩❲❱☛✆✹❋ ❙ ❩✂❋❨❤❨❳ ❙ ❬ ❲ ❩ ❬ ❏ ❖✐❙ ❊ ❙❯❚✸❱ ❍ ❬❩P❪❋ ❚✝❙ ❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏✐❊ ❱ ❬ ❩♠P✌❩❬◗ ● ❤ ❏❨P ❱ ❬❬ ❏ ●❭■ ❋ ❲ ❍ ❲✂❱ ❏✐❍ P❪❍ ❩❫◗ ●❴■■❲ ❏ ❲●❱ ❬❵❍◆❍❉❍❊P❚◗ ❩ ❱ ❩❯P▲❍ ❖✐❙ ❊❛❍❇❑ ❙✻❜ ❬✱❍◆❩ ❙ ❍◆❍❉❍❊P❚◗ ❩ ❱ ❩✞❏❇▼✧❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ❩✧❍ ❍ ❚✣❚ ❍ ❲ ❍ ❩ ❲ ❊●❋ ❬ ❲ ❋■❊ ❙ ❩♠P❍◆❍ ❚ ❬ ❏ ●❭■ ❋ ❲ ❍ ❲✂❱ ❏✐❍❝❍❇P ❍ ❋ ● ❤ ❙ ❊ ❲ ❋ ❙ ❏✐❊❬◗❪❱

☛ ❞☞ ✡ ✝✙✍ � ✝✙✆ ☞ � ✁✄✂ ☎ ✆ ✝❡✞ ✠ ✡ ☞ ☛❢✏

✑✓✒✔✒✖✕✘✗✙✑✓✒✔✒✛✚

✾❀✿❂❁✱❃❅❄❇❆❉❈❊❃✘ ❙ ❩✌❍■❏ ❲●❙ ❩ ❚✝❙ ❩■❘❙✱● ❱ ❍❉❍ ❱ ❊ ❙ ❩ ❊ ❙✱■ ❊■❘❙ ❩ ❙ ❍ ❲●❙ ❍ ❲ P ❙ ❩✧❍✐❬ ❲●❙ ❩❯P ■ ❏✐❋❨❊❂P❣❍ ■ P❪❋ ■ ❍◆❊ ❲✌❙ ❍❴❍◆❍✽❑❨P❣❍ ❱ ❩❯P ❚✐❤ ❋■❍ ❩■❘❙❥●❦❱ ❍❉❍ ❱ ❊ ❙❬ ❏✐❍■❩✻❍✐❬ ❊■❘❙◆❦❍❧P ❤ ❍ ❍❉❍❇P❚◗✝❩ ❙✞❚✐❤ ❍❇P❚❑ ❏✐❊ ❱❳❲ ❋ ●❦❙ ❩ ❙ ❲ ❍◆❋♥♠ ❚ ❏ ● ❍ ❱ ❍ ❙ ❩✌❬ ❏ ❍■❍ ❙ ♠ ❙ ❩❅❱ ✑ ❙ ❩ ❲ ❋ ❦❙✱● ❙ ❩♦❍ ❤ ❏ ❊ ❚ ❘❙ ❩ ❬ ❏ ●❴■ ❊ ❙ ❍ ❜❍ ❙ ❍ ❲✹♣ ❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏ ❱ ❊ ❙ P ❬❥❍❇P ❬ ❋▲P♥▼ ❏✐❊ ● ❙ P✟P❲❍ ❍❉❍❇P❚◗✝❩ ❙ ❍◆❩❬◗ ●❭■■❲ ❏ ❲✂❱ ❵ ❋ ❙ P❇❍◆❍❝❍❇P❚◗✝❩ ❙✞❙ ❍ ● ❏❇◗ ❙ ❍■❍ ❙✞❚✐❤ ❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ●❦❙ ❩❙ ❲✡❚✝❙ ❩ ❲ ❊✂❋ ❬ ❲ ❋■❊ ❙ ❩ ❚✝❙q❚ ❏✐❍❨❍ ❘❙ ❙ ❩♠Pq❍ ❱ ❍■❩ ❱✜❵ ❋ ❙q❚✝❙ P❣❍ ❲ ❋✞❘❙ ❏ ❊ ❱❳❙ ❍❇P❚❑ ❏✐❊ ❱❳❲ ❋ ●❦❱ ❵ ❋ ❙✞❚✝❙ ❩✡❍❨❏ ● ❤■❊ ❙ ❩❲❱

Page 5: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 6: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☎✄✝✆✟✞✡✠☞☛✍✌✏✎✒✑✓✑✕✔✖✎✗✠✝❜✏�✂✞✘ ❣✌❣✚✙✜✛ ✘ ❣✌❣✣✢✤✦✥★✧✪✩✬✫✮✭✰✯★✱✳✲✵✴✷✶✸✺✹☎✻✪✼✳✽ ✫★✥✿✾

✾❀✿❂❁✱❃❅❄❇❆❉❈❊❃✆✹❋ ❙ ❩ ❙ ❩ ❙✱● ❱ ❍❉❍◆❊ ❍■❏ ❲✂❙ ❩✣❊ ❙✱■ ❊ ❙ ❩ ❙ ❍ ❲ ❲ ❋ ❙❏■ ❊✂❏■❬ ❙ ❙❯❚✝❱ ❍▲❑✐❩✣❏❊▼◆❍ ❩ ❙✱● ❱ ❍❉❍◆❊ ❚✝❙✱❖ ❏ ❲✂❙❯❚ ❲ ❏ ❲ ❋ ❙ ❍◆❍❉❍❊P❘◗✝❩ ❱ ❩❏❇▼❙❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ❩❙❍ ❍ ❚ ❊ ❙ P❯❍ ❲✂❙❯❚ ❲ ❏ ■❨❱ ❬ ❩❲❱☛✆✹❋ ❙ ❩✂❋❨❤❨❳ ❙ ❬ ❲ ❩ ❬ ❏ ❖✐❙ ❊ ❙❯❚✸❱ ❍ ❬❩P❪❋ ❚✝❙ ❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏✐❊ ❱ ❬ ❩♠P✌❩❬◗ ● ❤ ❏❨P ❱ ❬❬ ❏ ●❭■ ❋ ❲ ❍ ❲✂❱ ❏✐❍ P❪❍ ❩❫◗ ●❴■■❲ ❏ ❲●❱ ❬❵❍◆❍❉❍❊P❚◗ ❩ ❱ ❩❯P▲❍ ❖✐❙ ❊❛❍❇❑ ❙✻❜ ❬✱❍◆❩ ❙ ❍◆❍❉❍❊P❚◗ ❩ ❱ ❩✞❏❇▼✧❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ❩✧❍ ❍ ❚✣❚ ❍ ❲ ❍ ❩ ❲ ❊●❋ ❬ ❲ ❋■❊ ❙ ❩♠P❍◆❍ ❚ ❬ ❏ ●❭■ ❋ ❲ ❍ ❲✂❱ ❏✐❍❝❍❇P ❍ ❋ ● ❤ ❙ ❊ ❲ ❋ ❙ ❏✐❊❬◗❪❱

❀❂❁✪❃❅❄❆❃❅❄❂❇❈❁❊❉❂❋❍●❏■❊❑❈❇❈❁✍●★❋✚●❏■❊❑▲❄▼❉◆❑▼❃❖❉P❄◗●★❋✬❄▼❉◆❘✖❃❖❙❯❚★❑❂❱❊❑❈●❊❲❳❉◆❉P❨❩❃❖❙❊❬❭❄◆❪❂❀❂❁❊❉✦❱❊❑❈❉◆❫❏❃❖●❏■❯❄❴●❏❙❊❉P❄❵❁❯❚❛❫❏❉☎❚★❱❊❱❯❉P❚✵❑❈❉P❨❜❚❩❄❞❝▼❡❣❢❴❝✐❤❢❂❉P❄▼❉P❚✵❑✿❲❈❁❥❢❂❉◆❱✜●❏❑❈❇✿❄❦❙✪■❊❘♠❧✜❉◆❑✿❄✂♥★♦❏♦★♣❊qsrt♥P✉❏✈✇❚★❙❯❨①r❏✉❩②❊♥❏❪❥❀❂❁❊❉✂❲❳●❏❙❭❇③❉◆❙❭❇✍●★❋④❇❈❁❊❉P❄▼❉✡❱❊❑❈●❊❲❳❉◆❉P❨❩❃⑤❙❊❬✪❄✟❲❳●❏❙❯❄✺❃❅❄▼❇❳❄⑥●★❋❄▼■❊❘⑥❘✍❚★❑▼❃❖❉P❄❂●★❋❵❇❈❁❊❉☎❇✿❚❛⑦❖⑧❊❄◆q❊■❯❄▼■❯❚☞⑦⑨⑦❖⑩✡❶▲❑▼❃❖❇❈❇❈❉◆❙✮❧✪⑩❷❚❸❑❈❉◆❱❯●❏❑③❇❈❉◆❑❂❋❍❑❈●❏❘✗❇❈❁❊❉♠❚✵■❯❨❩❃⑤❉◆❙❯❲❳❉❏❪❀❂❁❊❉❹❱❊❑▼❃❖❘❜❚★❑❈⑩✡❬❏●❭❚❛⑦✬●✵❋❞❇❈❁✪❃❅❄❣❄▼❉◆❘❸❃⑤❙❯❚✵❑✦❃❺❄✦❇③●❜❲❳●★❫❏❉◆❑❣❇③❁❊❉♠❘✍❚★❻▼●❏❑❂❘⑥❉◆❇❈❁❊●❊❨❊❄✦●★❋❞❇❈❁❊❉♠❚❛❫❏❉◆❑❳❚★❬❏❉◆❼✐❲◆❚❏❄▼❉④❚✵❙❯❚❛⑦❖⑩❽❄✺❃❅❄✦●★❋

❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘❜❄▲❚★❙❯❨✮❨❊❚★❇❳❚⑥❄▼❇❈❑❈■❯❲❳❇③■❊❑❈❉P❄◆❪❵❡▲❉❳❃❖❬❏❁✪❧❯●❩■❊❑▼❃❖❙❊❬✮❇❈●❏❱✪❃❅❲◆❄❂●★❋❞❄▼❇❈■❯❨✪⑩✮❚★❑❈❉④❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❲◆❄◆q❯❄▼⑩✪❘✖❧❯●★⑦❿❃❅❲✖❲❳●❏❘⑥❱❊■❊❼❇✿❚★❇❾❃⑤●❩❙✟❚★❙❯❨✮❚❏❄▼⑩✪❘⑥❱❊❇❈●❏❇❾❃❺❲☎❚✵❙❯❚❛⑦❖⑩❽❄✺❃❅❄◆❪➀ ❉◆❫❏❉◆❑✿❚☞⑦✷❚★❑❈❇❾❃❺❲③⑦❖❉P❄▲❨✪❉P❚☞⑦✷❶❴❃⑤❇③❁✟❲❳●❏❘✖❧✪❃⑤❙❯❚✵❇❈●❏❑▼❃❅❚❛⑦✰●❏❧❊❻▼❉P❲❳❇✿❄✺➁➂❇❈❁❊❉❳❃❖❑❣❨✪❉P❄❈❲❳❑❾❃⑤❱❊❇❾❃⑤●❩❙✮●❏❑❂❇❈❁❊❉❳❃❖❑▲❑✿❚★❙❯❨✪●❏❘➃❬❏❉◆❙❊❉◆❑✿❚★❇❾❃⑤●❩❙✪➁

❇❈❁❯❚★❇▲❚★❑③❉☎■❯❄▼❉❳❋➄■✪⑦✣❋❍●❏❑▲❄✺❃❖❘♠■✪⑦❅❚★❇❾❃⑤●❩❙❯❄❣❚★❙❯❨➅❉◆❘⑥❱✪❃❖❑▼❃❅❲◆❚❛⑦❞❄▼❇❈■❯❨❩❃❖❉P❄◆❪➆ ●❏❘❦❱❊■❊❇❈❉◆❑④❚❛⑦❖❬❏❉◆❧❊❑✿❚✍❱✪⑦❅❚❛⑩❽❄☎❚✵❙✟❃❖❙❯❲❳❑❈❉P❚❩❄✺❃❖❙❊❬★⑦❖⑩✂❃❖❘⑥❱❯●❏❑③❇✿❚★❙✪❇☎❑❏➇●★⑦❖❉❹❃⑤❙➈❇❈❁✪❃❅❄④❚★❑❈❉P❚t❪☎❝✐❇☎❱❊❑❈●★❫❩❃❅❨✪❉P❄④❚✍❲❳●★⑦❿⑦⑤❉P❲❳❇❾❃⑤●❩❙✏●★❋

❇❈●✪●★⑦❅❄▲❇③❁❯❚★❇▲❱❯❉◆❑③❘✖❃❖❇❣❇❈●✍❚★❇❈❇✿❚❏❲③⑧❜❲❳●❏❘❦❱✪⑦⑤❉❳➉✂❘⑥●❊❨✪❉❳⑦❺❄➊●★❋s❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❲◆❄❣❚★❙❯❨✍●✵❋❞❇❈❁❊❉④❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄✦●★❋❆❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘❜❄◆➋✰❚★❇❇❈❁❊❉☎❄❈❚★❘⑥❉➊❇▼❃❖❘⑥❉❏q❩❃⑤❇❆❃❖❙❯❄▼❱✪❃❖❑❈❉P❄▲❇③❁❊❉❣➌❏■❊❉P❄❾❇❞❋❍●❏❑❂❨✪❉◆❫❏❉❳⑦❖●❏❱✪❃❖❙❊❬⑥❉◆❫❏❉◆❑❞❘❦●❏❑❈❉❣❄▼⑩❊❄▼❇❈❉◆❘✍❚★❇▼❃❅❲▲❄▼●★⑦❖■❊❇▼❃❖●❏❙❯❄❴❇❈●☎❇❈❁❊❉☎❚★❙❯❚❛⑦❖⑩❽❄✳❃❺❄◗●★❋❶❂❉❳⑦❿⑦❆❲③❁❯❚★❑✿❚❏❲❳❇③❉◆❑▼❃❖➍◆❉P❨✟❲③⑦❅❚❏❄❈❄▼❉P❄➊●★❋❞❱❊❑❈●❩❧✪⑦⑤❉◆❘✍❄◆❪❂❝✐❙✂❇❈❁✪❃❅❄➊❫❏❉❳❃❖❙✚q❯❇❈❁❊❉❹❙❊●❏❇❈❉P❄✦❲❳●❏❙✪❇✿❚❛❃❖❙➎❄▼❉◆❫❩❉◆❑✿❚❛⑦✬❑❈❉P❲❳❉◆❙✪❇❣❨✪❉◆❫❏❉❳⑦❖●❏❱❊❘❦❉◆❙❭❇✿❄❑❈❉◆❬❭❚✵❑✿❨❩❃❖❙❊❬⑥❇❈❁❊❉♠❚✵■❊❇❈●❏❘❜❚★❇❾❃❺❲➊❘❜❚★❙✪❃❖❱❊■✪⑦❅❚★❇▼❃❖●❏❙✂●★❋❞❨❩❃❿➏✚❉◆❑❈❉◆❙❭❇❾❃❺❚☞⑦✕❚★❙❯❨✮❑③❉P❲❳■❊❑❈❑❈❉◆❙❯❲❳❉④❉P➌❩■❯❚★❇▼❃❖●❏❙❯❄➐❪❤☎❄▼⑩❭❘❦❱❊❇❈●❏❇▼❃❅❲✮❘❦❉◆❇❈❁❊●❽❨❊❄❦❁❯❚❛❫❏❉✟❧✜❉◆❉◆❙❥❲❳●☞❫❩❉◆❑❈❉P❨➑❉❳➉❊❇❈❉◆❙❯❄✺❃❖❫❏❉❳⑦❖⑩➑❃❖❙①❇❈❁❊❉✡❱❊❑❈❉◆❫❏❃❖●❏■❯❄✍❫❩●★⑦❖■❊❘⑥❉P❄⑥●✵❋④❇❈❁✪❃❅❄❜❄▼❉◆❘❸❃⑤❙❯❚✵❑P❪

❀❂❁❊❉P❄▼❉☎❱❊❑③●❽❲❳❉◆❉P❨❩❃❖❙❊❬❭❄◗❃❖❙❯❲③⑦❖■❯❨✪❉⑥❚★❱❊❱❊❑❈●❭❚❩❲❈❁❊❉P❄◗❇❈●⑥❨❩❃❖❫❏❃❅❨✪❉◆❼✐❚★❙❯❨✪❼✐❲❳●❩❙❯➌❏■❊❉◆❑☎❑❈❉P❲❳■❊❑③❑❈❉◆❙❯❲❳❉P❄▲❚★❙❯❨❦❇❈●⑥❄▼●❏❘⑥❉✦❱❊❑❈●❏❧❯❚✵❧✪❃⑨⑦❿❃❅❄▼❇▼❃❅❲❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄▲❶❴❃⑤❇③❁✟❚★❱❊❱✪⑦❿❃❺❲◆❚✵❇▼❃❖●❏❙❯❄✦❇❈●❜❄▼❉◆❫❩❉◆❑✿❚❛⑦✬❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✍❄◆❪❀❂❁❊❉⑥✉❊♥✖❚★❑❈❇▼❃❅❲③⑦❖❉P❄➊❃❖❙❯❲③⑦❖■❯❨✪❉P❨➈❃⑤❙✂❇❈❁✪❃❅❄✦❧✜●❭●❏⑧✡❑❈❉◆❱❊❑❈❉P❄▼❉◆❙✪❇④❄▼❙❯❚★❱❯❄❾❁❊●❏❇✿❄➊●★❋❴❲❳■❊❑❈❑③❉◆❙❭❇✦❑❈❉P❄▼❉P❚★❑❳❲❈❁✡❃❖❙✂❇❈❁❊❉P❄▼❉⑥❚★❑❈❉P❚❏❄➐❪❣❤

❇❈❉◆❙✪❇✿❚★❇▼❃❖❫❏❉☎●❩❑❈❬❭❚★❙✪❃❖➍P❚★❇▼❃❖●❏❙✮●✵❋✕❇❈❁❊❉❳❃❖❑❣❲❳●❩❙❭❇❈❉◆❙✪❇✿❄◗❃❅❄➊❬★❃❖❫❏❉◆❙✮❧❯❉❳⑦❖●★❶④❪

➒s➓✮➔☎→✗➣★↔◗↕⑥➙⑥➛➝➜✖➣◆➞✟➓④→❸➙❸➔✍➣❛↕⑥➟❝✐❙✍❚❏❨❊❨❩❃❖❇▼❃❖●❏❙❜❇③●✦❃⑤❇❳❄❵●★❶▲❙✖❇❈❑✿❚❏❨❩❃❖❇▼❃❖●❏❙❯❄❆❑❈●✪●❏❇❈❉P❨➠❃❖❙❜❘❜❚✵❇❈❁❊❉◆❘❜❚★❇▼❃❅❲◆❄◆q★❇③❁❊❉❣❄▼❇❈■❯❨✪⑩✖●★❋❵➡✿➢❏➤⑥➥➐➦❅➧✜➨❏➩❍➢❏➫❳➦❅➨❏➭✜➤✖➢P➯❏➲❛➭➵➳❣❚✵❑▼❃❅❄▼❉P❄

❙❯❚★❇❈■❊❑❳❚❛⑦❿⑦⑤⑩➠❃❖❙⑥❇❈❁❊❉❂❱❊❑❈●❊❲❳❉P❄❈❄✣●★❋➸❚★❙❯❚❛⑦❖⑩✪➍❳❃❖❙❊❬♠❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘❜❄✣❇❈❁❯❚★❇✣●★❋❍❇❈❉◆❙☎❃❖❙✪❫❏●★⑦❖❫❏❉❣❲③⑦❅❚❏❄❈❄✳❃❺❲◆❚☞⑦➸❲❳●❏❘✖❧✪❃⑤❙❯❚✵❇❈●❏❑▼❃❅❚❛⑦❯❄▼❇❈❑❈■❯❲❳❇③■❊❑❈❉P❄⑦❿❃❖⑧❏❉♠❄▼❇③❑▼❃❖❙❊❬❭❄◆q❊❇❈❑③❉◆❉P❄◆q❊❬❏❑✿❚✵❱❊❁❯❄◆q✪❱❯❉◆❑❈❘✖■❊❇✿❚★❇❾❃⑤●❩❙❯❄◆❪❝✐❙①➺➼➻❏➽❈q✚❚★❙✏❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘➾❋❍●❏❑☎❑✿❚✵❙❯❨✪●❏❘➾❬❏❉◆❙❊❉◆❑✿❚★❇❾❃⑤●❩❙✇●★❋❣❄▼❉◆❇✿❄✦●★❋✦➚❍❃✐❪➪❉❏❪⑥❶❴❃⑤❇③❁❊●❏■❊❇④❑❈❉◆❱✜❉◆❇▼❃❖❇▼❃❖●❏❙✰➶❣●✵❋❴❫★❚★❑▼❃❖●❏■❯❄❹❲❳●❏❘⑥❼

❧✪❃❖❙❯❚★❇❈●❏❑❾❃❺❚☞⑦❴●❩❧❊❻✳❉P❲❳❇❳❄✦❃❅❄✖❨✪❉P❄❈❲❳❑▼❃❖❧❯❉P❨✰❪✂❤☎❄▼❱❯❉P❲❳❇❳❄④●✵❋❣❇❈❁❊❉❜❄▼❇③■❯❨✪⑩✇●★❋❣❢▲❡➊❤➹❚★❑③❉⑥❇❈❁❊❉✮❄▼■❊❧❊❻▼❉P❲❳❇④●★❋❸➺❺➘✪➽❈❪✍❤❣■❊❇❈●❩❘❜❚★❇▼❃❅❲❄▼❉P➌❩■❊❉◆❙❯❲❳❉P❄☎❚★❙❯❨✮❇③❁❊❉❳❃⑤❑④❲❳●❩❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩✟❚★❑❈❉✖❨❩❃❺❄③❲❳■❯❄❈❄▼❉P❨✡❃❖❙➴➺❿➷t➽❈❪ ➀ ●❏❘⑥❉④❨✪●❏■❊❧✪⑦❖❉❜❄❾❉P➌❏■❊❉◆❙❯❲❳❉P❄☎❚★❙❯❨➅❇❈❁❊❉❳❃❖❑➬❚❩❄▼⑩❭❘❦❱❊❇❈●❏❇▼❃❅❲❱❊❑❈●❏❱✜❉◆❑❈❇▼❃❖❉P❄④❚✵❑❈❉❜❄▼❇❈■❯❨❩❃❖❉P❨➮❃❖❙➱➺❐✃❯➽❈❪⑥❒❮❃❖❙❯❚❛⑦❿⑦❖⑩❏q❣➺❺❰❭➽❂❬★❃❖❫❏❉P❄☎❚✵❙✏❚★❑▼❃❖❇❈❁❊❘⑥❉◆❇❾❃❺❲❸❃❖❙❭❇③❉◆❑❈❱❊❑❈❉◆❇✿❚★❇❾❃⑤●❩❙➎❇③●➎❄✺❃❖❘⑥❱✪⑦❖❉✍●❏❱❯❉◆❑✿❚✵❇▼❃❖●❏❙❯❄●❏❙✮❧✪❃❖❙❯❚★❑❈⑩✮❇③❑❈❉◆❉P❄◆❪Ï ✆✹❋ ❱ ❩✦Ð ❏ ❊✐Ñ✮Ð✹❍◆❩ ❩✂❋ ■✽■ ❏ ❊ ❲✂❙♠❚✗❱ ❍ ■ ❍◆❊ ❲ ❤❪◗ ❲ ❋ ❙ ✕✤✄■♦✌✖✞�✟✆❅�✂�✂� ❉ ❍◆❩ ❱ ❬ ✖ ❙ ❩ ❙ ❍◆❊ ❬❫❋ ☞✒❬ ❲●❱ ❏ ❍ ♦✦❊●❏❨❑ ❊❛❍ ●❭●❦❙ ❏❊▼ ❲ ❋ ❙ ✕✹❱ ✘✭❱❋■❍ ❚▲❙ ❊✒❬ ❏ ❍ ❲ ❊❛❍ ❬ ❲ ☞✒✑ ✘✞✍✎✢ �✂�◗Ò➄Ó☎Ô ❥❈Õ ❥❳Ö ❱

Page 7: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➺➼➻❩➽✁�▲❙✪❃❿❋❍●❏❑❈❘ ❢▲❚✵❙❯❨✪●❏❘✄✂❣❉◆❙❊❉◆❑❳❚★❇▼❃❖●❏❙✮❋❍●❏❑❂❇❈❁❊❉✆☎✣●☞❶❂❉◆❑✿❄❾❉◆❇ ➆ ●❏❙❯❄❾❇❈❑❈■❯❲❳❇▼❃❖●❏❙✚❪✞✝✠✟☛✡✌☞✎✍✑✏✓✒✔✒✖✕✘✗✙✒✖✟✛✚☛✚➺❺➘✪➽☎❤❣❙✢✜✤✣❷❲③❃❖❉◆❙❭❇✥☎❵❚★❑✿❄▼❉◆❑✧✦✇❉❳⑦❿⑦ ➀ ■✪❃❖❇❈❉P❨✡❇❈●⑥❢▲❡➊❤ ❒❊●✵⑦❺❨❩❃❖❙❊❬❯❪✧★✩✟☛✪✫✗✬✏✮✭✯✕✱✰✲✕✘✳✴✕✛✪✶✵✫✗✯✕➺❿➷t➽✁☎❵❚❏❄❈❲◆❚❛⑦✸✷➵❄❂❀❮❑▼❃❅❚★❙❊❬★⑦❖❉❏q❯❤✦■❊❇❈●❏❘✍❚★❇✿❚❊q✪❚★❙❯❨✢✹✡■❯❄✺❃❅❲★❪✧✺✶✕✻✟✫✚✑✼✽✝✠✟✾✡✌☞✎✿❀☞❁☞❃❂✾✡❄✭✬❅✑✕➺❐✃✜➽④❢◗❃❖●❏❑✿❨❊❚★❙✡❤❣❑❈❑❳❚P⑩❊❄❂❚★❙❯❨✍❇❈❁❊❉❳❃❖❑✦❤❣❱❊❱✪⑦❿❃❅❲◆❚★❇▼❃❖●❏❙❯❄◆❪❇❆❈❂✫✚✑✟❊❉✬✕✙☞❋☞❃✟❍●■✕✘✗✬☞❋✏✓✚❄✏➺❺❰✪➽ ➀ ❇❈❑❈■❯❲❳❇❈■❊❑❈❉P❨✮❡➊■❊❘✖❧❯❉◆❑✿❄➐❪✥❏✎✏❑✚✩✭✯✕✘✚✑❉▼▲✠☞❃❂✛✚✩◆❄✕✙☞

➒❂➓✮➔☎→ ➣P➣★↔◗➟✩❖✟➛➝➜❦➙◗P◗➣❛↕➾↕⑥➙❸➛➝➒❈❘✮→❂➓④→④➣❛➙⑥➞✹✡●❭❄▼❇⑥❉❳➉❯❚❏❲❳❇▼⑦❖⑩①❄▼●★⑦❖❫☞❚★❧✪⑦❖❉✇❘❦●❽❨✪❉❳⑦❅❄✮●✵❋♠❲❳●❏❘✖❧✪❃⑤❙❯❚✵❇❈●❏❑▼❃❅❲◆❄✮❚★❙❯❨①❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄✍●★❋♠❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘❜❄✍❑❈❉P❄▼❇✍●❏❙➱❚➑❄❾■✪❃⑤❇❳❚★❧✪⑦❖❉

❚❛⑦❖❬❏❉◆❧❊❑✿❚✦●✵❋❚❙❏➲P➧✜➲P➫▼➨❏➩❍➦➼➧❊❙❱❯❳❲✪➧❯➡❛➩❍➦❅➢❩➧❊➳◆❪✲❨▲❙❯❲❳❉▲❇❈❁✪❃❅❄❵❁❯❚❏❄❮❧❯❉◆❉◆❙✍❑❈❉P❲❳●❏❬❩❙✪❃⑤➍◆❉P❨✰q✪❚★❙❹❃❖❘⑥❱❯●❏❑③❇✿❚★❙✪❇✬❬❏●✪❚❛⑦❭❃❅❄✣❇❈●❬❩❯❙❯❨✖❨✪❉P❲③❃❅❄✺❃❖●❏❙❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉P❄❴❋➄●❏❑▲❲③⑦❅❚❏❄❈❄❾❉P❄▲●★❋❵❬❏❉◆❙❊❉◆❑✿❚✵❇▼❃❖❙❊❬✖❋➄■❊❙❯❲❳❇❾❃⑤●❩❙❯❄◆❪ ➆ ●❏❘❦❱❊■❊❇❈❉◆❑❣❚❛⑦❖❬❏❉◆❧❊❑✿❚❦❄▼⑩❽❄❾❇❈❉◆❘❜❄❂❱❊❑❈●★❫❩❃❅❨✪❉④❚✖❶▲❚P⑩❦●★❋✕❇③❉P❄▼❇▼❃❖❙❊❬❚★❙❯❨❸❃❖❘⑥❱✪⑦❖❉◆❘⑥❉◆❙❭❇❾❃⑤❙❊❬✍❇❈❁❊❉✦❘⑥❉◆❇❈❁❊●❊❨❊❄◆q❊❚★❙❯❨❦❇❈❁❊❉❣❱❊❑③●❏❧✪⑦❖❉◆❘ ●✵❋✷●❩❱❊❇▼❃❖❘✖❃❖➍❳❃⑤❙❊❬✍❇❈❁❊❉☎❲❳●❏❑❈❑❈❉P❄❾❱❯●❏❙❯❨❩❃❖❙❊❬⑥❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉P❄◗●★❋❍❇❈❉◆❙❑❈❉◆❱❊❑❈❉P❄❾❉◆❙❭❇✿❄➊❚✖❙❊●❏❙❊❼❍❇❈❑▼❃❖❫❩❃❅❚❛⑦✕❱❊❑③●❏❧✪⑦❖❉◆❘ ●★❋❵❄▼⑩❭❘✖❧✜●★⑦❿❃❺❲✖❲❳●❏❘❦❱❊■❊❇✿❚★❇▼❃❖●❏❙✚❪❤✦❙✖❃❖❘⑥❱❯●❏❑③❇✿❚★❙✪❇s❲③⑦❅❚❏❄❈❄◗●★❋✚❬❏❉◆❙❊❉◆❑✿❚✵❇▼❃❖❙❊❬④❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄❆❃❅❄❆❋➄●❏❑③❘⑥❉P❨✖❧✪⑩❸❄❾●★⑦❖■❊❇▼❃❖●❏❙❯❄◗●★❋✰⑦⑨❃❖❙❊❉P❚★❑▲❨❩❃❿➏✚❉◆❑❈❉◆❙✪❇▼❃❅❚❛⑦✚❉P➌❏■❯❚★❇❾❃⑤●❩❙❯❄◆❪

❤➊⑦⑤❇③❉◆❑❈❙❯❚★❇▼❃❖❫❏❉❳⑦❖⑩❏q✪❇❈❁❊❉▲❲❳●❭❉✯✣✮❲③❃⑤❉◆❙✪❇✿❄❆●★❋➸❇❈❁❊❉P❄❾❉s❬❩❉◆❙❊❉◆❑✿❚★❇▼❃❖❙❊❬✦❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄❞❲◆❚★❙❦❧❯❉❂❬★❃❖❫❏❉◆❙⑥❧✪⑩♠❚➊⑦❿❃❖❙❊❉P❚★❑❞❑③❉P❲❳■❊❑❈❑❈❉◆❙❯❲❳❉❏❪❵❤✦❙❭⑩⑧❩❃⑤❙❯❨✡●★❋s❄❾●★⑦❖■❊❇▼❃❖●❏❙✟❇❈●✍❇❈❁❊❉P❄▼❉❹❉P➌❏■❯❚✵❇▼❃❖●❏❙❯❄❣❲◆❚✵❙✟❧❯❉✖■❯❄▼❉P❨✡❇❈●❦❁❊❉❳⑦⑤❱✂❇❈❁❊❉✖❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄◆❪❭☎✣●★⑦❖⑩✪❙❊●❏❘✖❃❅❚❛⑦❞❄▼●★⑦❖■❊❇▼❃❖●❏❙❯❄✦●★❋❵❫❏❉◆❑❈⑩❬❏❉◆❙❊❉◆❑✿❚☞⑦➸⑦❿❃❖❙❊❉P❚★❑✦❉P➌❏■❯❚✵❇▼❃❖●❏❙❯❄▲❲◆❚★❙✮❧✜❉✦❋➄●❏■❊❙❯❨✮❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✖❃❅❲◆❚❛⑦❿⑦❖⑩✏➺❫❪❭➽❈❪❵❴➊❃❖❫❏❉◆❑❈❬❏❉◆❙✪❇▲❄▼❉◆❑▼❃❖❉P❄➊●★❋➄❇③❉◆❙❜●❊❲◆❲❳■❊❑❣❚❏❄❂❄▼●★⑦❖■❊❇▼❃❖●❏❙❯❄❇❈●✍⑦❿❃❖❙❊❉P❚★❑♠❨❩❃❿➏✚❉◆❑❈❉◆❙✪❇▼❃❅❚❛⑦s❉P➌❩■❯❚★❇▼❃❖●❏❙❯❄➐q✚❧❊■❊❇④❄▼❉◆❫❏❉◆❑❳❚❛⑦s❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✍❄✦❘❜❚★⑧❏❉❹❃❖❇④❱✜●❭❄❈❄✺❃❖❧✪⑦❖❉❜❇③●✟❨✪❉P❚❛⑦❞❶❂❃❖❇❈❁✇❇❈❁❊❉◆❘ ➺❋❛t➽❈❪④❤❬❏❉◆❙❊❉◆❑✿❚☞⑦❞❋❍❑✿❚★❘⑥❉◆❶❂●❏❑❈⑧➅❋➄●❩❑④❇❈❁❊❉⑥❘✍❚★❙✪❃❖❱❊■✪⑦❺❚✵❇▼❃❖●❏❙➑●★❋❂⑦❿❃⑤❙❊❉P❚✵❑♠●❩❱❯❉◆❑✿❚★❇③●❏❑✿❄④❚✵❙❯❨✂❱❊❑❈●✪●★❋▲●★❋❣❲❳●❏❘✖❧✪❃⑤❙❯❚✵❇❈●❏❑▼❃❅❚❛⑦◗❃❺❨✪❉◆❙✪❇▼❃❖❇▼❃❖❉P❄❃❅❄✖❇❈❁❊❉✟❄▼■❊❧t❻✳❉P❲❳❇⑥●✵❋❦➺❋❜t➽❈❪✇❝✐❙ ➺➼➻❄❝❊➽❈q❞❚➮❑❈❉◆❘❜❚★❑❈⑧✝❚★❧❯●❏■❊❇✖❇❈❁❊❉✮■❯❄❾❉✟●★❋➬❄❾■❯❲❈❁➑❇❈❉P❲③❁❊❙✪❃❅➌❏■❊❉P❄❸❋❍●❏❑❡❞❛❼➼❃❅❨✪❉◆❙❭❇▼❃❖❇▼❃❖❉P❄❦⑩❏❃❖❉❳⑦❅❨❊❄❄▼❁❊●❏❑③❇❣❱❊❑❈●✪●★❋✐❄✦●★❋s❄▼●❏❘❦❉♠●✵❋❞❇❈❁❊❉⑥❢❂●❏❬❏❉◆❑✿❄❾❼✐❢▲❚★❘❜❚★❙✪■★❻❈❚★❙✡❃❺❨✪❉◆❙✪❇▼❃❖❇▼❃❖❉P❄◆❪ ➀ ❉◆❑▼❃❖❉P❄☎❨✪❉✯❩❯❙❊❉P❨➈❧❭⑩✂❄▼⑩❊❄▼❇❈❉◆❘❜❄➊●★❋❞❙❊●❏❙❊❼➼⑦❿❃❖❙❊❉P❚★❑❨❩❃❿➏✚❉◆❑❈❉◆❙❭❇❾❃❺❚☞⑦s❉P➌❩■❯❚★❇▼❃❖●❏❙❯❄④❲◆❚✵❙✇❧❯❉⑥❘✍❚★❙✪❃❖❱❊■✪⑦❺❚✵❇❈❉P❨✝❉❳➏✚❉P❲❳❇▼❃❖❫❏❉❳⑦❖⑩❏q✕❚✵❙❯❨✡❃❖❙✇❱❯❚★❑❈❇▼❃❅❲❳■✪⑦❅❚★❑✖❇❈❁❊❉❳❃❖❑④❉P➌❩■✪❃❖❫☞❚❛⑦❖❉◆❙❯❲❳❉✮❱❊❑❈●❩❧✪⑦⑤❉◆❘❃❅❄❜❄❾●★⑦❖❫☞❚★❧✪⑦❖❉➴➺➼➻✜➻❏➽❈❪✝❤ ❋➄❑✿❚✵❘⑥❉◆❶❂●❏❑❈⑧✂❋❍●❏❑⑥❚❏❄▼⑩✪❘⑥❱❊❇❈●❏❇❾❃❺❲✍❉❳➉❊❱❯❚★❙❯❄✺❃❖●❏❙❯❄❦❧✪⑩➴❲❳●❏❘❦❱❊■❊❇❈❉◆❑❜❚❛⑦❖❬❏❉◆❧❊❑✿❚➎❃❺❄❦❬★❃❖❫❏❉◆❙✝❃❖❙ ➺➼➻t➘❭➽❈❪❨▲❇❈❁❊❉◆❑✂❲❳●❏❘⑥❱❊■❊❇❈❉◆❑✂❚❛⑦❖❬❏❉◆❧❊❑✿❚➑❇③●❏❱✪❃❅❲◆❄✟❚★❑❈❉✂❇❈❁❊❉✝❨✪❉◆❇❈❉◆❑❈❘✖❃❖❙❯❚★❇▼❃❖●❏❙✓●★❋✖❇❈❁❊❉✏❄✺❃❖❬❏❙❥●✵❋❸❨✪❉◆❇❈❉◆❑❈❘❸❃⑤❙❯❚✵❙❭❇✿❄➅❶❂❃❖❇❈❁ ❄✺❃❖❙❊❬★⑦❖❉◆❼❱❊❑❈❉P❲③❃❅❄✺❃❖●❏❙①❚★❑▼❃❖❇❈❁❊❘⑥❉◆❇▼❃❅❲✇➺❋❢t➽❈q✚❋✐❚❏❄▼❇✖❲❳●❏❘⑥❱❊■❊❇✿❚✵❇▼❃❖●❏❙✏●❩❙✏❘❜❚✵❇❈❑▼❃❅❲❳❉P❄✖●★❫❏❉◆❑♠❚❣❩❯❙✪❃❖❇❈❉✖❩❯❉❳⑦❅❨ ➺➼➻✪➷❊➽❈q❮❋✐❚❏❲❳❇❈●❏❑▼❃❖➍P❚★❇❾❃⑤●❩❙✏●★❫❏❉◆❑❩❯❙✪❃❖❇❈❉✥❩❯❉❳⑦❅❨❊❄✖➺➼➻❏✃✜➽❈q❭❉✯✣✮❲③❃⑤❉◆❙✪❇❣❲❳●❏❘❦❱❊■❊❇✿❚★❇▼❃❖●❏❙❯❄❂❶❴❃⑤❇③❁✟❚❛⑦❖❬❏❉◆❧❊❑✿❚❛❃❅❲④❲❳■❊❑③❫❏❉P❄④➺➼➻❊❰✪➽❈q❭❚★❙❯❨❦❃❖❙✪❇❈❉◆❬❏❑✿❚✵❇▼❃❖●❏❙✮●★❋❵❁❭⑩✪❱❯❉◆❑❈❉❳⑦❿⑦❿❃❖❱❊❇▼❃❅❲❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄♠➺➼➻❄❢❊➽❈❪

➺❋❢t➽✁✜❵❫☞❚☞⑦⑤■❯❚✵❇▼❃❖❙❊❬ ➀ ❃❖❬❏❙❯❄➊●★❋✤❴✦❉◆❇❈❉◆❑③❘✖❃❖❙❯❚★❙❭❇❳❄◆❪✧✺✶✕✻✟✛✚✑✼✽❆❈✟✫✚❄✏✽✕✙☞❵▲❀❂❤✏❑✐✙✐✯❂✛✚☛✚✑✟❄❉➺❫❪✪➽✁☎✣●★⑦❖⑩❭❙❊●❏❘❸❃❺❚☞⑦ ➀ ●★⑦❖■❊❇▼❃❖●❏❙❯❄➊●★❋❱❥➸❃⑤❙❊❉P❚✵❑✁❨▲❱✜❉◆❑✿❚★❇❈●❏❑❬✜❞➌❩■❯❚★❇▼❃❖●❏❙❯❄◆❪✞●■✟✛✗❧❦❄❂✱✝✠✕❤❉✸❦✾❂♠✵✲♥✐❳✕✘❦➺❋❛t➽ ➀ ⑩❭❘✖❧❯●✵⑦⑨❃❅❲❹❚★❙❯❨✟❡➊■❊❘⑥❉◆❑▼❃❅❲◆❚❛⑦✤✹✂❚★❙✪❃❖❱❊■✪⑦❅❚★❇▼❃❖●❏❙❯❄✦●✵❋✤❴➊❃❖❫❏❉◆❑❈❬❏❉◆❙✪❇❭☎✣●★❶❂❉◆❑ ➀ ❉◆❑❾❃⑤❉P❄➐❪❇✺✶✕✻✟✫✚♣♦✎❅✑❂✛✒q✟✛✚☛✚➺❋❜t➽✁r▲●★⑦❖●❏❙❊●❩❘✖❃❅❲ ➀ ⑩❊❄▼❇❈❉◆❘❜❄▲❚✵❙❯❨✍❤❣■❊❇❈●❩❘❜❚★❇▼❃❅❲✥☎❵❑③●❭●★❋✐❄◗●★❋❵❝✳❨✪❉◆❙✪❇▼❃❖❇▼❃❖❉P❄◆❪❇★s✗✉t✕❤◆❇t✕✘✗✬✏✮✭✥✈❵❅♠✇✾①✫✟✛❦➺➼➻❄❝❊➽ ➀ ❁❊●❏❑❈❇▲❚★❙❯❨✢✜◗❚❏❄▼⑩ ➆ ●❏❘⑥❱❊■❊❇❈❉◆❑❭☎❆❑❈●✪●★❋ ❄❴●★❋✤☎❵❚★❑❈❇❾❃⑤❇❾❃⑤●❩❙✟❚★❙❯❨✢❞❛❼❍❝✳❨✪❉◆❙✪❇▼❃❖❇▼❃❖❉P❄◆❪✧✝✠✕❤❉✬✕✘✗❇✝✠✟✾✡✌☞❃✕➺➼➻✜➻❏➽✆✜✣➏✚❉P❲❳❇▼❃❖❫❏❉☎❝✳❨✪❉◆❙✪❇▼❃❖❇▼⑩❷❀❮❉P❄▼❇▼❃❖❙❊❬❦❃❖❙②✜✣➉❊❇❈❉◆❙❯❄✺❃❖●❏❙❯❄➊●★❋✞❴➊❃❿➏✷❉◆❑③❉◆❙❭❇▼❃❅❚❛⑦✬❒❮❃❖❉❳⑦❅❨❊❄◆❪❇✿❬✗✬✏❃✟✛✚✑✕❭✝③t✕✙☞✽✟❄◆❄✟✛✚✑✼⑤④❬✕✘✗✙✒q✟➺➼➻t➘❭➽❹❤❣■❊❇❈●❩❘❜❚★❇▼❃❅❲✦❤☎❄▼⑩❭❘❦❱❊❇❈●❏❇▼❃❅❲◆❄◆❪✠✺✶❂✛✗⑥✏✓✐❈✵✻✟✫✚⑦◆❄✕✘✗❇⑧⑨❂❊✕❤✵♠✕✘✚➺➼➻✪➷❊➽✖❡▲●❏❑③❘❜❚❛⑦✎⑩❂❚❏❄▼❉P❄▲❚★❙❯❨ ➆ ❚★❙❊●❏❙✪❃❅❲◆❚❛⑦✕❢▲❚✵❇▼❃❖●❏❙❯❚❛⑦✕❒t●❏❑❈❘➾➚✙❨▲❫❩❉◆❑❴❒❮❃❖❙✪❃❖❇❈❉⑥❒❮❃❖❉❳⑦❅❨❊❄❳➶✿❪✧❆❈✟✛✚❄✏❃✕✙☞✎✿❍✡❷❶✑❂❊❉➺➼➻❩✃❯➽✖❒❯❚❏❲❳❇❈●❩❑▼❃❖❙❊❬◗☎✣●✵⑦⑤⑩✪❙❊●❏❘✖❃❅❚❛⑦❅❄⑨❨▲❫❏❉◆❑❣❒❮❃❖❙✪❃❖❇❈❉⑥❒❮❃❖❉❳⑦❺❨❊❄➐❪▼❆❈✟✛✚❄✏❃✕✙☞✎✝✠✟✫✚✑✟✛✗✬✏❃❂➺➼➻t❰❭➽✖❀❂❁❊❉☎❝✐❙✪❇❈❉◆❬❏❑✿❚☞⑦✉⑩❂❚❏❄✳❃❺❄➊●★❋❞❚★❙✮❤➊⑦⑤❬❩❉◆❧❊❑✿❚❛❃❅❲④❒t■❊❙❯❲❳❇▼❃❖●❏❙➎❒❮❃❖❉❳⑦❅❨✰❪▼●■✟✛✗❧❦✢✵❷✟✛✚❸⑧✥❂❄✕✙✏ ❹➺➼➻❄❢❊➽ ➀ ⑩❭❘✖❧❯●✵⑦⑨❃❅❲ ➆ ●❏❘⑥❱❊■❊❇✿❚✵❇▼❃❖●❏❙✮●★❋✞r▲⑩✪❱❯❉◆❑❈❉❳⑦❿⑦❿❃❖❱❊❇▼❃❅❲✖❝✐❙✪❇❈❉◆❬❏❑❳❚❛⑦❅❄◆❪✞✰✲✟✾✡✫✗❳✕✘✚s❉✞▲❀✕✘✗✻❉❺✗✯✟✛✚✩◆

➒❂➓✮➔☎→✗➣P➣❛➣★↔❵➓✡➟❚❖✟➛➝➒❹→✖➙⑥→④➣❛↕ ➓✮➞✟➓❸P✑❖✂➟✚➣❛➟❤☎❄▼⑩❭❘❦❱❊❇❈●❏❇▼❃❅❲❵❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄❮❃❅❄✬❚★❙☎❉P❄③❄▼❉◆❙❭❇❾❃❺❚☞⑦❭❃❖❙❊❬❏❑❈❉P❨❩❃❖❉◆❙✪❇✚❃❖❙✖❇❈❁❊❉✣❃❖❙✪❇❈❉◆❑❈❱❊❑❈❉◆❇✿❚✵❇▼❃❖●❏❙④●★❋❯➌❩■❯❚★❙❭❇❾❃⑤❇❳❚★❇▼❃❖❫❏❉❞❑③❉P❄▼■✪⑦❖❇✿❄✬❄❾■❊❱❊❱✪⑦⑨❃❖❉P❨

❧✪⑩❜❇❈❁❊❉☎❑③❉P❄▼●★⑦❖■❊❇▼❃❖●❏❙✟●✵❋❆❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❚❛⑦✬❘⑥●❊❨✪❉❳⑦❅❄◆❪❤✦❙✟❃❖❘⑥❱✜●❏❑❈❇✿❚✵❙❭❇❣❲③⑦❅❚❏❄③❄✦●★❋❞❱❊❑❈●❏❧✪⑦❖❉◆❘❜❄➊❃❖❙✪❫❏●★⑦❖❫❏❉P❄✦❑❈❉P❲❳●★❫❏❉◆❑▼❃❖❙❊❬✍❇❈❁❊❉⑥❚❏❄▼⑩✪❘⑥❱❊❇❈●❏❇❾❃❺❲➬❋➄●❩❑❈❘ ●✵❋❞❇❈❁❊❉♠❲❳●✪❉✯✣❷❲③❃❖❉◆❙❭❇❳❄✦●★❋s❚

❋❍■❊❙❯❲❳❇▼❃❖●❏❙✖❋❍❑❈●❏❘ ❚❏❄▼⑩✪❘⑥❱❊❇❈●❩❇▼❃❅❲❞❱❊❑③●❏❱❯❉◆❑❈❇❾❃⑤❉P❄❆●★❋➸❇③❁❊❉❞❋❍■❊❙❯❲❳❇▼❃❖●❏❙✖❃❖❇✿❄❾❉❳⑦⑨❋❈❪❞❀❂❁✪❃❅❄◗❚★❱❊❱❊❑❈●❭❚❏❲③❁❹❃❅❄❵❇✿❚★⑧❩❉◆❙④❃❖❙➎➺➼➻❻❪❭➽✰❇❈●☎❚★❙❯❚❛⑦❖⑩✪➍◆❉❄▼●❏❘❦❉❸❨❩❃❖❫❩❃❅❨✪❉◆❼✐❚★❙❯❨✪❼✐❲❳●❏❙❯➌❩■❊❉◆❑❜❑❈❉P❲❳■❊❑③❑❈❉◆❙❯❲❳❉P❄④❚★❙❯❨➎❃⑤❙①➺➼➻❊❜❊➽❂❇❈●✟❄❾❇❈■❯❨✪⑩✇❄▼❇✿❚★❇▼❃❅❄▼❇❾❃❺❲◆❄✦❑③❉❳⑦❺❚✵❇❈❉P❨✂❇❈●✟❄▼●❩❘⑥❉⑥❱❊❑❈●❏❧❯❚✵❧✪❃⑨⑦❿❃❅❄▼❇▼❃❅❲❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘❜❄◆❪➝❀❂❁❊❉➎❚❩❄▼⑩❭❘❦❱❊❇❈●❏❇▼❃❅❲✮❧✜❉◆❁❯❚❛❫❏❃❖●❏■❊❑✡●★❋♠❄▼●★⑦❖■❊❇▼❃❖●❏❙❯❄✍❇❈●➑❄▼●❏❘❦❉✟❙❊●❏❙❊❼➼⑦❿❃❖❙❊❉P❚★❑➎❨❩❃❿➏✚❉◆❑❈❉◆❙✪❇▼❃❅❚❛⑦④❉P➌❩■❯❚★❇▼❃❖●❏❙❯❄❸❃❺❄❨✪❉P❄❈❲❳❑▼❃❖❧✜❉P❨ ❃❖❙ ➺➼➻❄❛❊➽❈❪ ❝✐❙ ➺❺➘☛❝❊➽❈q▲❄▼❇③❑❈■❯❲❳❇❈■❊❑✿❚❛⑦➊⑦⑨❃❖❘✖❃❖❇✿❚✵❇▼❃❖●❏❙❯❄✮●★❋♠❄❾●❏❘⑥❉➎❲③⑦❅❚❏❄③❄▼❉P❄⑥●✵❋♠❚❏❄▼⑩✪❘⑥❱❊❇❈●❏❇▼❃❅❲➅❉❳➉❽❱❯❚★❙❯❄✳❃⑤●❩❙❯❄✮❚★❑❈❉❱❯●✵❃⑤❙✪❇❈❉P❨➅●❏■❊❇P❪

❱❳❱

Page 8: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➺➼➻❻❪❭➽❹❤➬❄▼⑩✪❘⑥❱❊❇❈●❩❇▼❃❅❲◆❄❂●★❋✤✹✂❚★❁✪⑦❖❉◆❑☎❢❂❉P❲❳■❊❑❈❑❈❉◆❙❯❲❳❉P❄◆❪✧✝✞❅❄✏❋☞❋✏✁�✂�✎✕❍❆ ✡✫✒q✟✛✐➺➼➻❄❛❊➽✔❨❣❄❈❲③❃❿⑦⑨⑦❅❚★❇❾❃⑤❙❊❬✟❢s❃⑤❫❩❉◆❑✿❄◆❪✧★s✗✯✟✛✚✩✭✬❦ ●③✏✮✭⑤❅✑✕✙☞➺➼➻❄❜❊➽❹❤❣❙❯❚❛⑦❖⑩✪❇▼❃❅❲◆❚❛⑦✬❤✦❱❊❱❊❑❈●❭❚❏❲③❁✮❇❈● ➀ ●❩❘⑥❉✁☎❵❑❈●❩❧✪⑦⑤❉◆❘✍❄▲❝✺❙❭❫❏●✵⑦⑤❫❩❃❖❙❊❬✢❨▲❑❳❨✪❉◆❑ ➀ ❇✿❚★❇▼❃❅❄▼❇❾❃❺❲◆❄➐❪☎✄❸❂✻❹❤✭✬✏❃✕❤✭✬❅✝✆✶①✞� ✟✛✚☛❦❄❂✠✟✞✐✙❦ ✏➺❺➘☛❝❊➽✖❀❂❁❊❉ ➀ ●★⑦❖■❊❇▼❃❖●❏❙✟❇③●❜❚ ➆ ●❏❙★❻▼❉P❲❳❇❈■❊❑❈❉☎●✵❋❱r✦❚★❑✿❨✪⑩❏❪✧✺ ❂✛❅☛✚✝✆❊❅✑✟❊✭✬❦❄✕✙☞❋☞

➒❂➓✮➔☎→ ➣✞✡✇↔✣➓✮➞✟➓❸P✑❖✂➟✚➣❛➟➑➙☞☛➃➓❸P✍✌✟➙⑥➔✍➣◆→☎✎✟➛➃➟➂➓✮➞✝✏✑✏✍➓④→❂➓ ➟✚→④➔ ❘✡↕✖→✁❘✮➔✓✒☎➟❀❂❁✪❃❅❄➊❱❯❚★❑❈❇▲❨✪❉P❚❛⑦❅❄▲❶❴❃⑤❇③❁✟❇❈❁❊❉④❚★❙❯❚☞⑦⑤⑩❊❄✺❃❅❄➊●★❋❆❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘❜❄▲❚✵❙❯❨✮❨❊❚★❇✿❚⑥❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉P❄◆❪✦①❁✪❃❿⑦⑤❉◗❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❚❛⑦❯❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄❮❃❺❄❮❇❈❁❊❉◗❘❜❚❛❃❖❙✖❇❈●❭●✵⑦❭●★❋✬➺❺➘➸➻❏➽✪❃❖❙✖❇❈❁❊❉❂❚★❙❯❚❛⑦❖⑩❽❄✳❃❺❄✣●✵❋❽❇❈❁❊❉❀✂➬❚★■❯❄③❄✰❑❈❉P❨✪■❯❲❳❇▼❃❖●❏❙⑥❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘✟q

❄✺❃❖❙❊❬❏■✪⑦❅❚★❑▼❃❖❇▼⑩➑❚★❙❯❚❛⑦❖⑩❽❄✳❃❺❄➠❃❅❄✖❚★❱❊❱✪⑦❿❃❖❉P❨✝❃❖❙ ➺❺➘❯➘✪➽▲❇❈●➎❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘❜❄➠❇❈❁❯❚★❇④❬❩❉◆❙❊❉◆❑✿❚❛⑦❿❃❖➍◆❉➎❄▼⑩✪❘✖❧❯●★⑦❿❃❅❲✮❨❩❃❿➏✷❉◆❑③❉◆❙❭❇▼❃❅❚★❇❾❃⑤●❩❙✚q❞❚★❙❯❨❱❊❑❈●❏❱✜❉◆❑❈❇▼❃❖❉P❄☎●✵❋❞❇❈❁❊❉ ✹✟❉❳⑦❿⑦❿❃❖❙✏❇③❑✿❚★❙❯❄✺❋❍●❏❑❈❘➾❚★❑❈❉✖❉❳➉❊❱✪⑦⑤●✵❃⑤❇③❉P❨✡❃❖❙➱➺❺➘❭✃✜➽s❇③●❷❚★❙❯❚☞⑦⑤⑩✪➍◆❉❜❲❳●❏❘❦❘♠■❊❙✪❃❅❲◆❚★❇❾❃⑤●❩❙➎❱❊❑③●❏❇❈●❊❲❳●★⑦❅❄◆❪④❤✦❙❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘➝❋❍●❏❑❞❑✿❚✵❙❯❨✪●❏❘ ❬❏❉◆❙❊❉◆❑❳❚★❇▼❃❖●❏❙❦❃❺❄❂❚★❙❯❚☞⑦⑤⑩✪➍◆❉P❨❸❃⑤❙✏➺❺➘❊➷❊➽❈❪❮❤❣❙❊●❏❇③❁❊❉◆❑❴❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘➝❋❍●❏❑❂❄▼●★⑦❖❫❏❃❖❙❊❬⑥❚☎❱❊❑③●❏❧✪⑦❖❉◆❘ ❇❈❁❯❚★❇❚★❑▼❃❅❄▼❉P❄❆❃❖❙✮❚★■❊❇❈●❏❘❜❚✵❇▼❃❅❲▲❨❩❃❿➏✷❉◆❑③❉◆❙❭❇▼❃❅❚★❇❾❃⑤●❩❙⑥❃❅❄◗❬★❃❖❫❏❉◆❙❦❃⑤❙✇➺❺➘✾❢t➽❈q❭❚★❙❯❨❸❇❈❁❊❉▲⑦❅❚❏❄❾❇❞❇▼❶❂●☎❙❊●❏❇❈❉P❄❞❨✪❉P❄③❲❳❑▼❃❖❧❯❉☎❱❊❑❈●❏❧✪⑦❖❉◆❘❜❄❴❑❈❉❳⑦❅❚★❇❈❉P❨❇❈●❜❲❳●❩❘⑥❱❊■❊❇✿❚★❇▼❃❖●❏❙❯❚☞⑦✷❬❩❉◆❙❊❉◆❇▼❃❅❲◆❄◆❪➺❺➘✰➻❏➽✖❀❂❁❊❉✆✂➬❚★■❯❄③❄▲❢❂❉P❨✪■❯❲❳❇▼❃❖●❏❙✡❤▲⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘✟❪▼▲✧✗✬✏ ❶❊✏✮❉✙❉⑥✕ ❏✩✟❤☞❋☞✶t✕✻✕➺❺➘✜➘❭➽❹❤❣❫❏❉◆❑❳❚★❬❏❉ ➆ ❚❏❄▼❉☎❤✦❙❯❚❛⑦❖⑩❽❄✳❃❺❄➊●★❋❞❀✚❑③❉◆❉④❢❂❉◆❶▲❑▼❃❖❇▼❃❖❙❊❬ ➀ ⑩❊❄▼❇❈❉◆❘❜❄◆❪❬✈✉✇❻✗⑥✏❁☞✧✈❵❅✑✟✾✪ ✟✾✡❄◆➺❺➘❊➷❊➽❹❝✐❙✪❇❈❉◆❑❈❫☞❚☞⑦✬❤▲⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘✗❋❍●❏❑❣❢▲❚★❙❯❨✪●❩❘ ❡▲■❊❘✖❧✜❉◆❑✁✂✦❉◆❙❊❉◆❑✿❚★❇▼❃❖●❏❙✚❪✞●■✟✛✒q❂✛✗❤✡❈⑧✥❂✛✐❧❅❄✏➺❺➘✪✃❯➽❹❤▲⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘✖❃❅❲✁☎❵❑③●❏❧✪⑦❖❉◆❘❜❄◗❃❖❙➎❡➊●❏❙❊❼ ➆ ❚★❧✪⑦❖❉P❨✂❡➊❉◆❇✳❶❂●❏❑③⑧❽❄◆❪✲✝✞❅❄✏❋☞❋✏✁�✂�✎✕ ✺✶✟❄✭✕✔✾✡ ✕❤❉➺❺➘✜❰❭➽✆✹✮❃❖❙✪❃❖❘❜❚❛⑦❵r★❼✐❨❩❃❖❘⑥❉◆❙❯❄✺❃❖●❏❙❯❚❛⑦✞☎✣❉◆❑▼❃❖●❽❨❩❃❅❲③❃❖❇▼❃❖❉P❄④❚✵❙❯❨❸✹➎❚☞➉❭❃❖❘❜❚❛⑦ ➀ ❱❯❚❏❲❳❉ ➆ ●★❫❏❉◆❑▼❃❖❙❊❬❭❄◆❪✠●✢✏❑✗✯✕✙✏❋☞❋☞❃✕☎✖⑦t✕✬❶✾✚❄✏❃✕✘✗➺❺➘☛❢❊➽✖❢❂❉◆❫❏❉◆❑✿❄✺❃❖❙❊❬✮❚✖❒❮❃⑤❙✪❃❖❇❈❉ ➀ ❉P➌❩■❊❉◆❙❯❲❳❉❏❪▼✰✤❂✘✗✙ ✭❭✝✠❂❊❉✙❉✴✏✽✕✘✗➺❺➘✑❪❭➽❹❤ ➆ ●❩❘⑥❱❊■❊❇❈❉◆❑ ➀ ■❊❱❊❱✜●❏❑❈❇❂❋❍●❏❑✥✂✦❉◆❙❊●❏❇▼⑩❭❱✪❃❖❙❊❬⑥❧✪⑩q✹✡■✪⑦❖❇▼❃❖❱✪⑦❖❉❳➉ ☎ ➆ ❢☎❪s✝❱✏✽✕✘✗❧✗✯✕✛✚❀✏✮✭✯❂✾◆✢✜✕✘✒✖✕➺❺➘☛❛❊➽✔✂❣❉◆❙❊●❏❘✖❃❅❲ ➀ ❉P➌❩■❊❉◆❙❯❲❳❉ ➆ ●❏❘⑥❱❯❚★❑❾❃❺❄❾●❏❙✚❪✞✝✠✟✶✵✫✕✙☞❚✝✠✕❤✵✌①❤✚✑✕✘✗

➒❂➓✮➔☎→✣✡✇↔❵➛➝➣❛➟✬↕✤✒❬P✞P◗➓✮➞❸❖❀❂❁✪❃❅❄✍❱❯❚★❑❈❇✮❲❳●❏❙✪❇✿❚❛❃❖❙❯❄✍❚★❙➑❃❖❙✪❇❈❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙❥❇❈●✏❲❳●❩❘⑥❱✪⑦❖❉❳➉➱❘✖■✪⑦❖❇▼❃❖❱✪⑦⑨❃❅❲◆❚★❇❾❃⑤●❩❙ ➺❺➘☛❜❊➽❈q▲❚★❙ ❃⑤❙✪❇❈❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙❥❇③●✏❄✺❃❖❘✖■❊❼

⑦❅❚★❇❈❉P❨✡❚★❙❊❙❊❉P❚❛⑦❿❃❖❙❊❬✏➺❿➷s❝❊➽❞❚✵❙❯❨✟❚★❙✟❚❛⑦❖❬❏❉◆❧❊❑❳❚❛❃❅❲☎❋❍❑✿❚★❘❦❉◆❶s●❩❑❈⑧✖❋❍●❏❑❣❲❳●❏❘⑥❱❊■❊❇❳❚★❇▼❃❖●❏❙✟❶❴❃⑤❇③❁✟❘✖■✪⑦❖❇▼❃❖❫☞❚★❑▼❃❅❚★❇③❉④❑✿❚★❇❾❃⑤●❩❙❯❚❛⑦✚❋❍■❊❙❯❲❳❼❇▼❃❖●❏❙❯❄④➺❿➷❮➻❏➽❈❪➺❺➘☛❜❊➽❹❝✐❙✪❇❈❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙✟❇❈● ➆ ●❩❘⑥❱✪⑦❖❉❳➉②✹✟■✪⑦❖❇▼❃❖❱✪⑦❿❃❅❲◆❚★❇▼❃❖●❏❙✚❪❇★✑✗✯✟✛✚✦✥✭✯❂❤✏❑✐❇●■❂✛✗✯✟✌✏✓✚➺❿➷✑❝❊➽❹❝✐❙✪❇❈❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙✟❇❈● ➀ ❃❖❘✖■✪⑦❅❚★❇❈❉P❨✮❤✦❙❊❙❊❉P❚❛⑦❿❃❖❙❊❬✟❚★❙❯❨✢⑩◗●★⑦❖❇❈➍◆❘✍❚★❙❊❙ ✷➵❄❇✹✂❚❏❲③❁✪❃❖❙❊❉❏❪▼●■✟✛✗✻✭✬✏❑✚✝✆❊❦✩✡☛✪✌✏❑✐✬①✫✕✧✟✞✐✙❦ ✏➺❿➷❮➻❏➽❹❤❣❙✮❤➊⑦❖❬❏❉◆❧❊❑✿❚❛❃❅❲☎❤✦❱❊❱❊❑❈●❭❚❩❲❈❁✡❇❈●⑥❢❂❉P❄✺❃❅❨✪■❊❉P❄➊❃❖❙ ➀ ❉◆❫❏❉◆❑✿❚☞⑦✩★❞❚★❑▼❃❅❚★❧✪⑦❖❉P❄◆❪✧▲❀✕✘✗✙✚✑✟✛✗✻◆ ●■❂✾✡✫✗✙✗❳✟❤✏❑✚

✪ ➡✕✫★➧❯➢✠✬❂➭❿➲✿➯✌❙❏➲P➤✖➲❛➧❯➩➼➳✧✭➾❀❂❁❊❉◗⑦❖❉P❲❳❇❈■❊❑❈❉P❄❞❄❾■❊❘⑥❘❜❚★❑▼❃❖➍◆❉P❨✖❁❊❉◆❑③❉s❉◆❘✍❚★❙❯❚★❇❈❉◗❋❍❑❈●❏❘ ❚✦❄▼❉◆❘✖❃❖❙❯❚★❑s❚✵❇❈❇❈❉◆❙❯❨✪❉P❨❹❧❭⑩✖❚☎❲❳●❏❘⑥❘✖■❊❼❙✪❃❖❇▼⑩⑥●★❋✚❑❈❉P❄▼❉P❚★❑❳❲❈❁❊❉◆❑✿❄❆❃❖❙✍❇❈❁❊❉➬❚✵❙❯❚❛⑦❖⑩❽❄✺❃❅❄❂●✵❋❮❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘❜❄◆q✵❃❖❙✮❇❈❁❊❉❣❤➊⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✍❄▼☎❆❑❈●❏❻▼❉P❲❳❇❞❚★❇◗❝✳❡✦❢❂❝✐❤✗➚⑤☎❆❁✚❪❭❒❮⑦❅❚★❻▼●★⑦❖❉◆❇Pq❒❂❪✩✹✟●❩❑✿❚❛❃❖❙✇❚★❙❯❨ ⑩❣❪ ➀ ❚☞⑦⑤❫✪⑩➎❚✵❑❈❉✖❇❈❁❊❉✖●❏❑❈❬❭❚★❙✪❃❖➍◆❉◆❑✿❄ ➶❴❚★❙❯❨➅❃❖❙✇❇❈❁❊❉✖❬❏❑③❉P❚★❇❈❉◆❑✥☎❵❚★❑▼❃❅❄☎❚★❑❈❉P❚❛➁➂❉P❄❾❱❯❉P❲③❃❅❚❛⑦❿⑦❖⑩✯✮✜❞❲❳●★⑦❖❉❡☎✣●✵⑦⑤⑩✪❼❇❈❉P❲③❁❊❙✪❃❅➌❏■❊❉✡➚✱✰❊❪➪❼✸✹✝❪ ➀ ❇❈❉◆⑩❭❚★❉◆❑③❇◆➶✿q✩�▲❙✪❃❖❫❏❉◆❑✿❄✳❃⑤❇▼⑩✂●★❋❇☎❵❚★❑▼❃❅❄ ➀ ■❯❨➈❚★❇✆❨▲❑✿❄❈❚❛⑩✇➚✬❴✖❪ ✂✦●❏■❊⑩❏●❏■❊❼✸⑩◗❉P❚★■❯❲③❁❯❚★❘⑥❱❯❄❳➶▲❚★❙❯❨✳✲✵✴✷✶✹✸➚⑤✹✝❪ ➀ ●❏❑▼❃❅❚✪➶✿❪❀❂❁❊❉✖❉P❨❩❃❖❇❈●❏❑☎❉❳➉❊❱❊❑❈❉P❄❈❄▼❉P❄➠❁✪❃❅❄✦❬❏❑✿❚★❇▼❃❖❇❈■❯❨✪❉✖❇❈●✍❇❈❁❊❉⑥❫★❚★❑▼❃❖●❏■❯❄✦❱✜❉◆❑✿❄▼●❏❙❯❄✦❶▲❁❊●✟❄❾■❊❱❊❱❯●❏❑❈❇③❉P❨➎❚❩❲❳❇▼❃❖❫❏❉❳⑦❖⑩➎❇③❁✪❃❺❄❴❻✳●✵❃⑤❙✪❇✦❉◆❙❊❼

❇❈❉◆❑❈❱❊❑❾❃❺❄❾❉❏q❯❘⑥●✪❄▼❇❂❙❊●❏❇✿❚★❧✪⑦❖⑩✦✺▼☎❆❁✪❃⑨⑦❿❃❖❱❊❱❯❉✖❴✦■❊❘❜❚❏❄◗❋❍●❏❑▲❁✪❃❅❄✦❲◆❚★❑❈❉❳❋❍■✪⑦✬❑❈❉◆❑❈❉P❚❏❨❩❃❖❙❊❬❯q✩✜✣❃❖❇❈❁❊❙❊❉ ✹✡■❊❑❈❑✿❚❛⑩✖❋❍●❏❑❣❄❾❇❈❑✿❚❛❃❖❬❏❁✪❇❈❉◆❙✪❃❖❙❊❬❄▼●❏❘❦❉✁✜❵❙❊❬★⑦❿❃❅❄▼❁✂❇❈❉❳➉❊❇✿❄◆q❊❚★❙❯❨✮❒❊❑ ✮❉P❨ ✮❉◆❑❾❃❺❲ ➆ ❁❭⑩✪➍P❚★⑧✰❪✕❀❴❁❯❚★❙❊⑧❽❄✦❚★❑❈❉④❨✪■❊❉✖❚❛⑦❅❄▼●⑥❇❈●✖❇❈❁❊❉✖❄▼❱❯❉P❚✵⑧❏❉◆❑✿❄▲❚★❙❯❨➅❇❈●✖❇❈❁❊❉♠❚✵■❊❇❈❁❊●❏❑✿❄●★❋❞❄▼■❊❘⑥❘❜❚✵❑▼❃❖❉P❄◆❪▼✹✂❚★❙✪⑩✍●★❋✕❇③❁❊❉◆❘ ❁❯❚❛❫❏❉♠❲❳●❏❘❦❉✦❋➄❑❈●❩❘✗❋ ❚✵❑❣❚❛❶❴❚❛⑩⑥❇③●❸❚✵❇❈❇❈❉◆❙❯❨✮●❩❙❊❉④❄▼❉◆❘✖❃❖❙❯❚★❑☎❚★❙❯❨✮❙✪❃❅❲❳❉❳⑦❖⑩➎❚❏❲◆❲❳❉◆❱❊❇③❉P❨❇❈●⑥❶➊❑▼❃❖❇❈❉☎❇❈❁❊❉④❄▼■❊❘⑥❘✍❚★❑❈⑩❏❪✦✇❉☎❚★❑❈❉❣❚☞⑦❺❄❾●♠❬❩❑❈❉P❚★❇▼⑦❖⑩✖❃❖❙❯❨✪❉◆❧❊❇❈❉P❨✍❇❈●✻★▲❃❖❑❈❬✵❃⑤❙✪❃❖❉ ➆ ●★⑦❿⑦❖❉◆❇❈❇❈❉➊❋➄●❏❑❂❘❜❚✵⑧❏❃❖❙❊❬⑥❚❛⑦❿⑦➸❇❈❁❊❉✦●❏❑❈❬✪❚★❙✪❃❖➍P❚★❇▼❃❖●❏❙✍❶s●❩❑❈⑧⑥❄▼❘⑥●✪●❏❇❈❁✪⑦❖⑩❏❪

❀❂❁❊❉✁✜◗❨❩❃⑤❇③●❏❑✼✤✽✿✾✂❀✢✲❂❁❄❃

❱❳❱❳❱

Page 9: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 10: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☎✄✝✆ ✘

✞✠✟☛✡✌☞✎✍✑✏✎✁✒✆✓✟☛✄✓✍✕✔✗✖

Page 11: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 12: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✏✎✍✂✁ ✟ ✄✓✡ ✞ ✁☎✏☎✄ ✟☛✡ ✄✝✆✒✏☎✆✒✄✓✁✒✆ ✍✑✟☛✏✞✁ ✟ ✄ ✆✠✟✡✆ � ✟☞☛✌✆✒✄✓✖✍✆✗✆ ✞✠✟☛✏✎✖ ✆✓✄✠✎ ✔ ✆ ✍✑✟☛✏

✏➊✯❊✧✪✱✒✑ ✼✔✓✕✓✗✖ ✥ ✓ ✯★✩✰✩❝✺❙❊❑▼❃❅❚❡❥✷●❏❑❈❑✿❚❛❃❖❙❊❉

❴✦❉P❲❳❉◆❘✖❧❯❉◆❑✖♥Pr❊q✰♥P♣❏♣✍✘✙ ❄▼■❊❘⑥❘❜❚✵❑❈⑩⑥❧✪⑩q✜✕❃⑤❇③❁❊❙❊❉❍✹✡■❊❑❈❑✿❚❛⑩✛✚

✾❀✿❂❁✱❃❅❄❇❆❉❈❊❃☞☎❍ ❍❊P❘❑ ❏✐❊ ❱❪❲ ❋ ● ▼ ❏✐❊ ❲ ❋ ❙ ❋■❍ ❱ ▼ ❏✐❊ ● ❊✻❍◆❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊❛❍ ❲●❱ ❏✐❍✰❏❊▼ ❲ ❋ ❙❭■ ❏◆Ð ❙ ❊●❩ ❙ ❲ ❬ ❏ ❍■❩ ❲ ❊✂❋ ❬ ❲✂❱ ❏✐❍ ❱ ❩ ■ ❊ ❙✻❜❩ ❙ ❍ ❲✂❙♠❚ ❱✌♣ ❱❚❖✐❙ ❍❀❍✎❬ ❏ ● ❤ ❱ ❍❝❍ ❲ ❏ ❊ ❱ ❍❇P✐❬❩P❯❍ ❩✂❩✢✜❨P ❲ ❏❨❑ ❙ ❲ ❋ ❙ ❊✬Ð ❱❳❲ ❋❀❍✎❬ ❏✐❋❨❍ ❲●❱ ❍▲❑ ■ ❊✂❏■❬ ❙❯❚ ❋■❊ ❙ ❍◆❍ ❚ ❍ ❍✳❋■❍❨❊❛❍◆❍❩Ñ ❱ ❍▲❑■ ❊✂❏■❬ ❙❯❚ ❋■❊ ❙ Ò ❏✐❊✦❩ ❱❚●❴■ P❘◗ ❍☎❊✻❍◆❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊❛❍ ❲✂❱ ❏✐❍ ■ ❊✂❏■❬ ❙❯❚ ❋❨❊ ❙✿Ö ▼ ❏✐❊✣✜■P ❲ ❋ ❱ ❩❂❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ■ ❊●❏ ❖ ❱ ❚✝❙ ❩ ❬ ❏✐❋■❍ ❲✂❱ ❍▲❑❍◆❍ ❚ ❋❨❍■❊❛❍ ❍❏Ñ ❱ ❍✽❑✖Ò ❏✐❊✎❊✻❍◆❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊✻❍ ❲●❱ ❏ ❍ Ö❵■ ❊✂❏■❬ ❙♠❚ ❋■❊ ❙ ❩✭▼ ❏✐❊✒✤✦✥★✧✪✩✬✫✛✭✯✮✛✰✱✭✯✲❩Ò✳✜ Ö ❱q✛■❏ ❊ ● ❏ ❩ ❲ ❬ ❏ ● ❤ ❱ ❜❍❉❍ ❲ ❏✐❊ ❱ ❍❊P ❩ ❲ ❊✂❋ ❬ ❲ ❋■❊ ❙ ❩❯P ❙ ❍✐❬❬❋✗❊❛❍ ❍ ❚ ❏ ●✌■ ❏◆Ð ❙ ❊✂❩ ❙ ❲ ❏❇▼✎❩ ❱✵✴ ❙✷✶✗❱ ❩ ■ ❊✂❏ ❚ ❋ ❬ ❙❯❚✗❱ ❍✹✸➠Ò ✶ P❳❏❨❑ ✶❊Ö ❍◆❊ ❱❳❲ ❋ ● ❙ ❲✂❱ ❬❏ ■ ❙ ❊❛❍ ❲✂❱ ❏✐❍■❩ ❱ ❍ ❲ ❋ ❙ Ð ❏✐❊●❩ ❲ ❬✱❍◆❩ ❙ P❉❍ ▼ ❲✂❙ ❊✒✸☎Ò ✶☞✺✿Ö ❬ ❏ ❙✼✻ ❬ ❱❳❙ ❍ ❲ ❩ ❋❝❍ ❖✐❙ ❤ ❙ ❙ ❍ ❬ ❏ ●❴■ ❋ ❲✂❙❯❚ ❱✦✆✹❋ ❱ ❩❵Ð ❏ ❊✐Ñ ❱ ❩ ❍ ❍❙ ♠ ❲✂❙ ❍■❩ ❱ ❏✐❍✰❏❊▼ ❲ ❋ ❙ ❍❇P❚❑✐❏ ❊ ❱❳❲ ❋ ● ❩ ❚✝❙✱❖ ❙ P❳❏ ■ ❙❯❚✔❱ ❍✾✽ ❥ P✌s❀✿✂P ❲ ❋❉❍ ❲ ❋❉❍ ❖ ❙ ❤ ❙ ❙ ❍ ❱❘●❭■ P ❙✱●❦❙ ❍ ❲●❙❯❚✣❱ ❍ ❲ ❋ ❙ ♣❧❍❂❁ ❃❣❍Ò ❍■❏◆Ð✧❬ ❏ ● ❤■❩ ❲ ❊✂❋ ❬ ❲✳Ö ✢✙❍ ■ P ❙✭■ ❍✐❬✺Ñ❨❍❇❑ ❙ ✽ Õ ✿❫❱

➻✜↔⑥➣✬❄❆❅❈❇✬❉❋❊❍●❏■✍❅❈❑▲❉▼❄✂▲❃❖❫❏❉◆❙✟❚✖❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❚❛⑦✬❲③⑦❺❚❩❄❈❄✡◆⑥●★❋✬■❊❙✪⑦❅❚★❧✜❉❳⑦⑨⑦❖❉P❨✂●❩❧❊❻✳❉P❲❳❇❳❄s❄❾■❯❲❈❁✍❇❈❁❯❚★❇◗❋❍●❏❑❂❉P❚❏❲❈❁❦❃❖❙❭❇③❉◆❬❏❉◆❑P❖✡❇❈❁❊❉✦❙❭■❊❘✖❧❯❉◆❑◗◆ ✙ ❖❘✚

●★❋✚●❏❧❊❻▼❉P❲❳❇✿❄✣●★❋✬❄✺❃❖➍◆❉❙❖❦❃❅❄✲❩❯❙✪❃❖❇❈❉❹➚✳❚★❙❯❨✰q★❋❍●❏❑❂❲❳●❏❙❭❫❩❉◆❙✪❃⑤❉◆❙❯❲❳❉❏q✛◆ ✙ ✈✍✚✣❚➱✈❽➶✿q★❇❈❁❊❉▲❱❊❑❈●❩❧✪⑦⑤❉◆❘➃❃❅❄❵❇③●④❬❏❉◆❙❊❉◆❑✿❚✵❇❈❉▲■❊❙✪❃❿❋➄●❩❑❈❘✖⑦❖⑩❜❚★❇❑✿❚★❙❯❨✪●❩❘ ❚★❙✮●❏❧❊❻▼❉P❲❳❇▲●★❋❞❄✺❃❖➍◆❉❯❖➎❋➄❑❈●❩❘❲❱❆❳✪❨❆❩✍❬❆❭✛❩✍❪❊➚❫◆✜➶✿q✪❶▲❁❊❉◆❑❈❉❙❱❆❳✪❨❆❩✍❬❆❭✛❩✍❪❭➚❴◆❯➶❞❘❦❉P❚★❙❯❄❂❇❈❁❊❉④❲③⑦❅❚❏❄❈❄➊●★❋❞❄▼❉◆❇✿❄❂❶❴❃⑤❇③❁❊●❏■❊❇❑❈❉◆❱✜❉◆❇▼❃❖❇▼❃❖●❏❙✟❘❜❚❩❨✪❉☎❋❍❑❈●❏❘✗●❏❧❊❻▼❉P❲❳❇✿❄◗❃❖❙❵◆✰❪❤☎❄❈❄▼●❊❲③❃❺❚✵❇❈❉☎❶❂❃❖❇❈❁✮❉P❚❏❲③❁❷❲❳●❩❘♠❧✪❃❖❙❯❚★❇③●❏❑▼❃❅❚❛⑦✬❲③⑦❅❚❏❄❈❄✒◆⑥❇▼❶❂●④❱❊❑③●❽❲❳❉P❨✪■❊❑❈❉P❄❴➁ ❚✖❲❳●❏■❊❙✪❇▼❃❖❙❊❬⑥❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉❜❛❝❳❝❞✛❡❢❪❘❣❭q❯❄▼■❯❲③❁

❇❈❁❯❚★❇❤❛✠❳✍❞✛❡❢❪❘❣✪➚✐❖❮➶s❬★❃❖❫❏❉P❄✦❇③❁❊❉♠❙✪■❊❘✖❧❯❉◆❑❤◆❯➚✐❖❮➶❂●★❋s●❩❧❊❻✳❉P❲❳❇❳❄▲●★❋▲❄✺❃❖➍◆❉✌❖✣q✚❚★❙❯❨✂❚★❙✂■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬✟❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉❜❞✛❡❢❬❘❥✬❡❢❦❘❣❶▲❁✪❃❅❲③❁✂❃❖❘⑥❱✪⑦❖❉◆❘⑥❉◆❙❭❇❳❄♠❚✍❧✪❃➪❻▼❉P❲❳❇▼❃❖●❏❙✝❧❯❉◆❇▼❶❂❉◆❉◆❙ ✙ ✈☞❧❂◆✜➚✐❖❮➶✢♠①♥✯✚❵❚★❙❯❨✂❇❈❁❊❉❜❄❾❉◆❇☎●★❋s●❏❧t❻✳❉P❲❳❇✿❄➊●★❋▲❄✺❃❖➍◆❉♥❖➮❋➄❑③●❏❘♦◆➸❪✖❀❂❁✪■❯❄❞✛❡❢❬❘❥❈❡☞❦❘❣❏➚✐❖♣❧rq✜➶❵❑❈❉◆❇❈■❊❑③❙❯❄❂❇❈❁❊❉☎●❏❧❊❻▼❉P❲❳❇▲●★❋❞❄✺❃❖➍◆❉❯❖✡❶▲❁❊●✪❄▼❉❜➫▼➨❏➧ ✫✖❃❺❄sq✰❪✂▲❃❖❫❏❉◆❙✡❇❈❁❊❉P❄▼❉❹❇✳❶❂●✖❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉P❄◆q✰❇❈❁❊❉✖❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✒❲❳●❏❙❯❄▼❇❈❑❈■❯❲❳❇❳❄❣❄✺❃❖❘✖❃❿⑦❅❚★❑✦❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄t❛❝❳❝❞✉❡☞❪✛✈❷❚★❙❯❨♥❞✉❡☞❬❘❥❈❡☞❦✉✈✍❇❈●

❲❳●❏■❊❙✪❇❣❚★❙❯❨✍❬❏❉◆❙❊❉◆❑❳❚★❇❈❉④❚★❇▲❑❳❚★❙❯❨✪●❏❘ ❇❈❁❊❉☎●❩❧❊❻✳❉P❲❳❇❳❄◗❋➄❑③●❏❘①✇②❚③❱❆❳✠❨❘❩✱❬❘❭✛❩✱❪❊➚❴◆❯➶✿❪❀❂❁❊❉⑥❚★❑❈❇❾❃❺❲③⑦❖❉ ✙⑤④ ✚✣❇❈❁✪❃❅❄☎❄▼❉◆❘✖❃❖❙❯❚★❑✦❃❅❄✦❧❯❚❏❄▼❉P❨✡●❏❙➅❃❺❄☎❚❛❫★❚❛❃❿⑦❺❚✵❧✪⑦⑤❉❦❋❍❑❈●❏❘ ❁✪❇❈❇❈❱❄✺✵⑥✪⑥P❶▲❶▲❶④❪ ⑦⑤●❩❑▼❃❅❚❊❪ ❋❍❑✯⑥✉⑦❛➍❳❃⑤❘❦❘⑥❉◆❑❈❘❜❚✛⑥❛❬❭❚❛❃❅❚❊❪

❝✐❇✦❲❳●❏❙❭❇❳❚❛❃❖❙❯❄❂❃❖❘⑥❱✪⑦❖❉◆❘⑥❉◆❙✪❇✿❚★❇▼❃❖●❏❙✂❨✪❉◆❇✿❚❛❃❿⑦❅❄◆q✜❱❊❑❈●❭●✵❋ ❄◆q✪❉❳➉❯❚★❘⑥❱✪⑦❖❉P❄✦❚★❙❯❨✮❉❳➉❊❱❯❉◆❑▼❃❖❘⑥❉◆❙✪❇✿❚❛⑦✣❑❈❉P❄▼■✪⑦❖❇✿❄◆❪

➘➸↔✍→❜⑧✣⑨✏↕❤❉❏●♣❄❆❅❈❑⑩❄✣❶➑➒❷❇✬❉❹❸♣❺▲⑨❘❻❀❂❁❊❉⑥❬❩❉◆❙❊❉◆❑✿❚★❇▼❃❖❙❊❬✍❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄❜✇❹➚✐❼✪➶❣❚★❙❯❨✕◆✜➚✐❼✪➶▲❄❈❚★❇❾❃❺❄✳❋➄⑩✂❇❈❁✪❃❅❄✦❃❅❨✪❉◆❙✪❇▼❃❖❇▼⑩➮❨✪■❊❉❦❇❈●✢☎ ✮●★⑦❖⑩❭❚ ✺❽✇❹➚❾❼✪➶❙❚➝❉❳➉❽❱✰➚❫◆✜➚✐❼✪➶❿♠

Ï✺◆❯➚❾❼ ✺ ➶☞➀ Ï➁ ◆✜➚✐❼ ➁ ➶❆♠ Ï➂ ◆✜➚✐❼ ➂ ➶☞➀✾➃❈➃✬➃❳➶r➄❊�✦❄✺❃❖❙❊❬✖❇❈❁✪❃❅❄❆❃❺❨✪❉◆❙✪❇▼❃❖❇▼⑩❷❚✵❙❯❨⑥❇❈❁❊❉➊●❏❱❯❉◆❑✿❚✵❇❈●❏❑➆➅✞❚➇❼☎➈➊➉✱➈✛❼✖➚✳❄▼❉◆❉ ✙ ♥➋✚❍➶✿q✵❃❖❇❞❃❅❄◗❉P❚❏❄▼⑩❇❈●☎●❏❧❊❇❳❚❛❃❖❙⑥❉P➌❏■❯❚✵❇▼❃❖●❏❙❯❄◗❇❈●④❲❳●❏❘⑥❱❊■❊❇❈❉➊❇❈❁❊❉❣❲❳●✪❉✯✣❷❲③❃❖❉◆❙❭❇✿❄✒✇ ✙ q✛✚✣❚ ✙ ❼✠➌➋✚✔✇❹➚✐❼❽➶✚❋❍●❏❑☎q➍❚ ♥✠❧✬➄▲➄▲➄▲❧➋❖➠❃⑤❙➏➎✖➚✐❖ ✺ ➶✚●❩❱❯❉◆❑✿❚★❇❾❃⑤●❩❙❯❄◆❪

➷❮↔❜➓➏❄♣❘➏❄❋❇✬➐✣❄❏➑❏❑⑩❄✣❶➑➓➒❺▲❶❘❉❹❇✍❑▲❅✍⑧♣❻❀❮●④❬❏❉◆❙❊❉◆❑✿❚✵❇❈❉❣❚☎❑❳❚★❙❯❨✪●❏❘ ●❩❧❊❻✳❉P❲❳❇◗●★❋✬❄✺❃❖➍◆❉❽❖❷❋➄❑③●❏❘ ❚❹❱❯●★❶❂❉◆❑✿❄▼❉◆❇Pq❏❲❳●❏❙❯❄✳❃❺❨✪❉◆❑➊❇❈❁❊❉▲❱❊❑❈●❏❧✪⑦❖❉◆❘➃❃❖❙❜❇▼❶❂●④❄▼❇❈❉◆❱❯❄➐❪❞❒❮❃❖❑✿❄▼❇Pq

❬❏❉◆❙❊❉◆❑✿❚✵❇❈❉✖❇❈❁❊❉✍➳r➓❭➨→➔❽➲✍❇❈❁❊❉✖❬❏❉◆❙❊❉◆❑✿❚★❇③❉P❨✟●❩❧❊❻✳❉P❲❳❇☎❶❴❃⑨⑦❿⑦❞❁❯❚❛❫❏❉❏q✰❇❈❁❯❚✵❇✦❃❺❄➐q✚❁❊●★❶ ❘✍❚★❙❭⑩✡●❏❧❊❻▼❉P❲❳❇✿❄➊●★❋s❉P❚❏❲③❁✇❄✺❃❖➍◆❉⑥❶❂❃❿⑦❿⑦s❧✜❉❱❊❑❈❉P❄▼❉◆❙✪❇❂❃❖❙✟❇③❁❊❉♠❄▼❉◆❇P❪ ➀ ❉P❲❳●❏❙❯❨✰qt❋❍●❏❑❂❉P❚❏❲❈❁✂❄✺❃❖➍◆❉④●★❋❵●❏❧❊❻▼❉P❲❳❇◗❃❖❙✟❇❈❁❊❉④❄▼❉◆❇❛q❊❬❏❉◆❙❊❉◆❑✿❚★❇③❉☎❇❈❁❊❉☎●❏❧❊❻▼❉P❲❳❇✿❄❂●★❋❵❇❈❁❯❚★❇▲❄✺❃❖➍◆❉❏❪

Page 13: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➷✚↔❍➻✜↔✍➟✢⑧✣➐✁�♣⑨ ✌✌⑨❘❄✣⑨❢❇✬➐☞❅❈❑ ❉❏❄❵↔④❀✚●❹❬❏❉◆❙❊❉◆❑✿❚★❇③❉❣❚☎❱✜●☞❶❂❉◆❑✿❄❾❉◆❇❵●★❋✬❄✺❃❖➍◆❉❽❖✣q❏❇③❁❊❉❣❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✗❲❈❁❊●✪●❭❄▼❉P❄❆❙❊●❏❙❊❼❍❙❊❉◆❬❭❚★❇❾❃⑤❫❩❉❃❖❙❭❇③❉◆❬❏❉◆❑✿❄❹➚✄✂ Ï ❧❈➄▲➄ ➄▲❧☎✂ ➌ ➶❴❄❾■❯❲❈❁✇❇③❁❯❚★❇❽❖ ❚✆✂ Ï ➀➂r✝✂ ✺ ➀ ➃❈➃❈➃✬➀✦q✞✂ ➌ ❪❹❝✐❇☎❘✖■❯❄▼❇☎❉◆❙❯❄❾■❊❑❈❉⑥❇❈❁❯❚★❇✦❇❈❁❊❉⑥❄▼❁❯❚★❱✜❉✖❃❅❄☎❬❏❉◆❙❊❉◆❑❳❚★❇❈❉P❨❶❂❃❖❇❈❁✟❚✖❱❊❑③●❏❧❯❚★❧✪❃❿⑦❿❃⑤❇▼⑩✮❧❯❚❏❄❾❉P❨✍●❏❙❜❇③❁❊❉☎❙❭■❊❘✖❧❯❉◆❑➊●★❋✕❱✜●★❶s❉◆❑❳❄▼❉◆❇✿❄❵❁❯❚❛❫❩❃❖❙❊❬❜❇❈❁❊❉☎❄▼❁❯❚★❱✜❉⑥➚✄✂ Ï ❧❈➄ ➄▲➄▲❧☎✂ ➌ ➶✿❪❵❀❂❁✪❃❅❄▲❱❊❑❈●❩❧❯❚★❧✪❃❿⑦⑨❃❖❇▼⑩❨✪❉◆❱❯❉◆❙❯❨❊❄❦●❏❙✪⑦❖⑩✝●❏❙✏❇③❁❊❉✮❙❭■❊❘✖❧❯❉◆❑❳❄❜◆ ✙ ✟ ✚✐q✷❋➄●❩❑ ✟ ❧❯❉◆❇▼❶❂❉◆❉◆❙①♥❷❚✵❙❯❨③❖✬❪✝❀❂❁✪■❯❄◆q❵●❏❙✪⑦❖⑩✝❇❈❁❊❉✮❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉✕❛❝❳❝❞✛❡❢❪❘❣✍❃❺❄❙❊❉◆❉P❨✪❉P❨①❇❈●➑❄▼●★⑦❖❫❏❉✂❇❈❁❊❉✇❄▼❁❯❚✵❱❯❉✇❬❏❉◆❙❊❉◆❑❳❚★❇▼❃❖●❏❙①❱❊❑❈●❏❧✪⑦❖❉◆❘✟❪ ❀❴❁✪❃❺❄✡❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❃❅❄✮❧❯❚❏❄❾❉P❨➂●❩❙➱❇③❁❊❉➮❨✪❉P❲❳●❩❘⑥❱❯●❭❄✳❃⑤❇❾❃⑤●❩❙✇✡✠✄☛ ☞ ❚①✈✉❬☞❳✍✌❽➚✐✇✎✠✏☛ ✺ ☞P❧➋✇✎✠✒✑✓☞✔☛ ✺ ☞➊➶✿q❵❶▲❁❊❉◆❑❈❉❵✇✡✠✏☛ ☞✓❃❺❄❸❇❈❁❊❉✟❄▼❉◆❇✖●★❋❣●❏❧t❻✳❉P❲❳❇✿❄❹●★❋❣❄✺❃❖➍◆❉ ✟ ➀✖✕✘✗✂q✣❶▲❁❊❉◆❑③❉✙✕✇❃❅❄⑥❚✡❙❊●❏❙❊❼❙❊❉◆❬❭❚★❇❾❃⑤❫❩❉▲❃❖❙✪❇❈❉◆❬❏❉◆❑Pq✓✗✗❃❅❄❂❚☎❱✜●☞❶❂❉◆❑◗●★❋✕r❊q✜♥✛✚ ✟ ✚✜✗✂q❭❚★❙❯❨ ✈✛❬❢❳✓✌✖❨✪❉◆❙❊●❏❇❈❉P❄◗❇❈❁❊❉❣❲◆❚★❑③❇❈❉P❄✺❃❅❚★❙✍❱❊❑❈●❽❨✪■❯❲❳❇❛❪❵❝✐❇❆❃⑤❙✪❫❏●★⑦❖❫❏❉P❄❲◆❚❛⑦❅❲❳■✪⑦❅❚★❇▼❃❖❙❊❬✕➎✖➚✐❖ ✺ ➶❂❄✺❃❖➍◆❉P❄▲●★❋❿✇ ✠✏☛ ☞ ❪➷✚↔➼➘✰↔ ✒✣✢ ●❹➐❆❺❴➟❋❑✥✤✠⑨ ✌➍⑨❆❄✣⑨☞❇❈➐☞❅❈❑ ❉❏❄❵↔✖❀❂❁❊❉❣❉P➌❩■❯❚❛⑦✬❄✺❃❖➍◆❉☎❬❏❉◆❙❊❉◆❑✿❚✵❇▼❃❖●❏❙❜❱❊❑③●❏❧✪⑦❖❉◆❘✗❃❅❄❂❉P➌❏■✪❃❖❫★❚❛⑦❖❉◆❙❭❇✦❇❈●④❇③❁❊❉❣❱❊❑❈●❩❧✪⑦⑤❉◆❘

●★❋✕❄❾❉❳⑦⑤❉P❲❳❇❾❃⑤❙❊❬❵q✮❨❩❃❅❄▼❇❾❃⑤❙❯❲❳❇✦❉❳⑦❖❉◆❘⑥❉◆❙✪❇✿❄✧✦ Ï ❧✬➄▲➄▲➄▲❧★✦ ➌ ❋❍❑❈●❏❘➾♥✠❧❳r☞❧❈➄ ➄▲➄✵❧r❖➅➚✳❲◆❚❛⑦❿⑦❖❉P❨✪✩◆❄▼❉❳⑦❖❉P❲❳❇▼❃❖●❏❙✂❄❈❚★❘⑥❱✪⑦❿❃❖❙❊❬✍✫❦❧❭⑩✭✬✦❙❭■❊❇❈❁ ✙ ✉✬✚❍➶✿❪❀❂❁❊❉◆❑❈❉☎❚★❱❊❱✜❉P❚★❑✿❄❵❇③●④❧❯❉☎❙❊●❹⑧❭❙❊●★❶▲❙✍❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✗❇❈●✖❨✪●④■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬✖❋❍●❏❑❵❇❈❁✪❃❅❄◗❱❊❑❈●❏❧✪⑦❖❉◆❘✗❃❖❙❵➎✖➚✐q✜➶✣❇▼❃❖❘⑥❉☎❚★❙❯❨❜❄❾❱❯❚❏❲❳❉❏❪☎✣❪✧✮t❃⑤❘❦❘⑥❉◆❑❈❘❜❚★❙❊❙①❱❊❑❈●❩❱❯●❭❄▼❉P❄✮❚✵❙➂■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬➂❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❋❍●❏❑✍❇❈❁❊❉✇❄▼❉❳⑦❖❉P❲❳❇▼❃❖●❏❙ ❄❈❚✵❘⑥❱✪⑦❿❃⑤❙❊❬➑❱❊❑③●❏❧✪⑦❖❉◆❘ ❇❈❁❯❚★❇✍❁❯❚❏❄➎✖➚✐q◗⑦❖●❏❬✒❖✚➶◗❶s●❩❑✿❄▼❇▲❲◆❚❏❄▼❉④❲❳●❏❘❦❱✪⑦⑤❉❳➉✪❃❖❇▼⑩❏❪❤ ❘❦❉◆❇❈❁❊●❽❨✡●★❋❂■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬✮❱❯●★❶❂❉◆❑✿❄▼❉◆❇✿❄➊❃❅❄✦❇❈❁❊❉◆❙✂●❏❧❊❇✿❚☞❃⑤❙❊❉P❨➮❧❭⑩✡■❯❄✺❃❖❙❊❬✟❇❈❁✪❃❅❄☎❄▼❉❳⑦❖❉P❲❳❇▼❃❖●❏❙✏❄③❚★❘⑥❱✪⑦❿❃❖❙❊❬➎❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘✟❪

⑩◗⑩✂❑❈❉◆❱✪⑦❅❚❏❲③❃❖❙❊❬✇❇❈❁❊❉⑥■❊❙❊❑✿❚✵❙❊⑧❏❃❖❙❊❬✂❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉⑥❋❍●❏❑❙◆✡❃❖❙✏❇③❁❊❉⑥■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬➮❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘ ❧✪⑩✇❚✮❑✿❚✵❙❯❨✪●❏❘ ❬❏❉◆❙❊❉◆❑❳❚★❇▼❃❖●❏❙❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉❏q④❚✝❑✿❚✵❙❯❨✪●❏❘ ❬❏❉◆❙❊❉◆❑✿❚★❇❾❃⑤●❩❙❥❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉✂❋❍●❏❑❵✇ ❃❅❄✟❚❛⑦❅❄▼●✝❋❍●❏❑❈❘❦❉P❨✰❪ ❀❂❁❊❉✝❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩❥❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄✮❋❍●❏❑❇❈❁❊❉✮■❊❙❊❑✿❚✵❙❊⑧❏❃❖❙❊❬✏❚❛⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘ ❨✪❉◆❱❯❉◆❙❯❨❊❄❦●❏❙➂❚✂❲❳●❏❙❯❨❩❃❖❇▼❃❖●❏❙➑●★❋④➳◆➩❍➨❏➧❯➯❩➨❏➫▼➯②❙❩➫✳➢ ✬❵➩ ➓✏●❏❙✝❇❈❁❊❉✟❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❏❑❾❃❺❚☞⑦➊❲③⑦❅❚❏❄③❄◆q❶▲❁✪❃❿⑦❖❉❜❇③❁❊❉❜❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄✦❋❍●❏❑☎❇❈❁❊❉⑥❑✿❚✵❙❯❨✪●❏❘➾❬❏❉◆❙❊❉◆❑✿❚★❇❾❃⑤●❩❙✏❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❁❊●★⑦❅❨❊❄✦❋❍●❏❑④❚❛⑦❿⑦❴❲❳●❩❘♠❧✪❃❖❙❯❚★❇③●❏❑▼❃❅❚❛⑦s❲③⑦❅❚❏❄❈❄▼❉P❄➐❪❡✹✡●❭❄▼❇❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❏❑❾❃❺❚☞⑦❆❲③⑦❅❚❏❄❈❄❾❉P❄❣❄❈❚✵❇▼❃❅❄✺❋➄⑩✮❇③❁✪❃❺❄✦❲❳●❏❙❯❨❩❃❖❇▼❃❖●❏❙✚q✰❧❊■❊❇✦●❏❇❈❁❊❉◆❑❈❶❴❃❺❄❾❉❏q➸❄▼■❯❲③❁✇❚❏❄◗❋❍●❏❑☎❚✖❑❈❉P❲❳■❊❑✿❄✺❃❖❫❏❉⑥❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉❹❶▲❁❊❉◆❑❈❉◆✮❨✪❉◆❱❯❉◆❙❯❨❊❄➊●❏❙✹✇✖q❊❇③❁❊❉◆❑❈❉✦❃❅❄❂⑦❿❃❖❇❈❇▼⑦❖❉☎❃❖❙✪❋❍●❏❑❈❘❜❚✵❇▼❃❖●❏❙➎❚★❧✜●❏■❊❇▲❇❈❁❊❉④❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✢✷➵❄❴❉✯✣❷❲③❃❖❉◆❙❯❲❳⑩❏❪

✯✱✰✞✲✠✴✴✳✦✴✷✶❄✴✶✵✷✳➑♥✘✽◗❤ ❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❏❑▼❃❅❚❛⑦▲❲③⑦❅❚❏❄❈❄❙◆✡❃❅❄☎●✵❋➬➳◆➩❍➨❏➧✜➯❏➨❏➫▼➯❸❙❏➫▼➢✠✬❵➩ ➓✡❃⑨❋✦❇❈❁❊❉❳❃❖❑④❉❳➉✪❃❺❄❾❇✿❄✖❚✮❲❳●❏❙❯❄▼❇✿❚★❙✪❇✹✸✗❄▼■❯❲③❁❇❈❁❯❚★❇❂❇❈❁❊❉❹❙❭■❊❘✖❧✜❉◆❑➆◆ ✙ ❖❆✚❮●★❋✕❄▼❇❈❑③■❯❲❳❇❈■❊❑❈❉P❄❂●★❋❞❄✺❃❖➍◆❉❯❖✂❄❈❚✵❇▼❃❅❄❺❩❯❉P❄➆◆ ✙ ❖❘✚✺✚✦❖✼✻✞✽✖❋❍●❏❑➆❖✇❄▼■❄✣❷❲③❃❖❉◆❙✪❇▼⑦❖⑩✍⑦❅❚★❑❈❬❏❉❏❪

✾❀✿❁✰✍✵✷❂✎✰✞❃ ♥✘✽❅❄❑❯✒◆✇➦❖➳④➨❩➧✁❆✍➡✿➢❏➤⑥➥➐➦❅➧✜➨❏➩❍➢❏➫❳➦❅➨❏➭❮➡P➭❿➨★➳❳➳☎❇❵➨❏➧❯➯❜❬❘❥✬❡✘✌✛❳❉❈▼❣❏➚✐❖❮➶s➓❭➨★➳④➨✝❊❛➲P➫▼➨❤❙❩➲⑥➡✿➢✵➳ ➩❍➎♠➚❾❖➊⑦⑤●❩❬ ❖❮➶❋❇❞➩ ➓❭➲❛➧❬❘❥❈❡✁✌✉❳●❈❘✈❊➚✐❖♣❧rq✜➶❂➨❏➭❐➳ ➢❤➓❭➨★➳✦➨✝❊P➲❛➫✳➨✌❙❏➲✦➡✿➢★➳◆➩▼➎♠➚❾❖➊⑦⑤●❩❬ ❖❮➶ ✭❍❄❑❯☎◆✮➦❖➳✦➨♠➡❳➢❏➤⑥➥◆➦➼➧❯➨❩➩❍➢❏➫✿➦➼➨❏➭✜➡P➭❿➨★➳❳➳s➢✬❯✦➳ ➩❍➨❩➧❯➯❏➨❏➫▼➯✥❙❏➫▼➢✠✬❵➩ ➓⑥➨❏➧✜➯❞✛❡❢❬❘❥❈❡☞❦❘❣❏➚✐❖♣❧rq✜➶➆➓✪➨★➳✤✬❵➢❏➫③➳◆➩❞➡❳➨★➳ ➲❤➎✖➚✐❖➊⑦❖●❏❬✒❖✚➶■❇❞➩ ➓❭➲P➧ ❞✛❡❢❬❘❥❈❡☞❦✛✈❊➚✐❖♣❧rq✜➶❣➨❩➭➵➳◆➢ ➓❭➨★➳✤✬❵➢❩➫❈➳◆➩❞➡❳➨★➳◆➲♠➡❳➢★➳◆➩❿➎✖➚✐❖➊⑦❖●❏❬✒❖✚➶✕✭

✃✣↔✍↕❷❉❏❄❏■✠❺✂●✡❏✬❑▲❉▼❄✦➐✣❄❏❊❥➙✱�♣⑨❘❄▲❑➍●✣⑨▼❏ ❅❈❑▲❉▼❄✡❏✂▲❃❖❫❏❉◆❙①❚★❙✪⑩➴❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❚❛⑦➬❲③⑦❅❚❏❄❈❄❜◆✰q❂❚✇❲❳●❏■❊❙✪❇▼❃❖❙❊❬✏❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉➅❋➄●❏❑ ◆➸q❂❚★❙❯❨➑❚✂❱❊❑❈●❊❲❳❉P❨✪■❊❑❈❉➅❋➄●❏❑❦■❊❙❊❑✿❚★❙❊⑧❩❃⑤❙❊❬

➚✐❑✿❚✵❙❯❨✪●❏❘ ❬❏❉◆❙❊❉◆❑✿❚★❇❾❃⑤●❩❙✰➶✖❋➄●❏❑➒◆✰q✦❇❈❁❊❉◆❑❈❉✂❃❅❄✡❚★❙❥❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❇❈●➂❨✪●➑■❊❙❊❑✿❚★❙❊⑧❩❃❖❙❊❬ ❚✵❙❯❨①❑✿❚★❙❯❨✪●❏❘ ❬❩❉◆❙❊❉◆❑✿❚★❇▼❃❖●❏❙①❋❍●❏❑✇ ❚ ❱❆❳✪❨❆❩✍❬❆❭✛❩✍❪❊➚❫◆✜➶✿❪ ➀ ●❏❘⑥❉❜➌❩■❊❉P❄▼❇▼❃❖●❏❙❯❄❹❑❈❉◆❘✍❚❛❃❖❙✚❪⑥❝✳❄❹❇❈❁❊❉◆❑③❉❜❚★❙③➎✖➚✐q✜➶☎❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❋➄●❏❑☎■❊❙❊❑❳❚★❙❊⑧❏❃❖❙❊❬✾q✪❼✐❄❈❚★❘❦❱✪⑦⑤❉P❄❃❖❙❥❚★❙➇❖✜❼✐❄▼❉◆❇❖◆ ❤❣❙❯❨ ❶▲❁❯❚★❇❸❃❺❄✍❇③❁❊❉✮❶s●❩❑✿❄▼❇❜❲◆❚❏❄❾❉➎❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃❖❇✳⑩ ●★❋☎❇❈❁✪❃❅❄❜❚❛⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘ ❶➊❁❊❉◆❙➇◆✝❁❯❚❏❄✍❚✂❑❈❉P❲❳■❊❑✿❄✳❃⑤❫❩❉❄▼❱✜❉P❲③❃❁❩➸❲◆❚✵❇▼❃❖●❏❙✎◆✟❤➊⑦❺❄❾●❯q❊❇❈❁❊❉☎❱❊❑❈❉◆❼❍❱❊❑③●❽❲❳❉P❄❈❄✳❃⑤❙❊❬✍❇▼❃❖❘⑥❉☎●★❋✣❇❈❁✪❃❅❄▲❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘➃❃❅❄➊❑✿❚★❇❈❁❊❉◆❑❂❁✪❃❖❬❏❁✂➚❂➎✖➚✐❖ ✺ ➶✕●❩❱❯❉◆❑✿❚★❇❾❃⑤●❩❙❯❄▲❚★❙❯❨❚★❧✜●❏■❊❇❙➎✖➚✐❖ ➂ ➶◗❇▼❃❖❘⑥❉★➶✿❪❞❀❂❁✪❃❅❄➊❱❊❑❈❉◆❼❍❱❊❑❈●❊❲❳❉P❄❈❄✺❃❖❙❊❬✮❲❳●❭❄▼❇❣❄▼❁❊●❩■✪⑦❺❨➅❧❯❉❹❑❈❉P❨✪■❯❲❳❉P❨✰❪

P❅◗ ✿❙❘✶◗✶❚✍❯❝❄❇❆✝❱✁❲✼❳✽ ❥ ✿✳✛ P❣❍✱❳ ❏❨P ❙ ❲ Ò ♦ ❋ ❱ P ❱❚■▲■ ❙✿Ö P❩❨ ❱❚●❴●❦❙ ❊ ● ❍◆❍➠Ò ♦ ❍◆❋▲P Ö P❪❍ ❍ ❚ ▼✧❍ ❍❦✘ ❋ ❲ ❩ ❙✱● Ò ❉ ❙ ❊✂❍❉❍ ❊ ❚❏Ö ❱❩❬r☞☛❬✱❍❇P ❬ ❋▲P❳❋■❩✥▼ ❏ ❊ ❲ ❋ ❙ ❊✻❍◆❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊ ❜❍ ❲●❱ ❏✐❍ ❏❇▼ P❣❍◆❤ ❙ P❚P ❙❯❚ ❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏✐❊ ❱ ❍❇P✐❩ ❲ ❊●❋ ❬ ❲ ❋❨❊ ❙ ❩❅❱❪❭✼❫✝❴✏❵❖❛✄❴❝❜✴❞❢❡✏❣❖❤✞✐❥❵❧❦✔♠✓♥❉❜✒❴■❛✷♦▼❡■❞❢❴■♣✍❡✏❴ P ❖ ❏ P ❱ ❥ ➣✐s❨P◆❍✝q ❥✻❜ s■P✓r☎s❉s❧t P ■✽■ ❱ ❥ ❬✠➣ ♥ ❱✽ s➋✿✳✛ P❣❍✱❳ ❏❨P ❙ ❲ Ò ♦ ❋ ❱ P ❱❚■▲■ ❙✿Ö P❖❨ ❱❚●❴● ❙ ❊ ● ❍◆❍■❍➊Ò ♦ ❍◆❋✽P Ö P❇❍◆❍ ❚ ▼✧❍◆❍ ✘ ❋ ❲ ❩ ❙✱● Ò ❉ ❙ ❊✂❍❉❍ ❊ ❚❏Ö ❱❖❬ ☞✸❬✱❍❇P ❬ ❋✽P❪❋❨❩ ❏❊▼ ❊❛❍ ❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊❛❍ ❲●❱ ❏✐❍ ♣✠✞❍✽P❯❍ ❤ ❙ P❘P ❙❯❚ ❩ ❲ ❊✂❋ ❬ ❲ ❋■❊ ❙ ❩❲❱ �✟❍ ■ ❊ ❙✱■ ❍◆❊✻❍ ❲●❱ ❏ ❍ ❱✽ ➣➋✿✣✉☎❍✝❋ ❲ ❋✍Ò ✓☎❏ ❍❉❍❇P ❚ ✕ ❱ Ö ❱❩❬▲❭✼❫✝❴✔✈✇❛✏❜✷❵✴①✛✐❥❵❧❦✔♠✓♥❉❜✒❴■❛✇②❥❛✄❵❝③❖❛✄❣❖❦④❦④❞⑤♣❩③❇❱●❬ ☞ ❚■❚✝❱ ❩✂❏ ❍ ❜⑦⑥✔❙ ❩❫P ❙ ◗✝P✞r☎s❉⑧⑨r✐P■s ❍ ❚ ❙❯❚✝❱❳❲✂❱ ❏✐❍ P ❖ ❏❨P ❱■s ♣✄ ❙✱● ❱ ❍ ❋ ●❦❙ ❊ ❱ ❬❥❍❇P■☞❵P❘❑ ❏✐❊ ❱❪❲ ❋ ● ❩❅❱✽ Õ ✿✣❨ ❱❚●❴● ❙ ❊ ● ❍ ❍■❍➑Ò ♦ ❍ ❋▲P Ö ❱⑩❬ ♣✩❍❀❁ ❃❣❍ ♣ ☞ ■ ❍✐❬✺Ñ❨❍❊❑ ❙ ▼ ❏✐❊ ❲ ❋ ❙ ❊❛❍ ❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊❛❍ ❲✂❱ ❏✐❍✻❏❇▼❑❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏✐❊ ❱ ❍❇Pq❩ ❲ ❊✂❋ ❬ ❲ ❋■❊ ❙ ❩❲❱

❶❷❣✏♠✓❤❸❴●❭▼❴✏❡❝❫ P ❖ ❏❨P ❱ ❥ P✝❍ q ❥ P✁r★s❉s❖t P ■✽■ ❱✠➣❉❹❺❬ Õ❼❻ ❱✽ ♥ ✿✣❨ ❱❚●❴● ❙ ❊ ● ❍ ❍■❍✖Ò ♦ ❍◆❋✽P Ö ❱⑨❬ ✠✞❍ ❱ ▼ ❏ ❊ ● ❊❛❍ ❍ ❚ ❏ ● ❑ ❙ ❍ ❙ ❊❛❍ ❲●❱ ❏✐❍✎▼ ❏✐❊ ❲ ❋ ❙ ■ ❏◆Ð ❙ ❊●❩ ❙ ❲ ❬ ❏✐❍■❩ ❲ ❊✂❋ ❬ ❲✂❱ ❏✐❍ ❱ �✟❍ ✑ ❙ ❬✻P ❙ ❊ ❬❹Ò ❉❵❱ Ö ❍ ❍ ❚✆✹❋ ❱ ❤ ❏✐❍⑥Ò✶❽❉❱ ❖❀❱ Ö Ò ❙♠❚✝❱❳❲ ❏✐❊●❩ Ö P✞❾✁❵❖❛❋❦✛❣❖❤❩♠✝❵❖❿❥❴■❛⑩➀☎❴❋❛❋❞✶❴✏➀✧❣❖♣✍➁➂❣❖❤➃③❉❴★➄❋❛✏❣❖❞❢❡④❡✏❵❖❦✛➄❋❞⑤♣✓❣★❜✒❵❖❛❋❞❢❡❝➀✱❱ ■✽■ ❱ ♥ ❹ ❧ ❬ ❻●➅❉➅ ❱❖❬ ✠✏❍ ❱❚❖✐❙ ❊●❩ ❱❳❲ ❘❙q❚✝❙✢✙❍ ❊✂❍ ❙✻❜ P❣❍ ❜ ▼✧❍❇P❚P♠❘❙ ❙ P✓r☎s●s❉➆✽❱ ♦✦❊●❏■❬ ❙ ❙❯❚✝❱ ❍▲❑ ❩q✄■✛✜✘ ☞ ❤ ❧ ♥ ❱

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Page 14: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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r✗✖ ✰★■✪❃❖❙➴♥❛♣❏♣ ④✙ ❄▼■❊❘⑥❘✍❚★❑❈⑩⑥❧✪⑩✟❒❯❚★❧❊❑❾❃❺❲❳❉✁❥✷❉❳❋➄❉◆❧✪❫❭❑③❉✯✚

➻✜↔⑥➣✬❄❆❅❈❇✬❉❋❊❍●❏■✍❅❈❑▲❉▼❄❝✐❙✟❢➊❡▲❤✖q✪❃❖❙❭❇③❉◆❑✿❚❏❲❳❇▼❃❖●❏❙❯❄❂❧✜❉◆❇▼❶s❉◆❉◆❙✍❙✪■❯❲③⑦⑤❉◆●❩❇▼❃❅❨✪❉P❄➊❋➄●❏❑③❘ ❧❯❚❏❄▼❉☎❱❯❚☞❃⑤❑❳❄▲❚★❙❯❨✰q❊❄▼❉◆❉◆❙✟❚★❇▲❚✖❁✪❃❖❬❏❁❊❉◆❑❂⑦❖❉◆❫❏❉❳⑦✐q✰❲❈❁❯❚✵❑✿❚❏❲❳❇❈❉◆❑❈❼

❃❅❄▼❇▼❃❅❲✦❄▼❉P❲❳●❏❙❯❨❊❚★❑❈⑩⑥❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉▲❘❦●❏❇▼❃❿❋ ❄◗❄▼■❯❲③❁❜❚❏❄❵❁❊❉❳⑦❿❃❅❲❳❉P❄◆q✪⑦❖●✪●❏❱❯❄❂❚★❙❯❨✖❧❊■✪⑦❖❬❏❉P❄◆❪◗❀❂❁❊❉P❄▼❉✦❘⑥●❏❇▼❃❿❋✐❄❵❚★❑❈❉▲●★❋✚❬❏❑③❉P❚★❇✣❃❖❙❭❇❈❉◆❑③❉P❄▼❇❇❈●⑥❧✪❃❖●★⑦❖●❏❬✵❃❺❄❾❇✿❄◆❪❞❀❂❁❊●❩■❊❬❏❁✟❇❈❁❊❉④❄❾❉P❲❳●❏❙❯❨❊❚★❑❈⑩✮❄▼❇❈❑❈■❯❲❳❇③■❊❑❈❉☎●★❋❞❢▲❡▲❤✓❃❅❄➊❘✖■❯❲❈❁✟❄✺❃❖❘⑥❱✪⑦❖❉◆❑✦❇❈❁❯❚★❙✍❃❖❇✿❄➊❇❈❉◆❑❈❇▼❃❅❚★❑③⑩❷❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉❏q❃❖❇❣❑③❉◆❘❜❚❛❃❖❙❯❄❣❨❩❃❋✣❷❲❳■✪⑦❖❇❹❇❈●❜❲❳●❏❘⑥❱❊■❊❇③❉④❧❯❉P❲◆❚✵■❯❄▼❉✖❇❈❁❊❉④❙✪■❊❘✖❧❯❉◆❑✦●★❋❆❄❾❉P❲❳●❏❙❯❨❊❚★❑❈⑩✟❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉P❄➊●★❋❞❚★❙➎❢▲❡➊❤➝●★❋ ❖✂❧❯❚❩❄▼❉P❄❬❏❑❈●★❶❣❄❹❉❳➉❊❱❯●❏❙❊❉◆❙✪❇▼❃❅❚❛⑦❿⑦❖⑩①❶❂❃❖❇❈❁✦❖ ✙ ♣✬✚✐❪ ➀ ❉◆❫❩❉◆❑✿❚❛⑦❣❘⑥❉◆❇③❁❊●❽❨❊❄❦❁❯❚❛❫❏❉✮❧❯❉◆❉◆❙①❉P❄▼❇✿❚✵❧✪⑦⑨❃❅❄▼❁❊❉P❨ ❋❍●❏❑❹❋➄●✵⑦❺❨❩❃❖❙❊❬➂❢▲❡➊❤☎❄◆q❂❇❈❁❯❚★❇❃❅❄☎❱❊❑❈❉P❨❩❃❅❲❳❇▼❃❖❙❊❬✇❢▲❡➊❤ ❄▼❉P❲❳●❏❙❯❨❊❚★❑❈⑩✇❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉❏❪✖❀❂❁❊❉✆❩❯❑✿❄❾❇☎❘⑥❉◆❇❈❁❊●❊❨✡❃❅❄☎❱❊❁✪⑩❏⑦❖●❏❬❏❉◆❙❊❉◆❇❾❃❺❲✍❚★❙❯❚❛⑦❖⑩❊❄✺❃❅❄☎●★❋❂❁❊●❏❘⑥●★⑦❖●❏❬❩●❏■❯❄❢▲❡➊❤➝❘⑥●★⑦❖❉P❲❳■✪⑦❖❉P❄◆❪❂❝✐❇✦❑❈❉❳⑦❿❃❖❉P❄▲●❩❙➎❲❳●❏❙❯❄▼❉◆❑③❫☞❚★❇▼❃❖●❏❙✡●★❋❞❄▼❇❈❑❈■❯❲❳❇❈■❊❑❳❚❛⑦✰❋➄❉P❚★❇③■❊❑❈❉P❄▲❨✪■❊❑▼❃❖❙❊❬✮❉◆❫❏●★⑦❖■❊❇▼❃❖●❏❙✚❪ ➀ ●❏❘⑥❉☎❱✜❉◆●❏❱✪⑦❖❉⑥❚★❑❈❉❇❈❑❈⑩❩❃❖❙❊❬④❇❈●☎❚★❱❊❱✪⑦❖⑩❜❚✦❬❏❑❳❚★❘⑥❘❜❚★❑❮❋❍●❏❑❈❘❜❚❛⑦❿❃❅❄▼❘➃❇❈●☎❇❈❁✪❃❅❄❵❘⑥❉◆❇③❁❊●❽❨ ✙ ✉✍✚✺❪✬❀❂❁❊❉❣❄❾❉P❲❳●❏❙❯❨✖❘⑥❉◆❇❈❁❊●❊❨✖■❯❄▼❉P❄◗❚☎❄✺❃❖❘⑥❱✪⑦❿❃❋❩❯❉P❨✍❇❈❁❊❉◆❑❈❼❘⑥●❊❨✪⑩❭❙❯❚✵❘✖❃❅❲✖❘⑥●❊❨✪❉❳⑦❞●★❋❴❢▲❡➊❤ ❄▼❉P❲❳●❏❙❯❨❊❚★❑③⑩➮❄❾❇❈❑❈■❯❲❳❇❈■❊❑❈❉✖❇❈●✖❩❯❙❯❨➮❇❈❁❊❉⑥❄▼❇❈❑❈■❯❲❳❇❈■❊❑③❉⑥❶❂❃❖❇❈❁✂❇❈❁❊❉✖⑦❖●★❶❂❉P❄▼❇✦❋➄❑③❉◆❉♠❉◆❙❊❉◆❑③❬❏⑩❏❪❀❂❁❊❉✍❇❈❁✪❃❖❑✿❨✝❘⑥❉◆❇❈❁❊●❊❨➈❁❯❚❏❄❹❧❯❉◆❉◆❙➑❑❈❉P❲❳❉◆❙✪❇▼⑦❖⑩✂❃❖❙❭❇③❑❈●❽❨✪■❯❲❳❉P❨✝❧✪⑩ r✦❚★■❯❄❈❄✺⑦❖❉◆❑✟➲❛➩❣➨❩➭ ✭ ✙ ✖✬✚❴❚✵❙❯❨✂❃❖❇✖❑❈❉❳⑦❿❃❖❉P❄⑥●❏❙ ➳ ➩❍➢❛➡✯➓❭➨★➳◆➩❍➦➼➡➡❳➢❏➧❯➩❍➲✙✘☞➩✛✚ ❯◆➫▼➲✿➲❇❙❩➫▼➨❏➤✖➤♠➨❩➫❈➳❹➚ ➀❊➆ ❒❱✂➬❄❳➶✰❇❈●④❘❦●❽❨✪❉❳⑦✚❲❳●❏❘⑥❘⑥●❏❙✍❄▼❉P❲❳●❏❙❯❨❊❚★❑❈⑩⑥❄▼❇③❑❈■❯❲❳❇❈■❊❑❈❉P❄❆●★❋✬❚✦❬★❃❖❫❏❉◆❙⑥❋✐❚★❘✖❃❿⑦❖⑩⑥●★❋✬❢▲❡➊❤☎❄◆❪❨▲■❊❑✦❱❯❚★❑✿❄▼❉◆❑❂❁❯❚❏❄❂❧✜❉◆❉◆❙✇❨✪❉P❄✺❃❖❬❏❙❊❉P❨✮❇❈●❦❉❳➉❽❱❊❑❈❉P❄③❄❂❉P❚❏❄✺❃❿⑦❖⑩✟❇❈❁❊❉✦⑦❅❚★❇③❉P❄▼❇▲❇▼❶❂●♠❘❦❉◆❇❈❁❊●❽❨❊❄➐❪

➘➸↔ ☛▼❉❹❺ ❊♣❑⑩❄✣❶③➐✣❄❋❊✢✜✤✣✐➐☞❅✯❅❈❇✍❑ ❸❿●✣❅✯⑨✾❶✣❇❈➐✣❻✗❻✕➐❆❇❼❏❝✐❇❸❃❺❄❸❶s❉❳⑦❿⑦❣⑧✪❙❊●★❶▲❙➑❇❈❁❯❚★❇⑥❄▼❉P❲❳●❩❙❯❨❊❚★❑❈⑩➑❄▼❇❈❑❈■❯❲❳❇❈■❊❑③❉P❄✖❶❂❃❖❇❈❁❊●❏■❊❇⑥❱❯❄❾❉◆■❯❨✪●❏❼❍⑧❭❙❊●❩❇✿❄✖●★❋④❚★❙➑❢▲❡▲❤➾❘✍❚P⑩➈❧❯❉➎❄❾❉◆❉◆❙➂❚❏❄

❨✪❉◆❑▼❃❖❫☞❚✵❇▼❃❖●❏❙✟❇❈❑③❉◆❉P❄❂●★❋❵❇❈❁✪❃❅❄▲❢▲❡➊❤✓❋➄●❏❑✦❚♠❄❾■✪❃⑤❇❳❚★❧✪⑦❖⑩➎❨✪❉✯❩❯❙❊❉P❨✟❲❳●❩❙❭❇❈❉❳➉❊❇❈❼➼❋❍❑❈❉◆❉☎❬❏❑✿❚✵❘⑥❘❜❚★❑➊➚ ➆ ❒❱✂④➶ ✙ ♦✯✚✐❪✲✦✇❉④❘❸❃⑤❬❩❁❭❇❂❋❍●❏❑❃❖❙❯❄▼❇✿❚★❙❯❲❳❉❹■❯❄▼❉④❇③❁❊❉✦❋➄●★⑦❿⑦❖●★❶❂❃❖❙❊❬❜❬❩❑✿❚★❘⑥❘❜❚✵❑❞❶❂❃❖❇❈❁✡❇❈❉◆❑❈❘✖❃❖❙❯❚❛⑦❅❄④✸❷❧✦✥❷❧✦✧✷❧✩★✻✺

✪✬✫✮✭✰✯✝✸✰✪✱✯✲✥✳✪✴✯✗✧✳✪✴✯✵★✶✪✷✯❩✸✰✪✸★✰✪✱✯✵★✰✪ ✸✶✪✴✯✲✧✳✪✹✥✁✪✴✯✲✧✳✪✸★✰✪✬✯✗✥✁✪✹✧✳✪✺✯✵★✰✪✹✧✁✪✦✇❉④❄▼❁❯❚☞⑦⑨⑦✣■❯❄▼❉④❇❈❁❊❉✦❋❍●★⑦❿⑦❖●★❶❂❃❖❙❊❬❷❲③⑦❅❚❏❄❈❄✳❃❺❲✖❨✪❉✯❩❯❙✪❃❖❇▼❃❖●❏❙✂●★❋✕❲❳●❩❙❭❇❈❉❳➉❊❇❈❼➼❋❍❑❈❉◆❉☎❬❏❑✿❚✵❘⑥❘❜❚★❑✿❄➊➚ ➆ ❒❵✂☎❄❳➶✿❪✯✱✰✞✲✠✴✴✳✦✴✷✶❄✴✶✵✷✳➑♥✘✽◗❤ ➆ ❒❵✂✴✧ ❚➝➚✕✻P❧✽✼➏❧r✇✒❧✙✜❞➶❵❲❳●❏❙❯❄✺❃❅❄▼❇✿❄✦●★❋✠❩❯❙✪❃❖❇❈❉⑥❄▼❉◆❇✿❄✦●★❋❞❇❈❉◆❑③❘✖❃❖❙❯❚❛⑦❅❄✾✻④q✜❙❊●❏❙✪❇❈❉◆❑❈❘✖❃❖❙❯❚❛⑦❅❄✁✼✝q

❱❊❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙❯❄❂➚✺❑❈❉◆❶▲❑▼❃❖❇▼❃❖❙❊❬☎❑❈■✪⑦❖❉P❄❳➶❿✇❥❚★❙❯❨❹●★❋✷❚☎❄❾❇✿❚★❑❈❇❵❄▼⑩✪❘♠❧✜●★⑦✿✜❁❀❂✼✝❪✎❥✰❉◆❇❄❃ ❚❅✼❅❆❄✻➂❨✪❉◆❙❊●❏❇❈❉❂❇❈❁❊❉▲❫❏●❊❲◆❚★❧❊■✪⑦❅❚★❑❈⑩●★❋❞❇❈❁❊❉❹❬❏❑✿❚★❘❦❘❜❚★❑P❪❇✜◗❚❏❲❈❁✡❱❊❑❈●❊❨✪■❯❲❳❇▼❃❖●❏❙✡❃⑤❙✾✇➃❁❯❚❏❄➊❇❈❁❊❉☎❋❍●❏❑❈❘ ✸❇✫❉❈◗q✰❶▲❁❊❉◆❑❈❉ ✸✴❀✄✼ ❚★❙❯❨✄❈❊❀❋❃✹●❛❪✣✸ ❃❅❄✦❇❈❁❊❉⑦❖❉❳❋➄❇③❼❍❁❯❚★❙❯❨✟❄✺❃❅❨✪❉❹●★❋✕❇③❁❊❉☎❱❊❑❈●❽❨✪■❯❲❳❇❾❃⑤●❩❙➮❚✵❙❯❨❍❈✂❃❖❇✿❄➊❑▼❃❖❬❏❁✪❇❈❼❍❁❯❚★❙❯❨✮❄✺❃❅❨✪❉❏❪❝✐❙✮●❩■❊❑▲❶❂●❏❑❈⑧✰q❭❶❂❉④❚❏❄③❄▼■❊❘⑥❉P❨✍❇❈❁❯❚★❇❂❇❈❁❊❉☎❬❩❑✿❚★❘⑥❘❜❚✵❑❞❃❅❄❂❱❊❑③●❏❱❯❉◆❑❹➚✐❙❊●✖■❯❄▼❉❳⑦❖❉P❄❈❄➊❑❈■✪⑦❖❉P❄▲●❏❑✦❄▼⑩❭❘✖❧✜●★⑦❅❄◆q❊❙❊●❏❙❊❼✐❲③❃❖❑✿❲❳■✪⑦❅❚★❑Pq

❉◆❱❯❄✺❃❿⑦❖●❏❙❊❼➼❋❍❑❈❉◆❉★➶✿❪✖✂❣❑❳❚★❘⑥❘❜❚★❑❳❄❂❶▲❁❊●❭❄▼❉⑥❨✪❉◆❑▼❃❖❫★❚★❇▼❃❖●❏❙✝❇❈❑❈❉◆❉P❄☎❨✪❉P❄❈❲❳❑▼❃❖❧✜❉❜❄▼❉P❲❳●❏❙❯❨❊❚★❑③⑩➮❄❾❇❈❑❈■❯❲❳❇❈■❊❑❈❉P❄➊❶❂❃❿⑦❿⑦❴❚❛⑦❖❶▲❚❛⑩❽❄➊❧❯❉✍❚★❘⑥❼❧✪❃❖❬❏■❊●❏■❯❄➊❧❯❉P❲◆❚★■❯❄❾❉♠❚✖❬★❃❖❫❏❉◆❙✂❢▲❡➊❤ ❚❛⑦❖❶▲❚❛⑩❽❄❴❁❯❚❏❄❂❘❜❚★❙✪⑩✮❨❩❃⑨➏✚❉◆❑❈❉◆❙✪❇❣❄▼❉P❲❳●❩❙❯❨❊❚★❑❈⑩✮❄▼❇❈❑❈■❯❲❳❇❈■❊❑③❉P❄◆❪➆ ❒❱✂➬❄▲❚☞⑦⑨⑦❖●★❶✓■❯❄▲❇❈●✍❬★❃❖❫❏❉✖❚❜❄▼⑩✪❙✪❇❈❁❊❉◆❇▼❃❅❲✖❨✪❉P❄❈❲❳❑▼❃❖❱❊❇▼❃❖●❏❙✇●★❋❞❚✍❄▼❉◆❇❣●✵❋s❄▼❉P❲❳●❏❙❯❨❊❚★❑❈⑩✟❄❾❇❈❑❈■❯❲❳❇❈■❊❑❈❉P❄➐q❯❧❊■❊❇✦❇❈❁❊❉◆⑩✟❨✪●✍❙❊●❏❇

❚❛⑦❿⑦❖●★❶➱■❯❄❆❇❈●♠❲③❁❊●✪●❭❄▼❉▲●❏❙❊❉✦❄▼❇❈❑❈■❯❲❳❇❈■❊❑③❉❣❚★❘⑥●❏❙❊❬❹❇❈❁✪❃❅❄❂❄▼❉◆❇P❪■✜✬❼✐❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉ ➆ ❒❱✂➬❄◗➚❏✜✬❼❍❤ ➆ ❒❱✂➬❄ ➶ ✙ ✘✍✚✰❚★❑❈❉❣❚★❙❦❉❳➉❽❇❈❉◆❙❯❄✳❃⑤●❩❙●★❋ ➆ ❒❱✂➬❄▲❚❛⑦❿⑦❖●★❶❂❃❖❙❊❬✮❇❈❁❊❉④❚❏❄❈❄✳❃⑤❬❩❙❊❘⑥❉◆❙❭❇✦●★❋s❚✖❫★❚❛⑦❖■❊❉✍➚✳❲◆❚❛⑦❿⑦❖❉P❨➎❚✵❇❈❇❈❑▼❃❖❧❊■❊❇❈❉★➶❞❇③●❜❉◆❫❏❉◆❑③⑩❜❫❏❉◆❑③❇❈❉❳➉✟●★❋❞❚⑥❨✪❉◆❑▼❃❖❫☞❚★❇❾❃⑤●❩❙➎❇③❑❈❉◆❉❏❪✦ ❃❖❇❈❁✇❚★❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄➐q✰❶s❉❹❘❜❚❛⑩✮❙❊●★❶ ❄▼❉❳⑦❖❉P❲❳❇④❨✪❉◆❑▼❃❖❫☞❚★❇▼❃❖●❏❙✝❇❈❑❈❉◆❉P❄➊❶❂❃❖❇❈❁✇❚✮❄✺❃❖❘⑥❱✪⑦❖❉❜❲❳❑▼❃❖❇❈❉◆❑❾❃⑤●❩❙✚❪④❝ ❋s❇❈❁❊❉⑥❚★❇❈❇③❑▼❃❖❧❊■❊❇❈❉✖●★❋s❚

Page 15: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❫❏❉◆❑❈❇③❉❳➉✮❃❺❄✦❚★❙✡❉◆❙❊❉◆❑❈❬❏⑩✟●❩❑❣❚⑥❱❊❑③●❏❧❯❚★❧✪❃❿⑦❿❃⑤❇▼⑩❏q❮❇❈❁❊❉♠❲❳❑▼❃❖❇❈❉◆❑❾❃⑤●❩❙➎❘✍❚P⑩✮❧✜❉④❇❈❁❊❉⑥❄▼❉❳⑦❖❉P❲❳❇▼❃❖●❏❙✂●★❋❞❇③❁❊❉♠❨✪❉◆❑▼❃❖❫☞❚✵❇▼❃❖●❏❙✇❇❈❑❈❉◆❉❹❶❂❃❖❇❈❁❇❈❁❊❉➊⑦❖●☞❶❂❉P❄▼❇◗❉◆❙❊❉◆❑❈❬❏⑩⑥●❩❑❞❇❈❁❊❉▲❁✪❃❖❬❏❁❊❉P❄❾❇▲❱❊❑❈●❏❧❯❚★❧✪❃❿⑦❿❃❖❇▼⑩❷❚★❇◗❇❈❁❊❉▲❑❈●✪●❏❇P❪❵⑩◗■❊❇▲❚★❇❈❇❈❑❾❃⑤❧❊■❊❇③❉P❄❞❚★❑❈❉➊❙❊●❏❇❂❑❈❉P❄▼❇❈❑▼❃❅❲❳❇❈❉P❨❸❇❈●♠❄✺❃❖❘⑥❱✪⑦❖❉❑❈❉P❚❛⑦❞❫★❚❛⑦❖■❊❉P❄✖❚★❙❯❨✇❘✍❚P⑩✡❧❯❉⑥❘❦●❏❑❈❉❜❲❳●❏❘❦❱✪⑦⑤❉❳➉✚❪③❨▲■❊❑♠❲❳●❏❙✪❇❈❉❳➉❊❇④●★❋❂■❊❇▼❃❿⑦❿❃⑤➍P❚✵❇▼❃❖●❏❙➑●★❋✶✜✣❼❍❤ ➆ ❒❱✂➬❄✦❁❯❚❏❄➊⑦❖❉P❨➈■❯❄❹❇❈●✮❇❈❁❊❉❋❍●★⑦❿⑦⑤●★❶❂❃❖❙❊❬✮❨✪❉✯❩❯❙✪❃❖❇▼❃❖●❏❙✡❋➄●❏❑➊❇❈❁❊●❭❄▼❉✦❬❏❑✿❚★❘❦❘❜❚★❑✿❄◆❪✯✱✰✞✲✠✴✴✳✦✴✷✶❄✴✶✵✷✳✇r ✽◗❤✦❙❁✜✣❼❍❤ ➆ ❒❱✂❥❃❅❄④❨✪❉◆❙❊●❩❇❈❉P❨✡❧❭⑩✄✧ ❚ ➚✕✻P❧✽✼➏❧r✇✒❧✙✜✢❧✁�✌❧✙✜✄✂❏❧✆☎✞✝✣➶✿❪④❀❂❁✪❃❅❄➊❃❅❄④❚✵❙➎❉❳➉❊❇❈❉◆❙❯❄✺❃❖●❏❙✂●★❋

❇❈❁❊❉⑥❱❊❑③●❏❱❯❉◆❑ ➆ ❒❱✂✱✧ ❚✗➚✝✻P❧✦✼❵❧➋✇✒❧✓✜❵➶✿qt❶▲❁❊❉◆❑❈❉⑥❚★❙✏❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉✠✟❊❀✡� ❃❅❄④❚★❇③❇✿❚❏❲③❁❊❉P❨✟❇③●✮❉P❚❏❲❈❁✇❄▼⑩✪❘✖❧❯●★⑦☞☛ ❀ ❃❦q❚★❙❯❨✂❚✮❄▼❇❈❑❾❃⑤❙❊❬✍●★❋▲❚★❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄ ✕❋❀✡� ● ❇❈●✍❉P❚❏❲③❁➮❄❾❇❈❑▼❃❖❙❊❬❂❈❅❀❁❃ ● ❪✹✜✌✂✝❃❺❄❹❚✖❋❍■❊❙❯❲❳❇▼❃❖●❏❙✂❋❍❑❈●❏❘ ✻➝❇❈●✍� ❚❏❄❈❄✳❃⑤❬❩❙✪❃⑤❙❊❬❚★❇❈❇③❑▼❃❖❧❊■❊❇❈❉P❄◗❇❈●✖❇❈❉◆❑❈❘✖❃❖❙❯❚❛⑦❅❄◆❪☞☎ ✝ ❃❅❄▲❚✖❄▼❉◆❇❂●★❋✚❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄◗❋❍❑❈●❏❘✎� ● ❇❈●✏�✍❪❵❤ ❋➄■❊❙❯❲❳❇▼❃❖●❏❙✒✑ ✻✄✓✕✔ ❃❺❄s❃⑤❙✒☎ ✝ ❃❿➏ ✸✢✫✮❈❃❅❄❂❃❖❙✕✇✖❪❀❂❁❊❉✖❚★❇❈❇❈❑▼❃❖❧❊■❊❇❈❉ ✕✟●★❋s❚⑥❄❾❇❈❑▼❃❖❙❊❬❂❈➈❃❅❄✦❇❈❁❊❉♠❲❳●❏❙❯❲◆❚✵❇❈❉◆❙❯❚★❇▼❃❖●❏❙✡●★❋❞❇❈❁❊❉♠❚✵❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄➊●★❋❞❇❈❁❊❉✖❄▼⑩❭❘✖❧✜●★⑦❅❄➊❃⑤❙❋❈◗❪❇✦①❁❊❉◆❙

❚❹❋❍■❊❙❯❲❳❇▼❃❖●❏❙✒✑ ✻✄✓✕✔ ❃❺❄➊❚★❱❊❱✪⑦❿❃⑤❉P❨✡❇❈●✖❇❈❁❊❉④❚✵❇❈❇❈❑▼❃❖❧❊■❊❇❈❉ ✕✍●★❋❆❚✖❄▼❇③❑▼❃❖❙❊❬✸❈✏❨✪❉◆❑❾❃⑤❫❩❉P❨✍❋❍❑❈●❏❘ ✸④q❩❃❖❇▲❑❈❉◆❇③■❊❑❈❙❯❄❂❇❈❁❊❉④❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉✟✝●★❋✣✸❹❪✇❀❂❁❭■❯❄➐q✚❋❍■❊❙❯❲❳❇▼❃❖●❏❙❯❄✖●✵❋✖☎✞✝❥❚★❑❈❉✍❑❈❉P❄▼❱✜●❏❙❯❄✺❃❖❧✪⑦❖❉✮❋❍●❏❑④❇❈❁❊❉✮❲❳●❏❘⑥❱❊■❊❇❳❚★❇▼❃❖●❏❙✚q❮❃❖❙➂❚✟❧✜●❏❇❈❇❈●❩❘⑥❼❍■❊❱✏❶▲❚❛⑩❏q✚●✵❋❣❇❈❁❊❉❚★❇❈❇③❑▼❃❖❧❊■❊❇❈❉P❄✦●★❋s❙❊●❩❙❭❇❈❉◆❑③❘✖❃❖❙❯❚❛⑦❅❄❀✸✓❃❖❙✏❨✪❉◆❑❾❃⑤❫★❚★❇▼❃❖●❏❙❯❄✹❈ ✸✕✗❅✫ ●✙✘ q✚❶▲❁❊❉◆❑❈❉ ✘ ❘✖■❯❄▼❇❣❧✜❉❳⑦❖●❏❙❊❬✂❇❈●✸✻ ● ❃❖❙✏●❩❑✿❨✪❉◆❑☎❇❈❁❯❚★❇❇❈❁❊❉④❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉☎●★❋✔✸❥❘✍❚P⑩✍❧❯❉✖❲❳●❏❘⑥❱❊■❊❇✿❚✵❧✪⑦⑤❉❏❪

➷❮↔❜→✙✚❜❉ ➑ ❄❹❉✛✚➒❄ �❏➐❆❇❩❏✬❑⑩❄✣❶✾➐❆❺ ❶❆❉❹❇✍❑ ❅✍⑧✢❻ ❏✦ ❃❖❇❈❁➂●❏■❊❑✍❚★❱❊❱✪⑦❿❃❺❲◆❚✵❇▼❃❖●❏❙❥●★❋☎❱❯❚★❑✿❄✺❃❖❙❊❬✝❇❈●➑❢▲❡▲❤☎❄◆q❂❶❂❉✟❶❴❃⑨⑦❿⑦☎❁❯❚❛❫❏❉✟❇❈● ❩❯❙❯❨➑●❏❙❊❉✂❨✪❉◆❑▼❃❖❫☞❚★❇▼❃❖●❏❙①❇❈❑③❉◆❉➎❚★❘⑥●❩❙❊❬✏❚

❱❯●❩❇❈❉◆❙❭❇❾❃❺❚☞⑦⑨⑦❖⑩✇❉❳➉❊❱❯●❩❙❊❉◆❙❭❇▼❃❅❚❛⑦▲❙✪■❊❘✖❧❯❉◆❑④●✵❋➊❨✪❉◆❑❾❃⑤❫★❚★❇▼❃❖●❏❙➑❇❈❑③❉◆❉P❄◆❪❡r➊❉◆❙❯❲❳❉❜❇❳❚★❧❊■✪⑦❅❚★❑♠❚❛⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘❜❄④❚✵❑❈❉❜❚✮❬❩●❭●❊❨✂❶▲❚❛⑩✟❇❈●❨✪❉P❚❛⑦❣❶❴❃⑤❇③❁➂❇❈❁✪❃❅❄❦❱❯❚★❑✿❄▼❉➅❋➄●❏❑③❉P❄▼❇⑥❄✺❃❖❙❯❲❳❉➎❇③❁❊❉◆⑩➑●❏■❊❇❈❱❊■❊❇❜❚✇❲❳●❩❘⑥❱❯❚❏❲❳❇❈❉P❨ ❑❈❉◆❱❊❑❈❉P❄▼❉◆❙✪❇✿❚★❇▼❃❖●❏❙➑●✵❋➬❇❈❁❊❉✡❱❯❚★❑✿❄▼❉✍❋❍●❏❑❈❉P❄❾❇✖❃❖❙❱❯●✵⑦⑤⑩✪❙❊●❏❘✖❃❅❚❛⑦❵❇▼❃❖❘⑥❉✏✜❸➚✐❖ ➁ ➶s❚✵❙❯❨✮❄▼❱❯❚❏❲❳❉✢✜❸➚✐❖ ✺ ➶✿❪❀❂❁❊❉④❄✺❃❖❘⑥❱✪⑦❖❉P❄▼❇④❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✗❃❅❄❂❇❈❁❊❉❹●❏❙❊❉☎●★❋ ➆ ●❊❲❈⑧❏❉◆❼✤✣❵●❩■❊❙❊❬❏❉◆❑❈❼✒✬☎❚❏❄❈❚✵❘✖❃ ✙ ♥✯✚ ✺

❥✰❉◆❇✹✧ ❧✜❉❷❚➅❱❊❑❈●❏❱❯❉◆❑ ➆ ❒❱✂➝❃❖❙ ➆ ❁❊●❏❘❜❄▼⑧✪⑩✟❙❊●❩❑❈❘❜❚❛⑦❵❋❍●❏❑❈❘✟❪✍❀❂❁❊❉✮❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❧❊■✪❃⑨⑦❅❨❊❄⑥❚➅❇✿❚★❧✪⑦❖❉✡➚✝✻✛✥◆➶ Ï✁✦ ✥ ✦ ✽ ❄▼■❯❲③❁❇❈❁❯❚★❇❄✻✛✥④❲❳●❏❙✪❇✿❚❛❃❖❙❯❄❂❇③❁❊❉✦❃⑤❇③❉◆❘ ✙ ✸❤❧☎✂✂✚❊❃❿➏✪✸✢✫ ✦★✧⑤✑ Ï ➄❈➄✬➄✒✦✩✥❏❪❒❊●❩❑✫✪✍❧✜❉◆❇✳❶❂❉◆❉◆❙✇♥④❚✵❙❯❨❵❖✣q❊❱❯❉◆❑❾❋➄●❏❑③❘ ❇❈❁❊❉✦❋❍●★⑦❿⑦⑤●★❶❂❃❖❙❊❬✮❄▼❇❈❉◆❱❯❄➚✿♥★➶❹❤➬❨❊❨ ✙ ✸❤❧✬✪❤♠➑♥✯✚✚❇❈●✹✻✛✥➊❃❿❋ ✸ ✫ ✦✭✥★➋➚✳r✪➶❹❤➬❨❊❨ ✙ ✸❤❧☎✂✂✚✰❇❈●✹✻✮✥➊❃❿❋✕✯✉q✱✰✡✪✍❄▼■❯❲③❁✟❇❈❁❯❚★❇ ✙✳✲ ❧☎✂✂✚✠❀❍✻ ➌ ❚★❙❯❨ ✙ ✥❤❧rq✛✚✿❀❍✻✛✥➬❚✵❙❯❨ ✸ ✫ ✲ ✥⑥➋➚✳✉✪➶✖❢❂❉◆❱❯❉P❚★❇➊❇❈❁❊❉④❱❊❑❈❉◆❫❩❃❖●❏■❯❄✦❄▼❇❈❉◆❱✮❶▲❁✪❃❿⑦❖❉✖❇❈❁❊❉◆❑❈❉☎❑❈❉◆❘❜❚☞❃⑤❙❯❄s❃⑤❇③❉◆❘❜❄▲❇③●♠❧✜❉♠❚❏❨❊❨✪❉P❨➅❇❈● ✻ ✥ ❪

❀❂❁❊❉④❄▼❇③❑▼❃❖❙❊❬ ✦ Ï ➄✬➄❈➄✒✦ ✽ ❧❯❉❳⑦❖●❏❙❊❬✪❄▲❇❈●✍✴❂➚✏✧❸➶✬❃❿➏ ✙ ✜✢❧❳✈✍✚✿❀❍✻ ✽ ❪➆ ✣✛✬✆✷➵❄❂❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✗❙❊❉◆❉P❨❊❄❂❬❩❑✿❚★❘⑥❘❜❚✵❑✿❄✣❃❖❙ ➆ ❁❊●❏❘✍❄▼⑧❭⑩❦❙❊●❏❑❈❘❜❚❛⑦✰❋❍●❏❑❈❘✟q✪❚★❙❯❨❦❃❖❇▲❨✪●❭❉P❄❂❙❊●❩❇❴❚❛❫❏●✵❃❺❨❦❘❜❚★❙✪⑩⑥■❯❄▼❉❳⑦❖❉P❄❈❄❨✪❉◆❑▼❃❖❫☞❚✵❇▼❃❖●❏❙✇❄▼■❊❧❊❇❈❑❈❉◆❉P❄◆❪❆❤ ❘✖■❯❲③❁✮❧❯❉◆❇❈❇❈❉◆❑✦❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✗❃❅❄❬✜❞❚★❑❾⑦⑤❉◆⑩✩✷➵❄▲❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘ ✙ ♥❩q❽r❝✚ ✺❥✰❉◆❇❄✧❥❧✜❉➬❚✦❱❊❑❈●❩❱❯❉◆❑ ➆ ❒❱✂♠❪ ❨▲❧❊❻✳❉P❲❳❇❳❄❵●★❋✚❇❈❁❊❉❂❋❍●❏❑❈❘ ✙ ✸ ✫✵☛ Ï ➄❈➄✬➄✬☛ ➌ ➃✬☛ ➌ ✑ Ï ➄✬➄❈➄✶☛✱☞P❧★✂⑩✚✐q❛❶▲❁❊❉◆❑❈❉✛✸❅✫✷☛ Ï ➄❈➄✬➄✬☛ ☞❚★❙❯❨✂✈✭✚ ✂✇✚ ❖✣q✚❚★❑❈❉♠❲◆❚☞⑦⑨⑦❖❉P❨✡❃❖❇❈❉◆❘✍❄◆❪☎❀❂❁❊❉⑥❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✒❧❊■✪❃❿⑦❺❨❊❄❹❚⑥❇❳❚★❧✪⑦❖❉❜➚✕✻✮✥❛➶ Ï✁✦ ✥ ✦ ✽ ❄▼■❯❲❈❁✡❇❈❁❯❚★❇✰✻✛✥♠❲❳●❏❙✪❇✿❚❛❃❖❙❯❄✦❚★❙❃❖❇❈❉◆❘ ✙ ✸❅✫✮❈➏➃✸✗☎❧★✂⑩✚✜❃❿➏✇❇❈❁❊❉◆❑❈❉☎❉❳➉✪❃❺❄❾❇✿❄✕✹✂❄▼■❯❲③❁✟❇❈❁❯❚★❇

✜ ✫ ● ✦ Ï ➄✬➄❈➄✏✦★✧✴✸✖✹❂✫ ✦ Ï ➄✬➄❈➄✏✦★✧✛❈✺✗✺✹ ✫ ● ✦ Ï ➄✬➄❈➄✒✦✩✥✸✗✺✹❤▲❇❂❇❈❁❊❉✦❧❯❉◆❬★❃❖❙❊❙✪❃❖❙❊❬❯q ✙ ✜ ✫ ➃ ❈✡❧✿✈✍✚✿❀❍✻✺✻❆❋➄●❏❑▲❚❛⑦❿⑦ ✜ ✫✮❈❞❪◗❀❂❁❊❉◆❙✚q❩❃⑨❋ ✙ ✸✢✫ ➃ ✲ ✗☎❧✿✈❝✚ ❀❍✻✺✻◆q✜❚❏❨❊❨ ✙✼✲ ✫ ➃✽✹ ❧❳✈✍✚❊❇❈●✹✻✺✻❋❍●❏❑❣❚❛⑦❿⑦ ✲ ✫✷✹❵❪❵❒❊●❏❑☞✪❦❧❯❉◆❇▼❶❂❉◆❉◆❙✏♥☎❚★❙❯❨➏❖✬qt❱❯❉◆❑▼❋❍●❏❑❈❘ ❇③❁❊❉✦❋➄●★⑦❿⑦❖●★❶❂❃❖❙❊❬❷❄❾❇❈❉◆❱❯❄

➚✿♥★➶✖❒❊●❏❑▲❚❛⑦❿⑦ ✙✳✲ ✫✮❈✕➃❖✦✾✗☎❧☎✂✂✚✠❀❍✻ ✥✸✿ Ï ❄▼■❯❲③❁✟❇③❁❯❚★❇✧✦✷❚ ✦ ✥ q❯❚❏❨❊❨ ✙✳✲ ✫✮❈❥✦❤➃✸✗☎❧★✂⑩✚✰❇❈●✹✻ ✥ ➋➚✳r✪➶❹❝❍❋ ✙ ✸❅✫✷✹❿➃▲❧★✂⑩✚ ❀ ✻✮✥★q❊❇③❁❊❉◆❙✍❋➄●❏❑✦❚❛⑦❿⑦ ✙✳✲ ✫✮❈✕➃❖✸✕✗☎❧➋q✛✚✠❀❍✻❀✧✐q❯❚❏❨❊❨ ✙✳✲ ✫✮❈❥✸ ➃✸✗☎❧➋q✛✚✰❇❈● ✻✛✥★➋➚✳✉✪➶❹❝❍❋ ✙ ✸❅✫✮❈✕➃ ✲ ✗☎❧☎✂✂✚✠❀❍✻✛✥☞q✜❚❏❨❊❨ ✙✳✲ ✫ ➃❁✹❿❧✶✪✉✚❊❇③● ✻✛✥➊❋❍●❏❑❣❚❛⑦❿⑦ ✲ ✫✷✹❵➋➚❫✘❊➶✖❢❂❉◆❱❯❉P❚★❇➊❇❈❁❊❉④❇▼❶❂●✖❱❊❑❈❉◆❫❏❃❖●❏■❯❄✦❄▼❇❈❉◆❱❯❄❴❶▲❁✪❃❿⑦⑤❉❹❇❈❁❊❉◆❑❈❉❹❑❈❉◆❘❜❚❛❃❖❙❯❄◗❃❖❇❈❉◆❘❜❄➊❇❈●✖❧❯❉✖❚❏❨❊❨✪❉P❨✮❇③● ✻✛✥❏❪

❀❂❁❊❉④❄▼❇③❑▼❃❖❙❊❬ ✦ Ï ➄✬➄❈➄✒✦ ✽ ❧❯❉❳⑦❖●❏❙❊❬✪❄▲❇❈●✍✴❂➚✏✧❸➶✬❃❿➏ ✙ ✜❋✫ ❈☎➃▲❧❳✈✍✚✿❀❍✻ ✽ ❪❤➊⑦⑨⑦❵❃❖❇❈❉◆❘✍❄▲❬❏❉◆❙❊❉◆❑❳❚★❇❈❉P❨✡❧❭⑩✢✜◗❚★❑▼⑦❖❉◆⑩✩✷➵❄☎❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘➾❚★❑❈❉✖■❯❄▼❉❳❋❍■✪⑦✣❃⑤❙➈❇❈❁❊❉♠❲❳●❏❙✪❇❈❉❳➉❊❇❣●✵❋❵⑦⑤❉❳❋❍❇☎❇❈●✍❑▼❃❖❬❏❁✪❇❣❱❯❚★❑❳❄▼❉✖●★❋❞❇❈❁❊❉❃❖❙❊❱❊■❊❇➬❄❾❇❈❑▼❃❖❙❊❬❯❪

Page 16: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✃✣↔✍➙✌●❏❇ �▼➐❆❇❼❏✬❑⑩❄✣❶✾➐❆❺ ❶❆❉✣❇✱❑ ❅✍⑧♣❻❨▲■❊❑✦❱❯❚★❑✿❄✺❃❖❙❊❬✮❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘✒●❏■❊❇❈❱❊■❊❇✿❄❴❃❖❇❈❉◆❘❜❄➊❶▲❁✪❃❅❲❈❁✇❚★❑③❉✦❃⑤❙✡❋✐❚❏❲❳❇❣❚❸❋ ❚❩❲❳❇❈●❏❑▼❃❖➍P❚★❇▼❃❖●❏❙✮●✵❋▼✜❞❚★❑▼⑦❖❉◆⑩✩✷➵❄❴❃⑤❇③❉◆❘❜❄❣❄❾❁❯❚★❑▼❃❖❙❊❬

❇❈❁❊❉❣❄③❚★❘⑥❉❂❑▼❃❖❬❏❁✪❇❵❱❯❚★❑❈❇❵❧❯❉❳❋❍●❏❑❈❉➊❇❈❁❊❉❣❨✪●❏❇✧✺✷❃❖❇❞❶❂❃❿⑦❿⑦➸❑❈❉◆❱✪⑦❅❚❏❲❳❉☎❚☎❄▼❉◆❇◗●★❋❯❃❖❇❈❉◆❘❜❄ ✙ ✸❅✫ ❈❷➃✤✗✡❧☎✂⑩✚✪❁❯❚❛❫❏❃❖❙❊❬❹❇❈❁❊❉❣❄❈❚★❘❦❉❴❄❾❇❈❑▼❃❖❙❊❬❈✝❧✪⑩✟❚❜❄✺❃❖❙❊❬★⑦❖❉❹❃❖❇❈❉◆❘ ✙✁� ✫❉❈☎❧★✂⑩✚✰❃❿❋ ❈✄✂❚ ✭◆q✜●❏❑✦❧❭⑩✮❙❊●❩❇❈❁✪❃❖❙❊❬⑥❃❿❋ ❈★❚ ✭ ✙ ②✪q ④ ✚✐❪ � ❃❅❄▲❇❈❁❊❉✖❄▼❉◆❇✦●★❋❞❙❊●❏❙❊❼❍❇❈❉◆❑❈❘❸❃⑤❙❯❚☞⑦❺❄❶▲❁✪❃❅❲③❁✟❶❂❉◆❑❈❉④❚★❇▲❇③❁❊❉✦⑦⑤❉❳❋❍❇❈❼❍❁❯❚★❙❯❨✡❄✺❃❅❨✪❉④●★❋❵❑❈❉◆❱✪⑦❅❚❏❲❳❉P❨❷❃⑤❇③❉◆❘❜❄◆❪❀❂❁❊❉④❚❛⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘ ❑❈❉◆❱✪⑦❅❚❏❲❳❉P❄❂❇③❁❊❉④❄▼❉P❚★❑✿❲③❁✮❱❯❉◆❑▼❋❍●❏❑❈❘❦❉P❨❦❃⑤❙✟❄❾❇❈❉◆❱➒✘✖●★❋❱✜◗❚★❑▼⑦❖❉◆⑩✩✷➵❄❂❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❧✪⑩✮❚★❙✮❉❳➉❽❇③❑✿❚❏❲❳❇▼❃❖●❏❙❦❃❖❙

❚✮❱❊❑❾❃⑤●❩❑▼❃❖❇✳⑩✇➌❩■❊❉◆■❊❉✆☎ ❁❊●★⑦❅❨❩❃⑤❙❊❬✂❱❯❚❛❃❖❑✿❄❸➚✬☛✕❧☎✂▼➶❂●★❋❣❄▼⑩✪❘✖❧❯●★⑦❅❄④❚✵❙❯❨✡❃❖❙❭❇❈❉◆❬❩❉◆❑✿❄◆❪ ✦➈❉❜❄❈❚❛⑩✟❇❈❁❯❚✵❇④❚✮❱❯❚❛❃❖❑⑥➚✶☛✹❧★✂▼➶❂❁❯❚❏❄☎❚❬❏❑❈❉P❚✵❇❈❉◆❑❞❱❊❑▼❃❖●❏❑❾❃⑤❇▼⑩⑥❇③❁❯❚★❙❷❚➠❱❯❚❛❃❖❑✦➚✞✝ ❧✶✪✜➶✰❃⑨❋✷✂✠✟✡✪✖●❩❑❵❃❿❋❪✂❍❚ ✪⑥❚★❙❯❨✡✝✴✫ ● ☛➑❪❵❀❂❁❊❉▲❋❍■❊❙❯❲❳❇▼❃❖●❏❙✍■❯❄▼❉P❨✍❇❈●❹❑❈❉◆❇❈■❊❑❈❙✮❚★❙❯❨❑❈❉◆❘⑥●★❫❏❉✦❇❈❁❊❉✖❄▼❉◆❇▲●★❋✬❘✍❚❛➉❭❃❖❘✖■❊❘✒❱❯❚❛❃❖❑✿❄❂●★❋✠☎✓❃❅❄✦❨✪❉◆❙❊●❏❇❈❉P❨✍❧✪⑩ ✪ ✟☞☛✍✌❩✦✏✎✑☛❳❪❥✰❉◆❇✸✧✒❧✜❉✟❚✡❱❊❑❈●❏❱❯❉◆❑ ➆ ❒❱✂♠❪❱❨▲■❊❑❜❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘ ❧❊■✪❃❿⑦❅❨❊❄✍❚✟❇❳❚★❧✪⑦❖❉✂➚✝✻✛✥P➶ Ï ✦ ✥ ✦ ✽ ❄▼■❯❲❈❁➑❇③❁❯❚★❇✹✻✮✥✍❲❳●❏❙✪❇✿❚❛❃❖❙❯❄✖❚★❙✝❃❖❇❈❉◆❘✙✁� ✫✮❈✡❧☎✂✂✚✜❃⑨➏❁❈✒✂❚ ✭✦❚★❙❯❨❦❋❍●❏❑❣❚❛⑦❿⑦❪✸❇❀ � ❇③❁❊❉◆❑❈❉☎❉❳➉❭❃❅❄▼❇❳❄ ✗➴❚✵❙❯❨✍✹➎❄▼■❯❲③❁✟❇❈❁❯❚✵❇

✜ ✫ ● ✦ Ï ➄✬➄❈➄✏✦★✧✴✸✖✹❂✫ ✦ Ï ➄✬➄❈➄✏✦★✧✛❈✺✗✺✹ ✫ ● ✦ Ï ➄✬➄❈➄✒✦✩✥✸✗✺✹✜❵❫❩❉◆❑❈⑩⑥❇▼❃❖❘⑥❉✖❚★❙✍❃❖❇❈❉◆❘ ✙✁� ✫✮❈✡❧☎✂✂✚✜❃❺❄➊❚❏❨❊❨✪❉P❨✍❇❈● ✻ ✥ q✪❱❯❉◆❑▼❋❍●❏❑❈❘✓☎ ✺✵❚✔☎ ❆✖✕✵➚✄✸❷❧★✂▼➶✘✗✗ ✸ ❀ �✚✙ ✸ ✫✮❈✘✛✪❪❵❤▲❇❂❇❈❁❊❉❧❯❉◆❬✵❃⑤❙❊❙✪❃❖❙❊❬❯q✚❚☞⑦⑨⑦✤✻✮✥☎❚★❑③❉☎❉◆❘⑥❱❊❇▼⑩❏❪✤❥✷❉◆❇ � ✻ ❚✢✜❼✸✢❀❂✼✮✯✾✯★✗✡❧✓✜❋✫ ✸✖✗✤✣❭❪◗❒❊●❏❑ ✪✍❧❯❉◆❇▼❶❂❉◆❉◆❙✇♥④❚★❙❯❨➒❖✡❱❯❉◆❑❾❋➄●❏❑③❘ ❇❈❁❊❉❋❍●★⑦❿⑦⑤●★❶❂❃❖❙❊❬✮❄▼❇❈❉◆❱❯❄

➚✿♥★➶✥☎ ✺✵❚✦✕✵➚✄✦ ✥ ❧✶✪❷♠➑♥★➶✧✛❏➋➚✳r✪➶❦➚✬☛✹❧★✂▼➶✩✺ ❚ ✪ ✟☞☛★✌❩✦✩✎✑☛▼➚★☎✖➶❳➋➚✳✉✪➶✳✻✮✥ ✺✵❚ ✻✛✥■❆✖✕ ✙✁� ✫✷☛✕❧☎✂✂✚ ✗✗ � ❚✢✜❩✸ ❀ � ✧ ✯✾✯★✗☎❧☎✸✢✫✷☛ ✗✤✣✪✂❚✄✫✬✛★➋➚❫✘❊➶✳✻✮✥ ✺✵❚ ✻✛✥■❆ ✕ ✙✁� ✫✮❈✞☛✕❧✮✭☞✚ ✗✗ ✯ ✙✁�✥✯ ✫✮❈✡❧✮✭☞✚✠❀ ✻ ✧❴❧ � ❚✢✜❼✸✢❀ �✥✯ ✯ ✯★✗☎❧★✸❅✫✮❈✞☛ ✗✤✣✪✂❚✔✫ ✛ ➋➚ ④ ➶✖❢❂❉◆❱❯❉P❚★❇✦❄▼❇❈❉◆❱❯❄✦r④❇③● ④ ❶▲❁✪❃❿⑦❖❉✪☎✓❃❅❄❂❙❊●❏❇▲❉◆❘❦❱❊❇✳⑩✰➋➚✏✖✪➶ ➆ ●❏❘⑥❱❊■❊❇❈❉ � ✥ ✺✵❚✄✰✲✱ ✳ ✓✕✔ ☛ ✧✵✴✷✶✑✸✺✹ ✜✼✻ ❀❂✼ ✯✾✯✍✸✢✫✮❈ ✲ ✗☎❧✸✯★✹❿❧★✸ ❀ �✚✙ ✲ ✫ ● ✻ ✹✽✣❭❪

❀❂❁❊❉◆❙✙✦ Ï ➄❈➄❈➄✏✦ ✽ ❀✒✴❂➚✏✧❸➶✣❃⑨➏✇❇❈❁❊❉◆❑③❉☎❉❳➉❭❃❅❄▼❇✿❄ ✙✁� ✫✮❈✡❧✿✈❝✚✠❀❍✻ ✽ ❄❾■❯❲❈❁✮❇❈❁❯❚✵❇✾✜❁❀ � ❚✵❙❯❨ ✜❋✫ ❈◗❪❝✐❙❦❇❈❁❊❉❂❬❏❉◆❙❊❉◆❑✿❚❛⑦❯❲◆❚❏❄▼❉❏q❩❇❈❁❊❉▲❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩✖●★❋➸●❩■❊❑✕❚❛⑦❖❬❏●❩❑▼❃❖❇❈❁❊❘➝❃❅❄ ✜✖➚❾❖ ➁ ➶✜❃⑤❙❦❇▼❃❖❘⑥❉❣❚★❙❯❨ ✜✖➚❾❖ ✺ ➶✜❃⑤❙✍❄▼❱❯❚❏❲❳❉❏❪❵❤☎❄✣❶❂❃❖❇❈❁

✜❞❚✵❑▼⑦❖❉◆⑩❚✷➵❄☎❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✟q✰❇❈❁❊❉P❄❾❉♠●❩❑✿❨✪❉◆❑✿❄✦❘✖❃❖❬❏❁✪❇☎❧❯❉✖❃❖❘⑥❱❊❑③●☞❫❩❉P❨✮❋❍●❏❑☎❬❏❑❳❚★❘⑥❘❜❚★❑❳❄❂❁❯❚❛❫❏❃❖❙❊❬➎❄❾●❏❘⑥❉♠❄❾❱❯❉P❲③❃❅❚❛⑦s❱❊❑③●❏❱❯❉◆❑❈❇❾❃⑤❉P❄❶▲❁✪❃❅❲③❁➎❚★❑❈❉☎●✵❋✕❙❊●✖❃❖❙✪❇❈❉◆❑❈❉P❄▼❇❴❃⑤❙✡●❏■❊❑❣❲◆❚❏❄❾❉✖➚✳❢▲❡➊❤✓❋➄●★⑦❅❨❩❃❖❙❊❬❊➶✿❪❡➊●☞❶①❇❈❁❯❚✵❇▲❶❂❉☎❁❯❚P❫❩❉④❚★❙✟❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❶▲❁✪❃❅❲❈❁✡❘❜❚❛⑩⑥■❯❄▼❉ ➆ ❒❵✂✖q❭❶❂❉☎❘❜❚❛⑩⑥❇③❑✿❚★❙❯❄✺❋❍●❏❑❈❘➃❃❖❇▲❇❈●⑥■❯❄❾❉✹✜✬❼❍❤ ➆ ❒❱✂✤✺✾ ❝✐❇❈❉◆❘❜❄➊❚★❑❈❉ ✙✁� ✫✮❈✡❧☎✂❀❧❖✕☞✚✐q★❶▲❁❊❉◆❑③❉✱✕⑥❃❅❄➊❇❈❁❊❉④❄▼❇❈❑❾❃⑤❙❊❬❦●★❋❆❚✵❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄▲❚✵❇❈❇✿❚❏❲③❁❊❉P❨✍❇❈● ❈❞➋✾ ☎❵❚❛❃❖❑✿❄➊➚✬☛✹❧★✂▼➶❵❚❏❨❊❨✪❉P❨✮❇❈●✿☎ ❚★❑❈❉☎❇③❑▼❃❖❱✪⑦⑤❉◆❇❳❄☎➚✬☛✕❧☎✂❀❧✆✟✷➶✿q★❶▲❁❊❉◆❑❈❉✏✟❷❃❺❄➊❇❈❁❊❉④❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉④❚★❇❈❇❳❚❏❲❈❁❊❉P❨✍❇③●✢☛➑➋✾ ❒❊■❊❙❯❲❳❇▼❃❖●❏❙❯❄✕✑ ✻✄✓✕✔ ❚✵❑❈❉❣❇❳❚★⑧❏❉◆❙✍❃❖❙❭❇③●❜❚❏❲◆❲❳●❏■❊❙✪❇❣❚★❇▲❇③❁❊❉☎❇▼❃❖❘⑥❉④●★❋✣❑❈❉P❨✪■❯❲❳❇▼❃❖●❏❙✂●★❋✚❃❖❇❈❉◆❘❜❄➐➋✾ ❀❂❁❊❉④❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❏❑▼❃❅❚❛⑦✚❉❳➉❊❱✪⑦❖●❭❄✺❃❖●❏❙✂●★❋✬❇❈❁❊❉❹❙❭■❊❘✖❧✜❉◆❑▲●★❋✣❃⑤❇③❉◆❘❜❄◗❃❅❄❣❚❛❫❏●✵❃❺❨✪❉P❨✍❶❴❃⑤❇③❁✟❲❳●❏❙❯❄▼❇❈❑✿❚☞❃⑤❙✪❇✿❄❁❀ ✻ q❊❚❏❄❈❄▼●❊❲③❃❖❼❚★❇❈❉P❨✍❶❂❃❖❇❈❁✡❙❊●❏❙❊❼❍❇❈❉◆❑❈❘✖❃❖❙❯❚❛⑦❅❄✛✸❹q❯❶➊❁✪❃❺❲③❁✂❑❈❉◆❱✪⑦❅❚❏❲❳❉♠❚✍❄▼❉◆❇▲●✵❋❞❇❈❑▼❃❖❱✪⑦❖❉◆❇✿❄☎➚✏✸❷❧★✂❂❧✆✟✷➶❵❶❂❃❖❇❈❁❸❩❊➉❊❉P❨ ✸➝❚★❙❯❨ ✂◗❧❭⑩✮❚❄✺❃❖❙❊❬★⑦❖❉④❇❈❑▼❃❖❱✪⑦❖❉◆❇❹➚✄✸❷❧★✂❂❧✑❂❊➶✣❶▲❁❊●❭❄▼❉④❚★❇③❇❈❑▼❃❖❧❊■❊❇❈❉❃❂❸❃❺❄✦❨✪❉P❨✪■❯❲❳❉P❨✍❋❍❑❈●❏❘✒❚★❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄s❃⑤❙✡❇❈❁❊❉☎❑❈❉◆❱✪⑦❅❚❏❲❳❉P❨✡❄▼❉◆❇P❪

❥✰❉◆❇❋✧ ❧❯❉➑❚❅✜✬❼❍❤ ➆ ❒❵✂✖❪❇✜❵❫❏❉◆❑③⑩➱❇❾❃⑤❘❦❉➴❚★❙ ❃⑤❇③❉◆❘ ✙✵� ✫ ❈✡❧☎✂❂❧❧✕☞✚▲❃❅❄✂❚❏❨❊❨✪❉P❨✓❇❈● ✻✮✥★q☎❱✜❉◆❑▼❋❍●❏❑❈❘❄☎ ✺✵❚❅☎ ❆✕ ➚✄✸❷❧★✂❂❧ ✑ ✻✄✓✖✔ ➚■✕➸➶③➶✆✗✗ ✸ ❀ �❆✙ ✸ ✫ ❈ ✛ ❪✂❤▲❇④❇③❁❊❉✮❧❯❉◆❬★❃❖❙❊❙✪❃❖❙❊❬❯q▲❚❛⑦❿⑦ ✻ ✥ ❚★❑❈❉✍❉◆❘⑥❱❊❇▼⑩❏❪⑦❥✰❉◆❇ � ✻ ❚❇✜❩✸ ❀ ✼ ✯✯★✗☎❧✙✜❋✫ ✸✖✗✤✣❭❪❞❒t●❏❑☎♥✛✚✡✪❷✚ ❖✂❱❯❉◆❑▼❋❍●❏❑❈❘ ❇❈❁❊❉✦❋➄●✵⑦⑨⑦❖●★❶❂❃❖❙❊❬✮❄▼❇❈❉◆❱❯❄

➚✿♥★➶✥☎ ✺✵❚ ✕ ➚✄✦✩✥✱❧✶✪❷♠➑♥✠❧✙✜✄✂❵➚✄✦✩✥❛➶❈➶ ✛ ➋➚✳r✪➶❦➚✬☛✹❧★✂❂❧ ✟✰➶❄✺✵❚❈❀☞❉❃❊ ✪ ✟☞☛★✌❩✦✩✎✑☛❈➚★☎❸➶✞❋P➋➚✳✉✪➶✳✻✮✥ ✺✵❚ ✻✛✥■❆✖✕ ✙✁� ✫✷☛✕❧☎✂❀❧✆✟➊✚ ✗✗ � ❚✢✜❼✸ ❀ � ✧ ✯✮✯★✗☎❧☎✸ ✫✷☛ ✗✤✣✪✂❚✔✫✬✛❩➋➚❫✘❊➶✳✻✮✥ ✺✵❚ ✻✛✥■❆✖✕ ✙✁� ✫✮❈✞☛✕❧✮✭❏❧❧✕✄✟☞✚ ✗✗ ✯ ✙✁� ✯ ✫✮❈✡❧✮✭▼❧❖✕☞✚ ❀❍✻❀✧❾❧ � ❚✢✜❼✸❇❀ � ✯ ✯✾✯★✗☎❧☎✸ ✫✮❈✞☛ ✗●✣✪✂❚✔✫✬✛❩➋➚ ④ ➶✖❢❂❉◆❱❯❉P❚★❇✦❄▼❇❈❉◆❱❯❄✦r④❇③● ④ ❶▲❁✪❃❿⑦❖❉✪☎✓❃❅❄❂❙❊●❏❇▲❉◆❘❦❱❊❇✳⑩✰➋➚✏✖✪➶ ➆ ●❏❘⑥❱❊■❊❇❈❉ � ✥ ✺✵❚✄✰ ✱ ✳ ✓✕✔ ☛ ✧✶☛ ❍■✴✷✶✑✸✺✹ ✜❏✻ ❀❂✼✮✯✮✯✍✸✢✫✮❈ ✲ ✗☎❧✸✯★✹❿❧★✸❅❀ �✚✙ ✲ ✫ ● ✻✠✹✽✣❭❪

❀❂❁❊❉◆❙✙✦ Ï ➄❈➄❈➄✏✦ ✽ ❀✒✴❂➚✏✧❸➶✣❃⑨➏✇❇❈❁❊❉◆❑③❉☎❉❳➉❭❃❅❄▼❇✿❄ ✙✁� ✫✮❈✡❧✿✈➊❧❖✕☞✚ ❀❍✻ ✽ ❄▼■❯❲③❁✮❇❈❁❯❚★❇ ✜❁❀ � ❚★❙❯❨ ✜ ✫✮❈❞❪❥✰❉◆❇❑✌▼▲❥♥✦❧❯❉✦❇❈❁❊❉❣❘✍❚❛➉❭❃❖❘✖■❊❘✗❙❭■❊❘✖❧✜❉◆❑s●✵❋✷❙❊●❩❙❭❇❈❉◆❑③❘✖❃❖❙❯❚❛⑦❅❄▲❚★❱❊❱❯❉P❚✵❑▼❃❖❙❊❬❸❚✵❇❞❇❈❁❊❉✦❑▼❃❖❬❏❁✪❇❈❼❍❁❯❚★❙❯❨✍❄✺❃❅❨✪❉☎●★❋✕❚★❙✪⑩✖❱❊❑❈●❏❼

❨✪■❯❲❳❇▼❃❖●❏❙✮●★❋ ✧⑥❪❞❀❂❁❊❉◆❙✍❇❈❁❊❉④❄▼❱❯❚❩❲❳❉④❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩❦❃❺❄✖✜✖➚✐❖❖◆◆➶❞❚★❙❯❨✍❇❈❁❊❉✦❇▼❃❖❘⑥❉④❲❳●❏❘❦❱✪⑦⑤❉❳➉✪❃❖❇▼⑩⑥❃❅❄✕✜❸➚✐❖❖◆ ✑ Ï ➶✿❪✧✂❣❑❳❚★❘⑥❘❜❚★❑❳❄Ô

Page 17: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

■❯❄▼❉P❨❷❃⑤❙✡❱❊❑✿❚❏❲❳❇▼❃❅❲❳❉❹■❯❄▼■❯❚❛⑦❿⑦❖⑩✟❫❏❉◆❑▼❃❿❋❍⑩ ✌❤❚➱r✖●❏❑➊❘❜❚❛⑩❜❧✜❉④❇❈■❊❑❈❙❊❉P❨❷❃❖❙❭❇❈●✍❚✖❬❏❑✿❚★❘❦❘❜❚★❑❂❫❏❉◆❑▼❃❿❋❍⑩❏❃❖❙❊❬ ✌❤❚ r❊❪✠r▲❉◆❙❯❲❳❉❹●❏■❊❑❚❛⑦❖❬❏●❏❑❾❃⑤❇③❁❊❘ ❁❯❚❏❄❂❇❈❁❊❉✖❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃⑤❇▼⑩✮●★❋❵❇❈❁❊❉④❨✪⑩✪❙❯❚★❘✖❃❅❲☎❱❊❑③●❏❬❏❑✿❚★❘❦❘✖❃❖❙❊❬❜❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ■❯❄▼❉P❨✮❧✪⑩ ✮✜■❊⑧❏❉◆❑ ✙ ♥P✈✬✚✚❇③●✁❩❯❙❯❨✡❚❄▼❉P❲❳●❏❙❯❨❊❚✵❑❈⑩❷❄❾❇❈❑❈■❯❲❳❇❈■❊❑❈❉☎●✵❋✕❘✖❃❖❙✪❃❖❘❜❚❛⑦❵❉◆❙❊❉◆❑❈❬❏⑩✍❶❂❃❖❇❈❁✡❇❈❁❊❉☎❇❈❁❊❉◆❑❈❘⑥●❊❨✪⑩✪❙❯❚★❘✖❃❅❲☎❘⑥●❊❨✪❉❳⑦✐❪❀❂❁❊❉✖❘❜❚❛❃❖❙✇❚❏❨✪❫★❚★❙❭❇❳❚★❬❏❉④●✵❋s●❏■❊❑☎❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘➾●★❫❏❉◆❑☎❚✍❄✺❃❖❘⑥❱✪⑦❖❉◆❑◗✜◗❚★❑▼⑦❖❉◆⑩➎❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘ ❃❺❄➠❇❈❁❯❚★❇Pq✜❶❂❃❖❇❈❁✂❇❈❁❊❉❹❋✐❚❏❲❳❇❈●❏❑❈❼

❃❖➍P❚★❇▼❃❖●❏❙✇❱❊❑③●☞❫❩❃❅❨✪❉P❨✂❧✪⑩➎●❩■❊❑✦❃⑤❇③❉◆❘❜❄◆q✰❘❜❚★❙✪⑩➎❨❩❃❿➏✚❉◆❑❈❉◆❙✪❇☎❃❖❇❈❉◆❘❜❄➠❘❜❚❛⑩✮❙❊●★❶➝❧❯❉⑥❑❈❉◆❱✪⑦❅❚❏❲❳❉P❨➈❧✪⑩➎❚✮❄✺❃❖❙❊❬★⑦❖❉❦❃⑤❇③❉◆❘✟❪♠❀❴❁✪❃❺❄❋❍❉P❚★❇❈■❊❑❈❉✦❃❅❄❴❃⑤❙✪❇❈❉◆❑❈❉P❄❾❇▼❃❖❙❊❬⑥❶❂❃❖❇❈❁ ➀❊➆ ❒❵✂☎❄❞❶❂❉☎■❯❄▼❉P❨➅❶❂❃❖❇❈❁✮●❏■❊❑❣❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✟❪

❰➸↔✍➔✷⑨✞❏✍●❏❺▲❅❉❏✦✇❉✮❁❯❚❛❫❏❉✮❑❈❉◆❇③❑▼❃❖❉◆❫❏❉P❨➑❧✪⑩✇❋❍❇❈❱ ❇❈❁❊❉✂✁✬➦➼➲P➧✜➧❯➨➍➔❊➨❏➡✕✫★➨❤❙❏➲❛❪➱❀❴❁✪❃❺❄❦❱❯❚❏❲③⑧☞❚★❬❩❉✍❃❺❄✍❚✇❄▼❉◆❇❦●★❋ ➆ ❄▼●❏■❊❑✿❲❳❉❣❩❊⑦⑤❉P❄❦❶▲❁✪❃❅❲③❁

❃❖❘⑥❱✪⑦❖❉◆❘⑥❉◆❙✪❇✿❄❹❇❈❁❊❉⑥●★⑦❅❨✇❄▼❇▼⑩❩⑦❖❉❜❨✪⑩❭❙❯❚✵❘✖❃❅❲⑥❱❊❑❈●❩❬❏❑✿❚★❘⑥❘❸❃⑤❙❊❬✮❑③❉❳⑦❺❚✵❇▼❃❖●❏❙❯❄☎❱✜●❏❱❊■✪⑦❅❚★❑▼❃❖➍◆❉P❨✝❧❭⑩ ✮❯■❊⑧❩❉◆❑☎❇❈●✖❩❯❙❯❨✇❇③❁❊❉♠❘❸❃⑤❙✪❃❖❼❘✖■❊❘ ❉◆❙❊❉◆❑③❬❏⑩➎❄▼❉P❲❳●❩❙❯❨❊❚★❑❈⑩➎❄❾❇❈❑❈■❯❲❳❇❈■❊❑❈❉❹●★❋s❚★❙✇❢▲❡➊❤➝❋❍●❏❑✦❇❈❁❊❉✖❶s❉❳⑦❿⑦❵⑧❭❙❊●★❶▲❙✂❇❈❁❊❉◆❑③❘⑥●❽❨✪⑩✪❙❯❚★❘✖❃❅❲❹❘⑥●❊❨✪❉❳⑦✐❪✥✦✇❉✖❇❈❁❊❉◆❙❲❳●❏❙✪❫❏❉◆❑❈❇❈❉P❨✍❇③❁❊❉☎❇❈❁❊❉◆❑❈❘⑥●❊❨✪⑩❭❙❯❚✵❘✖❃❅❲☎❘⑥●❊❨✪❉❳⑦✬❉◆❘✖❧❯❉P❨❊❨✪❉P❨➅❃❖❙✟❇❈❁✪❃❅❄❂❱❯❚❩❲❈⑧★❚★❬❏❉☎❃❖❙✪❇❈●❜❚⑥❄❾■✪❃⑤❇❳❚★❧✪⑦❖❉ ✜✬❼❍❤ ➆ ❒❵✂✖q❭❚★❙❯❨➅❇❈❁❊❉◆❙❃❖❙❭❇③●❸❚ ➆ ❄▼●❩■❊❑✿❲❳❉❣❱❯❚✵❑✿❄▼❉◆❑❂❧❭⑩⑥❚ ✣❵❤ ➆▲➆ ❼➼⑦⑨❃❖⑧❏❉✦❇❈●✪●★⑦➸❶➊❁✪❃❺❲③❁✍❶s❉✦❶▲❑❈●❩❇❈❉❏❪✎⑩◗❉P❲◆❚★■❯❄▼❉☎❇③❁❊❉◆⑩⑥■❯❄▼❉✦❇❈❁❊❉❣❄❈❚★❘❦❉❣❘⑥●❊❨✪❉❳⑦✐q✪●❏■❊❑❬❏❉◆❙❊❉◆❑✿❚✵❇❈❉P❨✍❱❯❚★❑✿❄▼❉◆❑✦❚★❙❯❨✮❇❈❁❊❉✄✁✣➦➼➲P➧❯➧✜➨❙➔❊➨❏➡✕✫★➨❤❙❏➲✖❶❴❃⑨⑦❿⑦❵❑❈❉◆❇❈■❊❑❈❙✮❇③❁❊❉♠❄❈❚★❘❦❉④❄▼❉P❲❳●❏❙❯❨❊❚★❑❈⑩✮❄▼❇❈❑③■❯❲❳❇❈■❊❑❈❉✦❋❍❑❈●❏❘ ❇❈❁❊❉④❄③❚★❘⑥❉❃❖❙❊❱❊■❊❇Pq❏❇③❁❭■❯❄❆❶s❉❂❘❜❚❛⑩④❲❳●❏❘❦❱❯❚★❑❈❉▲❨✪⑩❭❙❯❚✵❘✖❃❅❲❂❱❊❑❈●❏❬❏❑❳❚★❘⑥❘✖❃❖❙❊❬④❚★❙❯❨❹❱❯❚★❑✿❄✳❃⑤❙❊❬✜❪✞❨▲❙✡♥✩✖✗✖✪♦❂❧❯❚❏❄▼❉P❄❆●★❋➸❢▲❡➊❤➱●❩❙❸❚✥❴✥✜ ➆ ❼❄▼❉◆❑❈❫❩❉◆❑➬r❊♥❛✈❏✈★❼ ④ ✈❏✈ ✹②☎✣q❊❇③❁❊❉✤★➊❃❖❉◆❙❊❙❯❚✮❱❯❚❏❲③⑧☞❚✵❬❏❉✖❑❈❉P➌❏■✪❃❖❑❈❉P❄☎✉ ④ ✈❜❄➐❪④❚★❙❯❨✝♥P♣✖✹✟❧✪⑩✪❇❈❉P❄◆q✰❶▲❁✪❃❿⑦❖❉⑥●❏■❊❑✦❱❊❑❈●❏❬❏❑❳❚★❘ ❙❊❉◆❉P❨❊❄r✗✖✗✖✖❄◆❪◗❚★❙❯❨ ④ ✈ ✹✡❧✪⑩❭❇❈❉P❄➐❪✕❀❴❁❭■❯❄❂●❩■❊❑s❱❯❚✵❑✿❄✺❃❖❙❊❬❷❚☞⑦⑤❬❩●❏❑▼❃❖❇❈❁❊❘✗❃❅❄◗❋✐❚❏❄▼❇❈❉◆❑➊❇❈❁❯❚★❙✮❄▼❇✿❚★❙❯❨❊❚★❑❳❨✮❨✪⑩❭❙❯❚★❘❸❃❺❲➠❱❊❑❈●❏❬❏❑❳❚★❘⑥❘✖❃❖❙❊❬❯q❚★❙❯❨➠❃❖❇✬■❯❄❾❉P❄❮⑦⑤❉P❄③❄✣❇❈❁❯❚★❙④❇③❁❊❑❈❉◆❉❂❇▼❃❖❘⑥❉P❄✬❚❩❄✚❘✖■❯❲③❁♠❘❦❉◆❘⑥●❏❑❈⑩❏❪✞✣❵❉◆❇Pq★❇❈❁❊❉▲❨✪❉P❄❈❲❳❑▼❃❖❱❊❇▼❃❖●❏❙✖●★❋❯❇❈❁❊❉❂❇❈❁❊❉◆❑③❘⑥●❽❨✪⑩✪❙❯❚★❘✖❃❅❲◗❘⑥●❊❨✪❉❳⑦❶❂❃❖❇❈❁ ✜✬❼❍❤ ➆ ❒❵✂ ❃❅❄☎❘✖■❯❲❈❁✂❄✺❃❖❘⑥❱✪⑦❖❉◆❑♠❚★❙❯❨✡❘✖■❯❲③❁➎❘❦●❏❑❈❉✆☎❯❉❳➉✪❃❖❧✪⑦❖❉⑥❃❖❙✇❇❈❁❊❉✖❉❳➉❊❱❊❑❈❉P❄❈❄✺❃❖●❏❙✂●★❋▲❄▼❇❈❑❈■❯❲❳❇③■❊❑✿❚❛⑦✕❲❳●❏❙❯❄❾❇❈❑✿❚❛❃❖❙✪❇✿❄❇❈❁❯❚★❙✟❨✪⑩✪❙❯❚★❘✖❃❅❲➠❱❊❑❈●❏❬❏❑✿❚✵❘⑥❘✖❃❖❙❊❬⑥❑❈❉❳⑦❅❚★❇▼❃❖●❏❙❯❄➐❪❨▲■❊❑④❱❯❚✵❑✿❄✺❃❖❙❊❬✟❚❛⑦❖❬❏●❏❑▼❃❖❇❈❁❊❘ ❘❜❚❛⑩✟❚❛⑦❅❄▼●✟❧✜❉⑥❑❈❉P❚❏❨❩❃❿⑦❖⑩✇❚★❱❊❱✪⑦❿❃❖❉P❨✇❇❈● ➀❊➆ ❒❵✂☎❄☎❄✺❃❖❙❯❲❳❉⑥❱❊❑❈●❏❧❯❚★❧✪❃❿⑦❿❃❖❇▼❃❖❉P❄✖●★❋▲❨✪❉◆❑▼❃❖❫☞❚★❇▼❃❖●❏❙❯❄

❇❈❑❈❉◆❉P❄➊❘❜❚❛⑩✮❉P❚❏❄✺❃❿⑦❖⑩✟❧✜❉❹❃⑤❙✪❇❈❉◆❑❈❱❊❑③❉◆❇❈❉P❨✂❚❏❄❣❚✵❇❈❇❈❑▼❃❖❧❊■❊❇❈❉P❄➊●★❋s❨✪❉◆❑▼❃❖❫☞❚✵❇▼❃❖●❏❙✇❇❈❑❈❉◆❉P❄➐❪❣❀❂❁❊❉❈❩❯❑✿❄▼❇✦❑❈❉P❄▼■✪⑦❖❇✿❄✦❚★❑❈❉❹❉◆❙❯❲❳●❏■❊❑✿❚★❬✵❃⑤❙❊❬❧❯❉P❲◆❚✵■❯❄▼❉④❶❂❉④❚★❑❈❉④✉❸❇▼❃❖❘⑥❉P❄◗❋✐❚❏❄▼❇❈❉◆❑▲●❩❙✮❇✿❢▲❡➊❤➬❄❂❇③❁❯❚★❙✮❇❈❁❊❉ ➆ ✣ ✬✦❼➼⑦❿❃❖⑧❏❉④❱❯❚✵❑✿❄▼❉◆❑▲■❯❄▼❉P❨➅❧❭⑩❸r✦❚★■❯❄❈❄✺⑦❖❉◆❑❤✷➵❄❴❇❈❉P❚★❘✟❪

P❅◗ ✿❙❘✶◗✶❚✍❯❝❄❇❆✝❱✁❲✼❳✽ ❥ ✿✒☞ ❋❨❏✟Ò ☞ P ▼ ❊ ❙♠❚ ▼ ❱ Ö ❍◆❍ ❚ ✠✹P❚P ● ❍ ❍✟Ò✶❽ ❙✞✝ ❊ ❙ ◗✸✓ ❱ Ö ❱✘❬ ❭✼❫ ❴✭❭✼❫ ❴✏❵❖❛✠✟ ❵ ①✛②❪❣❧❛✏➀❋❞⑤♣❩③☛✡✹❭✓❛✄❣❖♣ ➀❝❤ ❣★❜✴❞❢❵❖♣☞✡❅❣❧♣✍➁ ✐❥❵❖❦⑩♠✍❞✥❤ ❞⑤♣❩③❇❱✘❬♦✦❊ ❙ ❍ ❲✂❱ ❬ ❙✻❜ ✙ ❍❊P❘P✟P❨�✟❍ ❬❇❱❳P✞r☎s✍✌✏✎■P ❖ ❏❨P ❱ ❥ ❱✽ s→✿ ✕❂❍ ❊❫P ❙ ◗✡Ò❢❽❉❱ Ö ❱✞❬ ☞✡❍ ❙✼✻ ❬ ❱❳❙ ❍ ❲ ❬ ❏ ❍ ❲✂❙ ♠ ❲ ❜ ▼ ❊ ❙ ❙❴■ ❍ ❊✂❩ ❱ ❍✽❑✟❍❊P❚❑✐❏✐❊ ❱❳❲ ❋ ● ❱✺✐❥❵❖❦④❦④♥❼♣⑨❞❢❡✏❣★❜✴❞❢❵❖♣✙❵✴①④❜✶❫ ❴④✈④✐✎❶rP ❖ ❏ P ❱ ❥ ➣■P ❍✝q s❨P✛ ❙ ❤■❊✂❋❝❍◆❊❫◗ r★s✏✌✏✑❨P ■✽■ ❱ ❧◆Õ ❬ ❥☎➅ s▲❱✽ ➣→✿ ✕ ❚■❚ ◗④Ò✟✄ ❙ ❍◆❍❦✖❧❱ Ö ❍◆❍ ❚ ✓☎❋■❊●❤ ❱ ❍④Ò✟✖ ❱ ❬❬❋❉❍◆❊ ❚❏Ö ❱■❬❑✖✡✁✏☞✗❩ ❙❯❵ ❋ ❙ ❍ ❬ ❙ ❍◆❍❉❍❊P❘◗✝❩ ❱ ❩ ❋■❩ ❱ ❍▲❑q❬ ❏ ❖ ❍ ❊ ❱ ❍◆❍ ❬ ❙✧● ❏ ❚✝❙ P❳❩❲❱✍✒ ♥✝❡■❤❸❴■❞❢❡✺✈✇❡■❞❢➁★➀

✓❪❴❝➀☎❴✄❣❧❛✄❡❝❫ P ❖ ❏❨P ❱✝s✐s❨P✝❍✝q ❥ ❥ P✞r☎s●s❖t P ■▲■ ❱ s ➅ Ô ❧ ❬▲s ➅ ❹❉❹✽❱✽ Õ ✿❍✉☎❍✝❋ ❲ ❋✍Ò ✓☎❏ ❍❉❍❇P ❚ ✕ ❱ Ö ❱❖❬✰✄ ❙✱● ❍◆❍ ❲✂❱ ❬ ❩ ❏❇▼ ❬ ❏✐❍ ❲✂❙ ♠ ❲ ❜ ▼ ❊ ❙ ❙ P❣❍◆❍✽❑✐❋❉❍❊❑ ❙ ❩❅❱✓❶ ❣❺❜❢❫✝❴❋❦✛❣★❜✴❞❢❡✏❣❖❤✓♦✔✟★➀✄❜✒❴■❦✧➀❀❭✼❫ ❴✏❵❧❛✕✟◆P ❖ ❏ P ❱✝s■P✓r☎s✍✖❉⑧❨P

■▲■ ❱ ❥ s❛Ô★❬ ❥③Õ ♥ ❱★❬ ✘ ❏✐❊●❊ ❙ ❬ ❲●❱ ❏✐❍ ♣ ❶❷❣★❜✶❫ ❴■❦✛❣★❜✴❞❢❡✏❣❖❤✞♦✔✟★➀✄❜✒❴■❦✧➀❀❭✼❫ ❴✏❵❧❛✕✟ ❖ ❏❨P ❱ ♥ P ❥❯❧ Ô ❥ P ■▲■ ❱ ❧✐♥ ❜ ❧●❻ ❱✽ ♥ ✿ ✁ ❙♠❚✝❙ ❊❫❋❨❏❇▼✬Ò✟✢✙❍◆❊✺Ñ ❜ ❽♥❍◆❍ Ö ❱★❬❑☞ ● ❋✽P ❲●❱ ❚✝❱ ❩❭❬ ❱❚■ P ❱ ❍❉❍♠❊❫◗ ❖✝❱❪❙ Ð ❏ ❍◗♦✤✑✜✖ ■ ❍ ❊✂❩ ❱ ❍✽❑❉❱◆�✟❍ ❭✎❿❥❴■♣❩❜⑦❞✶❴✏❜✶❫✘✗ ❵❖❛✞✙★➀✏❫ ❵❝♠ ❵❧♣✛✚✁❣❖♣ ③❺♥✝❣★③❉❴

❭✞❴✏❡✏❫❩♣✍❵❖❤ ❵✏③✜✟✛✢❇❱ ❬ ✓ ❙ ❬ ❙❥● ❤ ❙ ❊✧r★s❉s✍✣▲❱✽ ❻ ✿ ✄▲❍➐Ñ❨❍◆Ñ ❱ ❤❉❍◆❊✻❍✇Ò ❖♦❍◆❩●❋■❤■❋ ● ❱❖Ö P✎❉✌❊●❏◆Ð✞❍①Ò ✢ ❱ ❬❬❋❉❍ ❙ P Ö P✳✢ ❱ ❍ ❍➂Ò �✱❱✒✄▲❍ ❱ ❊❛❍ Ö Pq✄✱❳✯❁❏ P❯❍ ❍ ❚✝❙ ❊➅Ò⑦✉ ❱❚●❴●❦❙ ❍ Ö P✡✠✏❍ ❚✝❙ ❊✺Ð ❏✝❏ ❚ Ò✟✖ ❙✻❜❤ ❙ ❬ ❬✱❍✗✘✭❱ Ö P✹❍◆❍ ❚ ✙❵❍◆❋■❩●❩❫P ❙ ❊✍Ò ✓✭❍ ❖✝❱ ❚❏Ö ❱✼❬ ❭✼❫ ❴✱❣❝♠❉♠✓❤ ❞❢❡✏❣★❜✴❞❢❵❧♣ ❵ ① ➀✏❜ ❵★❡✏❫✝❣★➀✏❜✴❞❢❡❷❡✏❵❧♣❩❜ ❴✥✤★❜✧✦ ①❋❛✏❴✏❴➂③❺❛✏❣❖❦④❦ ❣❧❛✏➀❀❜✒❵✛①★❵❖❤❸➁❧❞⑤♣❩③☛✡

❣❖❤ ❞ ③❖♣✝❞⑤♣❩③ ❣❧♣✍➁④❦✛❵☎➁●❴❋❤ ❞⑤♣❩③✧❫✝❵❖❦✛❵❖❤❸❵❝③❉❵❖♥●➀★✓✩✒✷✈ ➀☎❴✞✪❋♥✝❴■♣✍❡✏❴✏➀✱❱●❬✣✆ ❙ ❬❫❋❨❍ ❱ ❬✱❍❇P ✖ ❙✱■ ❏✐❊ ❲ ❍⑨q ✠✡✘✞✄❨✘ ❜ ✘✞✖☎✑ ❜✂❧◆Õ❇❜ ❥❈Õ P◆✠✞❍ ❱❚❖✐❙ ❊✂❩ ❱❳❲ ◗❏❇▼ ✘✹❍❊P ❱ ▼ ❏ ❊✂❍ ❱ ❍❨P✐✄▲❍◆❍ ❲ ❍✳✘ ❊●❋ ✴ P ✄✽❍◆❍ ❲ ❍ ✘ ❊●❋ ✴ ✘ ☞ ❧✐♥❉➅●❻◆Õ ✠✡✄✝☞ P✁r★s❉s✏✣✽❱✽➪Ô→✿ ✄ ❙ ❍ ❊❫P❳❩▲Ò✟✓✭❍ ❖ ❱ ❚ ❉❵❱ Ö ❱❩❬✔✆✹❋ ❙ P ❱ ❍▲❑✐❋ ❱ ❩ ❲✂❱ ❬ ❩✞❏❇▼✌✓✎✁✞☞❙❱✝✈✇❦✛❴■❛❋❞❢❡✏❣❖♣ ♦✞❡❋❞❢❴■♣❩❜✴❞ ➀✏❜ P ❖ ❏❨P ❱❩❹ ➅ P✞r★s❉s✍✎■P ■▲■ ❱ ♥ Ô ❧ ❬ ♥✐❧❨❥ ❱✽➃❹→✿✒▼✌❏ ❱ ❩ ❱ ❍✏Ò✟✛ ❱ Ö ❱✎❬ ☞ ❤ ❏ ❲✂❲●❲ ❏ ●❀❜ ❋ ■ ❍ ❚ ❍ ■■❲ ❍ ❲●❱ ❏ ❍✗❏❇▼✳✕❂❍◆❊❬P ❙ ◗ ❤ ❩ ■ ❍◆❊●❩ ❱ ❍▲❑ ❍❊P❘❑ ❏✐❊ ❱❪❲ ❋ ● ❱ �✟❍ ②❥❛✄❵❝③❖❛✄❣❖❦④❦④❞⑤♣❩③✫✚✘❣❧♣❩③❺♥✝❣❺③❧❴❝➀

✬❋❦⑩♠✍❤ ❴❋❦✛❴■♣❩❜ ❣❺❜⑦❞✶❵❖♣✱❣❖♣✍➁✭✚✁❵❝③❺❞❢❡ ②❥❛✏❵✏③❖❛✄❣❧❦✣❦④❞⑤♣❩③☛✡✮✬■♣❩❜✒❴❋❛❋♣✓❣★❜✴❞❢❵❖♣✍❣❧❤✯✗ ❵❖❛✞✙★➀✏❫ ❵❝♠ P ■▲■ ❱ ❥❈Õ❩❻ ❬ ❥☎❻❉➅ ❱■❬ ✄ ■ ❊ ❱ ❍▲❑ ❙ ❊ ❜ ▼ ❙ ❊❫P❣❍❇❑ P✐✢✙❍❅◗r☎s●⑧❉⑧✽❱

✽ ❧ ✿ ⑥ ❍ ❲●❙ ❊ ● ❍◆❍❦Ò ✢✷❱ ✄✐❱ Ö ❱●❬ ✄ ❙ ❬ ❏✐❍ ❚ ❍ ❊❫◗✣❩ ❲ ❊✂❋ ❬ ❲ ❋■❊ ❙ ❏❇▼ ❩ ❱ ❍▲❑❨P ❙✻❜ ❩ ❲ ❊❛❍◆❍ ❚✝❙❯❚ ❍✝❋ ❬✻P ❙ ❱ ❬✩❍ ❬ ❱ ❚ ❩❲❱✘♦✝❜✴♥ ➁❧❞❢❴❝➀✣❞⑤♣ ❾✁❵❖♥❩♣✍➁●❣★❜✴❞❢❵❖♣❩➀✛❣❖♣✍➁✐❥❵❖❦✛➄■❞⑤♣✍❣★❜✒❵❖❛■❞❢❡✏➀✞✡✁✈✇➁✜✰❖❣❖♣✍❡✏❴❝➀✣❞⑤♣ ❶❷❣★❜✶❫ ❴■❦✛❣★❜✴❞❢❡✏➀✇♦✍♥★♠●♠✍❤❸❴■❦✛❴❋♣❩❜✒❣❖❛✠✟✛♦✝❜✴♥✝➁❖❞❢❴❝➀ P ❖ ❏❨P ❱ ❥ P✞r☎s✏✌●⑧■P ■ ❱ ❥★❻ Ô✽❱

✽ ❥☎➅ ✿❍❨ ❋❏Ñ ❙ ❊❵Ò ✢ ❱ ❬❬❋❉❍ ❙ P Ö ❱■❬ ✆✹❋ ❙ ❋❨❩ ❙ ❏❇▼ ❚ ◗✝❍❉❍ ● ❱ ❬ ■ ❊●❏❨❑ ❊❛❍ ●❭●❦❱ ❍▲❑♦❍❊P❚❑✐❏✐❊ ❱❳❲ ❋ ● ❩ ❱ ❍✳✖☎✁✞☞✗❩ ❙ ❬ ❏✐❍ ❚ ❍ ❊❫◗q❩ ❲ ❊●❋ ❬ ❲ ❋❨❊ ❙ ■ ❊ ❙❯❚✝❱ ❬ ❲●❱ ❏✐❍ ❱�✟❍ ⑥ ❍ ❲✂❙ ❊ ● ❍◆❍❂Ò✟✢ ❱ ❬❬❋❉❍ ❙ P■✄✐❱ Ö Ò ❙❯❚✝❱❳❲ ❏ ❊ Ö P●❶❷❣★❜✶❫ ❴■❦✛❣★❜✴❞❢❡✏❣❖❤●❶❷❴✏❜✶❫ ❵★➁★➀✍①★❵❖❛✲✱✳✒❪✈ ♦▼❴✞✪❋♥✝❴■♣✍❡✏❴✏➀ P✐✘ ❋❝❍ ■■❲●❙ ❊➸Ô❨P ■✽■ ❱ ❥♠♥✐❧ ❬ ❥ ❹ Õ ❱ ❬✘✞✖✞✘✚♦✦❊ ❙ ❩●❩❯P✎r☎s●⑧❉s✽❱

Page 18: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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✄ ✖ ✯★✩✆☎✳✏➊✯❊✧❭✱✞✝❹✱❅✱✺✫❽✧ ✎✠✟✢✖�▲❙✪❃❖❫❏❉◆❑❳❄✺❃❖❇ ✮❉✖❨✪❉✁✹➎❚✵❑✿❄▼❉❳❃❿⑦❿⑦⑤❉❴✦❉P❲❳❉◆❘✖❧❯❉◆❑ ④ q✚♥❛♣❏♣✍✘

✙ ❄▼■❊❘⑥❘✍❚★❑❈⑩⑥❧✪⑩q☎❆❁✪❃❿⑦⑨❃❖❱❊❱✜❉❡❴✦■❊❘❜❚❏❄❾✚

❀❂❁❊❉✍❑❈❉P❨✪■❯❲❳❇▼❃❖●❏❙➑●★❋❭☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄❹❇❈❑▼❃❅❚★❙❊❬★⑦❖❉✍❘⑥●❽❨✪■✪⑦❖●✏❚➅❱❊❑▼❃❖❘⑥❉✮❙✪■❊❘♠❧✜❉◆❑☛✡✚q❵●❏❑✖❚✟❱✜●★❶s❉◆❑❹●★❋➬❚➅❱❊❑▼❃❖❘⑥❉✮❙❭■❊❘✖❧✜❉◆❑Pq❁❯❚❏❄➊❧❯❉◆❉◆❙✡❃❖❙❭❇③❉◆❙❯❄✺❃❖❫❏❉❳⑦❖⑩➮❄❾❇❈■❯❨❩❃❖❉P❨✰❪❣❝✺❇▲❃❅❄✦⑧✪❙❊●★❶▲❙✟❇❈❁❯❚✵❇▲❇❈❁❊❉✖❑❈❉P❨✪■❯❲❳❇▼❃❖●❏❙✂❱❊❑❈●❊❨✪■❯❲❳❉P❄☎❚⑥❱❊❁❊❉◆❙❊●❩❘⑥❉◆❙❊●❏❙✇❲◆❚❛⑦❿⑦❖❉P❨➎❚✵■❊❇❈●❏❼❄✺❃❖❘✖❃❿⑦❅❚★❑▼❃❖❇▼⑩➸➋❩❙❯❚★❇❈■❊❑✿❚☞⑦❭❁❊●❏❘⑥●❏❇③❁❊❉◆❇▼❃❖❉P❄✚❶❂❃❖❇❈❁✖❲❳●❏❙✪❇❈❑✿❚❏❲❳❇▼❃❖●❏❙❹❑✿❚★❇▼❃❖●④♥❝➉☞✡ ➌ ❚✵❱❊❱❯❉P❚★❑Pq❏❚✵❙❯❨④❚◗⑦❿❃❖❘✖❃❖❇s❄▼❉◆❇✷❃⑤❙✖❇❈❁❊❉❂❄▼❉◆❙❯❄▼❉◗●★❋❯❇❈❁❊❉r✦❚★■❯❄❈❨✪●❏❑▼➏✮❘⑥❉◆❇❈❑❾❃❺❲❴❉❳➉❭❃❅❄▼❇✿❄➐➋❭❘❦●❏❑❈❉◆●★❫❏❉◆❑✣❇❈❁❊❉❂⑦❿❃❖❘✖❃❖❇❣❄▼❉◆❇❵❁❯❚❏❄✕❋➄❑✿❚❩❲❳❇✿❚❛⑦❯❨❩❃⑤❘❦❉◆❙❯❄✺❃❖●❏❙✍⑦❖●❏❬ ❊✍✌ ✑ Ï

✺❋ ➉✚⑦❖●❏❬✆✡✚❪❵❀❂❁❊❉▲❑❈❉P❨✪■❯❲❳❇❾❃⑤●❩❙

❘⑥●❊❨✪■✪⑦❖●④❚☎❲❳●❏❘⑥❱❯●✪❄✺❃❖❇❈❉❂❙❭■❊❘✖❧❯❉◆❑❵❨✪●✪❉P❄✣❙❊●❏❇❵❱❊❑❈●❊❨✪■❯❲❳❉s❇③❁✪❃❺❄✣❱❊❁❊❉◆❙❊●❩❘⑥❉◆❙❊●❏❙⑥●★❋➸❚✵■❊❇❈●❏❼✐❄✺❃❖❘✖❃❿⑦❅❚★❑▼❃❖❇▼⑩➸➋❩❁❊●★❶s❉◆❫❩❉◆❑✚❃❖❇❮❃❺❄◗❄▼❇▼❃❿⑦❿⑦❱❯●✪❄❈❄✺❃❖❧✪⑦❖❉❣❇❈●✦❘❜❚★⑧❩❉s❚➊⑦❿❃❖❘✖❃❖❇s❄▼❉◆❇❞❲❳●❏❘❦❉❞●❏■❊❇ ✙ ♦✯✚✐❪✣❀❂❁✪❃❅❄❵❇✿❚☞⑦⑤⑧✖❄▼❁❊●★❶❣❄✣❚▲❶▲❚❛⑩☎❇❈●④❨✪❉P❄❈❲❳❑▼❃❖❧✜❉▲❇❈❁❊❉▲❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃⑤❇▼⑩✖●★❋➸❄▼■❯❲③❁⑥❚❨✪●❏■❊❧✪⑦❖❉④❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏❪s❀❴❁❊❉☎❧❯❚❏❄✺❃❅❲▲❇③●❭●★⑦✜❃❅❄❂❇❈❁❊❉☎❲❳●❏❙❯❲❳❉◆❱❊❇▲●★❋✕❚✖❨✪●❏■❊❧✪⑦❖❉④❚★■❊❇③●❏❘❜❚★❇▼❃❅❲✦❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏❪❞❒❮❃❖❑✿❄▼❇❂❶❂❉▲❃❖❙✪❇❈❑❈●❊❨✪■❯❲❳❉❚★■❊❇❈●❩❘❜❚★❇▼❃❅❲⑥❄▼❉P➌❩■❊❉◆❙❯❲❳❉P❄⑥❚★❙❯❨➈❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩✝●★❋❣❄▼❉P➌❏■❊❉◆❙❯❲❳❉P❄❹●★❫❏❉◆❑✖❚✖❩❯❙✪❃❖❇❈❉✮❄▼❉◆❇P➋❞❚❏❄❹❚★❙➈❃⑨⑦❿⑦❖■❯❄▼❇❈❑❳❚★❇▼❃❖●❏❙✝❃❖❇☎❃❅❄✖❄▼❁❊●★❶▲❙❇❈❁❯❚★❇➊❇❈❁❊❉◆❑❈❉♠❚✵❑❈❉♠❚★❧✜●❏■❊❇❹➚✄✗ ➀★❖❮➶ ✺ ❨❩❃❅❄▼❇▼❃❖❙❯❲❳❇☎❑❈❉P❲❳❇❳❚★❙❊❬❏■✪⑦❅❚★❑✦❧✪⑦⑤●❊❲③⑧❽❄✦❶❂❃❖❇❈❁✙✗➾❑❈●★❶❣❄➊❚★❙❯❨✕❖✇❲❳●★⑦❖■❊❘⑥❙❯❄➊❃❖❙⑦☎❵❚❏❄❈❲◆❚❛⑦✸✷➵❄❇❈❑▼❃❅❚★❙❊❬✵⑦⑤❉❹❑❈❉P❨✪■❯❲❳❉P❨✡❘⑥●❊❨✪■✪⑦⑤●✮❚✖❱❊❑▼❃❖❘⑥❉❹❙❭■❊❘✖❧✜❉◆❑ ✙ ♥➋✚✐❪❂❡➊❉❳➉❽❇▲❶❂❉☎❬★❃❖❫❏❉✖❚⑥❄▼❇✿❚✵❇❈❉◆❘⑥❉◆❙✪❇❣❚★❧❯●❩■❊❇▲❇❈❁❊❉④❚★■❊❇❈●❩❘❜❚★❇▼❃❅❲③❃❖❇▼⑩❜●★❋❄▼●❏❘❦❉▲⑦❿❃❖❙❊❉P❚★❑☎❲❳❉❳⑦⑨⑦❖■✪⑦❅❚★❑④❚★■❊❇③●❏❘❜❚★❇❈●❩❙✚q❭❚★❙❯❨✮❄▼❱✜❉P❲③❃❋❩➸❲◆❚❛⑦❿⑦⑤⑩✡●★❋✤☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄❂❇❈❑▼❃❅❚★❙❊❬✵⑦⑤❉☎❑③❉P❨✪■❯❲❳❉P❨✮❘⑥●❊❨✪■✪⑦❖●❜❚★❙✍❃❖❙❭❇③❉◆❬❏❉◆❑ ✙ r✍✚✐❪❒❮❃❖❙❯❚❛⑦❿⑦❖⑩➎❚★❙✟❚★❱❊❱✪⑦❿❃❅❲◆❚★❇▼❃❖●❏❙✂❇❈●✖❘✖■❯❄✺❃❅❲◆❚❛⑦✕❲❳●❩❘⑥❱❯●❭❄✳❃⑤❇❾❃⑤●❩❙✮❃❅❄▲❘❦❉◆❙❭❇▼❃❖●❏❙❊❉P❨ ✙ ✉✪q ④ ✚✐❪

➻✜↔❜➓➏●✣❅✯❉❏❻✕➐☞❅❈❑✔■ ❏✯⑨✞✢♣●✣⑨❆❄❏■✍⑨✞❏❒❊●❩❑❈❘❜❚❛⑦❊⑦❅❚★❙❊❬❏■❯❚✵❬❏❉❣❇③❁❊❉◆●❏❑❈⑩✖❱❊❑❈●★❫❏❃❅❨✪❉P❄❂❚❹❶▲❚P⑩❹❇❈●♠❨✪❉✯❩❯❙❊❉✦❃❖❙❄❩❯❙✪❃❖❇❈❉❹❶s●❩❑✿❨❊❄❵❚❏❄❱❩❊➉❽❉P❨❦❱❯●✵❃⑤❙✪❇✿❄◗●★❋✚❘⑥●❏❑③❱❊❁✪❃❺❄❾❘❜❄◆❪❵❤☎❄

❚★❙✮❉❳➉❯❚★❘⑥❱✪⑦❖❉❏q✜❇✿❚★⑧❏❉✦❇❈❁❊❉♠❚☞⑦⑤❱❊❁❯❚✵❧❯❉◆❇▼✜☞✈☞❧P♥ ✣➬❚★❙❯❨✍❇❈❁❊❉❹❑❈❉P❲❳■❊❑❈❑❈❉◆❙❯❲❳❉✎ ✻✒❚①✈☞❧ ✎ ✽ ✑ Ï ❚ ✎ ✽ ✎ ✽ ❧

❶▲❁❊❉◆❑❈❉✦❇❈❁❊❉✦❧❯❚★❑❂❘⑥❉P❚★❙❯❄❆❉❳➉t❲③❁❯❚★❙❊❬❏❉☎✈✖❚★❙❯❨✟♥❩➋❏❇❈❁❊❉❀❩❯❑✿❄▼❇◗❋❍❉◆❶➱❇③❉◆❑❈❘❜❄❵●✵❋✷❇③❁❊❉➬❄▼❉P➌❩■❊❉◆❙❯❲❳❉④❚★❑❈❉✦❇❈❁❊❉➊❋➄●✵⑦⑨⑦❖●★❶❂❃❖❙❊❬✖❶❂●❏❑✿❨❊❄◆q✎ ✻✒❚➱✈✎ Ï ❚➱✈t♥✠❧✎ ✺ ❚➱✈t♥❏♥P✈☞❧✎ ➁ ❚➱✈t♥❏♥P✈❊♥P✈❩✈❊♥✠❧✎ ➂ ❚➱✈t♥❏♥P✈❊♥P✈❩✈❊♥❏♥P✈❏✈t♥P✈✪♥❏♥P✈☞❧✎✑✏ ❚➱✈t♥❏♥P✈❊♥P✈❩✈❊♥❏♥P✈❏✈t♥P✈✪♥❏♥P✈❊♥◆✈❏✈❊♥◆✈❊♥❩♥P✈★✈❊♥❏♥P✈✪♥P✈❏✈✪♥✠➄

�❴⑦⑤❇❾❃⑤❘✍❚★❇❈❉❳⑦❖⑩➎❚★❙✍❃❖❙❄❩❯❙✪❃❖❇❈❉⑥❶❂●❏❑❳❨✮❚★❱❊❱❯❉P❚★❑❳❄◆❪▲❀❂❁✪❃❅❄▲❶❂●❏❑❳❨❦❃❺❄➊❇❈❁❊❉✖❀❂❁❭■❊❉◆❼✸✹✡●❏❑❳❄▼❉④❶❂●❏❑✿❨✰q✪❶▲❁✪❃❅❲③❁✡❃❺❄✦❚◗❩❊➉❽❉P❨➅❱❯●★❃❖❙✪❇❣●★❋❇❈❁❊❉④❄▼■❊❧❯❄❾❇▼❃❖❇❈■❊❇▼❃❖●❏❙ ✙ ✖✍✚

✒ ➚✳✈✪➶❿❚➱✈❊♥✪❧ ✒ ➚✿♥★➶❿❚ ♥❛✈☞➄❤✦❙❊●❏❇❈❁❊❉◆❑④❉❳➉❯❚★❘⑥❱✪⑦❖❉✖❃❅❄✖❨✪❉✯❩❯❙❊❉P❨✝❚❏❄➊❋➄●✵⑦⑨⑦❖●★❶❣❄◆❪✍❀❂❶❂●✍⑦❖❉◆❇❈❇❈❉◆❑✿❄◆q✣❚✍⑦❖❉❳❋❍❇④❧❊❑✿❚❏❲❳❉ ✜❷❚★❙❯❨✇❚✍❑❾❃⑤❬❩❁❭❇❹❧❊❑✿❚❏❲❳❉ ✣❜❚★❑③❉⑥❇❈❁❊❉

❉❳⑦❖❉◆❘⑥❉◆❙✪❇✿❄▲●✵❋✕❇❈❁❊❉④❚☞⑦⑤❱❊❁❯❚✵❧❯❉◆❇P❪❂❀❂❁❊❉④❄▼❉P➌❩■❊❉◆❙❯❲❳❉✖●★❋✬❶❂●❏❑✿❨❊❄✧✸ ✽ ❃❅❄▲❨✪❉✯❩❯❙❊❉P❨✡❧✪⑩❜❇❈❁❊❉☎❑③■✪⑦⑤❉P❄✸ ✻✒❚✢✜ ✣✉❧ ✸ ✽ ✑ Ï ❚✢✜❼✸ ✻❏➄❈➄✬➄✒✸ ✽ ✣✉➄

Page 19: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❀❂❁❊❉✦⑦❿❃❖❘✖❃❖❇④❄▼❉P➌❩■❊❉◆❙❯❲❳❉☎❃❅❄❣❚❍❩❊➉❽❉P❨➅❱❯●★❃❖❙✪❇❣●★❋

✕✰➚ ✜❏➶❿❚✢✜ ✜ ✣✉❧ ✕✰➚ ✣❏➶♣❚✲✣ ✣✉❧

❚★❙❯❨✍❱❊❑❈●★❫❩❃❅❨✪❉P❄▲❇❈❁❊❉④❄❾❉P➌❏■❊❉◆❙❯❲❳❉✖●★❋✬❙❯❚✵❇❈■❊❑✿❚❛⑦✚❃❖❙✪❇❈❉◆❬❏❉◆❑✿❄➐q❯❚❏❄❂❨✪❉✯❩❯❙❊❉P❨✡❧❭⑩❸⑩◗●❏■❊❑❈❧❯❚★⑧❩❃✐❪

��✁�� ��✁�✁�✁�� ��✂� �✁�� � � ��✁�✂�✁�✁�✁�✁�✂�� ��✁� �✁�� � � ��✁�✁�✁� �✂�✁�✁�� � � ��✁� �✂� �✁� �✁�� � � � � � � ��✁�✁�✁�✁�✁�✂�✁�✁�✁�✁�✂�✁�✁�✁�✁�� ��✄� �✁�� � � ��✁�✄�✁� �✁�✁�✄�� � � ��✁� �✁� �✁� �✁�� � � � � � � ��✁�✁�✁�✄�✁�✁�✁� �✁�✁�✁�✁�✄�✁�✁�� � � ��✁� �✁� �✁� �✁�� � � � � � � ��✂�✁�✁� �✁�✁�✁� �✂�✁�✁� �✁�✁�✁�� � � � � � � ��✁� �✁� �✁� �✂� �✁� �✁� �✁� �✂�� � � � � � � � � � � � � � � ��✁�✁�✂�✁�✁�✁�✁�✄�✁�✁�✁�✁�✁�✂�✁�✁�✁�✁�✂�✁�✁�✁�✁�✁�✄�✁�✁�✁�✁�✂�✁�� �☎☎✁☎☎✝✆✞☎☎ �✁� ☎☎✠✟ ✟✡☎☎☞☛✞✟✁✟✝☛✌☎☎ � ✆ � ☎☎✁☎ � ☛✁☛ � ☎✂☎☎✝✆✍✟✎✆✏✟✎✆✏✟✎✆✑☎☎ � � ☎☎✠✟ � � ✟✡☎☎✒☛✌☎ � � ☎✒☛✌☎☎ ✟ � � ✟ ☎☎✁☎ ✟✡☎ � � ☎✓✟ ☎✁☎☎✝✆✞☎✠✟✝☛✑✟ � � ✟✝☛✑✟✡☎✝✆✞☎☎ �✁� ☛ �✁� ☎ �✁� ☎ �✂� ☛ �✁� ☎☎✔✟ ✆✁✆ ✟✁✟ ✟✁✟ ✆✁✆ ✟✡☎☎✕☛✞✟✎✆✏✟✎✆✏✟✖✆✏✟✁✟✎✆✏✟✖✆✏✟✎✆✏✟✝☛✌☎☎ � ✆ � ☎☎✁☎ �✁� ✆✁✆ �✁� ☎✄☎☎✝✆✏✟ � ✆✏✟✎✆ � ✟✗✆✞☎☎ � ✟ �✁� ✆ ✆ �✁� ✟ � ☎☎✠✟ � ✟✘☎ � ✆✁✆ ✆✁✆ � ☎✠✟ � ✟✡☎☎✒☛✌☎✁☎✕☛✌☎ �✁� ✆✍✟✎✆✁✆✏✟✎✆ �✁� ☎✒☛✌☎✄☎✒☛✌☎☎ ✆ ✟ � ✆ ✟ ✆ � ✟ ✆ ☎☎✁☎ ✆✁✆ ✟✁✟ � ☛✡✆ ✟✁✟ ✆✓☛ � ✟✁✟ ✆✄✆ ☎✁☎☎✙✆✞☎✝✆✏✟✎✆✚✟✎✆✞☎✝✆✞☎✙✆✏✟✎✆✏✟✎✆✞☎✙✆✞☎✝✆✏✟✎✆✚✟✎✆✞☎✝✆✞☎☎ �✁�✁� �✁�✁�✁� �✂�✁�✁� �✁�✁� ☎☎✠✟ � � � � � � ✟✛☎☎✒☛✑✟ �✁� �✁� �✂� �✁� �✁� �✁� ✟✝☛✜☎☎ � ✟ � � � � � � � � � � � � ✟ � ☎☎✁☎ � ☎✁☎ �✁�✁�✄�✁�✁�✁�✁�✁�✂�✁�✁�✁�✁�✂�✁�✁�✁�✁�✁�✄�✁� ☎✁☎ � ☎✁☎☎✝✆✏✟✁✟✖✆✏✟ ✟✎✆✏✟✂✟✎✆✞☎✢✿✴✤✣✦✥✺❂✎✰★✧✂✽ ☎❵❚❏❄❈❲◆❚❛⑦✸✷➵❄➠❇❈❑▼❃❅❚★❙❊❬★⑦❖❉⑥❑③❉P❨✪■❯❲❳❉P❨✝❘⑥●❽❨✪■✪⑦❖●✂r✂➚✐❇❈●❩❱✰➶▲●❏❑④❘⑥●❊❨✪■✪⑦❖●❋✖✂➚✐❧✜●❏❇❈❇❈●❏❘➅➶✿➋✰❇❈❁❊❉❄✺❃❖➍◆❉❣●★❋✬❚❹❨✪●❏❇✣❃❅❄❞❱❊❑③●❏❱❯●❏❑③❇▼❃❖●❏❙❯❚❛⑦❯❇❈●❹❇❈❁❊❉▲❫☞❚☞⑦⑤■❊❉✦●★❋✰❇❈❁❊❉❣❑③❉P❄✺❃❅❨✪■❊❉▲❃❖❇❞❑③❉◆❱❊❑❈❉P❄▼❉◆❙✪❇✿❄◆❪✣❝✐❙✍❇❈❁❊❉✧❩❯❑✿❄❾❇❞❲◆❚❏❄▼❉❇❈❁❊❉✖❱✪❃❺❲❳❇③■❊❑❈❉❹❃❺❄☎❚✵■❊❇❈●❏❼✐❄✺❃❖❘✖❃❿⑦❅❚★❑Pq✰❧❊■❊❇✦❙❊●❏❇➊❃⑤❙➈❇❈❁❊❉♠❄▼❉P❲❳●❩❙❯❨✟●❩❙❊❉❏❪❣❡➊❉◆❫❏❉◆❑❈❇❈❁❊❉❳⑦❖❉P❄❈❄◆q✜❃❖❙✂❧❯●❩❇❈❁✇❲◆❚❏❄▼❉P❄◆q❚❹⑦❿❃⑤❘❸❃⑤❇④❄❾❉◆❇▲❉❳➉❭❃❅❄▼❇❳❄◗❃❖❙✟❇❈❁❊❉✆r❣❚★■❯❄③❨✪●❏❑▼➏➎❘❦❉◆❇❈❑▼❃❅❲★❪

❤➊⑦⑨⑦✚❇❈❁❊❉P❄❾❉❣❄▼❉P➌❩■❊❉◆❙❯❲❳❉P❄▲❚★❑❈❉❣r✵❼✐❚★■❊❇❈●❏❘❜❚✵❇▼❃❅❲★❪❞➚▼❀❂❁❊❉➬r➠❑❈❉❳❋❍❉◆❑✿❄❵❇❈●❹❇❈❁❊❉➊❋ ❚❏❲❳❇◗❇❈❁❯❚★❇◗❇❈❁❊❉❣❚❛⑦❖❱❊❁❯❚★❧✜❉◆❇▲❁❯❚❏❄❵❇▼❶❂●☎⑦❖❉◆❇❈❇③❉◆❑✿❄◆❪❿➶❀❂❁❊❉④❨✪❉✯❩❯❙✪❃❖❇▼❃❖●❏❙✂❘❜❚❛⑩✍❧❯❉♠❚❩❨❊❚★❱❊❇❈❉P❨✍❇❈●❜❨✪●❩■❊❧✪⑦⑤❉✖❄▼❉P➌❩■❊❉◆❙❯❲❳❉P❄◆❪s❒t●❏❑❂❃❖❙❯❄▼❇✿❚✵❙❯❲❳❉④❇❈❁❊❉☎❘⑥●❩❑❈❱❊❁✪❃❅❄▼❘

✗❆➚✳✈✪➶❿❚✗✩ ✈ ✈✈ ✈✫✪ ❧ ✗❵➚✿♥★➶❿❚✗✩ ♥ ✈

♥ ♥✬✪❥☎➅

Page 20: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❚★❱❊❱✪⑦❿❃❖❉P❨✡❇❈●⑥❇❈❁❊❉④❄▼❇❳❚★❑❈❇▼❃❖❙❊❬⑥❱✜●★❃❖❙❭❇④♥➠❬★❃❖❫❏❉P❄❇☎❵❚❏❄❈❲◆❚☞⑦✴✷❐❄❂❇❈❑▼❃❅❚★❙❊❬★⑦❖❉❹❑❈❉P❨✪■❯❲❳❉P❨✮❘⑥●❊❨✪■✪⑦❖●❷rtq�✁✁✁✁✁✁✁✁✁✁✁✂

♥ ✈ ✈ ✈ ✈ ✈ ✈ ✈♥ ♥ ✈ ✈ ✈ ✈ ✈ ✈♥ ✈ ♥ ✈ ✈ ✈ ✈ ✈♥ ♥ ♥ ♥ ✈ ✈ ✈ ✈♥ ✈ ✈ ✈ ♥ ✈ ✈ ✈♥ ♥ ✈ ✈ ♥ ♥ ✈ ✈♥ ✈ ♥ ✈ ♥ ✈ ♥ ✈♥ ♥ ♥ ♥ ♥ ♥ ♥ ♥

✄✆☎☎☎☎☎☎☎☎☎☎☎✝

➘➸↔➅↕❷❉❏❻ �♣❺▲⑨✟✞✢❑ ❅✡✠❀❂❁❊❉✖❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩✟●✵❋s❚❜❄▼❉P➌❩■❊❉◆❙❯❲❳❉✖●★❫❏❉◆❑➬❚◗❩❯❙✪❃❖❇❈❉⑥❚❛⑦❖❱❊❁❯❚★❧❯❉◆❇✦❃❅❄☎❨✪❉✯❩❯❙❊❉P❨✂❚❏❄✦❚★❙❊●❏❇❈❁❊❉◆❑☎❄▼❉P➌❩■❊❉◆❙❯❲❳❉☛✡✰➚✐❖❮➶✿q✜❶▲❁❊❉◆❑❈❉

✡✰➚✐❖❮➶✜❃❅❄✣❇❈❁❊❉❂❙❭■❊❘✖❧❯❉◆❑❵●✵❋✷❨❩❃❅❄▼❇▼❃❖❙❯❲❳❇❵❋✐❚❏❲❳❇❈●❩❑✿❄✰❶❂❃❖❇❈❁❹⑦❖❉◆❙❊❬❏❇❈❁✌❖❸❃❖❙✖❇❈❁❊❉❂❬★❃❖❫❏❉◆❙⑥❄▼❉P➌❏■❊❉◆❙❯❲❳❉❏❪ ❨▲❧❭❫❩❃❖●❏■❯❄✺⑦❖⑩✖❇❈❁❊❉▲❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩❄❈❚★❇❾❃❺❄⑤❩❯❉P❄

♥✛✚ ✡✰➚✐❖❮➶✔✚ ❞ ✽ ❧❃❿❋s❇❈❁❊❉✖❚❛⑦❖❱❊❁❯❚★❧❯❉◆❇✦❃❅❄✦●★❋s❄✳❃⑤➍◆❉ ❞✪❪❣❀❴❁❊❉♠❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃❖❇✳⑩✡❑❈❉☛☎❯❉P❲❳❇✿❄➊❁❊●★❶❥❃❖❙✪❇❈❑▼❃❅❲◆❚★❇❈❉✖❇❈❁❊❉✖❄▼❉P➌❏■❊❉◆❙❯❲❳❉❸❃❺❄➐❪❣❒❊●❩❑▲❃❖❙❯❄▼❇✿❚✵❙❯❲❳❉❏q❊❃❿❋❋❍●❏❑s❚★❙✪⑩✷❖✮❇❈❁❊❉❴❃⑤❙❊❉P➌❩■❯❚❛⑦❿❃❖❇▼⑩ ✡✰➚❾❖✚➶✇✚✦❖❦❃❅❄❂❄❈❚★❇▼❃❅❄❺❩❯❉P❨✰q✪❇❈❁❊❉☎❄▼❉P➌❩■❊❉◆❙❯❲❳❉▲❃❅❄◗■✪⑦❖❇▼❃❖❘❜❚★❇❈❉❳⑦❖⑩✍❱❯❉◆❑▼❃❖●❊❨❩❃❺❲★❪❂❝✺❙❜❇③❁❊❉❣❲◆❚❏❄▼❉✦●★❋✚❇❈❁❊❉❀❂❁✪■❊❉◆❼✸✹✡●❏❑✿❄▼❉④❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏q✜❇❈❁❊❉④❄▼❉P➌❩■❊❉◆❙❯❲❳❉④●★❋✕❨❩❃❿➏✚❉◆❑❈❉◆❙❯❲❳❉P❄✞✡✰➚❾❖❜➀➂♥★➶❏♠ ✡✷➚✐❖❮➶✬❃❅❄✦r★❼✐❚★■❊❇❈●❩❘❜❚★❇▼❃❅❲★❪ ➆ ●❏❧❊❁❯❚★❘ ❄▼❁❊●★❶❂❉P❨❇❈❁❯❚★❇❂❉◆❫❏❉◆❑③⑩✟❚★■❊❇❈●❏❘❜❚✵❇▼❃❅❲❣❄▼❉P➌❩■❊❉◆❙❯❲❳❉✖❁❯❚❏❄▲❲❳●❏❘❦❱✪⑦⑤❉❳➉✪❃❖❇▼⑩✒✜✖➚✐❖❮➶ ✙ ✘✠✚✐❪❒❊●❩❑❞❨✪●❏■❊❧✪⑦❖❉❣❄▼❉P➌❩■❊❉◆❙❯❲❳❉P❄◆q✪❇❈❁❊❉▲❄▼❁❯❚★❱❯❉➊●★❋➸❧✪⑦❖●❊❲❈⑧✖❇❈●☎■❯❄▼❉❴❃⑤❙❦❇❈❁❊❉❣❨✪❉✯❩❯❙✪❃❖❇▼❃❖●❏❙✍●★❋✷❲❳●❏❘❦❱✪⑦⑤❉❳➉✪❃❖❇▼⑩④❃❅❄❆❑✿❚★❇❈❁❊❉◆❑❞❚★❑③❧✪❃⑤❇③❑✿❚★❑❈⑩❏❪

❤➾❙❯❚★❇❈■❊❑❳❚❛⑦❣❲❈❁❊●★❃❅❲❳❉✡❃❅❄⑥❇③●✏❲❳●❏❙❯❄✺❃❅❨✪❉◆❑✮❑❈❉P❲❳❇✿❚✵❙❊❬❏■✪⑦❅❚★❑⑥❧✪⑦❖●❽❲③⑧❊❄◆❪❥❀❂❁❊❉◆❙✚q❂❇❈❁❊❉✂❲❳●❏❘⑥❱✪⑦❖❉❳➉❭❃❖❇▼⑩✝❃❅❄✮❚✇❨✪●❏■❊❧✪⑦❖❉✇❄▼❉P➌❩■❊❉◆❙❯❲❳❉✇❹➚✄✗✕❧➋❖✚➶▲❶➊❁❊❉◆❑❈❉✷✇❹➚✄✗✕❧r❖❮➶❂❃❅❄✦❇❈❁❊❉⑥❙✪■❊❘✖❧❯❉◆❑☎●★❋▲❨❩❃❺❄❾❇▼❃❖❙❯❲❳❇♠❑③❉P❲❳❇✿❚★❙❊❬❏■✪⑦❅❚★❑☎❧✪⑦❖●❊❲❈⑧❊❄☎❶❂❃❖❇❈❁ ✗ ❑③●☞❶✦❄❣❚★❙❯❨ ❖✏❲❳●★⑦❖■❊❘⑥❙❯❄●❊❲◆❲❳■❊❑❈❑▼❃❖❙❊❬⑥❃❖❙✡❇❈❁❊❉☎❬★❃❖❫❏❉◆❙➎❨✪●❩■❊❧✪⑦⑤❉✖❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏❪❒❊●❩❑ ☎❵❚❩❄❈❲◆❚❛⑦✸✷➵❄❂❇❈❑❾❃❺❚✵❙❊❬★⑦❖❉④❑❈❉P❨✪■❯❲❳❉P❨➅❘⑥●❽❨✪■✪⑦❖●✮r❊q❩❃❖❇▲❃❅❄➊❑❈❉P❚❏❨❩❃❿⑦❖⑩✮❙❊●❏❇▼❃❅❲❳❉P❨✮❇❈❁❯❚✵❇▲❇❈❁❊❉④❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃❖❇✳⑩✟❄③❚★❇▼❃❅❄❺❩❯❉P❄

✇ ✺ ➚✄✗✕❧r❖❮➶❿❚➇✇ ✺ ➚✿♥✠❧☎✗ ➀★❖➍♠➑♥★➶r➄✹✡●❏❑❈❉◆●★❫❏❉◆❑❂❇❈❁❊❉☎❑❈❉❳⑦❅❚★❇❾❃⑤●❩❙

➚✿♥✡➀ ✟✰➶ ✺☞☛ ❚ ➚✿♥✒➀ ✟ ✺ ➶ ☛❄▼❁❊●★❶❣❄❂❇③❁❯❚★❇❂❑❈●★❶✔☛▲❨✪❉◆❇❈❉◆❑③❘✖❃❖❙❊❉P❄▲❑❈●★❶❣❄❂r✼☛▲❚★❙❯❨✮r ☛❏➀➱♥❩➋❽❚❩❄▲❚⑥❲❳●❏❙❯❄▼❉P➌❩■❊❉◆❙❯❲❳❉④❇③❁❊❉☎❋❍●❏❑❈❘✖■✪⑦❅❚

✇ ✺ ➚✿♥✠❧➋❖✚➶♣❚➇❖ ✺ ♠ ❖ ➀➴r❃❅❄☎❄❈❚★❇▼❃❅❄❺❩❯❉P❨✰❪✆✹✡●❏❑❈❉❹❬❏❉◆❙❊❉◆❑✿❚❛⑦❿⑦❖⑩❏q✎☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄✦❇❈❑▼❃❅❚★❙❊❬★⑦❖❉✖❑❈❉P❨✪■❯❲❳❉P❨✂❘❦●❽❨✪■✪⑦❖●➎❚❦❱❊❑▼❃❖❘⑥❉ ✡✡❁❯❚❏❄☎❲❳●❏❘❦❱✪⑦⑤❉❳➉✪❃❖❇▼⑩➎●❩❑✿❨✪❉◆❑❽❖ ✺ ❪❀❂❁❊❉❹❱❊❑❈●❭●✵❋✕❑❈❉❳⑦❿❃❖❉P❄✦●❏❙✮❇❈❁❊❉➠❋ ❚❩❲❳❇▲❇❈❁❯❚★❇❣❨❩❃❿➏✚❉◆❑❈❉◆❙❯❲❳❉P❄➊●★❋❞●❏❑✿❨✪❉◆❑✦r✖●★❋☎✇ ✌ ➚✿♥✪❧r❖❮➶✣❋➄●❏❑③❘ ❚ ✡❊❼✐❚★■❊❇③●❏❘❜❚★❇▼❃❅❲☎❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏❪❂❝❍❋❇❈❁❊❉⑥❘❦●❽❨✪■✪⑦❖■❯❄➠❃❅❄④❙❊●❩❇♠❚✮❱❊❑❾❃⑤❘❦❉⑥❧❊■❊❇❹❃❺❄❹❄❈➌❩■❯❚★❑❈❉◆❼➼❋❍❑❈❉◆❉❏q❮❋➄●❏❑☎❉❳➉❯❚★❘⑥❱✪⑦❖❉❦❃❿❋❣❇❈❁❊❉⑥❘⑥●❊❨✪■✪⑦❖■❯❄✖❉P➌❩■❯❚❛⑦❅❄✁✖❊q❮❇❈❁❊❉ ➆ ❁✪❃⑤❙❊❉P❄❾❉❑❈❉◆❘❜❚☞❃⑤❙❯❨✪❉◆❑✦❇❈❁❊❉◆●❏❑③❉◆❘ ❄▼❁❊●★❶❣❄◗❇❈❁❯❚★❇

✇✍✌◆➚❳♥✠❧r❖❮➶✷✚✦✇ ✺ ➚✿♥✠❧➋❖❮➶✐✇ ➁ ➚✿♥✪❧r❖❮➶r➄❤☎❲❳❇❈■❯❚❛⑦❿⑦❖⑩❏q❊❇❈❁❊❉④➌❩■❯❚★❙❭❇❾❃⑤❇❾❃⑤❉P❄➊❚★❑❈❉▲❉P➌❩■❯❚❛⑦✐q❯❄✺❃❖❙❯❲❳❉④❇③❁❊❉❣❑❈❉P❄✳❃❺❨✪■❊❉P❄❴❘⑥●❽❨✪■✪⑦❖●❜r✖❚★❙❯❨✍❘❦●❽❨✪■✪⑦❖●⑥✉❹❘❜❚❛⑩⑥❧❯❉④❲❳●❏❙❯❄✳❃❺❨✪❉◆❑③❉P❨✮❚❏❄❃❖❙❯❨✪❉◆❱❯❉◆❙❯❨✪❉◆❙✪❇P❪❇✹✡●❏❑❈❉✦❬❏❉◆❙❊❉◆❑✿❚❛⑦❿⑦❖⑩❏q❊❇❈❁❊❉☎❲❳●❏❘⑥❱✪⑦❖❉❳➉✪❃❖❇✳⑩➒✇✍✎◆➚✿♥✪❧r❖❮➶✬●★❋✎☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄◗❇❈❑▼❃❅❚★❙❊❬★⑦❖❉☎❑❈❉P❨✪■❯❲❳❉P❨✍❘⑥●❊❨✪■✪⑦❖●❜❚✖❄❈➌❩■❯❚★❑❈❉❋❍❑❈❉◆❉❞❙✪■❊❘✖❧❯❉◆❑✞❞◗❃❅❄✣❄▼❁❊●★❶▲❙④❇❈●➊❧❯❉❂●★❋❯●❏❑✿❨✪❉◆❑❿❖ ✺✑✏✓✒ ✎✕✔ q❛❶▲❁❊❉◆❑❈❉✗✖▲➚⑤❞❩➶❊❃❅❄✚❇③❁❊❉s❙✪■❊❘✖❧❯❉◆❑✣●★❋❯❱❊❑▼❃❖❘⑥❉◗❋✐❚❏❲❳❇❈●❏❑✿❄✷●★❋❻❞✪❪❵❀❂❁❊❉❂❲◆❚❏❄▼❉●★❋❯❱❊❑▼❃❖❘⑥❉➊❱❯●★❶❂❉◆❑✿❄✚❘✍❚P⑩☎❧✜❉▲❇✿❚❏❲③⑧❩⑦⑤❉P❨❹❧✪⑩♠❚❴❋➄●❩❑❈❘✖■✪⑦❺❚☎❨✪■❊❉❂❇❈●✛✬✦■❊❘⑥❘⑥❉◆❑❛q❏❙❯❚★❘⑥❉❳⑦❖⑩✙✘◆➚✿♥✒➀ ✟✰➶ ✌✛✚✢✜✤✣✦✥ ✌ ❚❥➚✿♥✒➀ ✟ ✌ ➶ ✌✧✚✢✜★✣❘⑥●❊❨ ✡✪✩★❪✇❀❂❁✪❃❅❄❹❑❈❉P❄▼■✪⑦❖❇⑥❬★❃❖❫❏❉P❄✖❚✡❘❜❚★❇③❁❊❉◆❘❜❚★❇▼❃❅❲◆❚❛⑦❂❘⑥❉P❚★❙✪❃❖❙❊❬✂❇❈●✂❇❈❁❊❉⑥❋❍❉◆❉❳⑦❿❃❖❙❊❬✇❇❈❁❯❚★❇ ☎❵❚❏❄❈❲◆❚☞⑦✴✷❐❄☎❇❈❑▼❃❅❚★❙❊❬✵⑦⑤❉✮❑③❉P❨✪■❯❲❳❉P❨❘⑥●❊❨✪■✪⑦❖● ✗ ❃❅❄➊❘⑥●❏❑❈❉☎❚★❙❯❨✮❘❦●❏❑❈❉④❲❳●❏❘⑥❱✪⑦❖❉❳➉➎❚❏❄◗❇❈❁❊❉❹❙❭■❊❘✖❧✜❉◆❑▲●★❋❵❱❊❑▼❃❖❘⑥❉☎❋✐❚❏❲❳❇❈●❏❑❳❄❞●✵❋ ✗ ❃❖❙❯❲❳❑❈❉P❚❏❄❾❉P❄◆❪

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Page 21: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➷✚↔⑥➓➏●✣❅✯❉❏❻✕➐☞❅❈❑✔■✠❑ ❅ ✠➇❉ ✁ ❺ ❑⑩❄✣⑨✉➐❆❇➏■✍⑨☞❺✔❺✂●❋❺ ➐❆❇➒➐✣●✣❅✯❉❏❻✕➐☞❅✯➐☎❵❚❏❄❈❲◆❚☞⑦✴✷❐❄④❇③❑▼❃❅❚★❙❊❬★⑦❖❉✍❃❅❄⑥❚★❙✝❉❳➉t❚★❘❦❱✪⑦⑤❉✮●✵❋➬❚➅⑦⑨❃❖❙❊❉P❚★❑✮❲❳❉❳⑦❿⑦❖■✪⑦❺❚✵❑❷❚★■❊❇③●❏❘❜❚★❇❈●❩❙✚❪✇❀❂❁❊❉◆❑❈❉❦❃❺❄❦❚★❙✝❃❖❙✪❃⑤❇❾❃❺❚☞⑦➬❄▼❇✿❚★❇③❉❏q❵❁❊❉◆❑❈❉

✂ ➚ ✟✰➶♣❚ ♥❏q❊❚★❙❯❨✮❚❹❑❈■✪⑦❖❉ ✌❩➚ ✟✷➶✢❚✓♥☎➀✡✟✚❪✣❤▲❇❂❇▼❃❖❘⑥❉✲☛❳q❊❇❈❁❊❉④❄▼❇❳❚★❇❈❉▲●★❋✣❇❈❁❊❉④❚★■❊❇❈●❏❘✍❚★❇❈●❏❙✖❃❅❄ ✂ ➚ ✟✷➶★✌❩➚ ✟✰➶ ☛ ❪✕❀❮●✖❑❈❉P❲❳●★❫❏❉◆❑▲❚❘⑥●❏❑③❉➬❲③⑦❅❚❏❄❈❄✳❃❺❲◆❚☞⑦✕❨✪❉✯❩❯❙✪❃❖❇▼❃❖●❏❙✡❋➄❑❈●❩❘ ❇❈❁✪❃❅❄❂●❏❙❊❉❏q❽❃⑤❇✦❄▼■❄✣❷❲❳❉P❄❂❇❈●⑥❲❳●❏❙❯❄✳❃❺❨✪❉◆❑➊❇❈❁❯❚★❇▲❲❳●❭❉✯✣✮❲③❃⑤❉◆❙✪❇✿❄❂●✵❋✬❇❈❁❊❉④❄▼❇✿❚✵❇❈❉➬❚✵❇s❇❾❃⑤❘❦❉✲☛❚★❑❈❉✦❇❈❁❊❉④❲❳●❏❙✪❇❈❉◆❙✪❇✿❄❵●✵❋✕❲❳❉❳⑦❿⑦❺❄✦❚★❑❈❑❳❚★❙❊❬❏❉P❨✍❚❛⑦❖●❏❙❊❬⑥❇❈❁❊❉➊❃❖❙❄❩❯❙✪❃⑤❇③❉④⑦❿❃❖❙❊❉④●✵❋✚❃❖❙❭❇❈❉◆❬❩❉◆❑✿❄☎✄④❪✩✹✡●❏❑❈❉◆●★❫❏❉◆❑❞❇③❁❊❉④❄▼❉◆❇❂●★❋✕❄▼❇✿❚✵❇❈❉P❄❵●★❋❚⑥❲❳❉❳⑦❿⑦❵❃❅❄✧❩❯❙✪❃❖❇❈❉❹❃❿❋❞❇❈❁❊❉❹❑▼❃❖❙❊❬❜●★❋s❲❳●✪❉✯✣❷❲③❃❖❉◆❙✪❇✿❄❂❃❅❄❀❩❯❙✪❃❖❇❈❉❏➋✜❁❊❉◆❑❈❉✖❇❈❁❊❉☎❑▼❃❖❙❊❬✍❃❅❄▲❇③❁❊❉④❑▼❃❖❙❊❬✍●★❋✬❃❖❙✪❇❈❉◆❬❏❉◆❑✿❄➊❘⑥●❊❨✪■✪⑦❖● ✗✂❪❞❝✺❙●❏❇❈❁❊❉◆❑☎❶❂●❏❑❳❨❊❄◆q✰❇❈❁❊❉⑥❨✪●❏■❊❧✪⑦❖❉❷❄❾❉P➌❏■❊❉◆❙❯❲❳❉⑥●✵❋s❧✪❃❖❙❊●❏❘✖❃❅❚❛⑦▲❲❳●❭❉✯✣❷❲③❃❖❉◆❙✪❇✿❄☎❑③❉P❨✪■❯❲❳❉P❨✇❘⑥●❊❨✪■✪⑦❖● ✗ ❄▼❁❊●★❶❣❄✦❇❈❁❊❉✖❉◆❫❏●✵⑦⑤■❊❇❾❃⑤●❩❙●★❋❞❚⑥❲③⑦❅❚❏❄❈❄✺❃❅❲◆❚❛⑦❮⑦⑨❃❖❙❊❉P❚★❑④❲❳❉❳⑦❿⑦❖■✪⑦❅❚★❑④❚★■❊❇❈●❩❘❜❚★❇❈●❏❙✚❪❝✐❇◗❃❅❄▲❄▼❁❊●★❶▲❙❦❇❈❁❯❚★❇Pq✪❶▲❁❊❉◆❙✍❑❈❉P❨✪■❯❲❳❉P❨✮❘❦●❽❨✪■✪⑦❖●⑥❚❹❱❊❑▼❃❖❘⑥❉☎❱❯●★❶❂❉◆❑ ✡ ✠ q❊❚✦⑦❿❃❖❙❊❉P❚★❑☎❲❳❉❳⑦❿⑦⑤■✪⑦❅❚★❑☎❚★■❊❇❈●❩❘❜❚★❇❈●❏❙❦❱❊❑❈●★❫❏❃❅❨✪❉P❄❂❚

✡❊❼✐❚★■❊❇③●❏❘❜❚★❇▼❃❅❲✦❨✪●❏■❊❧✪⑦❖❉♠❄▼❉P➌❩■❊❉◆❙❯❲❳❉❏❪❂❀❂❁❊❉④❱❊❑❈●✪●★❋✬❙❊❉◆❉P❨❊❄✦❚★❙✮❚❏❨❊❨❩❃❖❇▼❃❖●❏❙❯❚❛⑦❞❲❳●❏❙❯❲❳❉◆❱❊❇✧✺❞❚❹❱✜●★⑦❖⑩❭❙❊●❏❘❸❃❺❚☞⑦●✌❩➚ ✟✷➶✬❃❅❄▲❄③❚❛❃❅❨✮❇❈●❁❯❚❛❫❏❉☎❇❈❁❊❉❀✗✍❼✐❒t❉◆❑❈❘❜❚★❇❂❱❊❑❈●❏❱✜❉◆❑❈❇▼⑩⑥❃❿❋❵❃❖❇❣❄❈❚✵❇▼❃❅❄❺❩❯❉P❄

✌❏➚✁✟ ☞ ➶❿❚✄✌❏➚✁✟✰➶ ☞ ➄❀❂❁❊❉✱✬✦■❊❘⑥❘⑥❉◆❑➠❋➄●❩❑❈❘✖■✪⑦❺❚✮❚✵❧❯●★❫❏❉✖❬★❃❖❫❏❉P❄☎❚★❙✂❉❳➉❯❚★❘⑥❱✪⑦❖❉⑥❶❂❃❖❇❈❁✪✗ ❚ ✡✝❚⑥❱❊❑▼❃❖❘⑥❉❦❙❭■❊❘✖❧❯❉◆❑❛❪✆✦➱❁❊❉◆❙✂❇❈❁❊❉❦❑❈■✪⑦❖❉✆✌❩➚ ✟✰➶❁❯❚❏❄❂❇③❁❊❉❀✗✍❼✐❒❊❉◆❑❈❘❜❚✵❇▲❱❊❑❈●❏❱✜❉◆❑❈❇▼⑩❏q❭❇③❁❊❉◆❙✟❇❈❁❊❉④❚❏❄③❄▼●❽❲③❃❅❚★❇③❉P❨✟❨✪●❏■❊❧✪⑦❖❉♠❄❾❉P➌❏■❊❉◆❙❯❲❳❉❹❃❅❄✧✗✍❼✐❚★■❊❇❈●❩❘❜❚★❇▼❃❅❲★❪❤☎❄♠❚✂❲❳●❏❙❯❄❾❉P➌❏■❊❉◆❙❯❲❳❉✢☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄❹❇❈❑▼❃❅❚★❙❊❬★⑦❖❉✍❑❈❉P❨✪■❯❲❳❉P❨✝❘⑥●❊❨✪■✪⑦⑤● ✗ ❃❅❄✱✗✍❼✐❚★■❊❇③●❏❘❜❚★❇▼❃❅❲❹❃❿❋❀✗ ❃❅❄✖❚✡❱❊❑▼❃❖❘⑥❉✮❱❯●★❶❂❉◆❑P❪

✹✡●❏❑❈❉◆●★❫❏❉◆❑✦❇❈❁❊❉⑥❲❳●❏❙✪❫❏❉◆❑✿❄▼❉❹❃❅❄✦❇❈❑❈■❊❉❏q✚❚★❙❯❨➅❃❖❇✿❄➠❱❊❑❈●❭●✵❋❞❑❈❉❳⑦❿❃⑤❉P❄❹●❏❙ ➆ ●❩❧❊❁❯❚★❘✢✷➵❄➊❇❈❁❊❉◆●❏❑❈❉◆❘➾❶➊❁✪❃❺❲③❁✇❚❏❄❈❄▼❉◆❑③❇✿❄✦❇❈❁❯❚★❇☎❚✮❄▼❉◆❼➌❩■❊❉◆❙❯❲❳❉❣❧✜●❏❇❈❁ ✡❊❼✐❚✵■❊❇❈●❏❘❜❚★❇❾❃❺❲➊❚★❙❯❨ ❞❛❼✐❚★■❊❇❈●❏❘✍❚★❇▼❃❅❲★q ✡✍❚★❙❯❨ ❞✦❧❯❉❳❃❖❙❊❬✖❱❊❑▼❃❖❘⑥❉☎❚★❙❯❨⑥❨❩❃❅❄▼❇▼❃❖❙❯❲❳❇Pq❩❃❅❄◗■✪⑦❖❇▼❃❖❘❜❚★❇❈❉❳⑦❖⑩⑥❱✜❉◆❑▼❃❖●❽❨❩❃❅❲★❪r➊❉◆❑❈❉❣❇③❁❊❉④❄▼❉P➌❏■❊❉◆❙❯❲❳❉☎■❯❄❾❉P❨❦❃❺❄❴❇❈❁❊❉➬❄❾❉P➌❏■❊❉◆❙❯❲❳❉☎●★❋❵❲❳❉◆❙❭❇❈❑❳❚❛⑦➸❧✪❃❖❙❊●❏❘✖❃❅❚❛⑦❅❄ ❊ ✺ ✽✽ ❋ ❪❞❀❂❁✪❃❅❄◗❑❈❉P❄▼■✪⑦❖❇▲❬★❃❖❫❏❉P❄❂❚❹❱❊❑❈❉P❲③❃❅❄▼❉➠❋➄●❏❑③❘♠■❊❼⑦❅❚★❇▼❃❖●❏❙✮●★❋✣❇❈❁❊❉▲❋✐❚❏❲❳❇❂❇❈❁❯❚★❇❇☎❵❚❏❄③❲◆❚❛⑦✸✷➵❄❵❇❈❑❾❃❺❚✵❙❊❬★⑦❖❉☎❑❈❉P❨✪■❯❲❳❉P❨✮❘⑥●❊❨✪■✪⑦❖●❜❚✖❲❳●❏❘⑥❱✜●❭❄✺❃❖❇❈❉☎❙✪■❊❘♠❧✜❉◆❑◗❃❺❄❴❘⑥●❏❑❈❉☎❲❳●❏❘⑥❱✪⑦❖❉❳➉✮❇❈❁❯❚★❙❶▲❁❊❉◆❙✡❑❈❉P❨✪■❯❲❳❉P❨✮❘⑥●❊❨✪■✪⑦❖●❷❚❸❱❊❑▼❃❖❘⑥❉④❱✜●☞❶❂❉◆❑P❪

✃✬↔✍➛ ●✡❏✬❑✔■✍➐❆❺✒■✍❉▼❻ �♣❉✎❏❈❑ ❅❈❑▲❉▼❄➀ ●❏❘⑥❉▲❲❳●❏❘❦❱❯●❭❄▼❉◆❑❳❄✚❁❯❚❛❫❏❉❂■❯❄▼❉P❨⑨❩❯❙✪❃❖❇❈❉❣❚★■❊❇③●❏❘❜❚★❇✿❚❴❇❈●❣❱❊❑③●❽❨✪■❯❲❳❉❂❘✖■❯❄✺❃❅❲◆❚❛⑦❯❘⑥●❏❇❾❃⑨❋✐❄◆❪✣❒❊●❏❑✣❃❖❙❯❄▼❇✿❚✵❙❯❲❳❉❴❀❮●❏❘ ✰★●❏❁❊❙❯❄▼●❩❙

❁❯❚❏❄❂■❯❄❾❉P❨✮❇❈❁❊❉☎❘⑥●❩❑❈❱❊❁✪❃❅❄▼❘➹❨✪❉✯❩❯❙❊❉P❨➅●❏❙✟❚✖❇▼❶❂●❏❼➼⑦❖❉◆❇❈❇❈❉◆❑▲❚❛⑦❖❱❊❁❯❚★❧✜❉◆❇✥✜✠➀❷❧❈♠ ✣☎❧✪⑩✆ ➚❂➀☎➶✡❚ ➀✦♠③➀❷❧ ✆ ➚➋♠✦➶☎❚ ♠③♠ ➀❷➄

❤ ➀ ❲❳●❽❨✪❉P❄⑥❚➮❘⑥❉❳⑦❖●❽❨❩❃❅❲✟❚❩❄❈❲❳❉◆❙❭❇❛qs❚★❙❯❨➑❚✗♠ ❲❳●❊❨✪❉P❄❜❚✡❘⑥❉❳⑦❖●❊❨❩❃❅❲➎❨✪❉P❄③❲❳❉◆❙❭❇P❪✝❝✺❙➂❇❈❁❊❉✟❄❈❚✵❘⑥❉❜❫❩❉❳❃⑤❙✚q◗❁❊❉✟❁❯❚❩❄④■❯❄❾❉P❨☎❵❚❏❄❈❲◆❚☞⑦✴✷❐❄✣❇❈❑▼❃❅❚★❙❊❬★⑦❖❉✦❑❈❉P❨✪■❯❲❳❉P❨⑥❘❦●❽❨✪■✪⑦❖●✍♦❭❪❵❀❂❁❊❉❂❃❖❙✪❇❈❉◆❑❈❉P❄▼❇◗●★❋✬❄▼■❯❲❈❁✍❚④❲❳●❏❘⑥❱✜●❭❄✺❃❖❇▼❃❖●❏❙❦❃❅❄❵❇❈❁❯❚★❇❞❚✵■❊❇❈●❏❘❜❚★❇❾❃❺❲➊❄▼❉P➌❏■❊❉◆❙❯❲❳❉P❄❚★❑❈❉④❚✵❇s❇③❁❊❉✦❋➄❑❈●❩❙❭❇▼❃❖❉◆❑▲❧✜❉◆❇▼❶s❉◆❉◆❙✮❱✜❉◆❑▼❃❖●❽❨❩❃❅❲③❃❖❇▼⑩➎❚★❙❯❨✮❲③❁❯❚★●❭❄➐❪✞⑩◗■❊❇❣❚❏❄❂❀✚●❩❘ ✰★●❏❁❊❙❯❄▼●❩❙✟❁✪❃❖❘❜❄▼❉❳⑦❿❋s❄❈❚❛⑩❊❄◆q✪❇❈❁✪❃❅❄▲❲◆❚★❙✮●❏❙✪⑦❖⑩❧❯❉✖❚✖❇❈●✪●★⑦✬❚★❙❯❨✮❲❳❉◆❑❈❇✿❚☞❃⑤❙✪⑦❖⑩✡❙❊●❏❇▲❚✖❶▲❚P⑩❦●★❋❆❲❳●❩❘⑥❱❯●❭❄✳❃⑤❙❊❬✍❘✖■❯❄✺❃❅❲✦❃❖❙➎❚❸❱❊■❊❑❈❉❳⑦❖⑩✟❚★■❊❇❈●❏❘❜❚✵❇▼❃❅❲➊❋ ❚❏❄❾❁✪❃⑤●❩❙✚❪

P❅◗ ✿❙❘✶◗✶❚✍❯❝❄❇❆✝❱✁❲✼❳✽ ❥ ✿q☞ P❚P❳❏✐❋ ❬❫❋ ❙ Ò✶❽❉❱ ❜ ♦ ❱ Ö ❱✝❬❇✄✝❋❨❊✩P❣❍❑❬ ❏ ●❴■ P ❙ ♠ ❱❳❲ ❘❙✳❚✝❙ ❩q❩●❋ ❱❳❲✂❙ ❩ ❱ ❍ ❫ ❍ ❱❳❙ ❩❅❱✞✝✷♥❼❤✥❤❸❴❝❜⑦❞⑤♣ ❵ ①④❜❢❫✝❴✟✝✔❴❋❤ ③❺❞✶❣❖♣ ❶❷❣❺❜❢❫✝❴❋❦✛❣★❜✴❞❢❡✏❣❖❤✎♦✞❵☎❡■❞❢❴❝❜ ✟◆P

❖ ❏ P ❱ ❥ P✞r☎s❉s❧t P ■▲■ ❱ ❥ ➣❈➣❺❬ ❥③Õ ➣▲❱✽ s➋✿q☞ P❚P❳❏✐❋ ❬❫❋ ❙ Ò❢❽❉❱ ❜ ♦ ❱ Ö P ❖ ❏✐❍❑✙❵❍ ❙ ❩ ❙ P ❙ ❊◗Ò ✛ ❱ Ö P■♦ ❙ ❱❳❲ ❑ ❙ ❍⑥Ò✟✙✩❱ ❜ ✍ ❱ Ö P ❍◆❍ ❚ ✄★Ñ✐❏ ❊ ❚✝❙✱❖ Ò✟♣❀❱ Ö ❱★❬ ✑ ❱ ❍ ❙ ❍◆❊ ❬ ❙ P❚P❪❋✽P❯❍ ❊♦❍ ❋ ❲ ❏ ● ❍ ❲ ❍■P ❫ ❍ ❱❪❲●❙❍◆❋ ❲ ❏ ● ❍ ❲ ❍ ❍ ❍ ❚ ♦❂❍◆❩ ❬✱❍❇P ❤ ❩ ❲ ❊ ❱ ❍◆❍▲❑ P ❙ ❱●❬ ✆✦❏❀❍ ■▲■ ❙ ❍◆❊ ❱ ❍r✓ ❱ ❩❭❬ ❊ ❙ ❲✂❙ ☞ ■▲■ P ❱❳❙❯❚ ✢✙❍ ❲ ❋ ❙✱● ❍ ❲✂❱ ❬ ❩♠P✍r★s❉s●➆▲❱✽ ➣➋✿q☞ P❚P❳❏✐❋ ❬❫❋ ❙ Ò❢❽ ❙ ❍◆❍ ❜ ♦ ❍◆❋▲P Ö ❍◆❍ ❚ ❽✐❏❨❋❨❍■❩✂❏ ❍⑥Ò ✆✦❏ ●♠Ö ❱■❬ ✛ ❱ ❍ ❱❳❲✂❙ ❍ ❋ ❲ ❏ ● ❍ ❲ ❍✭❍◆❍ ❚ ● ❏✐❊ ■ ❋ ❱ ❩ ● ❩ ❱ ❍ ❍ ❩✂❩ ❱ ❩ ❲✂❙❯❚❭● ❋■❩ ❱ ❬❥❍❇P■❬ ❏ ●❭■ ❏ ❜❩ ❱❳❲●❱ ❏ ❍ ❱❧❬ ♦✦❊ ❙✱■ ❊ ❱ ❍ ❲ P❙r★s❉s●➆▲❱✽ Õ ✿✳✘ ❏✐❤✽❋❉❍ ● Ò ☞ P❣❍ ❍ Ö ❱❧❬ ✠✞❍ ❱ ▼ ❏ ❊ ● ❲ ❍❇❑q❩ ❙❯❵ ❋ ❙ ❍ ❬ ❙ ❩❲❱✼❶❷❣★❜✶❫ ❴■❦ ❣❺❜⑦❞✶❡✄❣❧❤✝♦✔✟★➀✄❜✒❴■❦✧➀✛❭✼❫ ❴✏❵❖❛✕✟◆P ❖ ❏ P ❱ ❻ P ❍✝q s❨P✍r★s✏✌✍✎■P ■▲■ ❱ ❥★❻◆Õ ❬ ❥❯❧ s▲❱✽ ♥ ✿✧❽✐❏ ❋■❍■❩●❏✐❍⑥Ò ✆✦❏ ●♠Ö ❱★❬ ❾✘❵❧❛❋❦④♥❼❤ ❣★➀✎①☎❵❖❛⑩♦✝❜✴❛❋❞⑤♣❩③✡✠❪♥✝❣❧❛✏❜ ❴❝❜ ❱❖❬ ✕ ❚✝❱❳❲✂❱ ❏✐❍■❩✣Ô ♥ P★Ô ♥ P✝❊✂❋ ❙✎❚✝❙ P❣❍q✖✞❏ ❵ ❋ ❙ ❲●❲✂❙ Ô ♥●➅■❥✐❥ ♦✯❍ ❊ ❱ ❩❯P✓r☎s●s❖t❝❱✽ ❻ ✿✳✑ ❏ ❲ ❋❉❍ ❱ ❊ ❙ Ò✟✢✷❱ Ö ❱⑨❬✆✐❥❵❧❦ ➄■❞⑤♣✍❣❺❜ ❵❧❛❋❞❢❡❝➀ ❵❖♣ ✗ ❵❖❛✏➁★➀✱❱✓❬☛☞ ❚■❚✝❱ ❩●❏✐❍ ❜✴⑥✔❙ ❩❫P ❙ ◗✝P✎r☎s●⑧✏✣■P☞☛❥♣✓❡✕✟❉❡■❤❸❵❝♠ ❴✏➁❖❞✶❣✱❵✴①❅❶❷❣★❜✶❫ ❴■❦ ❣❺❜⑦❞❢❡❝➀❀❣❖♣✍➁

❞ ❜✶➀❪✈ ♠❉♠✍❤ ❞❢❡✏❣★❜✴❞❢❵❖♣ ➀ P ❖ ❏❨P ❱ ❥ Ô✽❱✽➪Ô➋✿ ⑥✸❱ P❚P❳❩✂❏✐❍✂Ò✟✄✐❱ Ö ❱✘❬ ✘ ❙ P❘P❳❋▲P❣❍ ❊❙❍◆❋ ❲ ❏ ● ❍ ❲ ❍ ❬✱❍◆❍ ❑ ❙ ❍ ❙ ❊❛❍ ❲●❙ ▼ ❊✻❍✐❬ ❲ ❍❇P❳❩❲❱ ✱✇❞ ➀☎❡❋❛✏❴✏❜✒❴✛✈✷♠●♠✍❤ ❞❢❴✏➁ ❶ ❣❺❜❢❫✝❴❋❦✛❣★❜✴❞❢❡❝➀ P ❖ ❏ P ❱❙❹❨P✔r☎s●⑧❖t P

■▲■ ❱ ❧❨❥ ❬ ❧✐❧ ❱

❥ s

Page 22: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✞ ✍✕✟☛✄✪✄✎✁☎✏ � ✄✓✄ ✁✁�✎✖ ✁☎✏☎✄ ✆✠✟☎✆✒✍✕✄✡�✄✂☎✂☛☎✑✍✕✔✗✁✒✆✓✍✕✟☛✏ ✖✆❦✫★✩✬✯ ✽❀✖ ✱➼✱✺✯✞✝ ✖ ✥❳✱ ✼ ✩ ✼�➊❙✪❃❖❫❏❉◆❑✿❄✺❃❖❇▼⑩✮●★❋❞❒❮❃❖❑❈❉◆❙❊➍◆❉❏q❊❝✐❇❳❚❛⑦❖⑩

❨❣❲❳❇❈●❏❧✜❉◆❑♠♥❛✈❊q✰♥P♣❏♣✍✘✙ ❄▼■❊❘⑥❘✍❚★❑❈⑩⑥❧✪⑩q❴☎❚✵❙✪❃✠✟❉❳⑦❖❉ ✂➬❚✵❑✿❨✪⑩✉✚

✾❀✿❂❁✱❃❅❄❇❆❉❈❊❃☞❂✖ ❱ ❏✐❊ ❚ ❍◆❍ ❍ ❊✂❊✻❍❅◗ ❱ ❩❙❍ ❚ ❏ ❋■❤▲P❚◗ ❱ ❍ ❚✝❙ ♠ ❙❯❚ ❩ ❙❯❵ ❋ ❙ ❍ ❬ ❙ ❏❊▼✒❬ ❏ ❙❾✻ ❬ ❱❳❙ ❍ ❲ ❩ ❏❇▼ ❍ ❤ ❱❚❖ ❍◆❊ ❱ ❍ ❲✂❙ ❑ ❙ ❍ ❙ ❊❛❍ ❲✂❱ ❍▲❑▼ ❋■❍ ❬ ❲●❱ ❏✐❍ ❱ ✆✹❋ ❱ ❩ ❲ ❍❊P⑨Ñ ■ ❊ ❙ ❩ ❙ ❍ ❲ ❩✡❩●❏ ● ❙ ❏❇▼ ❲ ❋ ❙ ❱ ❊ ■ ❊✂❏ ■ ❙ ❊ ❲✂❱❳❙ ❩❯P ❲ ❋ ❙ ❍✣❩❫❋■❏◆Ð✞❩✹❋❨❏◆Ð ❲ ❋ ❙ ◗❑❬❥❍◆❍✣❤ ❙ ❋■❩ ❙ ▼ ❋▲P ❱ ❍❬ ❏ ● ❤ ❱ ❍❉❍ ❲ ❏ ❊ ❱ ❍❇P ■ ❊●❏✐❤▲P ❙✱● ❩❲❱

➻❯↔✍➔✌❑ ❉❹❇✍❊▼➐✣❄③➐❆❇✱❇✬➐✟✠❥❏❀❂❁❊❉☎❇❈❉◆❑③❘☛✡▲➦❅➢❏➫▼➯❏➨❩➧➎➨❩➫✿➫▼➨✝❆✍❶▲❚❏❄❆❃❖❙❭❇❈❑③●❽❨✪■❯❲❳❉P❨➅❑❈❉P❲❳❉◆❙❭❇❾⑦⑤⑩✮❇③●❸❨✪❉◆❙❊●❩❇❈❉♠❚⑥❲❳●❩❙❯❲❳❉◆❱❊❇❂❋ ❚✵❘✖❃❿⑦⑨❃❅❚★❑➊❃❖❙➎❲❳●❏❘✖❧✪❃❖❙❯❚★❇❈●❩❑▼❃❅❲◆❄◆➋

❃❖❇❂❃❅❄❣❚❦❨✪●❏■❊❧✪⑦❖⑩✍❃⑤❙❯❨✪❉❳➉❊❉P❨✂❄▼❉P➌❩■❊❉◆❙❯❲❳❉✆✜✍➈ ✽ ☛ ➌ ➋➋❖✢❧➋q ❀✌☞ ✣❭q✪❨✪❉✯❩❯❙❊❉P❨✮❋❍●❏❑▲❇▼❶❂●☎❋❍●❏❑❈❘✍❚❛⑦✬❄▼❉◆❑▼❃❖❉P❄P➈t➚✞☛③➶s❚★❙❯❨ ✭✰➚ ☛❈➶❞❧✪⑩➈ ✽ ☛ ➌ ❚ ✙ ☛ ✽ ✚ ✜✱➈t➚✞☛❈➶③➚✞☛★✭✷➚✞☛❈➶❈➶ ➌ ✣✉❧ ●❏❑ ✍

✽ ☛ ➌➈ ✽ ☛ ➌ ☛ ✽ ✘ ➌ ❚

➈t➚✞☛❈➶♥ ♠ ✘ ☛✍✭✰➚✞☛③➶ ➄➚✿♥★➶

✦✇❉☎■❯❄▼❉❹❇❈❁❊❉④❙❊●❩❇✿❚★❇▼❃❖●❏❙✂➚✐➈❘❧✮✭✷➶ ✺ ❚✢✜✱➈ ✽ ☛ ➌ ✣❭❪❵❤ ❢◗❃❖●❏❑✿❨❊❚✵❙➎❚★❑❈❑❳❚P⑩❸❃❺❄ ➔➸➫▼➢➋➔❊➲P➫❹❶▲❁❊❉◆❙✹➈ ✽ ☛ ✽ ✂❚➱✈♠❋➄●❏❑✦❚❛⑦❿⑦ ❖✣q❊❃✐❪➪❉❏❪❵❶➊❁❊❉◆❙✭✰➚▼✈✪➶❑✂❚➱✈❊❪✎④❂▼✵✿✸✞✰✞❂ ✶✦❃➝♥✘✽✑✏❏➓❭➲❙➈ ✽ ☛ ➌ ➳◆➨❏➩❍➦❺➳✽❯❖❆⑥➨✮➫▼➲✿➡✌❲❭➫❳➫▼➲P➧✜➡✿➲☎➫▼➲P➭❿➨❏➩❍➦➼➢❏➧

➈ ✽ ✑ Ï ☛ ➌ ✑ Ï ❚▲✦ ✻r➈ ✽ ☛ ➌ ➀✪✦ Ï ➈ ✽ ☛ ➌ ✑ Ï ➀➇➃✬➃❈➃❆➄➚✳r✪➶❀❂❁❊❉❀✦✾✧⑤✷❐❄▲❨✪❉✯❩❯❙❊❉♠❚⑥❄❾❉◆❑▼❃❖❉P❄✣✸➠➚✐❼✪➶❿❚✓✒ ✧ ✦✾✧⑩❼ ✧ ❚✵❙❯❨✮❇❈❁❊❉④❄▼❉◆❑❾❃⑤❉P❄ ✭✟❄③❚★❇▼❃❅❄❺❩❯❉P❄❂❇❈❁❊❉❹❉P➌❏■❯❚✵❇▼❃❖●❏❙ ✭✰➚✞☛③➶☎❚▲✸➠➚✞☛✍✭✰➚✞☛③➶❈➶✿❪❝❍❋✰❇❈❁❊❉▲❑❈❉P❲❳■❊❑③❑❈❉◆❙❯❲❳❉▲❑❈❉❳⑦❅❚★❇▼❃❖●❏❙➅➚✳r✪➶✰❁❊●★⑦❅❨❊❄✣❋❍●❏❑❞❄▼●❏❘⑥❉▲❄▼❉P➌❩■❊❉◆❙❯❲❳❉P➈ ✽ ☛ ➌ q★❇❈❁❊❉◆❙❦❇❈❁✪❃❅❄❵❄▼❉P➌❏■❊❉◆❙❯❲❳❉➊❃❅❄❞❚✦❱❊❑❈●❩❱❯❉◆❑❞❢◗❃❖●❏❑✿❨❊❚✵❙❚★❑❈❑❳❚P⑩❏q❆❶❂❃❖❇❈❁✦➈❊➚ ☛❈➶④❇❈❁❊❉✮❬❩❉◆❙❊❉◆❑✿❚★❇▼❃❖❙❊❬✂❋❍■❊❙❯❲❳❇▼❃❖●❏❙➂●✵❋❣❇❈❁❊❉✟❄▼❉P➌❩■❊❉◆❙❯❲❳❉ ✜✱➈ ✽ ☛ ✻■✣✘✺➒➈❊➚✞☛③➶✷❚ ✒ ✽ ➈ ✽ ☛ ✻✍☛ ✽ qs❚✵❙❯❨❈✭✰➚✞☛③➶④❇❈❁❊❉➚✐■❊❙✪❃❅➌❩■❊❉★➶❴❄▼●✵⑦⑤■❊❇❾❃⑤●❩❙✟●★❋❵❇❈❁❊❉☎❉P➌❩■❯❚★❇▼❃❖●❏❙ ✝ ❚▲✸➠➚✞☛✞✝❦➶✿❪✾❀✿❁✰✍✵✷❂✎✰✞❃ ♥✘✽✕✔✚➲P➩✺✑❮➚✐❼✪➶❿❚✖✒ ➌ ✑ ➌ ❼✠➌✘✗❞➩ ➓❭➲P➧✍

➌➈ ✽ ☛ ➌ ✑ ➌ ❚ ✙ ☛ ✽ ✚ ✜✱➈t➚✞☛❈➶✁✑✚➚ ☛★✭✰➚ ☛❈➶❈➶ ✣✛➄✙✛✚❄❀✷❃ ✸✂✲✝✰ ✽▲❀❂❁❊❉☎❧✪❃❖❙❊●❏❘❸❃❺❚☞⑦✕❙✪■❊❘✖❧❯❉◆❑✿❄✥❊ ✽ ➌ ❋☎❚★❑❈❉④❨✪❉✯❩❯❙❊❉P❨➅❧❭⑩❵➈t➚✞☛③➶❿❚✔✭✰➚✞☛③➶❿❚ ♥✍➉❏➚❳♥ ♠ ☛❈➶ ✺✜ ❖

q✣✢✖✤✦✥★✧✪✩✬✫✮✭✰✯✲✱ ✳✴ ✳✛✵ ✧✷✶ ✭✰✸✺✹✮✻ ✤✦✥★✧✼✩✽✯✲✾ ✧ ✭✴ ✳✿✵ ✧❀✶ ✭❁✸✺✹❃❂❅❄❆✛❇✲❈❊❉✬❈●❋✲❈●❍❁■❑❏▼▲◆❋✲❉P❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋✌❚✽❖✛❏✷❇✲❈❯■❲❱✷❱▼❚✲❙❀▲❳■❑❏✷❈❩❨✌❱▼❈❩❬✬◗✲❈●❋❃❙✰❈❪❭❴❫✬❵✪❛❜▲❳❱❝❱❞▲❢❡✑❣✁❤❢✐❦❥ ✴ ✧✷✶✕✤ ✳✛❧ ✧❁♠ ■❑❋❃❨♥❏❀❇✲❈♦❱♣❚✬q✼❙●■✘❤r❤◆❈❩❨st◗✁❤◆❈●❍✉❏✷❍❁■✽❋❃❱❞❖❘❚✬❍❀❡✈▲✇❱✉❨✁❈●❍▼▲◆①✬❈❩❨P❖②❍✷❚✬❡③❆✛❇✲❈●❚❲❍✷❈●❡ ✳✬④⑤ ✭ ✜✣⑥⑦ ✢✉⑧ ✭ ✤✦✥★✧ ✩ ✯✮✱ ✳✳✿✵ ✧ ⑧✌⑨ ✳✳✿✵ ✧✽⑩ ✻✑❄❶❁❷

Page 23: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☎✄✝✆✟✞✡✠☞☛ ❄✂✌✎✍ ✆✑✏✒☛ ✌✔✓✖✕✘✗ ✞ ✕✙✝✚✟✛✢✜✤✣✂✛✎✥✧✦✔★✪✩✬✫✢✭✯✮✱✰✳✲✴✭✶✵✝✷✸✵✺✹✼✻✾✽❀✿❂❁✼✵❄❃✧❅✼✭❆✻✔✭❆✵❇✹❈✲❊❉●❋❂✭❂✽❍✹✒✽⑤ ✭ ✜ ⑥ ❧ ❫ ⑦■ ❧ ❏ ⑦ ✢✉⑧ ✭ ✤✦✥★✧ ✩ ✯ ✾ ✧▲❑✴ ✳✛✵ ✧❀✶ ❑ ✸✺✹ ⑧ ✜ ✧❇▼ ✫❖◆✴ ✳✛✵ ✧✷✶ ▼ ✢ ❂ ✴ ❏◗P ❫ ✶❄❘✤✦✥★✧ ❑ ✯✎❙ ✴ ✳✛❧ ✧❀✶ ✩ ⑧❯❚ ✴ ✳☎❧ ✧✷✶ ◆ ✧ ✫ ▼❲❱✼❳ ✴ ❏◗❨❬❩ ✶ ❄❆✛❇✲❈●❚✬❍❀❈●❡❭✦ ■✽❣✲❣✁❤r▲◆❈❩❱✉❏✷❚ ❱▼◗✲❡✞❱☎▲◆❋✁①✬❚✽❤◆①❲▲❢❋✲❉❅❏❀❇✲❈❫❪ ■✽❏❁■✘❤✇■✽❋❅❋✁◗✲❡❫❴❃❈●❍❁❱◗❵ ✭ ✤ ❚✸❛ ✭✭ ❱✶❜ ✴ ⑦ ❧✖✳ ✶❞❝ ❖②❚✬❍✛❈❄❡✣■✽❡✑❣✁❤❢❈⑤ ✭ ✜❦⑥ ❧ ⑦■ ❧ ✦ ⑦ ✢ ✴ ✵❝✳ ✶ ✭ ❵ ✭ ✤ ✜ ⑥ ✵ ✳■ ✵ ✳ ✢ ❄❢✼❏❝❨✁❚✁❈❩❱✉❋✲❚✬❏ ■❑❣✲❣✁❤❢✐✌❨❲▲◆❍✷❈❩❙✰❏▼❤◆✐✌❏✷❚❤❣✬❏♣▲❢❍♣❤ ▲◆❋✲❉❅❋✁◗✲❡❫❴❃❈●❍❁❱✉❚✽❖ ❏❀❇✲❈❥✐❃❍❁❱▼❏❝■✽❋❃❨✌❱▼❈❩❙✰❚✬❋❃❨❧❦❲▲◆❋❃❨♥♠ ✩ ✭ ♦ ■✽❋❃❨ ❙ ✩ ✭ ❳ ❝ ❇✲❚✒♣✛❈●①✬❈●❍❏✷❇✲❈ ❱✪▲◆❡ ❣✁❤◆❈❜▲✇❨✁❈●❋ ❏♣▲❢❏♣▲❢❈❩❱ ⑤ ✩

⑦ q⑥ qsr ⑥ ⑦✎t ✧✼✩✑✤ ❤◆❚✬❉ ✭ ✳✳✕✵ ✧ ❝ ⑤ ✩⑦ q⑥ q ✱ ⑥ ⑦ ✻ ✧✼✩ ✤ ✴❇✉❂✈ ✵ ✳ ✶▼✭■✘❤r❤◆❚✒♣ ◗❃❱✿❏❀❚❯◗❃❱♣❈❯■❊❡ ❚✲❨❲▲✴✐❃❈❩❨P❖②❚✬❍✷❡③❚❑❖ ▲◆❏✶✇❞❒✣❚✬❍✛❈❄❡✣■❑❡ ❣✁❤◆❈ ♠ ❆✛❇✲❈●❚❲❍✷❈●❡❭✦ ■✘❖②❏✷❈●❍✿❱▼❚✬❡✑❈ ■✘❤◆❉✬❈❂❴✲❍❁■❊❉✽▲◆①✬❈❩❱⑤ ✭ ✱ ■ ⑦ ✻ r

⑦ ❧ ✳① t ✴ ✵❝✳ ✶ ✭●✫✒②●✸✺✹⑦ ❧✖✳ ✤ ✳■ ❧ ✳ ✜ ■ ❧ ✳① ✢❍③ ❑ ✫✒② ✸✺✹ ❘♣✿❇✲❈●❍✷❈ ③ ✩ ▲❳❱✕■⑤④☎❈●❍✷❋✲❚✬◗✁❤r❤r▲ ❋ ◗✲❡❫❴❃❈●❍❆✇➷ ✁⑤⑥ ❄⑧⑦✑⑨ ✏ ✕ ☛●✆ ❄❶⑩ ✆✑✏❈✞ ✗✬✓❀❷❆✛❇✲❈◗❸✑✵✺❁✶❹✼✰✳❺✶✷✛❚❑❖ ❏✺♣ ❚❫❻☎▲◆❚✬❍❁❨✲■✽❋♥■❑❍✷❍❁■✘✐✮❱❽❼ ✤ ✴✺❾✲✴ ✧❀✶❞❘❞❿ ✴ ✧✷✶❀✶ ✤ ❭ ❾ ✩❈➀ ✭ ❛ ■✽❋❃❨☎➁ ✤ ✴ ⑧ ✴ ✧✷✶❞❘➃➂ ✴ ✧✷✶✷✶ ✤ ❭ ⑧ ✩✼➀ ✭ ❛✉▲✇❱✛❏✷❇✲❈❨✁❚✬◗✎❴✁❤◆❈❯❱♣❈❩❬✬◗✲❈●❋❃❙✰❈P❭ ➂ ✩✼➀ ✭ ✤➅➄➇➆ ❾ ✩✼➀ ➆ ⑧ ➆ ➀ ✭ ❛✢✇➈➉✣❖✜➋➊✎✛✎✣➍➌✂➎♥✦✔★✪✩✬✫✢✭◗❸✑✵✺❁❆❹✼✰✢❺❆✷s❁✺✿❫✷✸➏✤❁❯➐➑❉❀❁✼✵✺❹✼✹❈✻✡✹❈✵❞✵✺✹✼➒❆✽✝❉●✽✝✹❯➐➓❉➔❁✼✵✺❹✼✹✼✻→✹✼✵❄✵✺✹✼➒✼➣

❼↕↔✶➁ ✤ ✴❇❾✣✴ ✧❀✶ ⑧ ✴ ✧❇❿ ✴ ✧✷✶✷✶❄❘❞❿ ✴ ✧✷✶✸➂ ✴ ✧❇❿ ✴ ✧✷✶❀✶✷✶ ❄❆✛❇✲❈✉▲✇❨✁❈●❋✁❏▼▲◆❏❞✐❅❈✰❤◆❈●❡ ❈●❋✁❏✕▲❳❱◗➙ ✤ ✴ ✳ ❘ ✳ ✶ ✇➈➉✣❖✜➋➊✎✛✎✣➍➌✂➎♥➛✔★✖➜➝❸✑✵✺❁❄❸✎✭✶✵✤➐➑❉➔❁✼✵✺❹✼✹✼✻⑤✹❈✵❞✵✺✹✼➒✖❼ ✤ ✴✺❾✲✴ ✧❀✶❞❘❞❿ ✴ ✧✷✶❀✶ ✫✢✹✒✽s✹✼✻✪❉❀✻⑧➞✶✭✶✵➟✽❂✭ ❾ ✫❃✹ ✤ ❭s➠❾ ✩❈➀ ✭ ❛ ✤ ✴ ➠❾✁✴ ✧✷✶❞❘ ➠❿ ✴ ✧✷✶✷✶❂➡➢ ❱✿■ ❙✰❚✬❋❃❱▼❈❩❬❲◗✲❈●❋❃❙✰❈ ♠ ♣ ❈❝❚❈❴✲❏❁■✘▲◆❋♥■✽❋❅▲◆❋✁①✬❈●❍❁❱✪▲◆❚✬❋❪❖❘❚❲❍✷❡❊◗✁❤❳■ ❖②❚✬❍ ❱▼◗✲❡P❱ ④⑤ ✭ ❾ ✩❈➀ ✭ ⑧ ✭ ✤➤➂ ✩❫➥❫➦ ⑤ ✭ ➠❾ ✩✼➀ ✭ ➂ ✭ ✤ ⑧ ✩ ❄❣✬◗❃❙❀❇✌❖❘❚❲❍✷❡❊◗✁❤●➧ ❨✲■❑❏✷❈❫❴❃■✬❙➨❦✌■✑❤◆❚✬❋✲❉♥❏▼▲◆❡ ❈ ❝ ❱▼❈●❈❊❖②❚✬❍❝❈❄❡❃■✽❡ ❣✁❤◆❈➩❻☎▲◆❚✬❍❁❨✲■❑❋✬➫ ❱❥❴✺❚ ❚✼❦ ✥➯➭✽✯ ✇❜❆✛❇✲❈❊▲◆❋ ①❲❈●❍❁❱✪▲◆❚✬❋✌❖②❚✬❍✷❡❊◗✁❤❀➧▲◆❋✌❏✷❇✁▲✇❱➑❴✺❚ ❚✼❦☎♣✛❈●❍✷❈❜❍✷❈❩❙✰❈●❋✁❏▼❤◆✐❅❍✷❈●①✬▲✇❱✪▲◆❏✷❈❩❨➲❴ ✐❧❣✬❣✲❍✷◗✲❉✬❋✲❚✽❤r▲ ✥ ✳❲✳ ✯✪♠ ♣✿❇✲❚P❣✲❍✷❚✽①✬❈❩❨P❏✷❇✲❈●❡☛■✽❉ ■✘▲◆❋♥◗❃❱❞▲❢❋✲❉❅❏❀❇✲❈ ❏✷❇✲❈●❚✬❍❀✐✞❚✽❖❻☎▲◆❚✬❍❁❨✲■❑❋✄■✽❍✷❍✰■❩✐✲❱ ❝ ❱▼❈●❈❯■✘❤✇❱▼❚ ✥ ✳ ❩ ✯ ✇ ❶➨➳

Page 24: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✃ ✁❯✄✝✆ ✓ ✆ ✗ ✏ ⑨✁�✄✂ ✌✔✓✆☎✬✕✝❦❈❝❙✰❚✬❋❃❱✪▲✇❨✁❈●❍✉❏✷❇✲❍✷❈●❈✉❏❞✐✁❣❃❈❩❱☎❚✽❖t❱▼❏✷❈●❣❃❱✛❚✬❋❅■❊❱✷❬❲◗❃■✽❍✷❈✕❤❳■❑❏✷❏▼▲✇❙✰❈ ④ ✞✕❚✬❍✷❏❀❇ ✴ ✞ ✶❁♠ s ■✬❱▼❏ ✴ s ✶ ■✽❋❃❨✟✞✕❚✬❍✷❏❀❇✲q✼s ■✬❱▼❏ ✴ ✞✉s ✶ ✇➢ ❋✄◗✲❋❃❨✁❈●❍✰❨❲▲❳■❑❉✬❚✬❋❃■✘❤s♣✿■✘❤ ❦❅▲✇❱✉❈●❋✁❏▼▲◆❍✷❈✰❤◆✐→❴❃❈✰❤◆❚✒♣✈❚✬❍✉❚✬❋✌❏✷❇✲❈❊❡✞■✘▲◆❋❦❨❲▲✇■✽❉✬❚✬❋❃■✘❤✡✠ ✤☞☛ ✇ ➢ ➏✤✭❄✹✍✌➍✲✴➒❯✰✢✻⑧❹✼✭✶✵✺❹✼❉➔✹✶❅✼❁❈✻✔✹✼✲➏✤✹✼✲✎✌❜▲❳❱✛■➉♣✿■✘❤ ❦ ❱▼◗❃❙❀❇✞❏✷❇❃■❑❏ ▲❢❏✰❱ ✐❃❋❃■✘❤ ❣❃❚✽▲◆❋✁❏ ▲✇❱☎❚✬❋ ❚❲❍✤❴❃❈✰❤◆❚✒♣✓❏❀❇✲❈ ❨❲▲✇■✽❉✬❚✬❋❃■✘❤▲✇✡✏ ❈●❏ ① ✩❈➀ ✭ ■✽❋❃❨✒✑ ✩❈➀ ✭ ❴✺❈✿❍✷❈❩❱▼❣✺❈❩❙✰❏▼▲◆①✬❈✰❤◆✐❏✷❇✲❈❊❋✁◗✲❡ ❴✺❈●❍❝❚✽❖ ◗✲❋❃❨✁❈●❍✰❨❲▲❳■❑❉✬❚✬❋❃■✘❤s♣✿■✘❤ ❦✲❱ ■✽❋❃❨ ❏✷❇✲❈❊❋✁◗✲❡❫❴❃❈●❍ ❚❑❖s♣ ❈❩■✘❦✬❤◆✐♥◗✲❋❃❨✁❈●❍✰❨❲▲❳■❑❉✬❚✬❋❃■✘❤s♣✿■✘❤ ❦✲❱ ♠ ♣✛▲◆❏✷❇ ⑥ ❱♣❏✷❈●❣❃❱■✽❋❃❨❊❈●❋❃❨❲▲◆❋✲❉✞■❑❏ ■ ❨❲▲✇❱▼❏❁■✽❋❃❙✰❈ ⑦ ❖②❍✷❚✬❡ ❏✷❇✲❈✉❨❲▲❳■❑❉✬❚✬❋❃■✘❤ ❝ ❏✷❇✲❈ ❨❲▲✇❱▼❏❁■❑❋❃❙✰❈ ⑦ ❙●■❑❋⑤❴❃❈✉❈✰▲◆❏✷❇✲❈●❍✿■✘❤◆❚✬❋✲❉ ❏✷❇✲❈✓✠✲q✼■❆❡✁▲✇❱t❚✬❍✛■✘❤◆❚✬❋✲❉❏✷❇✲❈ ☛ q✼■❆❡✁▲❳❱ ✇❢②❖✿❏✷❇✲❈●❍❀❈❊▲✇❱❝❚✬❋✁❤◆✐✌❚✬❋✲❈⑤❦❲▲◆❋❃❨❦❚✽❖✿❱▼❏✷❈●❣❦❚❑❖ ❈❩■✬❙❀❇❦❏▼✐ ❣✺❈ ♠ ❏✷❇✲❈●❋➝♣ ❈❊❇❃■✘①✬❈✞■✟✔ ❚✬❏✖✕❂❦✬▲◆❋❶♣✿■✘❤ ❦ ♠ ❙✰❚✬❍✷❍❀❈❩❱▼❣❃❚✬❋❃❨❲▲◆❋✲❉✌❏✷❚✔ ❚✬❏✗✕❂❦❲▲◆❋ ♣✛❚✬❍✰❨✲❱❂✇ ➢ ❉✬❈●❋✲❈●❍✰■✘❤r▲✘✕❩■❑❏▼▲◆❚✬❋✞■✘❤r❤◆❚✒♣ ❱ ❖②❚✬❍t❨❲▲✚✙ ❈●❍❀❈●❋ ❏✤❦❲▲◆❋❃❨✲❱ ❚✽❖❃❇✲❚✬❍▼▲✛✕●❚✬❋✁❏❁■✘❤ ✴ s ✶✰♠ ①✬❈●❍❀❏▼▲✇❙●■✘❤ ✴ ✞ ✶ ❚❲❍ ❨❲▲✇■✽❉✬❚❲❋❃■✘❤✴ ✞✉s ✶ ❱♣❏✷❈●❣❃❱ ✥✚✜❩✯ ✇✡✏ ❈●❏❝❫ ♠ ❏ ■❑❋❃❨✟✢➉❴❃❈❊❏✷❇✲❈❝❋✁◗✲❡ ❴✺❈●❍ ❚❑❖ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏ ❱▼❏❀❈●❣❃❱☎▲◆❋♥❏✷❇✲❈❊s ■✬❱▼❏ ♠ ✞✕❚✬❍✷❏❀❇✲q✼s ■✬❱▼❏✉■✽❋❃❨✟✞✿❚❲❍✷❏✷❇❨❲▲◆❍✷❈❩❙✰❏▼▲◆❚✬❋❃❱ ❝ ❏✷❇✲❈●❋❧♣ ❈❝❇❃■✘①✬❈✉❏✷❇✲❈ ❖❘❚✽❤r❤◆❚✒♣✛▲◆❋✲❉✞❍❀❈❩❱▼◗✁❤◆❏✶✇✙✝✚✟✛✢✜✤✣✂✛✎✥✧➛✔★✪✩✬✫✢✭✑❭ ① ✩❈➀ ✭ ❛❶✹✼✻⑧❹ ❭✣✑ ✩✼➀ ✭ ❛→✹✼✵✺✭❯➐➓❉➔❁✼✵✺❹✼✹✼✻➤✹❈✵❞✵✺✹✼➒❆✽⑤✽❂✰✢❺ ✫❶✷➔✫✢✹✼✷❥✷➔✫✢✭☎✹✒✽❄✽❂❁✶❺✶❉➔✹✼✷✸✭❄❹✞❥ ✿❂✰✳✻✔❺✶✷✸❉➔❁✼✻ ❉ ✽❥ ✴ ✧✷✶t✤ ❫ ❧ ❏ ✧ ❧ ✢ ✧ ❛✥✤ ✹✼✻✔❹ ✤ ➏✤❉➔✷➔✫✧✦ ✤ ✳✿✵ ✦ ❏ ✧ ❧ ✴ ❏ ❛ ✵ ★ ❫✩✢ ✶✼✧ ❛✥✤❭ ① ✩✼➀ ✭ ❛ ✤ ✪ ✳✿✵ ❏ ✧ ✵✬✫ ✦✦✬❫✭✢ ✧ ❛ ❘ ✳✕✵ ❏ ✧ ✵✮✫ ✦✦✯✢ ✧ ❛ ✢ ❝❭✣✑ ✩❈➀ ✭ ❛ ✤ ✪ ✳✫ ✦ ❘ ✳✕✵ ❏ ✧ ✵ ✫ ✦✦✯✢ ✧ ❛ ✢ ❄✰✲✱ ✞ ✞ ⑨✳✍ ✏➍☛✆✳ ✂❫✌✔✓✆☎✬✕ ✁ ✝✖❇✲❈●❋ ❏✷❇✲❈●❍✷❈☎▲✇❱ ❏✷❇✲❈✿❱✷■✽❡ ❈✛❋✁◗✲❡❫❴❃❈●❍t❚✽❖ ❙✰❚✽❤◆❚✬◗✲❍❁❱ ❖②❚✬❍ s☎■✬❱▼❏t■✽❋❃❨✴✞✿❚❲❍✷❏✷❇ ❱▼❏✷❈●❣❃❱ ✴ ❫ ✤ ✢ ✶❁♠❏✷❇✲❈●❋ ▲◆❏ ▲✇❱P❣✺❚ ❱✷❱✪▲ ❴✁❤◆❈❦❏✷❚ ❨✁❈●❍♣▲❢①❲❈ ❱♣❚✬❡ ❈❅▲◆❋✁❏✷❈●❍✷❈❩❱▼❏♣▲❢❋✲❉ ▲✇❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱❂✇➝❒✲❚✬❍P❈❄❡❃■✽❡ ❣✁❤◆❈ ♠ ❤◆❈●❏ ❭ ⑧ ✭ ❛→❴❃❈✌❏✷❇✲❈♥❣✺❈●❍▼▲◆❚✮❨❲▲✇❙❱▼❈❩❬❲◗✲❈●❋❃❙✰❈❝❭ ✳ ❘ ❩ ❘ ✵❝✳ ❘ ❩ ❘ ✳ ❘ ❩ ❘ ✵❝✳ ❘ ❄●❄❩❄ ❛ ❝ ❏✷❇✲❈●❋ ➄ ✭ ① ✩❈➀ ✭ ⑧ ✭ ✤ ❏ ✩ ✇ ❆ ❇✲❈ ■❴❤❢❉❲❈❂❴✲❍❁■✘▲✇❙✛❣✲❍✷❚✁❚✽❖ ❚❑❖ ❏✷❇✁▲✇❱ ❈❩❬❲◗❃■✘❤r▲❢❏▼✐❜▲✇❱t❈❩■✬❱♣✐ ❝❏✷❇✲❈●❍✷❈❅■✘❤✇❱▼❚✌❈❄❡✁▲❳❱♣❏❁❱ ■♥❙✰❚❲❡ ❴✁▲◆❋❃■✽❏❀❚✬❍▼▲✇■✘❤✛▲◆❋ ❏✷❈●❍❀❣✲❍✷❈●❏❁■✽❏▼▲◆❚✬❋ ④ ❆✛❇✲❈●❍✷❈✑▲✇❱ ■❧❴✁▲ ✵▼❈❩❙✰❏▼▲◆❚✬❋➤❴✺❈●❏❇♣✛❈●❈●❋ ❏✷❇✲❈❅◗✲❋❃❨✁❈●❍❁❨❲▲✇■✽❉✬❚❲❋❃■✘❤♣✿■✘❤ ❦✮❱ ❈●❋❃❨❲▲❢❋✲❉❅■✽❏✿❨❲▲✇❱▼❏❁■✽❋❃❙✰❈ ⑦ ♠ ♣✿❇✲❚ ❱▼❈✕❤✇■✬❱▼❏✿❋✲❚✬❋✲q✶✞✉s ❱♣❏✷❈●❣P▲✇❱✷✞ ♠ ■✽❋❃❨P❏✷❇✲❈❥♣✿■✘❤ ❦✮❱☎❈●❋❃❨❲▲◆❋✲❉❅■✽❏✿■ ❨❲▲✇❱▼❏❁■✽❋❃❙✰❈ ⑦ ❧ ✦♣✿❇✲❚ ❱♣❈✉❤❳■❲❱▼❏✿❋✲❚✬❋✲q✶✞✉s✖❱▼❏✷❈●❣P▲✇❱ s◗✇❰ ✁✹✸ ✕✺✱ ✞✼✻ ✍ ✆ ✍ ☛✆✳ ✕❫⑩ ✆✑✏✽✳✒✆ ❄✔⑦ ✆ ✓✸✗✂✍ ☛ ✆ ❄ ✞ ✌✎✍ ✏✒☛✆✳ ⑨❖✕❆✛❇✲❈P❍✷❈✰❖②❈●❍✷❈●❋❃❙✰❈ ❖②❚✬❍❜❏✷❇✁▲✇❱❯❱♣❈❩❙✰❏▼▲◆❚✬❋❦▲✇❱ ✥✿✾✽✯ ✇❀✏ ❈●❏ ➁ ❴✺❈ ■❑❋ ■✽❋❃■✘❤◆✐✁❏▼▲✇❙✑❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋ ❱❂✇★❏❆✇❤➁ ✴ ❩ ✶❜✤ ✳ ♠ ■✽❋❃❨ ❨✁❈❄✐❃❋✲❈➁ ✩ ✴ ✠ ✶t✤ ✥✿❁ ✩ ✯ ❭➍➁ ✴ ❁✮✶✶❂ ❛✢✇ ❆✛❇✁▲✇❱☎▲✇❱✉■❜❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤ ❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❅❚❑❖ ❨✁❈●❉✬❍❀❈●❈ ⑥ ♠ ❱✷■✽❏▼▲✇❱✪❖②✐✬▲◆❋✲❉✞■❊❙✰❚✬❋✁①✬❚✽❤◆◗✲❏▼▲◆❚✬❋ ❣✲❍✷❚✬❣✺❈●❍✷❏▼✐ ④➁ ✩ ✴ ✠ ❧ ☛✣✶t✤ ✩⑤✭✥❃✁❄ ➁ ✩✬✫✲✭ ✴ ✠ ✶ ➁ ✭ ✴ ☛✣✶ ❄❆✛❇✲❈ ⑧ ✩❈➀ ✭ ✤ ✥ ✠ ✭ ✯ ❭ ⑥ q ➁ ✩ ✴ ✠ ✶ ❛ ✤ ✥ ✠ ✭ ❁ ✩ ✯ ❭ ⑥ q ➁ ✴ ❁✁✶ ❂ ❛ ❨✁❈❄✐❃❋✲❈ ■✽❋ ▲◆❋✳✐❃❋✁▲❢❏❀❈➅❺❄❁✼✻✔➞❆❁✼✲✴✰✢✷✸❉➔❁✼✻ ❃❫✹✼✷✸✵❞❉❆❅ ✥ ✳ ♠✷❇✽✯ ✇❈✏ ❈●❏❾ ✩✼➀ ✭ ④ ✤ ✭✺❉✩❊❉ ⑧ ✩✼➀ ✭ ❝ ❏✷❇✲❈●❋ ❾ ✩❈➀ ✭ ✤ ⑤ ⑦ q⑦ ✹ q ⑦ ❛ q ⑦❊❋ q ↔❆↔✶↔ ⑨ ⑧ ✹✳ q ⑩ ✭✥● ⑨ ⑧ ❛✦ q ⑩ ✭✗❍ ⑨ ⑧

❋➛ q ⑩ ✭✖■ ❄❩❄❩❄ ❘♣✿❇✁▲✇❙❀❇ ❱♣❇✲❚➍♣✉❱❊❏✷❇❃■✽❏❅❭ ❾ ✩❈➀ ✭ ❛❅▲✇❱❅■❶❻ ▲❢❚❲❍❁❨✲■✽❋ ■✽❍✷❍❁■✘✐ ④ ❭ ❾ ✩❈➀ ✭ ❛ ✤ ✴ ✳ ❘ ✴ ❤◆❋➑➁ ✴ ❁✁✶✷✶ ❜ ❁✁✶ ✇ ❢✼❋ ❚✬❏✷❇✲❈●❍P❏✷❈●❍✷❡✞❱ ♠ ⑧ ✩✼➀ ✭ ✤✴ ⑥ q ❜ ⑦ q ✶❁✥✿❁ ✩ ✯❖❙ ✴ ❤◆❋❥➁ ✴ ❁✁✶✷✶ ✭ ❳ ✇❏✬❁✼✵❯✹✒❑▲❅➍✭❄❹ ✵✺✹✼✷✸❉➔❁ ① ✤ ⑥ ❜ ⑦ ♠ ♣ ❈❅❇❃■✘①✬❈♥■❑❋ ■✬❱▼✐✁❡ ❣✲❏✷❚✬❏▼▲✇❙P❈❩❬❲◗✁▲◆①❴■✘❤◆❈●❋✁❏❅❚✽❖ ❾ ✩✼➀ ✭ ♠ ❚✬❍ ❈❩❬❲◗✁▲❢①✽■✘❤◆❈●❋ ❏♣❤❢✐✖❚✽❖ ⑧ ✩❈➀ ✭ ④▼✉❈❄✐❃❋✲❈ ■ ✤ ⑥ ✵ ⑦ ■✽❋❃❨ ◆

② ✴ ❁✁✶t✤ ⑨ ❤◆❋❍➁ ✴ ❁✁✶❁ ⑩ ✹✶❖◗P ②✘✫❃✹✶❘ ✤ ⑨ ❤◆❋❥➁ ✴ ❁✁✶❁ ⑩❀❙❚ ❝❏✷❇✲❈●❋ ❾ ✩❈➀ ✭ ✤ ✥✿❁ ❑ ✯ ❭ ◆ ② ✴ ❁✮✶ ❑ ❛✢✇ ➢ ❱ ❤❢❚❲❋✲❉ ■❲❱ ① ▲✇❱✯✐✎❡✲❈❩❨ ♠ ♣✛❈✞❙●■✽❋ ❨✁❈❄✐❃❋✲❈❤❵ ✴❱❯ ✶❝✤ ➄ ❑ ✥✿❁ ❑ ✯ ❭ ◆ ② ✴ ❁✮✶ ❑ ❛ ❯ ❑ ✇ ➢❖②❚✬❍✷❡ ❚✽❖ ❏✷❇✲❈❜❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ❵ ✴❱❯ ✶ ❙●■✽❋→❴❃❈✞❙✰❚❲❡ ❣✲◗✲❏✷❈❩❨✌■✬❱✕❖②❚✽❤r❤❢❚✒♣ ❱ ✇ ❆✛❇✲❈●❍✷❈❊❈❄❡✁▲❳❱♣❏❁❱ ■✑◗✲❋✁▲✇❬✬◗✲❈❅■✽❋❃■✘❤◆✐✁❏▼▲✇❙●■✘❤t❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋❶❳❲

Page 25: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✴ ❁✁✶ ❱❂✇ ❏✶✇ � ✴ ❩ ✶ ✤ ❩ ■❑❋❃❨ � ✴ ❁✁✶ ✤☞❁◆② ✴ � ✴ ❁✮✶✷✶ ✇ ▼✉❈❄✐❃❋✲❈♦■❯❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋✂✁↕❴✁✐✄✁✆☎ ✴❱❯ ✶ ✤ ✳ ❜

◆② ✴❱❯ ✶❞❝ ❏❀❇✲❈●❋ ♠ ❴✁✐❅❏✷❇✲❈✏ ■✽❉❲❍❁■✽❋✲❉✬❈❥❢✪❋ ①✬❈●❍✰❱✪▲◆❚✬❋➎❒✣❚✬❍✷❡❊◗✁❤✇■ ♠✥✿❁✽✩❲✯ ❭✝✁ ✴ � ✴ ❁✮✶✷✶ ❛ ✤ ✳⑥ ✥ ❯ ✩✬✫✺✹✼✯ ✞ ✁ ☎ ✴ ❁✁✶ ◆ ② ✴❱❯ ✶✼✩✠✟P✤ ✳⑥ ✥ ❯ ✩❲✫❃✹②✯ ❙ ◆ ② ✴❱❯ ✶✼✩❲✫❃✹ ❳ ❄➢ ❣✲❣✁❤❢✐❲▲◆❋✲❉❅❏✷❇✁▲✇❱✛❖②❚✬❍✷❡❊◗✁❤✇■ ❴❃■✬❙➟❦✢♣✿■✽❍❁❨✲❱ ❏✷❚ ✥✿❁ ❑ ✯ ❭ ◆ ② ✴ ❁✁✶ ❑ ❛ ❉✽▲◆①✬❈❩❱❾ ✩❈➀ ✭ ✤ ✥ ❯ ❑ ✯ ❭➍❵ ✴◗❯ ✶ ❛ ♣✛▲◆❏✷❇ ❵ ✴❱❯ ✶t✤ ❯ � ☎ ✴❱❯ ✶� ✴◗❯ ✶ ✤ ✳✳✿✵ ❯ ◆ ☎② ✴ � ✴❱❯ ✶✷✶ ❄✝✖❇✲❈●❋❅❏✷❇✲❈❝❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ◆

② ▲✇❱✖♣✛❈✰❤r❤◆q✸❴❃❈●❇❃■✘①✬❈❩❨ ♠ ■✽❋♥■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✕❈❩❬✬◗✁▲◆①❴■❴❤❢❈●❋✁❏❝❚✽❖ ❾ ✩❈➀ ✭ ❙●■❑❋❤❴❃❈❝❚❈❴✲❏❁■✘▲◆❋✲❈❩❨☎❴✁✐ ❱❞▲❢❋✲❉❲◗✲q❤✇■✽❍▼▲◆❏▼✐✄■✽❋❃■❴❤❢✐✲❱✪▲✇❱❂✇✍❒✲❚✬❍✉❈❄❡✣■❑❡ ❣✁❤◆❈ ♠ ■❲❱✷❱▼◗✲❡ ❈❊❏✷❇❃■✽❏✉❏✷❇✲❈ ❍✰■✬❨❲▲◆◗❃❱❝❚✽❖✿❙✰❚✬❋ ①❲❈●❍✷❉✬❈●❋❃❙✰❈❊❚✽❖ � ✴ ❁✁✶ ▲✇❱ ✐❃❋✁▲❢❏❀❈ ♠ ■✽❋❃❨✌❏❀❇❃■✽❏ �❇❃■✬❱☎■❯❱❞▲❢❋✲❉❑❤❢❈ ❱❞▲❢❋✲❉❲◗✁❤❳■❑❍▼▲◆❏❞✐☛✡✉❚✬❋ ▲◆❏❁❱☎❙❀▲◆❍❁❙❀❤◆❈ ❚✽❖ ❙✰❚✬❋✁①✬❈●❍✷❉✬❈●❋❃❙✰❈ ♠ ❨✁❈❄✐❃❋✲❈❩❨❅■✬❱☎❏✷❇✲❈ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋✞❚✽❖t❱▼❡✞■✘❤r❤◆❈❩❱▼❏✛❡ ❚✲❨✁◗✁❤❢◗❃❱☎❚✽❖❏✷❇✲❈❜❈❩❬✬◗❃■✽❏♣▲❢❚❲❋ ❁◆ ☎② ✴ � ✴ ❁✁✶✷✶t✤ ✳ ✇ ✏ ❈●❏✌☞ ✤ � ✴ ✡ ✶❄❝ ■❲❱✍☞ ✤ ✡ ◆ ② ✴ ☞ ✶❁♠ ♣✛❈❝❉✬❈●❏✿❏✷❇❃■❑❏✌☞ ◆ ✎② ✴ ☞ ✶ ✤

◆② ✴ ☞ ✶ ✇✛❆✛❇✁▲✇❱✛❤◆❈❩■✬❨✲❱✐❃❋❃■✘❤r❤◆✐♥❏✷❚❊❏✷❇✲❈ ■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✕❖②❚✬❍✷❡❊◗✁❤✇■

❾ ✩❈➀ ✭✑✏◆ ☎② ✴ ☞ ✶✒ ✦ ◆ ② ✴ ☞ ✶ ◆ ☎ ☎② ✴ ☞ ✶

◆ ☎② ✴ ☞ ✶ ❑★ ❑ ✪ ✦ ■■ ✢ ❄✴ ➛ ✶❢②❖ ❨✁❈❩❱✪▲◆❍✷❈❩❨ ♠ ❏✷❇✁▲✇❱✛❈❩❬❲◗✁▲◆①❴■✘❤◆❈●❋✁❏ ❙●■✽❋☎❴❃❈❜❈❄❡✮❣❃■❑❋❃❨✁❈❩❨❅▲◆❋✁❏✷❚✞■✽❋♥■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✉❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋♥❏❀❚♦■❑❋ ✐P❚✬❍❁❨✁❈●❍✶✇✓✕✔✗✖✤✥➉➊✠✘✼✛✑★ ➢ ❱▼✐✁❡ ❣✲❏✷❚✬❏▼▲✇❙✑❈❩❱▼❏▼▲◆❡✞■✽❏❀❈❩❱❝❖②❚✬❍✪❣✬❏▼▲◆❍▼❤r▲❢❋✲❉ ❋✁◗✲❡ ❴✺❈●❍❁❱❊❚✽❖✉❏✷❇✲❈ ❱♣❈❩❙✰❚✬❋❃❨ ❦✬▲◆❋❃❨ ❇❃■✘①✬❈❯❴❃❈●❈●❋ ❚✼❴✲❏✰■✘▲◆❋✲❈❩❨❴✁✐♥❱▼❈●①✬❈●❍❁■✘❤t■✽◗✲❏✷❇✲❚✬❍❁❱ ✴ ❱▼❈●❈ ❖❘❚❲❍✿❈❄❡✣■❑❡ ❣✁❤◆❈ ✥ ✳ ✦ ✯ ❖②❚✬❍ ■P❱▼◗✲❍✷①✬❈●✐❅❚❑❖ ❍✷❈❩❱▼◗✁❤◆❏❁❱✉■✽❋❃❨❪❖❘❚✬❍✕◗✲❋✁▲ ❖②❚✬❍✷❡☛❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❃❱ ✶❞❝ ❱♣❚✬❡ ❈❈❩❱▼❏▼▲◆❡✞■❑❏✷❈❩❱❝❙●■✽❋❦■✘❤✇❱▼❚☎❴❃❈P❨✁❈●❍▼▲◆①✬❈❩❨ ❖②❍✷❚✬❡ ✴ ➛ ✶ ④ ❒✣❚✬❍ ⑧ ✩✼➀ ✭ ✤ ❙ ✩ ✭ ❳ ♠ ♣✛❈❊❇❃■❩①❲❈ ❾ ✩✼➀ ✭ ✤ ✴ ⑦ q ❜ ⑥ q ✶❂❙ ✩ ✭ ❳ ■✽❋❃❨

◆② ✴ ❁✁✶✿✤❿ ✴ ❁✁✶ ✹✶❖◗P ②✘✫❃✹✶❘ ♣✛▲◆❏✷❇ ❿ ✴ ❁✁✶✉✤ ✴❇✉✚✙ ✵✖✳ ✶ ❜ ❁ ✇❊❆✛❇✲❈ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ❨✁❈❄✐❃❋✁▲❢❋✲❉✂☞ ❱❞▲❢❡✑❣✁❤ ▲✴✐❃❈❩❱❜▲◆❋✁❏✷❚ ✉✜✛ ✤ ① ❜ ✴ ① ✵ ☞ ✶ ✇❯❆ ❇✲❈●❋◆

② ✴ ☞ ✶t✤ ✳ ❜ ✴ ① ✵ ☞ ✶ ✭✥❖ ❑ ♠◆ ☎② ✴ ☞ ✶t✤

◆② ✴ ☞ ✶ ❜ ☞✉■✽❋❃❨ ◆ ☎ ☎② ✴ ☞ ✶t✤

◆② ✴ ☞ ✶ ✴ ① ✴ ☞ ✵ ① ❧♥✳ ✶✷✶ ❜ ✴ ☞ ❛ ✴ ① ✵❅✳ ✶✷✶ ✇ ❆✛❇✲❈ ■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙❈❩❬❲◗✁▲❢①✽■✘❤◆❈●❋ ❏ ✴ ➛ ✶ ❉✽▲◆①✬❈❩❱ ■❴❖❘❏✷❈●❍✿❱▼❚❲❡ ❈ ❙✰❚✬❡ ❣✲◗✲❏❁■❑❏▼▲◆❚✬❋✱ ⑥ ⑦ ✻ ✏ ⑥ q⑦ q✣✢

◆② ✴ ☞ ✶✦✤☞ ❛◆ ☎ ☎② ✴ ☞ ✶ ✪ ✦ ⑥ ✵ ✦ ⑦⑥ ✵ ⑦ ✢ ⑨

◆② ✴ ☞ ✶★ ☞ ⑩ ❑

✏ ⑥ q⑦ q ✢ ⑦ ✴ ⑥ ✵ ⑦ ✶✦ ⑥ ✴ ⑦ ☞ ✵ ⑥ ❧ ⑦ ✶ ✪ ✦ ⑥ ✵ ✦ ⑦⑥ ✵ ⑦ ✢ ⑦ ✭✴ ★ ☞ ✶ ✩❲✫✮✭ ✴ ⑥ ✵ ☞ ⑦ ✶ ✭ ❄✞✕◗✲❡ ❈●❍▼▲✇❙●■✘❤✿❍✷❈❩❱▼◗✁❤◆❏❁❱ ❖②❚✬❍⑤❣✬❏▼▲◆❍▼❤r▲◆❋✲❉❦❋✁◗✲❡❫❴❃❈●❍❁❱❜❚✽❖✿❏✷❇✲❈✞❱♣❈❩❙✰❚✬❋❃❨❶❦❲▲◆❋❃❨ ■✽❍✷❈ ❏❀❇✲❈●❋ ❣✲❍✷❈❩❱♣❈●❋ ❏✷❈❩❨ ❖②❚✬❍ ❉✽▲◆①✬❈●❋ ⑥ ■❑❋❃❨ ⑦ ♠■✽❋❃❨ ❇✲❈●❋❃❙✰❈ ① ❝ ❏✷❇✲❈ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱ ❚✽❖ ■❑❣✲❣✁❤ ▲✇❙●■✽❏♣▲❢❚❲❋ ❚✽❖✛❏✷❇✲❈❜❖❘❚❲❍✷❡❊◗✁❤❳■ ✴ ➛ ✶ ■✽❍✷❈❊❋✲❚✬❏❝❱✷■✽❏▼▲✇❱❲✐❃❈❩❨ ✴ ❏✷❇✲❈❜❖❘❚❲❍✷❡❊◗✁❤❳■P❇✲❚❑❤❳❨✲❱❖②❚✬❍❍❺❄❁✼✻✎✽❂✷✸✹✼✻⑧✷ ① ■✽❋❃❨ ⑥✦✥ ❧★✧ ✶ ❴✲◗✲❏✛❏✷❇✲❈ ■❑❣✲❣✲❍✷❚❆❡ ▲◆❡✞■✽❏♣▲❢❚❲❋❃❱ ❙✰❚❲❡ ❣✲◗✲❏✷❈❩❨P■✽❍✷❈✉①✬❈●❍✷✐✞❙❀❤◆❚ ❱▼❈✉❏✷❚❊❏✷❇✲❈❝■✬❙✰❏✷◗❃■✘❤ ①❴■✘❤◆◗✲❈❩❱ ♠♣✿❇✁▲✇❙❀❇ ❱▼◗✲❉✬❉✬❈❩❱♣❏❁❱✉❏✷❇❃■✽❏❝❏✷❇✲❈✑❍❁■✽❋✲❉✬❈❊❚✽❖✿■✽❣✲❣✁❤r▲❳❙●■❑❏▼▲◆❚✬❋ ❚❑❖ ✴ ➛ ✶ ▲✇❱ ❡❯◗❃❙❀❇❶♣✛▲✇❨✁❈●❍❜❏✷❇❃■✽❋ ▲◆❋❃❨❲▲❳❙●■❑❏✷❈❩❨ ♠ ■✽❋❃❨ ❏✷❇❃■✽❏ ❱♣❚✬❡ ❈❦❲▲❢❋❃❨❪❚✽❖t◗✲❋✁▲ ❖②❚✬❍✷❡♦▲❢❏▼✐❅❍✷❈❩❱♣◗✁❤❢❏✉❱▼❇✲❚✬◗✁❤✇❨❅❇✲❚✽❤✇❨✂✇❢✼❋❃❨✁❈●❈❩❨ ♠ ❖❘❚✬❍✛■✯✐✎❡✮❈❩❨✑❍❁■✽❏▼▲◆❚ ① ✤ ⑥ ❜ ⑦ ♠ ❏✷❇✲❈ ■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✕❈❄❡✮❣❃■✽❋❃❱❞▲❢❚❲❋❅❉✽▲◆①✬❈●❋➩❴✁✐ ✴ ➛ ✶ ❙●■✽❋ ■❴❤❳❱♣❚ ❴✺❈❝❚✼❴✲❏❁■✘▲◆❋✲❈❩❨✪❴ ✐■❅❱✷■✬❨✲❨❲❤◆❈●q②❣✺❚✽▲◆❋ ❏ ■✽❣✲❣✲❍✷❚❆❡✁▲◆❡✞■✽❏▼▲◆❚✬❋✬✇ ✝ ❈❯❉❑▲❢①❲❈ ❇✲❈●❍✷❈❊❏✷❇✲❈ ❙✰❚✬❡ ❣✲◗✲❏❁■❑❏▼▲◆❚✬❋ ❖❘❚✬❍❝❏❀❇✲❈✝✐❃❍✰❱▼❏❝❏✷❈●❍✷❡☛❚✽❖ ❏❀❇✲❈❯❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋ ❝❏✷❇✲❈ ❖❘◗✁❤r❤ ■✬❱▼✐✁❡ ❣✲❏✷❚❲❏▼▲✇❙❝❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❦❙●■✽❋♥❣✲❍❀❚✼❴❃■✒❴✁❤◆✐❤❴✺❈❯❚❈❴✲❏❁■✘▲◆❋✲❈❩❨❪▲❢❋❦■P❱✪▲◆❡❊▲r❤✇■✽❍❥♣✿■❩✐✼✇✦❒✲❚✬❍ ⑥ ✵ ⑦ ✤ ■ ✥ ❧★✧ ♠♣✛❈❝❇❃■✘①✬❈❝❏✷❚✞❙✰❚✬❡✑❣✲◗✲❏✷❈ ✥✿❁✒❑☎✯ ◆ ❑② ✴ ❁✁✶ ✇ ❆✛❇✲❈❊❱✷■✬❨✲❨❲❤◆❈●q②❣❃❚❑▲❢❋✁❏★✩ ❄ ▲✇❱ ❨✁❈❄✐❃❋✲❈❩❨➇❴ ✐❅❏✷❇✲❈❝❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ❁◆ ☎② ✴ ❁✁✶ ❜

◆② ✴ ❁✁✶t✤ ✳ ❝❏✷❇✲❈❝◗✲❋✁▲✇❬❲◗✲❈●❋✲❈❩❱✷❱✉❚✽❖t❏✷❇✲❈ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋ ❚✬❋ ✯ ❩ ❘ ❧★✧ ✥ ❱▼❇✲❚✒♣ ❱☎❏✷❇❃■✽❏✍✩ ❄ ✤ ☞❈✇ ❆✛❇✲❈●❋

✥✎❁ ❑ ✯ ❭ ◆ ❑② ✴ ❁✮✶ ❛ ✏◆② ✴ ☞ ✶ ❑☞ ❑ ✫ ✦✤✪ ■✬✫ ❛ ♣✛▲◆❏✷❇ ✫ ❛ ✤ ☞ ❛ ✪ ◆ ☎ ☎②◆ ② ✴ ☞ ✶ ✵

◆ ☎ ❛②◆ ❛② ✴ ☞ ✶ ❧◆ ☎② ✴ ☞ ✶☞ ◆ ② ✴ ☞ ✶ ✢ ❄✴ ★ ✶ ❶✮✭

Page 26: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➢ ❱ ◆ ☎② ✴ ☞ ✶ ❜◆② ✴ ☞ ✶t✤ ✳ ❜ ☞✉❇✲❈●❍✷❈ ♠ ✫ ❛ ▲✇❱✿❱✪▲◆❡ ❣✁❤◆✐✬☞ ❛

◆ ☎ ☎② ✴ ☞ ✶ ❜◆② ✴ ☞ ✶ ✇ ❢✼❋✍✵▼❈❩❙✰❏▼▲◆❋✲❉P❏✷❇✁▲✇❱☎▲◆❋ ❏✷❚ s☎❬✬◗❃■✽❏♣▲❢❚❲❋ ✴ ★ ✶❁♠ ■✽❋❃❨❯♣✛▲◆❏✷❇◆

② ✴ ☞ ✶t✤ ☞ ◆ ☎② ✴ ☞ ✶❁♠ ♣✛❈❝❉✬❈●❏ ✥✿❁ ❑ ✯ ❭ ◆ ❑② ✴ ❁✁✶ ❛ ✏◆ ☎② ✴ ☞ ✶ ❑ ✸✺✹✒ ✦✤✪ ■ ◆

② ✴ ☞ ✶ ◆ ☎ ☎② ✴ ☞ ✶ ❘♣✿❇✁▲✇❙❀❇❅▲✇❱✿❈❄❡❃■✬❙✰❏▼❤◆✐ ✴ ➛ ✶ ▲r❖✤♣✛❈❝◗❃❱▼❈⑤❣✬❏▼▲◆❍▼❤r▲◆❋✲❉✔➫ ❱✉■✽❣✲❣✲❍✷❚❆❡✁▲◆❡✞■✽❏▼▲◆❚✬❋P❖②❚✬❍✿❏✷❇✲❈✉❖✼■✬❙✰❏✷❚❲❍▼▲✇■✘❤ ④ ❚ ❛ ❑❑ ❱ ★ ✫ ❑ ✏ ✳ ❜ ✫ ✪ ■ ✇❆✛❇✁◗❃❱ ♠ ❏✷❇✲❈❦■✽❣✲❣✲❍✷❚✁■✬❙✷❇ ❣✲❍✷❈❩❱▼❈●❋✁❏✷❈❩❨ ▲◆❋✓❏❀❇✁▲❳❱P❏✰■✘❤ ❦ ❙●■✽❋❬❴✺❈ ❱♣❈●❈●❋ ■❲❱✞■✽❋ ■✘❤◆❏✷❈●❍❀❋❃■✽❏▼▲◆①✬❈♥❏❀❚ ❏✷❇✲❈✌❱✷■✬❨✲❨❲❤◆❈●q②❣❃❚❑▲❢❋✁❏■✽❣✲❣✲❍✷❚✁■✬❙✷❇ ❝ ▲◆❋❃❱▼❏✷❈❩■✬❨ ❚✽❖ ❱▼❚✽❤◆①❲▲◆❋✲❉❅❏✷❇✲❈❊❈❩❬✬◗❃■✽❏♣▲❢❚❲❋ ☞ ◆ ☎② ✴ ☞ ✶✛✤◆② ✴ ☞ ✶❁♠ ▲◆❏✿❤◆❈❩■✬❨✲❱✉❏✷❚❅❱▼❚✽❤◆①❲▲◆❋✲❉❅❏✷❇✲❈ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ � ✴ ✡ ✶ ✤✡ ◆ ② ✴ � ✴ ✡ ✶❀✶❁♠ ♣✿❇✁▲✇❙❀❇♥❡✞■✘✐⑤❴✺❈❯❱✪▲◆❡ ❣✁❤◆❈●❍✉▲◆❋✄❱♣❚✬❡ ❈ ❙●■✬❱▼❈❩❱ ✇❆ ❚✞❱▼❇✲❚✒♣✖❇✲❚➍♣ ♣ ❈ ❙●■❑❋❅❚✼❴✲❏❁■✘▲◆❋✄■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✉❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❃❱ ❖❘❚✬❍✿■❜❤✇■✽❍❀❉✬❈❝❍❁■✽❋✲❉✬❈❝❚❑❖ ⑥ ■✽❋❃❨ ⑦ ♠ ♣✛❈❥♣✿❍▼▲◆❏✷❈✥✎❁ ❑ ✯ ❭ ◆ ❑② ✴ ❁✮✶ ❛ ✤✦✥✿❁ ❑ ✯ ❙ ⑧ ✴ ❁✁✶ ✭ ❳ ♣✛▲◆❏✷❇ ⑧ ✴ ❁✁✶t✤ ❤◆❚✬❉✖➁ ✴ ❁✁✶❁ ❄✞✕❚➍♣ ⑧ ✭ ✴ ❁✁✶t✤ ◆

② ✴ ❁✁✶▲❑ ■✽❋❃❨❅❏❀❇✲❈ ❱✷■✬❨✲❨❲❤◆❈●q②❣❃❚✽▲◆❋✁❏ ■✽❣✲❣✲❍✷❚❆❡✁▲❢❡P■✽❏▼▲◆❚✬❋❅❉✽▲◆①✬❈❩❱✥✿❁ ❑ ✯ ❭ ⑧ ✭ ✴ ❁✁✶ ❛ ✏ ⑧ ✴ ✩ ✹ ✶ ✭✫ ✩ ❑ ✹ ✫ ✦✤✪ ⑦ ❘✴ ✁ ✶❖②❚✬❍✍✩ ✹ ❏✷❇✲❈ ✴ ◗✲❋✁▲✇❬❲◗✲❈ ✶ ❍✷❈❩■❴❤ ❣❃❚ ❱❞▲❢❏♣▲❢①❲❈❯❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋ ❚✽❖t❏✷❇✲❈❝❈❩❬✬◗❃■❑❏▼▲◆❚✬❋ ❁ ⑧ ☎ ✴ ❁✁✶ ❜ ⑧ ✴ ❁✁✶t✤ ■ ❜⑦ ■❑❋❃❨✫ ❛ ✤ ✩ ❛ ✹ ✴✷✴ ⑧ ☎ ☎ ❜ ⑧ ✶ ✴ ✩ ✹ ✶ ✵ ✴ ⑧ ☎ ❛ ❜ ⑧ ❛ ✶ ✴ ✩ ✹ ✶ ❧ ✴ ⑧ ☎ ✴ ✩ ✹ ✶ ❜ ✩ ✹ ⑧ ✴ ✩ ✹ ✶✷✶ ❄✞✕❚➍♣ ⑧ ☎ ❜ ⑧ ✤ ✴ ■ ❜ ⑦ ✶ ✴ ◆ ☎② ❜

◆② ✶ ■✽❋❃❨ ❏✷❇✲❈✞❱❀■✬❨✲❨❲❤◆❈●q②❣❃❚✽▲◆❋✁❏❊▲✇❱ ❱▼❏▼▲r❤r❤✍✩ ✹ ✤ ☞ ❝ ■✘❤✇❱▼❚ ✫ ❛ ✤ ✴ ■ ❜ ⑦ ✶ ✩ ❛ ✹ ✴

◆ ☎ ☎② ❜◆② ✶ ✴ ✩ ✹ ✶❞❝❇✲❈●❋❃❙✰❈ ❏✷❇✲❈❊❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ✴ ✁ ✶ ▲✇❱❝❱✪▲◆❡ ❣✁❤◆✐ ■✽❋✲❚✬❏❀❇✲❈●❍❍♣✿■✘✐❅❚✽❖s♣✿❍▼▲◆❏▼▲◆❋✲❉ ✴ ➛ ✶ ❚✬❍ ✴ ★ ✶ ✇✄✂✿❚✒♣✛❈●①✬❈●❍ ♠ ▲◆❋✌❏✷❇✁▲✇❱✉❤✇■✬❱▼❏✉❖②❚✬❍✷❡ ♠ ▲◆❏▲✇❱❜❈❩■✬❱▼✐❦❏✷❚✌◗✲❋❃❨✁❈●❍❁❱♣❏❁■✽❋❃❨➝♣✿❇ ✐ ❏✷❇✲❈ ■❑❣✲❣✲❍✷❚❆❡ ▲◆❡✞■✽❏♣▲❢❚❲❋ ✴ ➛ ✶ ❇✲❚✽❤✇❨✲❱ ❖❘❚❲❍ ⑥ ❜ ⑦ ❋✲❚ ❤◆❚✬❋✲❉✬❈●❍ ✐✎❡✮❈❩❨ ④ ❆✛❇✲❈P❈❩❬✬◗✁▲◆①❴■❴❤❢❈●❋✁❏■✽❣✲❣✲❍✷❚❆❡✁▲◆❡✞■✽❏▼▲◆❚✬❋ ✴ ✁ ✶ ❇❃■✬❱◗❴❃❈●❈●❋✌❣✲❍✷❚✽①✬❈❩❨✑❖②❚✬❍ ■ ✤✆☎ ✴ ⑦ ✶ ✥ ✦ ♠ ✁ ✯ ❚✬❍ ❖❘❚✬❍ ■ ✤✞✝ ✴ ⑦ ✶✉✥ ➛ ♠ ★ ✯ ✇ ❆✛❇✁▲✇❱✕▲◆❋❃❨❲▲❳❙●■❑❏✷❈❩❱✉❏✷❇❃■✽❏❏✷❇✲❈❝■✬❱▼✐✁❡ ❣✲❏✷❚✬❏♣▲❳❙✕❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋ ✴ ➛ ✶ ▲✇❱✛①✽■✘❤r▲❳❨➇♣✛▲◆❏✷❇✲❚✬◗✲❏✛❍✷❈❩❱▼❏❀❍▼▲✇❙✰❏▼▲◆❚✬❋❅❚✬❋ ① ✤ ⑥ ❜ ⑦ ♠ ■✬❱ ❤◆❚✬❋✲❉✞■✬❱ ⑥ ✤ ⑦ ❧ ✟ ✴ ⑦ ✶❁♠ ■✽❋❃❨■ ✤ ⑥ ✵ ⑦ ✥ ❧★✧ ✇

✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛✽r❶✼✿✣✢✥✤✖✦★✧✪✩✬✫★✭✯✮✱✰✳✲✵✴✶✲✸✷✺✹✼✻★✽✒✾❀✿❁✩❂✤❃✧✎✿❄✧❅✤❃✻❆✻❈❇❃❉✎✫★✦❆✩❅✤✖❊✘❋✸●✘✧❅✤✖✦✥✤✖✦★✦❍✤❏■❑✻❀✲▼▲❖◆❃P❅P✬◗❄❘❁❙❯❚❃❱✒◗❄❚✯❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫✌❘❍❚❃❴✘❵✸❇❛✧❜✲❞❝✸❡✘❴❣❢❏❤❛✐❛❥❦❴❛✽❦✽✚✲✒❝✘❷❏✷ ❲✸❧✘✲✽✵❝→✿✣♠♥✤✖❊✘✩✪✾♦✧✪✻♥✮❜♣q✲✘r✥✲✵✴♦✲❩✷ts❦✤❛✉✘✉❑✧✪✾♦✽✔❇❛✩✪❊❑✫❈✤✖✽❦✽✘✦❆❇❏✈✘✩✪✇①✤❃✫❆✩✪❇✖❊✘✻✳✩✪❊②✻★✫❍✤❃✫❆✩✪✻❆✫★✩❂✿❁✻❀✲❣③♥❱✘❱✒❚❃P✵④⑤◆❜⑥♥❲❳❚❪❙⑦❨✘◗♦❬✄❚❏❙❜❫⑦❘❄❚✖P⑨⑧✘❙❯❚❪❙✱❫❂④❍❙❜❫⑦❘❁④♦❴❛❵✸❇❛✧❜✲✘❝ ❲❦❴

❢❀❤✸⑩✖❶✔❴❑✽✘✽✚✲✤✭❩❷❲❶❄✷✤✭ ❲❛❷❦✲✽★❷→✿✣♠❸✦❆✇❹❇❛✫❍✤✺✮✱❺❻✲✵✴♦✲✜✷❼✹✆❽✘✩✪❵❛✤✖✦❆✩❅✤❃✫❆✾①✤❃✻❆■❑✇②✽❦✫❆❇❛✫★✩❅✿✯✾❄✈✘✽✒✤✖❊✘✻★✩✪❇❛❊❾❇✖❉q✿❄❇❑✾ ✻ ✿❄✩✪✾♦❊❑✫❆✻❹❇✖❉❿✽✔❇✖➀➁✾♦✦❆✻✄❇❃❉❿❋❛✾✶❊✘✾♦✦❍✤❃✫❆✩✪❊✘❋➂❉⑦●❦❊✒✿❄✫❆✩✪❇✸❊✘✻❀✲➃❖➄❑➅❍◆❁➆❩◗❄❚❃❱✺➇❑◆✖➄❑➅♦❱✔❚✖P✎◆❯⑥✯▲❖◆✖❬✄➈♦❫❅❱✔❚❏❙❆◆✖➅♦❫⑦❘❁④♦❴❑❵❛❇✸✧✱✲✲❶✥❲✘❴❣❢❏❤❛❤✖❶✔❴❛✽❦✽✚✲❃❶✰❷❛➉❏✷✲❶❳❲✸❝✘✲✽ ➳ ✿✣➊q✤❃✦❍✉❑■➋✮✱♠✯✲✵✴♦✲✔✷➌s❑❇❛✇❹✾q✦❆✾♦✻★●✘✧✪✫❆✻✯❇❛❊❻✫★➍✘✾②✤✖✻★■❞✇❹✽✘✫❆❇✸✫❆✩❅✿☛❽✒✾♦➍✔✤❏❵❞✩✪❇✸●✘✦♥❇✖❉❿✿❄❇❑✾ ✻ ✿❄✩✪✾♦❊❑✫★✻⑤❇❃❉➎✧❅✤✖✦★❋❛✾✄✽✔❇✖➀❖✾✶✦❆✻q❇❃❉❖❉⑦●❦❊✒✿❄✫❆✩✪❇✸❊✘✻❀✲➏❿❫❂④✶❘✶➅❍◗❁❙❆◗♥❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄④♦❴❣❢❏❤❛❤❛⑩❦✲✽ ❲→✿✣➊♥❇❑❇✘✉☛✮⑦➐♦✲❏➑✒✲✵✴♦✲❁✷⑤s✘✤❛✉✘✉❩✧✬✾❁➒✱✽✔❇❛✩✪❊❑✫❣✇②✾♦✫★➍✘❇✘✉❑✻❣❉✌❇❛✦❣✫❆➍❦✾✳✇✄●✘✧✪✫❆✩✪❊✘❇✸✇✄✩❂✤❃✧❀✉❑✩✪✻❆✫★✦❆✩✪❽✘●✘✫★✩✪❇❛❊✚✲❏③♥❱✘❱✒❚✖P➓④➎◆❜⑥➔❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫✌❘❍❚❃P✸⑧✘❙❯❚❪❙✱❫❂④❍❙❜❫⑦❘❁④♦❴

❵❛❇✸✧❜✲✘❝❛❧✘❴❣❢❏❤❛⑩✸✐✘❴✸✽✘✽✚✲✘❧ ✭❲❶❄✷✘❧❛❧✬❶✸✲✽ ✭→✿✣→❸❊❑●✘✫❆➍❻✮❜♠✯✲✘r✥✲✵✴♦✲✸✷➣✢➁❇❛❊❑❵❛❇✸✧✬●❦✫❆✩✪❇❛❊✄✽✔❇❛✧✪■❑❊✘❇❛✇❹✩❅✤✖✧✪✻❀✲✚↔✜❨✘◗♥❲❳❚❪❙⑦❨✘◗♦❬✄❚❏❙❜❫⑦❘❄❚②➇❑◆✖➄❑➅♦❱✔❚✖P↕❴❑❵✸❇❛✧❜✲✘❝✘❴❣❢❏❤❛❤✸➙✘❴✸✽✘✽✚✲ ✭✸❡❏✷✘❡❛❧✘✲✽✵❡→✿✣❺➛✾♦✦★✧✪✩✬❊❦✩❈✮❜♠⑤✲✵✴✶❴✚s❑✽✘✦★●✘❋❛❊✘❇✸✧✪✩✥✮✱➜☛✲ ✴✶❴✚✤✖❊✔✉➂➝✳✾♦✦❆✦★✩❈✮❜❺❻✲✚✢♥✲✵✴♦✲➞✷➟✹❈✧✪❋❛✾✶❽✘✦❍✤❃✩❂✿✄✤❃❊✒✉❻✿❄❇✸✇✄❽✘✩✪❊✒✤✖✫★❇❛✦❆✩❅✤❃✧❣✽✘✦❆❇✸✽✒✾♦✦★✫❆✩✪✾♦✻✄❇❃❉➎✻★✩✬✇❹✽✘✧✪✾❛❴

✿❄❇✸✧✬❇✸●✘✦❆✾❏✉②➀✥✤✖✧✪➠❑✻❀✲❑➐❜❊❾▲✚③❸③♥➡❖❴✔➢✚◗❄❘❄❙❜➄❑➅❍◗❸➤q◆❏❙❆◗❄④q❫❅❱❻▲❖◆❃❬❈➆✔➄✸❙❯◗✶➅♥⑧➞❘✶❫⑦◗✶❱✒❘❄◗♦❴❦❵❛❇❛✧❜✲❑❡❛❧✸❡✘❴❑✽✘✽✚✲✘❝❲❶❀❧❪✷❩❝❩❷✘❷✘✲❃✷➥❢❏❤❛❤❃❶✒✲✽✵❧→✿✣❺➛✾♦✦★✧✪✩✬❊❦✩✚✮❜♠⑤✲✵✴✶❴❞s❑✽❦✦❆●✘❋✸❊✘❇❛✧✪✩✜✮✱➜q✲✵✴✶❴❞✤❃❊✒✉✄➝✳✾✶✦❆✦❆✩▼✮❜❺❻✲❑✢♥✲ ✴✶✲✖✷➦✹❸✻❆■❑✇②✽✘✫★❇❛✫★✩❂✿❁✻▼❉⑦❇❛✦➁✫❜➀➁❇✖➒❆✉❑✩✪✇②✾♦❊✘✻★✩✪❇❛❊✒✤❃✧❩✤❃✦❆✦❄✤❏■❞✻❏➧✎✿❁❇❛❊❑❵❛❇✸✧✬●❦✫❆✩✪❇❛❊

✇①✤❃✫❆✦★✩❂✿❁✾♦✻❀✲✸✷❻➑❛●✘❊❦✾②❢❀❤✸❤✖❶✒✲✽✵➉→✿✣➜✥✩✪❇✸✦❍✉✘✤❃❊➦✮⑦➑✔✲✵✴♦✲❑✷✼▲❖◆✖❬✄➈✶❫❅❱✒❚❏❙❆◆✖➅✶❫⑦❚✖P❣❫⑦➨✸◗♦❱❩❙✱❫✪❙❜❫⑦◗❁④♦✲✸✷✺➩➫✩✪✧✪✾♦■❑❴❞➭➯✾♦➀➳➲❖❇❛✦★➠➞❴❣❢❏❤❛❥✸➵✘✲

✽r❶❀❷→✿✣s❑✽✘✦★●✘❋❛❊❦❇❛✧✪✩▼✮✱➜☛✲ ✴✶✲✸✷t➜➯✩✪❇❛✦❍✉❦✤✖❊①✤❃✦❆✦❄✤❏■❞✻❈✤❃❊✒✉➛✿❄❇❛✇✄❽❦✩✬❊✔✤✖✫❆❇✸✦❆✩❅✤✖✧❦✻❆●✘✇❹✻❀✲❦➏❿❫✪④❀❘✶➅❍◗❁❙❯◗✣❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫⑦❘❁④♦❴❣❢❀❤✸❤✖❶✒✲✽r❶❩❶✼✿✣s❑✽✘✦★●✘❋❛❊❦❇❛✧✪✩▼✮✱➜☛✲ ✴✶✲✸✷✺✹✼●❦❊✘✩✪✫❍✤✖✦★■①✤❃✽✘✽✘✦❆❇❑✤❛✿★➍➛✫❆❇✄✿❄❇❛✇✄❽❦✩✬❊✔✤✖✫❆❇✸✦❆✩❅✤✖✧❦✩✬❊❑❵✸✾♦✦❆✻★✩✬❇✸❊✘✻❀✲✸✷➣➑✸●✘❊✘✾✄❢❀❤✸❤✖❶✔✲✽r❶❀❝→✿❿➸▼✾♦✇②✇❹✾➫✮❜➭q✲⑤❺t✲ ✴✶✲♥✷ ✹❈✻❆■❑✇❹✽✘✫❆❇✸✫❆✩❅✿➋✾♦✻❆✫★✩✬✇➛✤✖✫★✾♦✻❻❇✖❉❳s❑✫★✩✬✦★✧✪✩✬❊❦❋✼❊❞●❦✇✄❽✒✾♦✦★✻❀✲➺⑧✘❙✱➄✘➨❃❫⑦◗❄④➫❫❅❱➻③✥➆❛➆✔P↕❫⑦◗❄➨➳❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄④♦❴

❵❛❇✸✧❜✲✘✰❣➼❈➼❸➼❈➐❜➼✯❴✘❊✘➽❩❷❦❴✚❢❀❤✸❤❛➾❦❴❛✽✘✽✜✲✘❝❩❷❩❷❪✷❩❝ ➳✶➳✒✲❶❀❡

Page 27: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 28: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☎✄☎✆✞✝✟✁✠✆✞✄☎✡☞☛✍✌✎✆✑✏✓✒✔✡☞✄☎✕

✖✘✗✚✙✜✛✣✢✤✙✂✥✘✦★✧✪✩✫✙✭✬✮✢✤✧❢❱✞➉❻✖❢ ➢ ❻✛❚✲❙●❬✬◗✲❈●❋❃❙✰❚✬◗✲❍❀❏➢ ❣✲❍▼▲r❤ ✳ ❩ ♠ ✳ ➭✼➭ ✁✥ ❱▼◗✲❡ ❡✞■❑❍✷✐⑤❴✁✐✰✯ ❇✁▲ ❤r▲◆❣✲❣❃❈✲✱ ❤❳■ ✵❞❚❑❤❢❈●❏ ✯✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶

➸✥➍❦✾q✫❍✤❃✧✬➠➦✉❑✾✶✻❍✿❄✦★✩✬❽✔✾♦✻⑤✤✼✻❆✧✪✩ ❉⑦✫❆✩✪❊✘❋✣✽q❇✖❉➁✫❆➍✘✾✯✻❆■❑✻❆✫★✾♦✇ ❇❃❉✳●✘❊✒✤✖✦★■➛✦❆✾♦✽✘✦★✾♦✻❆✾✶❊❞✫❄✤✖✫★✩✬❇✸❊✘✻q❇❃❉❖❊❑●✘✇✄❽✒✾✶✦❆✻✥✩✪❊❑✫❆❇①✤✻❆■❑✻❆✫★✾♦✇ ❇✖❉▼✫❆✦★✾♦✾❄➒❜✧✬✩✪➠✸✾❈✦❆✾✶✽✘✦❆✾♦✻★✾♦❊❑✫❍✤❃✫❆✩✪❇❛❊✘✻❏✲➁✹❈✧✪✫❆✾♦✦★❊✒✤✖✫★✩✪❵❛✾♦✧✪■❑❴❛✫★➍✘✩✪✻➎✿♦✤❃❊②❽✔✾♥✻❆✾♦✾♦❊➦✤❃✻❈✤✖❊①✤❃✦❆✩✪✫❆➍❦✇②✾♦✫★✩❂✿➁✉❑✾♦✻❄✿❄✦❆✩✪✽❑➒✫❆✩✪❇❛❊✯❇✖❉✎✿❄✾✶✦❆✫❍✤❃✩✪❊①✿❄❇✸✇✄❽✘✩✪❊✒✤✖✫★❇❛✦❆✩❅✤❃✧❞✽❦✦❆❇❛✽✔✾♦✦★✫❆✩✪✾♦✻✥❇✖❉✚✫★✦❆✾♦✾✶✻❀✲✳➐❜❊❹✽✒✤✖✦★✫❆✩❅✿❄●✘✧❅✤❃✦❀❴❑✤❛✉✘✉❑✩✪✫★✩✬❇✸❊✚❴✖✇✄●✘✧✪✫★✩✬✽❦✧✬✩❅✿♦✤❃✫❆✩✪❇✖❊✚❴✖✤✖❊✔✉✾❄✈✘✽✒❇✸❊✘✾♦❊❑✫❆✩❅✤✖✫★✩✪❇❛❊②❇❃❉✎✫★✦❆✾♦✾♦✻q✿♦✤❃❊➛❽✒✾q✉❑✾✿✾✔❊✘✾❀✉➛✩✪❊➦✤q❊✔✤✖✫❆●❦✦❍✤✖✧✜➀➎✤❏■❑✲❆✛❇✁▲✇❱✛❏❁■❴❤ ❦♦▲❳❱➓❴❃■✬❱▼❈❩❨P❚✬❋ ✥ ✳ ✯ ✇ ✝❦❈❝❱▼❏❁■❑❍✷❏✖♣✛▲◆❏✷❇✞❏❀❇✲❈✉❖✠■✽❡♦▲ ❤◆✐P❚✽❖✱❺❄❁✼❃◗❸✑✲✴✭✶✷✸✭❁❀❂❉➔✻✔✹✼✵❄➒⑤✷✸✵✺✭❞✭ ✽ ✥ ➛ ✯✼♠ ♣✿❇✲❈●❍❀❈❝❈❩■✬❙✷❇P❋✲❚✲❨✁❈❇❃■✬❱✕❈✰▲◆❏✷❇✲❈●❍ ❩ ❚✬❍❥✦✞❱▼◗❃❙●❙✰❈❩❱❀❱▼❚✬❍❁❱❂✇❝❆✛❇✲❈❊❏✷❍❀❈●❈❩❱❝❙✰❚✬❋❃❱✪▲✇❨✁❈●❍✷❈❩❨❦■✽❍❀❈ ❍✷❚✁❚✬❏✷❈❩❨ ■✽❋❃❨ ❈●❡ ❴✺❈❩❨✲❨✁❈❩❨ ▲◆❋✌❏✷❇✲❈❊❣✁❤❳■❑❋✲❈ ♠ ❱▼❚❅❏✷❇❃■✽❏❤◆❈✰❖❘❏✿■✽❋❃❨✑❍▼▲◆❉✬❇✁❏ ■✽❍❀❈ ❨❲▲✇❱▼❏▼▲◆❋✲❉✬◗✁▲✇❱▼❇✲❈❩❨✂✇✷✞✕❚✮❨✁❈❩❱❽♣✛▲◆❏✷❇✲❚✬◗✲❏✛❱▼◗❃❙●❙✰❈❩❱✷❱▼❚❲❍❁❱✛■✽❍✷❈✿❏✷❇✲❈✉❈❄❡✲❏✷❈●❍✷❋❃■✘❤ ❋✲❚✮❨✁❈❩❱ ♠ ❱▼❚❲❡ ❈●❏▼▲◆❡ ❈❩❱ ❙●■❴❤ ❤◆❈❩❨❤◆❈❩■✘①✬❈❩❱❂✇ ❆✛❇✲❈❫➏✤✭✶❉✴❅✒✫✳✷t❚✬❍ ❱❞▲✘✕●❈❝❚❑❖ ■❜❏✷❍❀❈●❈ ✧ ▲✇❱✛❏❁■✒❦✬❈●❋✑❏✷❚✝❴✺❈ ❏✷❇✲❈✉❋✁◗✲❡ ❴✺❈●❍✛❚✽❖ ▲◆❏❁❱☎❈❄❡✮❏❀❈●❍✷❋❃■✘❤ ❋✲❚✲❨✁❈❩❱✛■✽❋❃❨♦▲❳❱✛❨✁❈●❋✲❚✬❏❀❈❩❨❴✁✐❃❂ ✧ ❂✴✇ ❢✼❏✛❇❃■✬❱✖❴✺❈●❈●❋❤♣✛❈✰❤r❤◆q✸❦ ❋✲❚✒♣✿❋P❖②❚✬❍✛❚✽①✬❈●❍✿■❯❙✰❈●❋✁❏✷◗✲❍✷✐ ✴ ❴✲❍❁■❲❙➨❦✬❈●❏♣▲❢❋✲❉❊❣✲❍✷❚❈❴✁❤❢❈●❡P❱ ♠ ❱▼❈●❈ ✥ ✦ ✯②✶ ❏✷❇❃■❑❏ ❏❀❇✲❈ ❋✁◗✲❡❫❴❃❈●❍✿❚✽❖❏✷❍✷❈●❈❩❱ ❚✽❖ ❱❞▲✘✕●❈ ⑥ ▲❳❱✕❉✽▲◆①✬❈●❋❧❴ ✐P❏✷❇✲❈❫❪ ■✽❏✰■✘❤✇■✽❋❅❋ ◗✲❡❫❴✺❈●❍ ♠

❄ ✩ ✤ ✳⑥ ✪ ✦ ⑥ ✵ ✦⑥ ✵ ✳ ✢ ❄✴ ✳ ✶❅ ❋✲❈✉❡✞■✘✐✝♣✛❈✰❤r❤ ①❲▲◆❈❂♣ ■❝❏✷❍✷❈●❈✕❚✽❖ ❱✪▲✛✕●❈ ⑥ ■✬❱☎■❝❏✷❍❀❈●❈●q ❤ ▲ ❦✬❈✉❍✷❈●❣✲❍✷❈❩❱♣❈●❋ ❏❁■❑❏▼▲◆❚✬❋✞❚❑❖ ▲◆❋✁❏✷❈●❉✬❈●❍ ⑥ ♠ ■✽❋❃❨♦❏✷❍✷✐❊❏✷❚❝❉✬❈●❋✲❈●❍❁■❴❤ ▲✛✕●❈❏✷❇✲❈✉◗❃❱▼◗❃■✘❤ ❚✬❣✺❈●❍❁■✽❏▼▲◆❚✬❋❃❱✛❚❑❖ ■❲❨✲❨❲▲❢❏♣▲❢❚❲❋ ♠ ❡❊◗✁❤◆❏▼▲◆❣✁❤r▲❳❙●■❑❏▼▲◆❚✬❋ ♠ ■❑❋❃❨❅❱▼❚ ❚✬❋ ♠ ❚✽❖ ❏✷❇✲❈✿▲◆❋✁❏✷❈●❉✬❈●❍❁❱ ✇✤❢✼❋❅❚✬❏❀❇✲❈●❍✱♣✛❚✬❍✰❨✲❱ ♠ ♣✛❈❝■✘❤✇❱▼❚❍✷❈●❉ ■❑❍❁❨P❏✷❍✷❈●❈❩❱✉■✬❱✛❈❄❡✲❏✷❈●❋❃❨❲▲◆❋✲❉❅❏✷❇✲❈ ◗✲❋❃■❑❍✷✐✞❍❀❈●❣✲❍✷❈❩❱▼❈●❋✁❏❁■✽❏▼▲◆❚✬❋ ❚✽❖ ▲◆❋✁❏✷❈●❉✬❈●❍❁❱◗♣✛▲◆❏✷❇✌❱▼❚✬❡ ❈❊❱▼◗✲❣✲❣✁❤◆❈●❡ ❈●❋ ❏✰■✽❍✷✐♥❱▼❏✷❍❀◗❃❙✰❏✷◗✲❍✷❈❱▼◗✲❣✺❈●❍▼▲◆❡ ❣❃❚ ❱♣❈❩❨ ♠ ❇✲❈●❋❃❙✰❈ ❏✷❇✲❈❝❋❃■✽❡✑❈❝❚✽❖✔❆➍✽ ✷✸✵❄✰✢❺❆✷✸✰✢✵✺✭❄❹➩✻⑧✰✢❃❇❀➟✭✶✵➟✽❉❈❯▲❢❋ ❏✷❇✲❈❝❏▼▲◆❏▼❤◆❈✼✇

❊⑧✁●❋✒✻ ⑨ ✏ ✌✎✍ ☛●✆ ❄✬✕✱ ▲◆❍❁❱▼❏ ♠ ✹✼❹❈❹✼❉❀✷✸❉➔❁✼✻ ▲✇❱✕❏✷❇✲❈❥❴❃■✬❱✪▲✇❙❝❚❲❣❃❈●❍❁■✽❏♣▲❢❚❲❋✄❨✁❈❄✐❃❋✲❈❩❨♥■❲❱✿■✬❱✷❱▼❚✲❙❀▲✇■✽❏▼▲◆❋✲❉P❏✷❚❊❏❇♣✛❚❊❏✷❍✷❈●❈❩❱ ♠ ❯ ■✽❋❃❨●❍ ♠ ❏✷❇✲❈❝❏❀❍✷❈●❈❯ ❧ ❍ ④ ✤ ✴❱❯ ↔■❍ ✶❚✼❴✲❏❁■❴▲❢❋✲❈❩❨✪❴✁✐ ❏❁■✒❦❲▲◆❋✲❉❯■❝❍❀❚ ❚✬❏☎❋✲❚✮❨✁❈❝■✽❋❃❨P■✽❣✲❣❃❈●❋❃❨❲▲◆❋✲❉ ❯ ■❑❋❃❨❏❍❜❏✷❚ ▲❢❏ ♠ ■❲❱ ❤◆❈✰❖❘❏✿■✽❋❃❨♦❍▼▲◆❉✬❇ ❏✿❱▼◗✎❴✲❏❀❍✷❈●❈❩❱t❍✷❈❩❱♣❣❃❈❩❙✰❏▼▲◆①✬❈✰❤◆✐✼✇❑ ▲◆①✬❈●❋❅❏❀❇❃■✽❏✖♣ ❈✰▲◆❉✬❇✁❏✛▲✇❱✿❨✁❈❄✐❃❋✲❈❩❨➇❴ ✐P❋ ◗✲❡❫❴✺❈●❍✿❚✽❖t❈❄❡✮❏✷❈●❍❀❋❃■✘❤ ❋✲❚✮❨✁❈❩❱ ♠ ❚✬❋✲❈❝❇❃■✬❱▲❂ ✧ ❂ ✤ ❂ ❯ ❂ ❧ ❂▼❍◆❂ ♠ ❱♣❚⑤♣✛❈ ❨✁❚✞❙●■❑❣✲❏✷◗✲❍✷❈▲◆❋❦■⑤♣✿■✘✐✞❏❀❇✲❈ ◗❃❱▼◗❃■✘❤ ■✬❨✲❨❲▲◆❏▼▲◆❚✬❋✌❚✽❖t▲◆❋✁❏✷❈●❉✬❈●❍❁❱❂✇ ❅ ❋♥❏✷❇✲❈❊❚✬❏❀❇✲❈●❍✿❇❃■✽❋❃❨ ♠ ▲◆❏✿▲✇❱❝❙❀❤◆❈❩■✽❍❝❏✷❇❃■❑❏ ■✬❨✲❨❲▲◆❏▼▲◆❚✬❋✌❚✽❖ ❱▼❏✷❍❀◗❃❙✰❏✷◗✲❍✷❈❩❨❋✁◗✲❡ ❴✺❈●❍❁❱☎▲✇❱✕❋✲❚✬❏✛▲◆❋♥❉✬❈●❋✲❈●❍✰■✘❤ ❙✰❚✬❡ ❡❊◗✲❏❁■❑❏▼▲◆①✬❈✼✇✔ ◗✁❤◆❏▼▲◆❣✁❤ ▲✇❙●■✽❏♣▲❢❚❲❋ ❱▼❇✲❚✬◗✁❤✇❨❶❴✺❈ ❨✁❈❄✐❃❋✲❈❩❨ ■❲❱❝■♥❱▼◗✁▲◆❏❁■✒❴✁❤◆❈✑▲◆❏✷❈●❍❁■✽❏▼▲◆❚✬❋ ❚✽❖✿■✬❨✲❨❲▲◆❏▼▲◆❚✬❋ ♠ ❈❄❡✲❣❃❚✬❋✲❈●❋✁❏▼▲✇■✽❏▼▲◆❚✬❋ ■✬❱ ■❑❋✌▲◆❏✷❈●❍✷q■✽❏▼▲◆❚✬❋✌❚✽❖ ❡❊◗✁❤◆❏▼▲◆❣✁❤r▲✇❙●■✽❏▼▲◆❚✬❋ ♠ ✭❆✷✸❺✶✇❫❣✬◗❃❙❀❇ ■✑❣✲❍✷❚✮❙✰❈❩❱❀❱✉▲✇❱✉❏❁■✒❦❲▲◆❋✲❉P▲❢❏✰❱✕▲❢❋❃❱♣❣✁▲❢❍✰■✽❏▼▲◆❚✬❋ ❖❘❍✷❚❲❡❭♣✿❇❃■❑❏ ❇❃■✬❱➉❴✺❈●❈●❋ ❨✁❚✬❋✲❈❊❖②❚✬❍❙✰❚✬❍✷❍❀❈❩❱▼❣❃❚✬❋❃❨❲▲◆❋✲❉❪▲❢❋✁❏✷❈●❉✬❈●❍❝❚❲❣❃❈●❍❁■✽❏♣▲❢❚❲❋❃❱ ❝ ▲◆❋❦❏✷❇❃■❑❏ ❙●■✬❱♣❈ ♠ ■❅❨✁❈●❋ ◗✲❡ ❈●❍✰■✒❴✁❤◆❈✞❙✰❚✽❤r❤◆❈❩❙✰❏▼▲◆❚✬❋ ❚❑❖ ❚✬❣✺❈●❍❁■✽❏▼▲◆❚✬❋❃❱✉❍✷❈❩❱♣◗✁❤❢❏❜❏✷❇❃■✽❏❤◆❈❩■✬❨ ❏✷❚P❏✷❇✲❈ ❙❀❤❳■❲❱✷❱✪▲✇❙●■✘❤ ➢ ❙➨❦✬❈●❍❀❡✞■✽❋✲❋❅❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❦❚❑❖ ❍✷❈❩❙✰◗✲❍❁❱✪▲◆①✬❈❜❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❦❏✷❇✲❈●❚✬❍❀✐✼✇ ❆✛❇✲❈❊❏❁■✘❤ ❦✌■✽❋❃❨❅❏✷❇✲❈❊❣❃■✽❣✺❈●❍ ✥ ✳ ✯❴❃❚❲❏✷❇❅❣✲❍✷❚✬❣✺❚ ❱▼❈ ❏❀❚❯❈❄❡❃■✽❡❊▲◆❋✲❈ ♣✿❇❃■✽❏ ❱▼◗✲❍❀①✬▲◆①✬❈❩❱✛❚❑❖ ❣✲❍✷❚❲❣❃❈●❍✷❏▼▲◆❈❩❱✕❚✽❖ ▲❢❋✁❏✷❈●❉✬❈●❍✰❱☎▲◆❋♥❏✷❇✁▲✇❱✉❙✰❚✬❋ ❏❀❈❄❡✮❏✶✇❶❀➉

Page 29: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➢ ♣✿❇✲❚✽❤◆❈⑤✫✢❉➔✭✶✵✺✹✼✵✺❺ ✫✢➒ ❚✽❖✤❴✁▲◆❋❃■✽❍✷✐❅❚✬❣✺❈●❍❁■✽❏▼▲◆❚✬❋❃❱ ❚✬❋❅❏✷❍✷❈●❈❩❱☎▲✇❱ ▲◆❋ ❏✷❍❀❚✮❨✁◗❃❙✰❈❩❨❪❍✷❈❩❙✰◗✲❍❁❱✪▲◆①✬❈✰❤◆✐✄■❲❱☎❖❘❚❑❤ ❤◆❚✒♣ ❱ ④❫✝↔ ✹ ❏ ✤ ❫ ❧ ❏ ❘ ❫❫↔ ✭❁✸✺✹ ❏ ✤ ✴ ❫✝↔ ✭ ❏ ❄ ✶ ↔ ✭ ✴ ❫ ↔ ✭ ❏ ✹ ✶❄❘♣✿❇✲❈●❍✷❈ ❏ ❄ ❘ ❏ ✹ ■✽❍✷❈❝❏✷❇✲❈✉❤◆❈✰❖②❏ ■✽❋❃❨P❍▼▲◆❉✬❇✁❏✿❍✷❚✁❚✬❏✿❱▼◗✎❴✲❏✷❍❀❈●❈❩❱✛❚✽❖ ❏ ✇ ✝ ❈❝❏✷❇ ◗❃❱☎❇❃■✘①✬❈❥❴✁✐✞❨✁❈❄✐❃❋✁▲◆❏▼▲◆❚✬❋❦❫✝↔ ✹ ❏ ✤ ❫ ❧ ❏ ♠ ■✽❋❃❨♣✛❈ ❨✁❈❄✐❃❋✲❈➩❃❫✰✳✲❊✷✸❉ ❸✑✲✴❉➔❺❞✹✼✷✸❉➔❁✼✻❦■✽❋❃❨→✭ ❅➨❸✎❁✼✻✔✭❆✻✔✷✸❉➔✹✼✷✸❉❀❁❈✻❤❴✁✐❫✁� ❏ ✤ ❫✝↔ ❛ ❏ ❘ ❫ ▼ ✤ ❫ ↔ ❋ ❏ ❄✞✕❚✬❏✷❈ ❏❀❇❃■✽❏ ❏❀❇✲❈❯❡❊◗✁❤◆❏▼▲◆❣✁❤r▲✇❙●■✽❏▼▲◆❚✬❋ ▲❢❋❦❫✂� ❏ ❙●■❑❋✡❴✺❈❊①✬▲◆❈❂♣✛❈❩❨❦■✬❱✕❏✷❇✲❈ ❣✲❍❀❚✮❙✰❈❩❱✷❱✉❚❑❖ ❉✬❍❁■❴❖❘❏▼▲◆❋✲❉❅❙✰❚✬❣✁▲◆❈❩❱✉❚✽❖ ❫♥■❑❏ ❈❩■✬❙❀❇❤◆❈❩■✘❖ ❚✽❖ ❏ ♠ ❏✷❇❃■✽❏☎▲✇❱✿❏✷❚ ❱✷■✘✐ ♠ ■❲❱✛❏✷❇✲❈ ❱▼◗✎❴❃❱▼❏♣▲❢❏❀◗✲❏▼▲◆❚✬❋ ❏ ✥ ❫ ✯ ✇✙✝✚✟✛✢✜✤✣✂✛✎✥ ✳ ✴☎✄ ✛✝✆✟✞➋✚✔➌ ➌☞✚✟✛✢✜✤✣✂✛✎✥ ✶ ★✡✠☎❉➔✷➔✫✞❫→✹✼✻✔❹ ❏ ✹❈✵ ❀ ❉❀✷✸✵✺✹✼✵❄➒➩✷✸✵✺✭❄✭❂✽ ✤ ❁✼✻✔✭✯✫✢✹✒✽❂★❫ ❧ ❏ ❂ ✤ ❂★❫ ❂ ❧ ❏ ❂ ❘ ❂★❫☛� ❏ ❂ ✤ ❂★❫◆❂❆↔✹❂ ❏ ❂ ❘ ❂ ❫ ▼ ❂ ✤ ❂★❫◆❂✌☞ ▼ ☞ ❄✱✲❚❲❍ ❇✁▲◆❉✬❇✲❈●❍✷q②❚✬❍✰❨✁❈●❍ ❚❲❣❃❈●❍❁■✽❏♣▲❢❚❲❋❃❱ ♠ ❏✷❇✲❈➉♣✛❈✰▲◆❉✬❇ ❏☎❚✽❖ ❏✷❇✲❈✉❍✷❈❩❱▼◗✁❤◆❏t▲✇❱☎❋✲❚❜❤❢❚❲❋✲❉✬❈●❍☎▲❢❋❃❨✁❈●❣✺❈●❋❃❨✁❈●❋ ❏✕❚✽❖ ❏✷❇✲❈ ❱♣❇❃■✽❣❃❈✉❚✽❖ ❏✷❇✲❈❚✬❣✺❈●❍❁■✽❋❃❨✲❱❂✇✙✝✚✟✛✢✜✤✣✂✛✎✥✧✦ ✴✎✍ ✆✟✏ ➌ ✣✑✆✓✒✕✔⑧➌✖✆✘✗✙✆●➌✂➎ ✶ ★☛✠☎❉❀✷➔✫✞❫ ❘ ❏ ❘ ✢✝✹✼✵✤❀❂❉➔✷✸✵✺✹✼✵❄➒➩✷✸✵✺✭❄✭❂✽ ✤ ❁✼✻⑧✭ ✫✢✹✒✽❫ ↔ ✭ ✴ ❏ ❧ ✢ ✶t✤ ✴ ❫ ↔ ✭ ❏ ✶ ↔ ✭ ✫❃✹ ✴ ❫❥↔ ✭ ✢ ✶❄❘ ❫ ↔ ✭ ✴ ❏ � ✢ ✶t✤ ✴ ❫✯↔ ✭ ❏ ✶ ↔ ✭ ✢ ❄✱✲❚❲❍ ▲◆❋❃❱▼❏✰■✽❋❃❙✰❈ ♠ ♣✛❈❝❇❃■✘①✬❈❝❏✷❇✲❈❝❋❃■❑❏✷◗✲❍❁■✘❤ ❉✬❈●❋✲❈●❍❁■❴❤ ▲✛✕❩■✽❏♣▲❢❚❲❋❃❱❫✚� ✴ ❏ ❧ ✢ ✶t✤ ❫✚� ❏ ❧ ❫✚�❀✢ ❘ ❫✛� ✴ ❏ � ✢ ✶t✤ ✴ ❫✚� ❏ ✶ � ✢ ❘❫ P ▼ ✸✢✜ ❘ ✤ ❫ ▼ �✄❫ ✜❞❘ ❫ ▼✤✣ ✜ ✤ ❚ ❫ ▼ ❱ ✜ ❄❆✛❇✲❈❩❱▼❈❜❏✺♣ ❚✑❏✷❇✲❈●❚✬❍✷❈●❡✞❱✉■✽❍✷❈❜❍✷❈●❣✲❍✷❈❩❱▼❈●❋✁❏❁■✽❏♣▲❢①❲❈❯❚❑❖ ❏✷❇✲❈❊❍✷❈❩❱♣◗✁❤❢❏✰❱✿❚✽❖ ✥ ✳ ✯ ✇ ❅ ❏✷❇✲❈●❍❝❣✲❍✷❚❲❣❃❈●❍✷❏▼▲◆❈❩❱✕▲◆❋❃❙❀❤◆◗❃❨✁❈ ❍▼▲◆❉✬❇✁❏ ❱❞▲❢❡✑q❣✁❤r▲✴✐ ■✒❴✁▲r❤ ▲ ❏❞✐ ❚✽❖ ❧ ❘ � ✴ ❏✷❇✲❈❝❣✲❍❀❚✬❣❃❈●❍✷❏▼✐❅❱▼❏✷❚✬❣❃❱✛■✽❏ ❤❢❈●①❲❈✰❤➋➛❜❚✽❖t❏✷❇✲❈ ❇✁▲◆❈●❍❁■❑❍❁❙✷❇✁✐ q ✶ ✇�✂✁✦✥✝✏✒☛ ✞ ⑨❧✍ ✏ ⑨✢⑨✎✕❢✼❏ ▲✇❱ ❙❀❤◆❈❩■✽❍❜❖❘❍❀❚✬❡☛❏✷❇✲❈❊▲◆❋✁❏✷❈●❍✷❣✲❍✷❈●❏❁■❑❏▼▲◆❚✬❋❦❚✽❖✿❡❊◗✁❤◆❏▼▲◆❣✁❤ ▲✇❙●■✽❏♣▲❢❚❲❋ ■✬❱ ❱▼◗✎❴❃❱♣❏▼▲◆❏✷◗✲❏▼▲◆❚✬❋ ❏✷❇❃■✽❏ ■❅❏❀❍✷❈●❈❊▲✇❱ ❙✰❚✬❡✑❣❃❚ ❱✪▲◆❏✷❈✑❚✬❍❋✲❚✬❋✲q②❣✲❍▼▲◆❡ ❈ ✴ ▲✇❱❝❋✲❚❲❋✲q②❏✷❍▼▲◆①✬▲✇■✘❤r❤◆✐ ❨✁❈❩❙✰❚✬❡ ❣❃❚✁❱✷■✒❴✁❤◆❈✞◗✲❋❃❨✁❈●❍❊❡❊◗✁❤◆❏▼▲◆❣✁❤r▲❳❙●■❑❏▼▲◆❚✬❋ ✶ ▲r❖ ■✽❋❃❨❦❚❲❋✁❤❢✐ ▲r❖✿❚✬❋✲❈ ❚✽❖✛▲◆❏❁❱✲❆❀❖❘❍♣▲❢❋✲❉❲❈❩❱✷❈❙✰❚✬❋❃❱✪▲✇❱▼❏✰❱ ❚❑❖ ▲✇❨✁❈●❋✁❏▼▲✇❙●■✘❤ ❏✷❍❀❈●❈❩❱❂✇ts ■✬❙❀❇ ❏✷❍✷❈●❈✉❏✷❇✲❈●❋✑❖✠■❲❙✰❏✷❚✬❍❁❱ ◗✲❋✁▲✇❬❲◗✲❈✰❤❢✐P▲◆❋✁❏✷❚❊❣✲❍▼▲◆❡ ❈❩❱ ✥ ✳ ✯ ✇✭✱✲❍✷❚❲❡✈❏✷❇✲❈●❍✷❈ ♠ ▲◆❏☎▲✇❱ ❋❃■❑❏✷◗✲❍❁■✘❤❏✷❚✞■❲❱✺❦⑤♣✿❇✲❈●❏✷❇✲❈●❍✉❏✷❇✲❈●❍✷❈✉▲✇❱✉❱▼❚✬❡ ❈ ❱♣❚✬❍✷❏✛❚✽❖ ■❊❣✲❍▼▲◆❡ ❈❯❨✁❈●❋❃❱❞▲❢❏▼✐❅❏✷❇✲❈●❚❲❍✷❈●❡ ❖②❚✬❍✿❱▼❏✷❍✷◗❃❙✰❏✷◗✲❍❀❈❩❨❅❋✁◗✲❡ ❴✺❈●❍❁❱❂✇ ❆ ❇✲❈❯■✽❋❃❱✺♣✛❈●❍♣✿■✬❱☎❚✼❴✲❏❁■✘▲◆❋✲❈❩❨✧✵❞❚✽▲◆❋✁❏▼❤◆✐☎❴ ✐P❏✷❇✲❈ ❱▼❣✺❈❩■✒❦✬❈●❍❝■✽❋❃❨P❏✷❇✲❈ ■✽◗✲❏❀❇✲❚✬❍✿❚✽❖t❏✷❇✁▲✇❱✿❱▼◗✲❡ ❡P■✽❍✷✐✼✇ ✝❦❈❥❴✲❍♣▲❢❈★✧❃✐❅❈❄❡✲❣✁❤✇■✘▲◆❋ ▲❢❏✉❇✲❈●❍✷❈✼✇❆✛❇✲❈✛❋✁◗✲❡ ❴✺❈●❍✭❄ ✩ ❚✽❖ ■✘❤r❤❃❏✷❍✷❈●❈❩❱ ❚✽❖ ❱✪▲✛✕●❈ ⑥ ▲✇❱ ❦ ❋✲❚✒♣✿❋❊■✽❋❃❨❜❉✽▲◆①✬❈●❋❫❴ ✐ ✴ ✳ ✶ ✇ ✏ ❈●❏✤➙ ✩ ❴✺❈✿❏✷❇✲❈ ❋✁◗✲❡❫❴❃❈●❍t❚✽❖❃❏❀❇✲❚ ❱▼❈✛❏✷❇❃■✽❏■✽❍✷❈❝❣✲❍♣▲❢❡✑❈❩❱ ❝ ❙❀❤◆❈❩■✽❍♣❤❢✐ ♠ ♣✛❈❝❡❊◗❃❱▼❏ ■✬❨✁❚✬❣✲❏◗➙ ✹ ✤ ❩ ✴ ✳ ▲✇❱✿❋✲❚✬❏✉■❊❣✲❍▼▲◆❡ ❈ q ✶ ✇▲✏ ❈●❏ ❄ ✴ ❁✁✶❁♠ ➙ ✴ ❁✁✶ ❴✺❈ ❏✷❇✲❈ ❙✰❚✬❍❀❍✷❈❩❱▼❣❃❚❲❋❃❨❲▲❢❋✲❉❉✬❈●❋✲❈●❍❁■❑❏▼▲◆❋✲❉❊❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋❃❱ ④❄ ✴ ❁✮✶t✤ ⑤✩✪✩✺✹ ❄ ✩ ❁ ✩ ✤ ❁ ❧ ❁ ❛ ❧ ✦ ❁

❋❧ ✁ ❁✬✫ ❧✖✳ ★ ❁✪✭ ❧ ★ ✦ ❁✪✮ ❧ ↔✶↔✶↔ ❘

➙ ✴ ❁✁✶t✤ ⑤✩✪✩✺✹ ➙ ✩ ❁ ✩ ✤ ❁ ❛ ❧ ✦ ❁❋❧ ★ ❁ ✫ ❧✖✳ ★ ❁ ✭ ❧ ➛ ✾✯❁ ✮ ❧ ↔✶↔❆↔ ❄❪ ❚✬❡❫❴✁▲◆❋❃■✽❏✷❚❲❍▼▲✇■✘❤ ❙❀❤❳■❲❱✷❱✪▲✇❙●❱ ✥ ✦ ✯ ❏✷❈❩■✬❙❀❇❅◗❃❱✛❏✷❇❃■❑❏

❄ ✴ ❁✁✶t✤ ✳✛✵ ✫ ✳✕✵ ★ ❁✦ ❄✞✕❚➍♣ ❨✁❈❩❙✰❚❲❡ ❣❃❚ ❱❞▲❢❋✲❉❊❏✷❍❀❈●❈❩❱t■✬❙●❙✰❚✬❍❁❨❲▲◆❋✲❉❊❏✷❚❝❏✷❇✲❈✰▲◆❍ ❣✲❍♣▲❢❡✑❈ ❆✰❏✷❍❁■❴▲ ❤◆❈●❍❁❱ ❈❝✐❲▲❢❈✰❤✇❨✲❱✛■❝❍❀❈✰❤❳■❑❏▼▲◆❚✬❋✞❨✁❈❄✐❃❋✁▲◆❋✲❉❫➙ ✴ ❁✮✶ ▲❢❡✑❣✁❤ ▲✇❙❀▲◆❏▼❤◆✐ ④❄ ✴ ❁✁✶t✤ ❁ ❧ ✯⑤✭❳❃ ❛ ❄ ✭ ➙ ✴ ❁ ✭ ✶❞❘ ❄ ✩ ✤✱✰ ✩✼➀★✹ ❧ ⑤

✲ ☞ ✩✼➀ ✲ ✩ ❛ ❄ ✩✣❖ ✲ ➙ ✲ ❄✴ ✦ ✶❝❛❷

Page 30: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✝❦❈❝❍✷❈❩❙✰❚❲❉✬❋✁▲✛✕●❈ ❇✲❈●❍✷❈❊■❊❣✲❍✷❚✲❨✁◗❃❙✰❏✿❚✽❖ ✴ ❖❘❚❲❍✷❡✞■✘❤ ✶ ▼✕▲◆❍▼▲✇❙✷❇✁❤◆❈●❏ ❱▼❈●❍▼▲◆❈❩❱❂✇◗❣✬❈●❏✷❏▼▲◆❋✲❉� ✴ ☞ ✶t✤ ✯⑤✩✣❃✺✹ ❄ ✩⑥ ✛✂❘ ✁

✴ ☞ ✶t✤ ✯⑤✩✣❃✺✹ ➙ ✩⑥ ✛✾❘♣✛❈❝❇❃■✘①✬❈❝❏✷❇✲❈❝❍✷❈✰❤✇■✽❏▼▲◆❚✬❋ ❡✞■✽❏❁❙❀❇✁▲◆❋✲❉ ✴ ✦ ✶ ④� ✴ ☞ ✶t✤ ✳ ❧ � ✴ ☞ ✶✂✁ ✴ ☞ ✶ ❚✬❍

✁✴ ☞ ✶ ✤ ✳ ✵ ✳� ✴ ☞ ✶ ❄❆✛❇✁◗❃❱✛❈❄❡✲❣❃■✽❋❃❨❲▲◆❋✲❉ ✳ ❜ � ✴ ☞ ✶ ■❲❱ ✴ ✳☎❧ ✄ ✴ ☞ ✶✷✶ ✫❃✹ ✐❲▲◆❈✰❤❳❨✲❱➙ ✩ ✤ ❄ ✩ ✵ ⑤

☎ ● ☎ ❍ ✆✞✝☎✠✟☛✡ ❍❄ ✲ ● ❄ ✲ ❍ ❧ ⑤

☎ ● ☎ ❍ ☎ ■ ✆☞✝☎✠✟☛✡ ❍❄ ✲ ● ❄ ✲ ❍ ❄ ✲ ■ ✵ ↔✶↔❆↔ ❄❢✼❋✌❣❃■✽❍❀❏▼▲✇❙✰◗✁❤❳■❑❍▲❄ ✩ ✵ ➙ ✩ ▲❳❱✉❈❩❬❲◗❃■✘❤t❏✷❚ ❩ ▲r❖ ⑥ ▲❳❱✕❣✲❍▼▲◆❡ ❈ ✴ ■✬❱ ▲◆❏ ❱▼❇✲❚✬◗✁❤✇❨ ✶❁♠ ▲✇❱✉❈❩❬✬◗❃■✘❤t❏✷❚ ✴ ❄ ② ✶ ❛ ▲r❖ ⑥ ✤ ① ❛ ▲✇❱✉❏✷❇✲❈❱✷❬❲◗❃■✽❍✷❈❊❚✽❖ ■P❣✲❍▼▲◆❡ ❈ ♠ ■❑❋❃❨ ▲✇❱✉❚✬❏✷❇✲❈●❍➨♣✛▲✇❱▼❈ ■✽❣✲❣✲❍❀❚✶❡✁▲◆❡✞■✽❏✷❈❩❨❧❴✁✐✡✦ ❄ ② ❄ ✩✍❖❀② ▲r❖ ① ▲❳❱ ❏✷❇✲❈ ❱▼❡✞■✘❤r❤◆❈❩❱▼❏❝❣✲❍▼▲◆❡ ❈P❨❲▲❢①❲▲✇❱▼❚✬❍❝❚✽❖⑥ ✇❈✂✕❈●❍✷❈❯■✽❍❀❈ ■❜❖②❈❂♣✖▲◆❋✁▲◆❏▼▲✇■✘❤ ①❴■❴❤❢◗✲❈❩❱ ✇⑥ ✳ ✦ ➛ ★ ✁ ❇ ✜ ✾ ➭ ✳ ❩ ✳✬✳ ✳ ✦❄ ✩ ✳ ✳ ✦ ✁ ✳ ★ ★ ✦ ✳ ➛✼✦ ★ ✦ ➭ ✳ ★ ➛ ❩ ★ ✾✯❇ ✦ ✳ ❇ ✜➍➭✯❇ ✁ ✾✭✜✣✾ ✦➙ ✩ ❩ ✳ ✦ ★ ✳ ★ ➛ ✾ ✳ ➛✼✦ ★ ✦ ❩ ✳ ★ ✦ ❇ ★ ✾ ➛ ★ ✳ ❇ ✜➍➭✯❇ ✁ ✾✯❇✯✾✯✾✞✕❚✬❏✷❈❝❏✷❇❃■✽❏✛❏✷❇✲❈ ■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✕❖②❚✬❍✷❡③❚✽❖ ❄ ✩ ❍✷❈❩❱▼◗✁❤◆❏❁❱☎❖②❍✷❚✬❡ ❣✬❏♣▲❢❍♣❤ ▲◆❋✲❉✔➫ ❱✛❖②❚✬❍✷❡❊◗✁❤✇■ ④

❄ ✩ ✏ ★ ✩❲✫❃✹✫ ✪ ⑥ ❋ ❄❪t❤◆❈❩■✽❍▼❤◆✐ ♠ ■✘❤◆❡ ❚✁❱▼❏ ❏❀❍✷❈●❈❩❱ ■❑❍✷❈❝▲◆❍✷❍✷❈❩❨✁◗❃❙❀▲ ❴✁❤◆❈ ④ ❏✷❇✲❈ ■✬❱▼✐✁❡ ❣✲❏✷❚✬❏♣▲❳❙❜❨✁❈●❋❃❱✪▲◆❏▼✐❅❚✽❖ ❣✲❍▼▲◆❡ ❈❩❱✕▲✇❱✉❏✷❇✁◗❃❱ ✳ ■✽❋❃❨P❖②◗✲❍✷❏✷❇✲❈●❍❝❙❀❇❃■✽❍✷q■✬❙✰❏✷❈●❍♣▲✘✕●❈❩❨➇❴ ✐P❏✷❇✲❈❝❍✷❈●❡P■✽❍➨❦✲❱✿■✒❴❃❚✽①✬❈✼✇✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛

✽r❶❾✿✍✌➔✧✬❇✸❊✒✉❑✾♦✧⑨✮⑦➝❈✩✪❊✒✿❁✾♦❊❑✫❍✴♦✲✸✷✏✎✥❊✘✾➯❉✱✤✖✇❹✩✪✧✬✧ ✾❖✉✒✑ ❇❛✽✔✓✾♦✦❍✤❃✫❆✾♦●✘✦★✻❖✻★●✘✦➁✧✬✾✶✻❖✤✖✦★❽✘✦❆✾♦✻➁❽✘✩✪❊✒✤❃✩✬✦★✾♦✻❀✲✜▲❖◆✖❬❸➆✘❙❆◗❁④✂✕✗✖✥◗♦❱✒➨❃➄✸④✣➨❛◗❸P✙✘ ③❿❘❄❚✸➨✛✚◗✶❬⑤❫⑦◗♥➨✸◗❄④⑧➞❘✶❫⑦◗✶❱✒❘❄◗❄④♦❴✘❵✸❇❛✧❜✲✽❷❛❝✬❶✸❴❣❢❀❤✸❤❛⑩✘❴✸✽✘✽✚✲❈➳❞➉❲❶❄✷➍➳❑➉❂➳✔✲

✽✵❝➋✿⑤✢➁❇❛✇✄✫★✾♦✫✥✮❜✰❣❇❛●❦✩✬✻❄✴♦✲❩✷t③♥➨✢✜✖❚✖❱✒❘❄◗❄➨➛▲❖◆❃❬❭➈✶❫❅❱✒❚❪❙❯◆❃➅♦❫⑦❘❁④♦✲✸✷t➜➯✾♦✩❅✉❑✾♦✧❜❴✘♠❸❇❛✦❍✉❩✦❆✾❀✿★➍❑✫❀❴▼❢❀❤✸✐✖❶✔✲✽★❷➋✿⑤→❸❊❑●✘✫❆➍➛✮❜♠❈❇✸❊✒✤✖✧❅✉✄r✥✲✵✴✶✲✖✷➫↔✜❨❩◗✥③♥➅❄❙❖◆❯⑥q▲❖◆✖❬❸➆✒➄✸❙❆◗♦➅➯➡❖➅❍◆✤✣✖➅❍❚✖❬✯❬✯❫❅❱✞✣✖✲✖✷➛✹❿✉✘✉❑✩✪✻★❇❛❊❑➒❜➩❻✾♦✻❆✧✪✾♦■❑❴✔❢❀❤❛❥✸➵✘❴✖❵✸❇❛✧❜✲✬❶✸➧✦✥❦●✘❊✒✉✘✤❃✇②✾♦❊❑✫❄✤✖✧

✹❈✧✪❋✸❇❛✦❆✩✪✫★➍✘✇②✻❏✲❛s❑✾❀✿❄❇✸❊✒✉➛✾❀✉❩✩✬✫★✩✪❇❛❊✚❴✲❶❏➉❛❡❩❷❦✲

❝✬❶

Page 31: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❝❛❝

Page 32: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁◆✄ ✁☎✄

�✝✆✑✏✓✒✟✞✡✠☞☛ ✝✍✌✎✞✵✏✑✏✑✆ ✁✒✁☞✁✒☛☞✞✡✓

Page 33: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 34: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁ ✁ ✠✪✆ ✁✮✁✒☛ ✓☎✄ � ☛✆✄✡✓✞✕ ✞✞✝✠✟ ✡ ✁☎✡✮✄☎✏✑☛ ✓ ✁ ✓✵✁☎✕☛✡ ✕ ☛☞✓☎✄ � ☛☞✓☎✄✡✠✪✡✌☞ �❇✄☎✡☞✝ ☛✪✕ ☛ ✞✡✓✎✍ ✄✒☛ ✁✑✏✞✏ ✡ ✁✒☛ ✝

✒ ✢✔✓ ✙✖✕✘✗✙✓ ✙ ✗✪✢✤✧ ✦ ✩ ✗✘✚✛✚✺✩✫✙◆✙✖✓ ✥❢❱✞➉❻✖❢ ➢ ❣✬❚✬❣✲❇✁▲✇■✽q ➢ ❋ ❏♣▲❢❣✺❚✽❤r▲✇❱✔✌■❩✐ ✳ ✁ ♠ ✳ ➭✼➭ ✁✥ ❱▼◗✲❡✑❡✞■✽❍✷✐⑤❴✁✐☎④ ❍♣▲❢❉❑▲❢❏❀❏✷❈✢✜ ■✘❤r❤✤✣❈●❈ ♠✦✥ ❋✁▲◆①✬❈●❍❁❱❞▲❢❏✌✣❈❯❨✁❈❫❪✛■✽❈●❋ ✯✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶

❺ ❇❛✻❆✫➁✉❑✾❀✿❄✩✪✻❆✩✪❇✸❊✘✻✳✩✪❊⑤❋✸✾♦❇❛✇❹✾♦✫❆✦★✩❅✿❖✤❃✧✬❋✸❇❛✦★✩✬✫★➍✘✇②✻▼✤✖✦★✾✥❽✒✤✖✻★✾❀✉✯❇❛❊✄✻★✩✬❋✸❊✘✻✳❇❃❉⑨✉❑✾✶✫❆✾♦✦★✇②✩✪❊✒✤✖❊❑✫★✻❀✲ ✥✘❇✸✦✎✾❁✈❦✤❃✇②✽✘✧✪✾❛❴✉❑✾❀✿❄✩❅✉❑✩✪❊✘❋♥✩ ❉➞✤❸✽✒❇✸✩✪❊❞✫▼❽✔✾♦✧✪❇❛❊✘❋✸✻✳✫❆❇q✤❸❋❛✩✪❵✸✾♦❊⑤➍✔✤✖✧ ❉❅➒❜✻❆✽✒✤✸✿❄✾❖❇✸✦✳✤❈❋✸✩✪❵❛✾♦❊✯❽✒✤✖✧✪✧❑✦❆✾❏✉❑●✒✿❄✾♦✻✥✫★❇♥✾♦❵❛✤✖✧✪●✒✤❃✫❆✩✪❊✘❋❈✫★➍✘✾✥✻❆✩✪❋✸❊❇✖❉➞✤q✉❩✾♦✫❆✾♦✦★✇②✩✪❊✒✤❃❊❞✫❏✲❣➐❜✫✳✩✪✻▼✫❆➍✘✾✶✦❆✾❄❉⑦❇✸✦❆✾♥✿❄✦❆●✒✿❁✩❂✤❃✧✘✫❆❇☛➍✒✤❏❵❛✾➁✦❆✾♦✧✪✩❅✤✖❽❦✧✬✾✥✤✖❊❦✻❆➀➁✾♦✦❆✻✳✫★❇q✻❆●✔✿❆➍✄✫★✾♦✻❆✫★✻➎✤❃❊✒✉☛✫❆❇♥✽✘✦❆❇✘✉❑●✔✿❄✾✦❆❇❛❽❦●✘✻❆✫❈✤❃✧✬❋✸❇❛✦★✩✬✫★➍✘✇②✻❏✲❣➸✥➍✘✾♦✦★✾q✾❄✈✘✩✪✻❆✫✥❽✒✤❃✻❆✩❅✿♦✤❃✧✬✧✪■✄✫❜➀➁❇❭✿✶✤✖✫❆✾✶❋❛❇❛✦★✩✪✾♦✻❈❇❃❉ ✤✖✽❦✽✘✦❆❇❑✤❛✿★➍✘✾♦✻❸✫❆❇✄✫❆➍❦✩✬✻✥❇✸❽★✧❄✾❀✿❄✫★✩✪❵❛✾❛➧

✷➫✦❆❇❛●❦❊✒✉❑✾❀✉✄✿❄❇✸✇②✽✘●❦✫❍✤✖✫★✩✪❇❛❊✘✻❏❴♦❉✌❇❛✧✪✧✪❇✖➀❖✾❀✉✣❽❞■✯✤❈✽❦✦❆❇❑❇✖❉❣❇✖❉❣✫❆➍✘✾✥✫★❇❛✽✔❇❛✧✪❇❛❋✸✩❅✿♦✤✖✧❑✿❄❇❛✦★✦❆✾❀✿❄✫★❊✘✾♦✻★✻✥❇✖❉❣✫❆➍✘✾✥✦★✾♦✻❆●✘✧✪✫✛✩✷➫✾❄✈✒✤❛✿❄✫➁✩✪❊❞✫★✾♦❋❛✾✶✦❈✿❄❇❛✇❹✽✘●✘✫❍✤❃✫❆✩✪❇❛❊❦✻✳✫❆➍✒✤❃✫❖●❦✻❆✾✫✪✭✬♥❽✘✩✪✫❆✻➔❉⑦❇❛✦➔✫❆➍✘✾q✿❄❇✸✇②✽✘●✘✫❄✤✖✫★✩✬❇✸❊⑤❇❃❉✎✤✖❊✠✪✠✮✯✪ ✉❑✾♦✫❆✾✶✦❆✇②✩ ➒❊✒✤✖❊❑✫✥➀✥✩✪✫❆➍✰✬❍➒❜❽✘✩✪✫✥✩✪❊❑✫❆✾♦❋✸✾♦✦❆✻❈✤❃✻✥✩✬❊❦✽✘●✘✫❆✻❏✲

♣✥✾♦✦★✾❛❴✖✫❆➍❦✾❖✻★✾❀✿❄❇❛❊✔✉⑤✤❃✽✘✽✘✦❆❇❑✤❛✿★➍q✩✪✻❣❉✌❇❛✧✪✧✪❇✖➀❖✾❀✉⑨❴♦✫❆➍❦✾❖❋✸❇❞✤✖✧✸❽✒✾✶✩✬❊❦❋❈✫❆❇❸●✘✻❆✾✥✤✖✻✜❉⑦✾✶➀❻❽✘✩✪✫❆✻✎✤❃✻✚✽✔❇❛✻★✻❆✩✪❽✘✧✪✾❖✫★❇❈✾♦❵❛✤❃✧✪●✒✤✖✫★✾✻❆✩✪❋❛❊✘✻♥❇❃❉➯✉❑✾✶✫❆✾♦✦★✇②✩✪❊✒✤✖❊❑✫★✻❀✲ ✥✘❇✸✦❿✉❑✩✪✇❹✾♦❊✘✻❆✩✪❇✸❊✘✻✫✪✲✱ ❝➛✤✖❊✒✉✳✪✴✱ ❷✘❴⑨✫❆➍✘✾②✤❃✧✬❋✸❇❛✦★✩✬✫★➍✘✇②✻✥✽❦✦❆❇❛✽✔❇❛✻★✾❀✉❻✦★✾✶✵✸●✘✩✪✦❆✾✦❆✾♦✻★✽✒✾❀✿❁✫❆✩✪❵❛✾♦✧✪■✠✬✄✤✖❊✒✉✂✬✸✷ ❶☛❽✘✩✪✫❆✻♥✤✖✦❆✩✪✫★➍✘✇②✾♦✫★✩❅✿✖❴✒✤❃❊✒✉➛✦❆●❦❊➦✩✪❊➦✽✒❇✸✧✪■❞❊❦❇❛✇②✩❅✤❃✧✒✫★✩✬✇❹✾♥✩✬❊✹✬❃➧➯✫❆➍✘✾♦■➛✽✔✾♦✦❜❉✌❇❛✦❆✇ ✩✪❊✫❆➍✘✾✥➀➁❇❛✦★✻❆✫✥✿♦✤✖✻★✾❈✦❆✾✶✻❆✽✔✾❀✿❄✫❆✩✪❵✸✾♦✧✪■✢✺✯✮✻✬❀✴➁✤✖❊✒✉✼✺✯✮✻✬

❋✴✳✾✶✧✬✾✶✇②✾♦❊❑✫❍✤❃✦❆■q❇✸✽✒✾✶✦❍✤✖✫★✩✪❇❛❊✘✻✞✽ ✤✸✉✘✉❑✩✪✫❆✩✪❇❛❊❦✻❀❴✖✻★●✘❽✘✫❆✦❄✤❛✿❄✫★✩✪❇❛❊✘✻❏❴

✿❄❇❛✇❹✽✒✤✖✦★✩✬✻★❇❛❊✘✻❏❴❛✤✖❊✔✉②r▼●✒✿❁✧✬✩❅✉❑✾❏✤✖❊①✉❩✩✬❵❑✩✪✻❆✩✪❇✸❊✘✻✾✽❼❇❛❊❹✩✬❊❑✫★✾♦❋❛✾♦✦★✻✥❇✖❉✌✬♥❇❛✦✿✬❀✷✌❶❸❽✘✩✪✫❆✻❏✲✳r✜✈✘✫❆✾♦❊✘✻★✩✪❵❛✾♥✻❆✩✪✇✄●✘✧❅✤✖✫★✩✪❇❛❊✘✻➍✒✤❏❵❛✾➁✻❆➍✘❇✖➀✥❊✄✫★➍✒✤✖✫▼✫★➍✘✾❿✤❃✧✬❋✸❇❛✦★✩✬✫★➍✘✇②✻❣✽✔✾♦✦❯❉⑦❇❛✦★✇ ➀➁✾♦✧✪✧✘✩✪❊✯✽✘✦❍✤✸✿❄✫❆✩❅✿❄✾❸✻❆❇q✫★➍✒✤✖✫▼✫❆➍❦✾❿✤❏❵❛✾✶✦❍✤✖❋✸✾❄➒❆✿♦✤✖✻★✾❈✿❄❇❛✇❹✽✘✧✪✾❄✈✘✩✬✫❜■✤✖✽✘✽✔✾❀✤✖✦★✻✥✫❆❇✯❽✒✾☛✇✄●✒✿★➍✄❽✒✾♦✫★✫❆✾♦✦❸✫❆➍✒✤❃❊➛✫❆➍✘✾♥➀➁❇❛✦❆✻★✫❜➒❆✿♦✤✖✻★✾⑤✿❄❇✸✇②✽✘✧✪✾❄✈✘✩✪✫❜■❞✲✔➸✥➍✘✩✪✻✥❇✸❽✘✻❆✾♦✦★❵❛✤✖✫★✩✬❇✸❊①✿♦✤❃❊➛❽✒✾♥✽✘✦★❇✖❵❛✾❀✉✩✬❊➛✫★➍✘✾⑤✫❜➀➁❇✖➒❆✉❑✩✪✇②✾✶❊✘✻❆✩✪❇❛❊✔✤✖✧✚✿♦✤❃✻❆✾❜✽ ✭❀✿❆✲ ✎✥❊✒✉❩✾♦✦♥➍✘✾♦●✘✦★✩✬✻★✫❆✩❅✿☛➍❞■❑✽✔❇❛✫★➍✘✾♦✻❆✾✶✻❀❴✜✫❆➍✘✾✯✽✘✦❆❇❑❇❃❉➔✿✶✤✖❊➂❽✒✾✯✾❄✈✘✫❆✾♦❊✔✉❑✾❀✉➂✫❆❇✫❆➍✘✾♥✫❆➍❦✦❆✾♦✾❄➒❆✉❑✩✪✇②✾✶❊✘✻❆✩✪❇❛❊✔✤✖✧✚✿♦✤❃✻❆✾❷✽ ❲❀✿❆✲❆✛❇✁▲✇❱☎❏❁■✘❤ ❦❜▲✇❱s❴❃■❲❱▼❈❩❨❊❚✬❋✞■ ✵❞❚❑▲❢❋✁❏ ❣❃■❑❣❃❈●❍✛❚✽❖✂✱✲❍❁■❑❋❃❙❀▲❳❱ ➢ ①✁❋❃■✘▲◆❡ ♠✌❁ ❈❩■✽❋✲q✶▼❝■❑❋✁▲❢❈✰❤☞④☎❚✽▲✇❱✷❱▼❚❲❋✲❋❃■✽❏ ♠ ❅ ❤r▲◆①❲▲❢❈●❍ ▼✉❈●①❲▲ ❤r❤◆❈●❍❁❱ ♠✱✲❍✰■✽❋❃❙✰❚ ✯ ✇ ✯ ❍✷❈●❣❃■✽❍❁■✽❏✰■ ♠ ■❑❋❃❨✬✔✌■✽❍▼▲◆❈●❏✷❏✷❈✂❂ ①❲▲◆❋✲❈❩❙ ✥ ✳ ✯ ✇❜❆✛❇✲❈✞■✽◗✲❏✷❇✲❚❲❍ ❚✽❖✛❏✷❇✲❈ ❱▼◗✲❡ ❡✞■❑❍✷✐♥❇❃■✬❱✕▲◆❋✁❏✷❈●❍✷❣✲❍✷❈●❏❀❈❩❨✄❱♣❚✬❡ ❈▲✇❨✁❈❩■✬❱✕❚✽❖ ❏❀❇✲❈❝❚✬❍▼▲◆❉✽▲◆❋❃■✘❤ ❤◆❈❩❙✰❏✷◗✲❍✷❈❊■✽❋❃❨❅❇❃■❲❱✛❣✲❍✷❚✽①✬❈●❋♥■ ❙✰❚✬❋✍✵▼❈❩❙✰❏✷◗✲❍✷❈ ❱♣❏❁■✽❏✷❈❩❨P❏✷❇✲❈●❍❀❈ ✥ ✁ ♠ ❇✽✯ ✇

❊⑧✁❄❃ ✂ ✆✦❅ � ☛ ✞ ⑨❘❄✬✕ ☛●✆ ❄✂✌✔✓ ✳ ✌✔✕❂⑨ ✁❆✛❇✲❈ ■✘▲◆❡ ▲✇❱✛❏✷❚ ❈●①✽■✘❤◆◗❃■✽❏✷❈ ❏❀❇✲❈ ❱✪▲◆❉✬❋♥❚✽❖ ■⑤✦ �✡✦♦❋✲❚✬❋ ❏❀❍▼▲◆①✬▲✇■✘❤ ❨✁❈●❏❀❈●❍✷❡❊▲◆❋❃■✽❋✁❏ ♠❼ ✤ ❨✁❈●❏ ⑨ ✠ ✹ ☛ ✹✠ ❛ ☛ ❛ ⑩ ❘♣✛▲◆❏✷❇✌❋✲❚✬❋✁✕●❈●❍✷❚✑▲◆❋ ❏❀❈●❉✬❈●❍❝❈●❋ ❏❀❍▼▲◆❈❩❱✿❚✽❖ ■❑❏ ❡ ❚✁❱▼❏❇❆✝❴✁▲◆❏❁❱ ✇ ④☎✐♥❨❲▲◆①❲▲❳❨❲▲◆❋✲❉✌❏✷❇✲❈✯✐❃❍❁❱▼❏❝❙✰❚✽❤◆◗✲❡ ❋→❴ ✐ ✠ ✹ ■✽❋❃❨ ❏✷❇✲❈❯❱▼❈❩❙✰❚❲❋❃❨❙✰❚✽❤◆◗✲❡ ❋❧❴ ✐ ☛ ✹ ♠ ❚❲❋✲❈ ❙●■✽❋❤♣✿❍♣▲❢❏❀❈✝❼ ✤ ✠ ✹ ☛ ✹ ❼ ✎ ♣✛▲◆❏✷❇❼ ✎ ✤ ❨✁❈●❏ ⑨ ✳ ✳✠ ☛ ⑩ ✤ ☛ ✵ ✠ ❘♣✿❇✲❈●❍✷❈ ☛✖✤ ☛ ❛ ❜ ☛ ✹ ■❑❋❃❨ ✠ ✤ ✠ ❛ ❜ ✠ ✹ ✇✓s ①❴■✘❤◆◗❃■✽❏♣▲❢❋✲❉ ❏❀❇✲❈✄❱✪▲◆❉✬❋ ❚✽❖❯■❶✦ � ✦ ❨✁❈●❏✷❈●❍✷❡❊▲◆❋❃■✽❋✁❏✞❏❀❇ ◗❃❱✑❍✷❈❩❨✁◗❃❙✰❈❩❱P❏✷❚❈●①❴■❴❤❢◗❃■❑❏▼▲◆❋✲❉ ❏✷❇✲❈♥❱❞▲❢❉❲❋ ❚✽❖ ❏❀❇✲❈♥❨❲▲ ✙ ❈●❍✷❈●❋❃❙✰❈❧❴❃❈●❏✺♣✛❈●❈●❋ ❏✺♣ ❚ ❍❁■✽❏▼▲◆❚✬❋❃■❴❤❳❱ ✠ ■✽❋❃❨ ☛ ✇ ✝❦❈♥❙✰❚✬❋❃❱✪▲✇❨✁❈●❍ ❏✷❇✲❈♥❱♣❈●❏❄❈✖❉ ❚✽❖❍❁■✽❏♣▲❢❚❲❋❃■✘❤✇❱☎▲◆❋♥❏✷❇✲❈ ▲❢❋✁❏✷❈●❍✷①✽■✘❤ ✯ ❩ ❘ ✳ ❜ ✦ ✯ ♣✿❇✲❚ ❱▼❈❝❋✁◗✲❡ ❈●❍❁■✽❏❀❚✬❍ ■✽❋❃❨❅❨✁❈●❋✲❚✬❡♦▲❢❋❃■❑❏✷❚✬❍✿❇❃■✘①✬❈ ■✽❏✕❡ ❚ ❱▼❏❊❆❥❴✁▲❢❏✰❱❂✇❝ ❲

Page 35: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❆✛❇✲❈❅❡✞■❴▲❢❋ ▲✇❨✁❈❩■✌▲✇❱❊❏❀❚✄❈❄❡✲❣❃■✽❋❃❨ ❴✺❚✬❏✷❇ ❍❁■✽❏▼▲◆❚✬❋❃■✘❤✇❱✒✠ ■❑❋❃❨ ☛ ▲◆❋ ❏✷❚ ❙✰❚✬❋ ❏♣▲❢❋✁◗✲❈❩❨ ❖②❍❁■✬❙✰❏▼▲◆❚✬❋❃❱ ④ ❏✷❇✲❈♥❙✰❚✬❡ ❣❃■❑❍▼▲✇❱▼❚✬❋❴❃❈●❏✺♣✛❈●❈●❋☎❴❃❚❲❏✷❇❅❈❄❡✮❣❃■❑❋❃❱✪▲◆❚✬❋❃❱ ✴ ◗✲❋❃❨✁❈●❍✿❤◆❈❄❡✁▲❳❙✰❚❲❉✬❍❁■✽❣✲❇✁▲✇❙❜❚✬❍❁❨✁❈●❍ ✶ ❱▼◗✁�❅❙✰❈❩❱✛❏✷❚✞❙✰❚✬❡✑❣❃■✽❍✷❈❝❏✷❇✲❈❝❍❁■❑❏▼▲◆❚✬❋❃■✘❤✇❱✛❏✷❇✲❈●❡✞❱♣❈✰❤❢①❲❈❩❱❂✇❆✛❇✲❈❝❚✬◗✲❏♣❤ ▲◆❋✲❈❊❚✽❖t❏✷❇✲❈ ■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ▲✇❱✿❏✷❇✁◗❃❱✛①✬❈●❍❀✐ ❱✪▲◆❡ ❣✁❤◆❈ ④➢ ❱ ❤❢❚❲❋✲❉✞■✬❱✡✠❅■❑❋❃❨ ☛ ❇❃■✘①✬❈✉❡✞■✽❏✰❙✷❇✁▲◆❋✲❉ ❙✰❚✬❋✁❏▼▲◆❋ ◗✲❈❩❨✑❖②❍❁■✬❙✰❏▼▲◆❚✬❋❃❱ ❈❄❡✮❣❃■❑❋❃❱✪▲◆❚✬❋❃❱ ♠ ❙✰❚✬❋✁❏▼▲◆❋✁◗✲❈❝❈❄❡✮❣❃■✽❋❃❨✁q▲❢❋✲❉ ❝ ❱▼❏✷❚✬❣♥■❲❱ ❱♣❚ ❚✬❋♥■❲❱✛❏✷❇✲❈ ❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❃❱✉❨❲▲✚✙ ❈●❍✶✇❆✛❇✲❈●❍✷❈P■✽❍✷❈ ❏✺♣✛❚❅①❴■✽❍♣▲❳■❑❋ ❏❁❱✉❚❑❖ ❏❀❇✲❈✞■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ♠ ♣✕❇✁▲❳❙❀❇ ❨✁❈●❣✺❈●❋❃❨ ❚✬❋❦❏✷❇✲❈⑤❦❲▲◆❋❃❨❦❚❑❖✕❙✰❚❲❋ ❏▼▲◆❋✁◗✲❈❩❨✌❖②❍❁■✬❙✰❏♣▲❢❚❲❋❦❏✷❇❃■✽❏▲✇❱✛◗❃❱▼❈❩❨ ④ ❆✛❇✲❈✄✂✑✷✸✹❈✻✔❹✼✹✼✵✺❹✆☎✝✂✑❉✴❅✼✻♥■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱◗❴❃■✬❱▼❈❩❨P❚✬❋♥❱▼❏✰■✽❋❃❨✲■✽❍❁❨P❙✰❚✬❋✁❏▼▲◆❋ ◗✲❈❩❨ ❖❘❍❁■❲❙✰❏▼▲◆❚✬❋❃❱✛❏✷❇❃■✽❏✿■✽❍❀❈❍❴✲◗✁▲r❤◆❏❥♣✛▲◆❏✷❇❏✷❇✲❈❝◗❃❱▼◗❃■❴❤ st◗❃❙❀❤r▲✇❨✁❈❩■✽❋❦❨❲▲◆①✬▲✇❱✪▲◆❚✬❋❦❫ ✤ ❏ ✑ ❧ ✡ ♣✛▲◆❏✷❇ ❩✟✞ ✡ ❨❬❏ ♣✿❇✁▲r❤◆❈❊❏✷❇✲❈✡✠s✭✶✻⑧✷✸✭✶✵✺✭❄❹✆☎☛✂✂❉❊❅❈✻ ■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱◗❴❃■✬❱▼❈❩❨❚✬❋❅❙✰❈●❋ ❏❀❈●❍✷❈❩❨❅❙✰❚✬❋✁❏▼▲◆❋ ◗✲❈❩❨✑❖②❍❁■✬❙✰❏▼▲◆❚✬❋❃❱☎❏✷❇❃■❑❏ ■✽❍✷❈➉❴✲◗✁▲r❤◆❏❍♣✛▲◆❏✷❇P❏✷❇✲❈❝❙✰❈●❋ ❏❀❈●❍✷❈❩❨❅st◗❃❙❀❤r▲✇❨✁❈❩■✽❋✄❨❲▲◆①❲▲✇❱✪▲◆❚✬❋✄❫ ✤ ❏ ✑ ❧ ✡✯♣✛▲◆❏✷❇❂ ✡ ❂ ✞ ❏ ❜ ✦✎✇☎❆✛❇✲❈✝♣✛❚✬❍❁❱♣❏✷q✼❙●■✬❱▼❈❝❚✽❖t❏✷❇✲❈❩❱▼❈❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡P❱ ■✽❍♣▲❳❱♣❈❩❱➑♣✿❇✲❈●❋ ✠✌■✽❋❃❨ ☛ ■✽❍✷❈❜❈❩❬✬◗❃■✘❤t■✽❋❃❨❅❏✷❇✲❈❊■✽❋❃■✘❤◆✐✲❱✪▲✇❱✉◗❃❱▼❈❩❱♣✛❈✰❤r❤❢q✸❦✁❋✲❚✒♣✿❋❊❍✷❈❩❱▼◗✁❤◆❏❁❱ ❚✽❖ ✏ ■✽❡ ✣❈ ✴ ✳ ✾ ★✒✁ ✶ ✥ ★ ✯ ■✽❋❃❨ ▼✉◗✲❣✲❍✌✣❈ ✴ ✳ ✾ ★ ❇✁✶ ✥ ➛ ✯ ❍✷❈✰❤✇■✽❏▼▲◆①✬❈✛❏✷❚✿❏❀❇✲❈ ❱▼❏❁■❑❋❃❨✲■✽❍❁❨ ■❑❋❃❨ ❙✰❈●❋✁❏✷❈●❍✷❈❩❨❜❉ ❙●❨■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ❍✷❈❩❱▼❣❃❈❩❙✰❏♣▲❢①❲❈✰❤❢✐✼✇✛❆✛❇✲❈ ■✘①✬❈●❍✰■✽❉✬❈ ❋✁◗✲❡❫❴❃❈●❍☎❚✽❖❃▲◆❏✷❈●❍❁■❑❏▼▲◆❚✬❋❃❱ ▲✇❱ ❬❲◗✁▲◆❏✷❈ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏t❖②❍✷❚✬❡ ❏✷❇✲❈✖♣✛❚✬❍❁❱▼❏t❙●■✬❱▼❈✉❱✪▲◆❋❃❙✰❈▲◆❏✉▲✇❱ ■✬❱▼✐✁❡ ❣✲❏✷❚❲❏▼▲✇❙●■✘❤r❤❢✐✌❙✰❚✬❋❃❱▼❏❁■❑❋ ❏ ✴ ▲▲✇★❈✼✇ ♠ ▲◆❋❃❨✁❈●❣❃❈●❋❃❨✁❈●❋✁❏ ❚✽❖ ❏❀❇✲❈❯❋✁◗✲❡❫❴❃❈●❍✰❆❯❚✽❖s❴✁▲◆❏❁❱ ❚✽❖ ❏✷❇✲❈❜▲◆❋✲❣✲◗✲❏ ✶❯✥✿❇✘✯ ✇ ✞✿❚✬❏❝❏❀❚ ❚❱▼◗✲❍✷❣✲❍♣▲❳❱❞▲❢❋✲❉❑❤❢✐❦❱✪▲◆❡❊▲r❤✇■✽❍ ❙✰❚✬❋❃❱♣❏❁■✽❋✁❏❁❱✿❱▼❇✲❚✒♣ ◗✲❣❅▲◆❋✌❏✷❇✲❈❯■✘①✬❈●❍❁■❑❉✬❈●q✼❙●■✬❱▼❈ ■✽❋❃■❴❤❢✐✲❱✪▲✇❱✉❚✽❖ ❤✇■✽❏✷❏▼▲✇❙✰❈❊❍✷❈❩❨✁◗❃❙✰❏▼▲◆❚✬❋❦■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡✞❱▲◆❋♥❏✷❇✲❈❝❏✺♣✛❚✬q✼❨❲▲◆❡ ❈●❋❃❱✪▲◆❚✬❋❃■❴❤ ❙●■✬❱▼❈ ✥ ✦ ✯ ✇✙✝✚✟✛✢✜✤✣✂✛✎✥ ✳ ★✌☞➑✻ ✵❇✹❈✷✸❉❀❁✼✻⑧✹✼✲ ✽ ✠♥✹✼✻⑧❹ ☛ ❁✺✿ ❈✖❉ ✤ ✷➔✫✢✭❧✹✼✲ ❅✼❁✼✵❄❉❀✷➔✫✳❃✝✽✯❸❖✭✶✵●✿❂❁✼✵❞❃ ✹→✻✔✰✳❃❇❀➨✭❆✵⑤❁✺✿➩❉➔✷✸✭✶✵✺✹✼✷✸❉➔❁✼✻✾✽✎✍ ✹✼✷❃❫❁✒✽❂✷ ✾ ❆ ✏ ✑✓✒ ❛✏ ✑✓✒ P ✹✼✸ ✔ ❛ ❘ ❘ ✿ ❁✼✵ ✷➔✫✢✭✕✠s✭✶✻⑧✷✸✭✶✵✺✭❄❹✆☎☛✂✂❉❊❅❈✻☎✹✼✲ ❅✼❁✼✵❄❉❀✷➔✫✳❃ ❘❆ ✏ ✑✖✒ ❛✏ ✑✓✒✁✗ ❘ ✿ ❁✼✵ ✷➔✫✢✭✌✂✑✷✸✹✼✻⑧❹✼✹✼✵✺❹✆☎✝✂✑❉✴❅✼✻→✹✼✲ ❅✼❁✼✵❄❉➔✷➔✫✢❃ ❄✘✚✙ ✭❆✵❇✭ ✤✜✛ ❉ ✽➩✷➔✫✳✭ ❅❈❁✼✲✴❹✼✭✶✻ ✵✺✹✼✷✸❉❀❁➝✭✣✢❆✰✢✹✼✲✖✷✸❁ ✛ ✤ ✴ ✳❝❧ ✫ ✁ ✶ ❜ ✦✥✤ ➡✧✦ ✿☎✷➔✫✢✭→✭✶✻⑧✷✸✵❞❉➔✭❂✽ ✠ ✹✼✻✔❹ ☛ ✹✼✵✺✭❤✷✸✹✍✌✒✭✶✻❬❉➔✻❬✷➔✫✳✭✽★✢✶✰✳✹✼✵✺✭✢❈✖❉ � ❈✖❉ ➏✤❉➔✷➔✫✡✹❧❹✼✭✶✻✾✽ ❉➔✷✸➒❫➁ ✴ ✠ ❘✥☛✲✶ ❸✑✵✺❁❄❸❖❁❈✵❞✷✸❉➔❁✼✻✔✹❈✲✤✷✸❁ ❂ ✠ ✵ ☛ ❂ ✩ ✘ ➏✤❉➔✷➔✫ ✡ P ✵❝✳ ✤ ✤ ✷➔✫✢✭❯✹✼➞❆✭✶✵✺✹✶❅✼✭✪✻✔✰✳❃ ❀➟✭✶✵❁✺✿✝❉➔✷✸✭✶✵✺✹✼✷✸❉➔❁✼✻✎✽✫✪ ✥ ✍ ✯ ❁✺✿✝✷➔✫✢✭✬✠s✭✶✻⑧✷✸✭✶✵✺✭❞❹✭☎☛✂✑❉✴❅✼✻☎✹❈✲ ❅❈❁✼✵❄❉❀✷➔✫✢❃ ❉●✽ ✹✒✽❂➒✒❃◗❸✑✷✸❁✼✷✸❉➔❺⑤✷✸❁

✮ ✴ ✡ ✶t✤ ★✯ ✴ ★ ❧ ✦✤✡ ✶ ✯⑤

✲ ❃✺✹ ✳❾ ❛ ✸ ✩ ✰ ✲ ✗ ❍✲✱⑤✜ ❃✴✳ ✲ ✗✶✵ ✳✢ ❛ ✸ ✩ ❘ ❆ ✥ ✧ ❘

✹✼✻⑧❹➩✷➔✫✢✭✪✹✼➞✶✭❆✵❇✹❆❅✼✭❫✻✔✰✳❃❇❀➨✭❆✵❥❁✺✿✝❉❀✷✸✭❆✵✺✹✼✷✸❉❀❁❈✻✎✽✫✪ ✥ ✍ ✯ ❁✺✿✝✷➔✫✢✭✄✂✂✷✸✹✼✻✔❹✼✹❈✵❇❹✭☎☛✂✑❉✴❅✼✻❧✹✼✲ ❅✼❁✼✵❄❉➔✷➔✫✢❃❭❉●✽✝✹✒✽❂➒✒❃➑❸✂✷✸❁✼✷✸❉❀❺✪✷✸❁❈ ✴ ✡ ✶t✤ ★

✯ ✴ ★ ❧ ✦✤✡ ✶ ✯⑤✲ ❃✺✹ ✳❾ ❛ ✸ ✩ ⑤

✲✸✷✜✝✹ ❛ ✲ ✳✢ ❛ ✸ ✩ ❘ ❆ ✥ ✧ ❄

✦ ✻❧❸✎✹✼✵❞✷✸❉➔❺✶✰✳✲✴✹✼✵ ✤ ➏ ✫✢✭❆✻➅✷➔✫✳✭❤❹✼✭❆✻✎✽❂❉❀✷✸➒☎➁ ❉●✽☎✰✢✻⑧❉ ✿❂❁✼✵❄❃ ✤ ✷➔✫✳✭✡✹❈➞✶✭✶✵✺✹✶❅❈✭❤✻⑧✰✢❃❇❀➟✭✶✵➟✽ ❁✺✿❤❉➔✷✸✭✶✵✺✹✼✷✸❉➔❁✼✻✾✽➩✹✼✵✺✭→✵❇✭ ✽▲❸✎✭❞❺❆✷✸❉❀➞❆✭✶✲✴➒✹✒✽❂➒✒❃➑❸✂✷✸❁✼✷✸❉❀❺✪✷✸❁✮ ④ ✤ ✮ ✴ ❩ ✶t✤ ★

✯ ✴ ★ ✶ ✯⑤✲ ❃✺✹ ✳❾ ❛ ✰ ✲ ✗ ❍ ✱⑤

✜ ❃✴✳ ✲ ✗✶✵ ✳✢ ❛ ✤ ✳ ❄ ❩ ✾✼➭ ✦✼✦ ❄✘❄●❄ ❘❈ ④ ✤ ❈ ✴ ❩ ✶t✤ ★

✯ ✴ ★ ✶ ✯⑤✲ ❃✺✹ ✳❾ ❛ ⑤

✲✶✷✜✝✹ ❛ ✲ ✳✢ ❛ ✤ ✳ ❄ ✦ ❩ ✦✼✦ ❇ ❄●❄❩❄▼❄

❢✼❋ ✱ ▲◆❉✔✇ ✳ ♠ ❏✷❇✲❈❯❨✁❚❲❡✞■✘▲◆❋❃❱ ✥ ✍ ✤ ⑦ ✯ ❍✷❈✰❤✇■✽❏▼▲◆①✬❈❊❏✷❚ ❏❀❇✲❈⑤❣✬❏❁■✽❋❃❨✲■❑❍❁❨✁q✺❣✽▲◆❉✬❋❦■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡☛■✽❍✷❈❝❍✷❈●❣✲❍❀❈❩❱▼❈●❋ ❏❀❈❩❨✄■❴❤❢❏❀❈●❍✷❋❃■✽q❏▼▲◆①✬❈✰❤◆✐P▲◆❋❤❴✁❤✇■✬❙➟❦ ✴ ❖②❚✬❍✛❚✮❨✲❨❪①❴■✘❤◆◗✲❈❩❱✕❚✽❖ ⑦ ✶ ■✽❋❃❨❯♣✿❇✁▲◆❏✷❈ ✴ ❖❘❚✬❍✛❈●①✬❈●❋ ①❴■✘❤◆◗✲❈❩❱✕❚✽❖ ⑦ ✶ ✇❝ ✭

Page 36: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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Page 37: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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� ✆✟✞ ✔✬✣✂✛✂✁✑★✉❆✛❇✲❈❊❱▼◗✎❴✲q✸❴❃❚❆❡☎✄ ✹ ✇❣❃■✽❍❁■❴❤ ❤◆❈✰❤◆❚✬❉✬❍✰■✽❡✲✯❤✇t❆✛❇✲❈✿▲◆❋✁❏✷❈●❉✬❈●❍☎①✬❈❩❙✰❏✷❚✬❍ ✞✈❨✁❈❩❙✰❚✬❡ ❣✺❚ ❱▼❈❩❱✛■✬❱ ✞ ④ ✤✝✆ ✥ ✹ ✞ ✞ ✹ ❧ ✆ ✥ ❛ ✞ ✞ ❛ ♣✿❇✲❈●❍❀❈ ✆ ✥ ✞ ❨✁❈●❋✲❚✬❏✷❈❩❱☎❏✷❇✲❈▲◆❋ ❏❀❈●❉✬❈●❍ ❋✲❈❩■✽❍❀❈❩❱▼❏❝❏✷❚❅❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ✥ ✇❯❆✛❇✲❈♦▲❢❋✁❏✷❈●❉✬❈●❍❝①❲❈❩❙✰❏✷❚✬❍★✞ ✎❋ ④ ✤ ✞ ❋ ✵ ✞ ▲✇❱★✞ ✎❋ ✤ ✩ ✹ ✞ ✹ ❧ ✩ ❛ ✞ ❛ ❧ ✩ ✪ ✙ ❄ ✂✕❈●❍✷❈ ♠❏✷❇✲❈ ❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏❁❱★✩ ❵ ■✽❍✷❈❊❍❁■✽❏♣▲❢❚❲❋❃■✘❤✇❱➉♣✛▲◆❏✷❇ ■✒❴❃❱▼❚❑❤❢◗✲❏❀❈❯①✽■✘❤◆◗✲❈ ❤◆❈❩❱✷❱ ❏✷❇❃■✽❋ ✳ ❜ ✦P■✽❋❃❨✌❏❀❇✲❈ ▲◆❋✁❏✷❈●❉✬❈●❍ ❁ ✎❋ ❨✁❈●❋✲❚✬❏✷❈❩❱ ❏✷❇✲❈①✬❈●❍✷❏♣▲❳❙●■❴❤ ❙✰❚❲❡ ❣❃❚✬❋✲❈●❋✁❏✿❚✽❖ ✞ ✎❋ ✇t❆✛❇✲❈❝①✬❈❩❙✰❏✷❚✬❍✕✩ ✹ ✞ ✹ ❧ ✩ ❛ ✞ ❛ ▲❳❱ ❏✷❇ ◗❃❱✛■❜①✬❈❩❙✰❏✷❚❲❍ ❚❑❖ ❣✁❤✇■✽❋✲❈✛✎ ♣✛▲◆❏✷❇❅❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ①✬❈●❍❀❏▼▲✇❙●■✘❤❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏ ❁ ✎ ④ ✤ ✩ ✹ ❁ ✹ ❧ ✩ ❛ ❁ ❛ ✇➉❣✽▲❢❋❃❙✰❈ ✩ ✤ ❁ ✎❋ ✵ ❁ ✎ ♠ ❏✷❇✲❈❯❱✪▲◆❉✬❋ ❚✽❖ ✩✑▲❳❱✉❈❩■❲❱▼✐✞❏❀❚✞❈●①✽■✘❤◆◗❃■✽❏✷❈ ❣✲❍❀❚❴①❲▲✇❨✁❈❩❨ ❏✷❇❃■✽❏➑♣✛❈❙●■✽❋ ❈●①❴■✘❤◆◗❃■✽❏✷❈❊❏✷❇✲❈ ❱❞▲❢❉❲❋✄❚❑❖ ❏✷❇✲❈❊❨❲▲✚✙ ❈●❍❀❈●❋❃❙✰❈ ❴✺❈●❏✺♣ ❈●❈●❋ ❏✷❇✲❈❝▲◆❋✁❏✷❈●❉✬❈●❍ ❁ ✎❋ ■✽❋❃❨❅❏❀❇✲❈ ❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ❁ ✎ ✇✛❆✛❇✁▲✇❱✕▲❳❱✕❏✷❇✲❈❊❙●■✬❱▼❈♣✿❇✲❈●❋ ❏✷❇✲❈❝①✬❈❩❙✰❏✷❚✬❍ ✞ ✎❋ ❨✁❚✁❈❩❱✿❋✲❚❲❏➑❴❃❈✰❤◆❚✬❋✲❉P❏✷❚ ❏✷❇✲❈❥❴✺❚❆❡✟✄❬♣✿❇✁▲✇❙❀❇♥▲✇❱✿❨✁❈❄✐❃❋✲❈❩❨✌■✬❱ ❖❘❚✽❤r❤◆❚✒♣ ❱ ④ ❆✛❇✲❈❝❈✰❤◆❈●❡ ❈●❋✁❏❁■✽❍✷✐☎❴✺❚✶❡✄✖▲✇❱❝❏❀❇✲❈❯◗✲❋✁▲◆❚✬❋ ❚✽❖ ❏✷❇✲❈❜❖②❚✬◗✲❍ ❱▼◗✎❴✲q✸❴✺❚✶❡✲❈❩❱✠✄t❵ ❝ ❏✷❇✲❈ ❱▼◗✎❴✲q✸❴✺❚✶❡✂✄t❵ ▲✇❱ ■❅❙✰✐❲❤r▲◆❋❃❨✁❈●❍❯❚❑❖ ❨❲▲❢❍❀❈❩❙✰❏▼▲◆❚✬❋ ✪ ✙ ♠ ❚✽❖s❴❃■✬❱✪▲✇❱✛✯✕❵ ♠♣✿❇✁▲✇❙❀❇❅▲✇❱ ❨✁❈✰❤r▲◆❡❊▲◆❏✷❈❩❨❧❴✁✐✞❏✺♣✛❚❊❇✲❚✬❍▼▲✛✕●❚✬❋✁❏❁■✘❤ ❣✁❤✇■✽❋✲❈❩❱ ♠ ♣✿❇✲❚ ❱♣❈❝❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱✿■✽❍✷❈ ④✡☛☛☛☛☞ ☛☛☛☛✌❁♦✤ ❩ ■✽❋❃❨ ❁♦✤ ✴ ❁ ✹ ❧ ❁ ❛ ✶ ❜ ✦ ❘ ❖②❚✬❍✎✍ ✤ ✳ ❝❁♦✤ ✵ ❁ ✹ ❜ ✦ ■❑❋❃❨ ❁❊✤ ❁ ❛ ❜ ✦ ❘ ❖②❚✬❍✎✍ ✤ ✦ ❝❁♦✤ ✵ ✴ ❁ ✹ ❧ ❁ ❛ ✶ ❜ ✦ ■❑❋❃❨ ❁❊✤ ❩ ❘ ❖②❚✬❍✎✍ ✤ ➛ ❝❁♦✤ ✵ ❁ ❛ ❜ ✦ ■❑❋❃❨ ❁❊✤ ❁ ✹ ❜ ✦ ❘ ❖②❚✬❍✎✍ ✤ ★ ✇❆✛❇✁◗❃❱ ♠ ❈❩■✬❙❀❇ ❱▼◗✎❴✲q✸❴✺❚✶❡ ❇❃■✬❱ ■❑❋ ❇✲❈✰▲◆❉✬❇✁❏ ❈❩❬❲◗❃■✘❤✿❏✷❚ ✴ ❁ ✹ ❧ ❁ ❛ ✶ ❜ ✦ ❝ ❏❀❇✲❈ ❱▼◗✎❴✲q✸❴✺❚❆❡✏✄ ✹ ▲✇❱✑❍✷❈●❣✲❍✷❈❩❱▼❈●❋✁❏✷❈❩❨ ▲◆❋✓✱ ▲◆❉ ✦✎✇❆✛❇✲❈P❋✲❈✰▲◆❉✬❇✢❴✺❚✬❍✷❚✁❚✮❨ ✕ ❚❑❖ ❣✁❤✇■✽❋✲❈✪✎ ▲✇❱❊❨✁❈❄✐❃❋✲❈❩❨ ■✬❱❝❏✷❇✲❈P◗✲❋✁▲◆❚✬❋ ❚✽❖ ■✘❤r❤✱❴✺❚❆❡✮❈❩❱❜❚✽❖✿❏✷❇✲❈✑❤✇■✽❏✷❏▼▲✇❙✰❈✪✬ ❚✼❴✲❏❁■✘▲◆❋✲❈❩❨➝❴ ✐❏✷❍❁■❑❋❃❱✪❤✇■✽❏▼▲◆❚✬❋❅❚✽❖✑✄❬❴✁✐ ■♦①✬❈❩❙✰❏✷❚✬❍✿❚❑❖ ❤✇■✽❏✷❏♣▲❳❙✰❈✛✬→✇❢②❖ ❏✷❇✲❈✛①✬❈❩❙✰❏❀❚✬❍✌✞ ❋ ❴❃❈✰❤◆❚✬❋✲❉ ❱☎❏✷❚❝❏✷❇✲❈✛❋✲❈✰▲◆❉✬❇✳❴❃❚✬◗✲❍❀❇✲❚ ❚✲❨✤✕ ♠ ❏✷❇✲❈✕①✬❈❩❙✰❏✷❚✬❍✌✞ ✎❋ ❴✺❈✰❤❢❚❲❋✲❉ ❱☎❏✷❚❝❏✷❇✲❈✖❴❃❚❆❡✒✄ ■✽❋❃❨ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏❙●■✬❱▼❈❩❱✕■✽❍✷❈❝❏✷❚⑤❴✺❈ ❙✰❚✬❋❃❱✪▲✇❨✁❈●❍✷❈❩❨ ④✩ ❢②❖ ❏✷❇✲❈✉①✬❈❩❙✰❏✷❚✬❍✌✞ ✎❋ ▲✇❱☎❣✲❍✷❚✯✵▼❈❩❙✰❏✷❈❩❨❜▲◆❋❃❱✪▲✇❨✁❈✛✯✿❵✺❖②❚✬❍✓✍ ✤ ✦❝❚✬❍✔✍ ✤ ★ ♠ ♣✛❈✛❤◆❈●❏✣✢ ❋ ④ ✤ ✞ ✎❋ ❝ ❏✷❇✲❈❝■✒❴❃❱▼❚❑❤❢◗✲❏❀❈ ①✽■✘❤◆◗✲❈❚✽❖ ❏✷❇✲❈✿❤✇■✬❱♣❏ ❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏ ❁ ✎❋ ❚✽❖ ①✬❈❩❙✰❏✷❚❲❍ ✢ ❋ ▲✇❱☎❤◆❈❩❱✷❱☎❏✷❇❃■✽❋ ❁ ❛ ❜ ✦ ♠ ■✽❋❃❨✑❏✷❇✲❈✉❚✬❏✷❇✲❈●❍✿❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏❁❱t❚✽❖ ①✬❈❩❙✰❏✷❚✬❍✢

❋ ❇❃■✘①✬❈ ■✘❤ ♣✿■✘✐✮❱✛■✽❏✿❡✑❚ ❱▼❏❊❆ ❴✁▲◆❏❁❱ ❝ ❏✷❇✲❈ ■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡ ❙✰❚✬❋✁❏▼▲◆❋✁◗✲❈❩❱➑♣✛▲◆❏✷❇ ❏✷❇✲❈ ❱▼✐✲❱▼❏✷❈●❡ ✴ ✞ ✹ ❘ ✞ ❛ ❘ ✢ ❋ ✶ ✇✩ ❢②❖ ❏✷❇✲❈✉①✬❈❩❙✰❏✷❚❲❍ ✞ ✎❋ ▲✇❱ ❣✲❍❀❚✯✵▼❈❩❙✰❏✷❈❩❨❊▲◆❋❃❱✪▲✇❨✁❈✛✯✿❵ ❖❘❚✬❍✔✍ ✤ ✳ ❚✬❍✔✍ ✤ ➛ ♠ ❏✺♣✛❚ ❱▼◗✎❴✲q✼❙●■✬❱▼❈❩❱✿■❑❍✷❈✿❏✷❚ ❴❃❈ ❙✰❚✬❋❃❱✪▲✇❨✁❈●❍✷❈❩❨ ④❂ ✩ ✹ ❂ ✞ ❂ ✩ ❛ ❂❲■✽❋❃❨ ❂ ✩ ✹ ❂✖✕ ❂ ✩ ❛ ❂ ✇ ❆ ❇✲❈✿①✬❈❩❙✰❏✷❚✬❍✌✢ ❋ ▲✇❱☎❏✷❇✲❈●❋✞❨✁❈❄✐❃❋✲❈❩❨P■✬❱ ❖❘❚✽❤r❤◆❚✒♣ ❱ ④ ✢ ❋ ▲✇❱t❏✷❇✲❈✕①✬❈❩❙✰❏✷❚✬❍✛■✽❡ ❚✬❋✲❉❏✷❇✲❈ ❏✺♣✛❚ ①✬❈❩❙✰❏✷❚❲❍❁❱✍✞ ✎❋ ❚✬❍✛✞ ❛ ✵ ✞ ✎❋ ♣✿❇✲❚ ❱▼❈❜❤✇■✬❱▼❏❝❙✰❚✬❡ ❣✺❚✬❋✲❈●❋ ❏✉❇❃■✬❱✉❏✷❇✲❈❊❱▼❡✞■✘❤r❤◆❈●❍❝❡ ❚✲❨✁◗✁❤◆◗❃❱ ✴ ▲◆❋✌❏✷❇✲❈❥✐❃❍✰❱▼❏❙●■✬❱▼❈ ✶ ✇✭✢ ❋ ▲✇❱✛❏❀❇✲❈❝①✬❈❩❙✰❏✷❚✬❍✿■✽❡ ❚❲❋✲❉ ❏✷❇✲❈❝❏✺♣✛❚ ①✬❈❩❙✰❏❀❚✬❍❁❱ ✞ ✎❋ ❚✬❍✣✞ ✹ ✵ ✞ ✎❋ ♣✕❇✲❚ ❱▼❈✕❤❳■❲❱▼❏ ❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏ ❇❃■❲❱✛❏✷❇✲❈❱▼❡✞■✘❤r❤◆❈●❍ ❡ ❚✲❨✁◗✁❤◆◗❃❱ ✴ ▲◆❋❦❏✷❇✲❈❅❱▼❈❩❙✰❚✬❋❃❨ ❙●■✬❱▼❈ ✶ ✇❯❢✼❋➝❴❃❚✬❏✷❇ ❙●■✬❱▼❈❩❱ ♠ ❏✷❇✲❈❊❤✇■✬❱♣❏❯❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏❯❚❑❖ ①✬❈❩❙✰❏✷❚❲❍✠✢ ❋ ▲❳❱▲❢❋❦■✒❴❃❱♣❚✽❤◆◗✲❏✷❈❊①❴■✘❤◆◗✲❈❊❤◆❈❩❱✷❱✉❏✷❇❃■❑❋ ❁ ❛ ❜ ✦✞■✽❋❃❨❪▲◆❏❁❱✉❚✬❏❀❇✲❈●❍ ❙✰❚✬❡✑❣❃❚✬❋✲❈●❋✁❏❁❱✉❇❃■✘①✬❈❯■❴❤ ♣✿■✘✐✲❱ ■✽❏✉❡ ❚ ❱♣❏❇❆✝❴✁▲◆❏❁❱ ❝ ❏✷❇✲❈■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❙✰❚❲❋ ❏▼▲◆❋✁◗✲❈❩❱✖♣✛▲◆❏✷❇ ❏✷❇✲❈ ❱▼✐✲❱▼❏✷❈●❡ ✴ ✞ ✹ ❘ ✞ ❛ ❘ ✢ ❋ ✶ ✇✝❦❈❝❉✽▲◆①✬❈❜❋✲❚✒♣✓❏❀❇✲❈ ❣✲❍✷❈❩❙❀▲✇❱▼❈❊❨✁❈❩❱✷❙✰❍▼▲◆❣✲❏▼▲◆❚✬❋✌❚✽❖ ❏✷❇✲❈❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡❧✇❝❛❧

Page 38: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✥✝✏ ⑨✎✓ ☛ ✞➲☛ ✆✂✌ ✏ ✱ ✕❂✍❂⑨ ✻s✁ ❅ ❍❁❨✁❈●❍✉❏✷❇✲❈❝①✬❈❩❙✰❏✷❚❲❍❁❱✣✞ ✹ ❘ ✞ ❛ ❘ ✞ ❋ ■❑❋❃❨ ♠ ▲r❖ ❋✲❈❩❙✰❈❩❱✷❱❀■✽❍✷✐ ♠ ❙❀❇❃■✽❋✲❉✬❈❊❱▼❚✬❡ ❈❝❚✽❖ ❏✷❇✲❈●❡▲◆❋ ❏✷❚✑❏✷❇✲❈✰▲◆❍ ❚✬❣✲❣✺❚ ❱✪▲◆❏✷❈ ♠ ▲◆❋✄❱▼◗❃❙❀❇♥■❫♣✿■✘✐ ❏✷❇❃■✽❏✿❏❀❇✲❈❝①✬❈●❍✷❏▼▲✇❙●■✘❤ ❙✰❚❲❡ ❣❃❚✬❋✲❈●❋✁❏❁❱ ✴ ❁ ✹ ❘✥❁ ❛ ❘✥❁ ❋ ✶ ■❑❍✷❈❝❣❃❚ ❱❞▲❢❏♣▲❢①❲❈■✽❋❃❨♥❱♣❚✬❍✷❏✷❈❩❨♦▲◆❋❅▲◆❋❃❙✰❍✷❈❩■✬❱✪▲◆❋✲❉❅❚✬❍✰❨✁❈●❍✶✇� ✄✬☛ ✓ ⑨ ❁ ❛ ✁✤ ❩ � ✆✳ ✇❽❪ ❚✬❡ ❣✲◗✲❏✷❈❝❏❀❇✲❈❝①✬❈❩❙✰❏✷❚✬❍✍✞ ❚✽❖ ❤❳■❑❏✷❏▼▲✇❙✰❈★✬→✇✡✏ ❈●❏✍✞ ✎❋ ④ ✤ ✞ ❋ ✵ ✞❯✇✦✎✇ ⑥ ⑩ ✞ ✎❋ ❨✁❚ ❈❩❱✛❋✲❚❲❏➑❴❃❈✰❤◆❚✬❋✲❉P❏✷❚⑤❴✺❚✶❡☎✄✍ ✄ ⑨ ✆❦❈●①✽■✘❤◆◗❃■✽❏✷❈ ❏❀❇✲❈ ❱✪▲◆❉✬❋♥❚✽❖t❨✁❈●❏ ✴ ❍ ✹ ❘ ❍ ❛ ✶ ■✽❋❃❨❅❈❄❡✁▲◆❏ ❝⑨✎✓❀✕ ⑨ ❙✰❚✬❡✑❣✲◗✲❏✷❈ ❏✷❇✲❈❝①❲❈❩❙✰❏✷❚✬❍✣✢ ❋

❝ ✞❋ ④ ✤ ✢ ❋ ✇ ❅ ❍❁❨✁❈●❍ ❏❀❇✲❈❝①✬❈❩❙✰❏✷❚✬❍❁❱ ✞ ✹ ❘ ✞ ❛ ❘ ✞ ❋ ■✽❋❃❨ ♠▲r❖ ❋✲❈❩❙✰❈❩❱✷❱✷■❑❍✷✐ ♠ ❙❀❇❃■✽❋✲❉✬❈❝❏✷❇✲❈●❡ ▲◆❋✁❏✷❚P❏✷❇✲❈✰▲◆❍✿❚✬❣✲❣❃❚✁❱✪▲◆❏✷❈❯❱▼❚✑❏✷❇❃■✽❏✛❏✷❇✲❈✰▲◆❍ ①❲❈●❍✷❏▼▲✇❙●■✘❤❙✰❚✬❡✑❣❃❚✬❋✲❈●❋✁❏❁❱✿■✽❍❀❈❝❣❃❚ ❱✪▲◆❏▼▲◆①✬❈ ■✽❋❃❨✑▲◆❋❪▲❢❋❃❙✰❍❀❈❩■✬❱✪▲◆❋✲❉✞❚❲❍❁❨✁❈●❍✶✇➢ ❏✉❈❩■✬❙❀❇♥▲◆❏✷❈●❍✰■✽❏▼▲◆❚✬❋ ♠ ❈✰▲◆❏✷❇✲❈●❍❝❏❀❇✲❈♦■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡☛❈●①❴■❴❤❢◗❃■❑❏✷❈❩❱❝❏✷❇✲❈ ❱✪▲◆❉✬❋ ❚✽❖ ✩ ✴ ▲r❖✛❏✷❇✲❈❊❏✷❈❩❱▼❏✕▲❢❋ ❱▼❏✷❈●❣❶✦✑▲✇❱✉❣❃❚ ❱✪▲◆❏▼▲◆①✬❈ ✶■✽❋❃❨P❏✷❇✲❈●❋P❏✷❈●❍✷❡♦▲❢❋❃■❑❏✷❈❩❱❽❴ ✐P❏✷❇✲❈✉❈●①❴■✘❤◆◗❃■✽❏▼▲◆❚✬❋ ❚✽❖ ■❫✦ �❯✦❯❨✁❈●❏❀❈●❍✷❡❊▲◆❋❃■✽❋✁❏ ♠ ❚✬❍☎▲◆❏✿❙✰❚✬❋ ❏♣▲❢❋✁◗✲❈❩❱☎▲◆❏✷❈●❍❁■❑❏▼▲◆①✬❈✰❤◆✐✞❚✬❋❅■❫➛ �➩➛❨✁❈●❏✷❈●❍✷❡♦▲❢❋❃■❑❋ ❏➉♣✿❇✲❈●❍✷❈❊❏✷❇✲❈ ❤❳■❑❍✷❉✬❈❩❱▼❏✉❚✽❖ ❏✷❇✲❈ ❤❳■❲❱▼❏ ❙✰❚❲❡ ❣❃❚✬❋✲❈●❋✁❏❁❱✕❇❃■✬❱➉❴❃❈●❈●❋❦❨❲▲◆①❲▲❳❨✁❈❩❨➲❴ ✐♥■✽❏✕❤◆❈❩■✬❱▼❏✉❏✺♣ ❚ ♠ ❏✷❇✲❈ ❚❲❏✷❇✲❈●❍❙✰❚✬❡ ❣✺❚✬❋✲❈●❋✁❏❁❱ ❍✷❈●❡✞■✘▲◆❋✁▲◆❋✲❉❊◗✲❋❃❙✷❇❃■❑❋✲❉✬❈❩❨✂✇ ❆✛❇✁◗❃❱ ♠ ❏✷❇✲❈✿❋✁◗✲❡❫❴❃❈●❍t❚✽❖✺▲◆❏✷❈●❍❁■✽❏▼▲◆❚✬❋❃❱ ❚✽❖ ❏❀❇✲❈ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱☎■✽❏t❡ ❚ ❱▼❏ ❈❩❬❲◗❃■✘❤❏✷❚➩➛✔❆✘✇➢ ❏✛❈❩■✬❙❀❇❅▲◆❏✷❈●❍❁■❑❏▼▲◆❚✬❋ ♠ ❚✬❋✲❈ ❙✰❚✬❡✑❣✲◗✲❏✷❈❩❱✛❏✷❇✲❈❜❋✲❈❩■✽❍✷❈❩❱▼❏✛▲◆❋✁❏✷❈●❉✬❈●❍❁❱ ❏✷❚ ❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ❋ ◗✲❡❫❴❃❈●❍✰❱ ✥ ✹ ■✽❋❃❨ ✥ ❛ ♠

✥ ✹ ✤ ❨✁❈●❏ ⑨ ✠ ❋ ☛ ❋✠ ❛ ☛ ❛ ⑩❨✁❈●❏ ⑨ ✠ ✹ ☛ ✹✠ ❛ ☛ ❛ ⑩ ❘ ✥ ❛ ✤ ❨✁❈●❏ ⑨ ✠ ✹ ☛ ✹✠ ❋ ☛ ❋ ⑩❨✁❈●❏ ⑨ ✠ ✹ ☛ ✹✠ ❛ ☛ ❛ ⑩ ❄❆✛❇✲❈❩❱▼❈✑❍❁■✽❏▼▲◆❚✬❋❃■✘❤t❋✁◗✲❡ ❴✺❈●❍❁❱❝■✽❍✷❈ ❬❲◗✲❚✬❏▼▲◆❈●❋✁❏❁❱✉❚✽❖ ❏✺♣✛❚❅❨✁❈●❏✷❈●❍✷❡❊▲◆❋❃■✽❋✁❏❁❱✉❚✽❖✛❚✬❍❁❨✁❈●❍✝✦✑❇❃■❩①❲▲◆❋✲❉✴❆●q✸❴✁▲◆❏❝▲◆❋ ❏❀❈●❉✬❈●❍❝❈●❋ ❏❀❍▼▲◆❈❩❱ ♠■✽❋❃❨✌❙●■✽❋✲❋✲❚✬❏❥❴✺❈ ❙✰❚✬❡ ❣✲◗✲❏✷❈❩❨✌❨❲▲◆❍✷❈❩❙✰❏▼❤◆✐✌▲◆❋❦❱✪▲◆❋✲❉✽❤◆❈ ❣✲❍✷❈❩❙❀▲✇❱✪▲◆❚✬❋✬✇ ❆✛❇✲❈❊❋✲❈❩■✽❍❀❈❩❱▼❏✿▲◆❋✁❏✷❈●❉✬❈●❍❁❱ ✆ ✥ ❵ ✞ ■✽❍✷❈ ❈●①✽■✘❤◆◗❃■✽❏✷❈❩❨ ♠ ❴✁▲❢❏❴✁✐➩❴✁▲◆❏➉❴ ✐P❡ ❈❩■✽❋❃❱✛❚❑❖ ■ ❨❲▲✇❙❀❇✲❚✬❏✷❚✬❡♦▲❳❙ ❣✲❍✷❚✲❙✰❈❩❱✷❱✛❏✷❇❃■✽❏✕◗❃❱▼❈❩❱✛❏✷❇✲❈❊❱✪▲◆❉✬❋❃❱✛❚✽❖ ❨✁❈●❏✷❈●❍✷❡❊▲◆❋❃■✽❋✁❏❁❱❨✁❈●❏ ⑨ ✠ ❋ ✵ ⑦ ✠ ✹ ☛ ❋ ✵ ⑦ ☛ ✹✠ ❛ ☛ ❛ ⑩ ❚✬❍ ❨✁❈●❏ ⑨ ✠ ❋ ✵ ⑦ ✠ ❛ ☛ ❋ ✵ ⑦ ☛ ❛✠ ✹ ☛ ✹ ⑩ ❘ ❂⑦❂ ✤ ✳ ❘ ✦ ❘ ★ ❘ ❄●❄●❄ ❘ ✦ ❉ ❘♣✛▲◆❏✷❇ ❈●❋ ❏✷❍♣▲❢❈❩❱✕❚✽❖ ■✽❏✉❡ ❚ ❱▼❏❊❆ ❧✓✳ ❴✁▲❢❏✰❱❂✇✿❆✛❇✁◗❃❱ ♠ ❏✷❇✲❈❊❙✰❚✬❡ ❣✲◗✲❏❁■✽❏♣▲❢❚❲❋♥❚✽❖t①✬❈❩❙✰❏✷❚✬❍ ✞✈◗❃❱♣❈❩❱ ■✽❏✉❡ ❚ ❱♣❏ ★ ❆ ❈●①❴■✘❤◆◗❃■✽❏▼▲◆❚✬❋❃❱❚✽❖ ❱✪▲◆❉✬❋❃❱✛❚✽❖s✦ �❤✦ ❨✁❈●❏❀❈●❍✷❡❊▲◆❋❃■✽❋✁❏❁❱➑♣ ▲❢❏❀❇❅❈●❋ ❏✷❍♣▲❢❈❩❱✕❚✽❖ ■✽❏✛❡ ❚ ❱▼❏❊❆ ❧ ✳ ❴✁▲◆❏❁❱ ✇✙✝✚✟✛✢✜✤✣✂✛✎✥✧✦✔★✄✂✬✭✶✷✔❼ ❀➟✭❥✹❥➛ �✝➛⑤❹✼✭❆✷✸✭✶✵❄❃❫❉❀✻⑧✹✼✻✔✷✬➏✤❉➔✷➔✫ ❆✆☎❉❀ ❉❀✷ ❉❀✻⑧✷✸✭❇❅❈✭✶✵✖✭✶✻⑧✷✸✵❞❉➔✭❂✽ ➡ ✩✬✫✳✭❍❹✼✭❆✷✸✭✶✵❄❃❫❉❀✻⑧✹✼✻✔✷✟✽ ❉✴❅✼✻❯✹✼✲ ❅✼❁✭☎✵❄❉❀✷➔✫✢❃↕✹✹❀➟❁✼➞✶✭❽❸✎✭✶✵●✿ ❁✼✵❄❃ ✽❍✹✼✷ ❃❫❁✒✽ ✷✂➛ ❆✝❉➔✷✸✭✶✵✺✹✼✷✸❉➔❁✼✻✎✽➑❉➔✻➩✷➔✫✢✭❥➏✤❁❈✵➨✽❂✷ ☎❇❺❄✹✒✽❂✭ ✤ ✭❄✹✼❺❂✫⑤❉➔✷✸✭✶✵✺✹✼✷✸❉➔❁✼✻☎❉➔✻✔➞✶❁❈✲❊➞❆❉❀✻✳❅❥✷➔✫✢✭❥✭❆➞✶✹✼✲✴✰✳✹✼✷✸❉❀❁❈✻❁✺✿❫✹✼✷s❃❫❁✒✽❂✷ ★ ❆ ❧ ➭ ✽❂❉❊❅❈✻✎✽❥❁✺✿ ❹✼✭❆✷✸✭✶✵❄❃❫❉❀✻⑧✹✼✻✔✷➔✽❍✦ �❤✦❧➏✤❉➔✷➔✫✠❆ ❧✖✳✆☎ ❀❂❉➔✷s❉➔✻✔✷✸✭✺❅✼✭❆✵❥✭✶✻⑧✷✸✵❞❉➔✭❂✽ ➡ ✦ ✻✡✷➔✫✳✭⑤➏✤❁✼✵➟✽ ✷ ☎✺❺❞✹✒✽❂✭ ✤ ✷➔✫✳✭✹✼✲ ❅✼❁❈✵❞❉➔✷➔✫✢❃✧✵✺✭ ✢✶✰✳❉❀✵✺✭ ✽➋➛✔❆ ❛ ✴ ★ ❆ ❧ ➭✁✶ ✭✶✲✴✭❆❃ ✭❆✻✔✷✸✹✼✵❄➒❥✽❂✷✸✭✺❸⑧✽ ✤ ✭❄✹✼❺❂✫⑤❁✺✿❍✷➔✫✳✭✶❃✧❉➔✻✔➞❆❁✼✲✴➞✶❉➔✻✢❅ ✟ ✴ ✳ ✶ ✹✼❹✼❹❈❉❀✷✸❉➔❁✼✻✎✽ ✤ ❺❄❁✼❃◗❸❖✹✼✵❄❉●✽ ❁✼✻✾✽✹✼✻⑧❹⑤✮✖✰✢❺❆✲❊❉➔❹✼✭❄✹✼✻→❹✼❉➔➞✶❉●✽ ❉➔❁✼✻✎✽❥❁✼✻✙❆ ❧✓✳✆☎ ❀ ❉❀✷❽❉❀✻⑧✷✸✭❇❅❈✭✶✵➟✽ ➡✞✕❚✬❏✷❈✉❏✷❇❃■✽❏ ❈❄❡✲❏✷❈●❋❃❱✪▲◆①✬❈❝❈❄❡✲❣❃❈●❍♣▲❢❡✑❈●❋ ❏❁❱✉❱▼❇✲❚✒♣ ❏❀❇❃■✽❏✛❏✷❇✲❈ ■✘①✬❈●❍✰■✽❉✬❈✿❋✁◗✲❡❫❴❃❈●❍✿❚✽❖ ▲❢❏❀❈●❍❁■✽❏▼▲◆❚✬❋❃❱ ▲✇❱✿■✽❍✷❚❲◗✲❋❃❨ ❚✬❋✲❈✼✇ ❅ ❋✲❈❡✞■✘✐ ❉✽▲◆①✬❈❦■ ❇✲❈●◗✲❍▼▲✇❱▼❏▼▲✇❙✌❈❄❡✲❣✁❤❳■❑❋❃■✽❏▼▲◆❚✬❋ ❏✷❚ ❏✷❇✁▲✇❱P❣✲❇✲❈●❋✲❚✬❡ ❈●❋❃■ ✥ ✁ ✯ ✇☞✞✕❚✬❏✷❈❦■✘❤✇❱▼❚ ❏✷❇❃■✽❏P❏✷❇✲❈❦■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ❙●■✽❋❬❴✺❈❉✬❈●❋✲❈●❍❁■❴❤ ▲✛✕●❈❩❨ ❏✷❚ ❇✁▲◆❉✬❇✲❈●❍❝❨❲▲◆❡ ❈●❋❃❱✪▲◆❚✬❋❃❱ ✥ ✁ ✯ ✇

✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛✝ ❶✟✞q✹❈❵❑❊✒✤❃✩✪✇ ✮ ✥➁✲✵✴♦❴ ✌➔❇❛✩✪✻❆✻★❇❛❊✘❊✔✤✖✫✯✮⑦➑✔✲ ➒❆♠✯✲✵✴♦❴✚♠❸✾♦❵❑✩✪✧✪✧✬✩✪✾♦✦★✻q✮✡✠⑤✲✵✴✶❴ ✥➁✲▼✮☞☛▼✦★✾♦✽✒✤❃✦❍✤✖✫❄✤❛✴✶❴✎✤❃❊✒✉➛➲♥❵❑✩✬❊❦✾❀✿❹✮✱❺❻✲✵✴✶✲✘✷✆➃ ✜✖❚✖P↕➄✘❚❪❙✱❫❅❱☞✣①④♦❫ ✣✖❱❑④

◆❜⑥❻➨❛◗❁❙❆◗♦➅♦❬✯❫❅❱✒❚❃❱❑❙✌④❳➄✸④❁❫ ❱✞✣➣④♦❫❅❱✞✣✖P✬◗✤✕❅➆✒➅❄◗❄❘♦❫✪④♦❫⑦◆❃❱ ❚✖➅✶❫✪❙⑦❨❑❬❭◗❁❙❜❫⑦❘❄④♦✲ ✷ ➜✥✾♦✻★✾❀✤✖✦❄✿❆➍ ➜➯✾♦✽✔❇❛✦❆✫➛❊✘➽❑❝❩❷✸❷ ✭✘❴➯➐❜❊✘✻❆✫★✩✬✫★●✘✫➦➭❈✤❃✫❆✩✪❇❛❊✒✤❃✧❿✉❑✾➜✥✾❏✿❆➍❦✾♦✦❍✿★➍✘✾q✾✶❊➦➐❜❊❑❉⑦❇✸✦❆✇①✤❃✫❆✩✻✵✸●✘✾✥✾♦✫✥✾♦❊➛✹❸●✘✫❆❇✸✇①✤✖✫★✩✻✵❛●❦✾❛❴✒❢❏❤❛❤❃❶✒✲

✝ ❝✌✞⑤♠♥✤✖●✒✉✛✓✾✄✮✱♣➯✾♦✦❆❵✛✓✾❀✴✶❴✦✥✜✧❅✤ ✧❄❇✸✧✬✾✶✫q✮☞☛ ➍✘✩✪✧✬✩✪✽✘✽✔✾❀✴✶❴➞✤❃❊✒✉➛➝❖✤❃✧✪✧ ✓✾✶✾✄✮ ✌➔✦❆✩✪❋❛✩✪✫★✫❆✾❀✴✶✲✘✷✼✹❈❊❻✤✖❊✔✤✖✧✪■❑✻❆✩✪✻❈❇❃❉ ✫★➍✘✾②➊q✤❃●✘✻❆✻★✩❂✤❃❊➦✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍✘✇ ❉⑦❇✸✦✧❅✤✖✫★✫❆✩❅✿❄✾✯✦❆✾❀✉❑●✔✿❄✫❆✩✪❇❛❊✜✲✚➐❜❊❻✹♥✉❑✧✪✾♦✇①✤❃❊➣✮❜✰✳✲✵✴☛✮⑦✾❀✉❑✩✪✫★❇❛✦❍✴✶❴✳③♥P ✣❛◆✖➅♦❫❂❙⑦❨❑❬⑤❫⑦❘☛➤♥➄❑❬❭➈❄◗✶➅➦↔✜❨❩◗❄◆✖➅✎✍ ⑧✏✍✖❬❈➆✘◆❏④♦❫❅➄❑❬✯❴✳➢✚◗❄❘❄❙❜➄❑➅❍◗❭➤✣◆❏❙❆◗❁④②❫❅❱▲❖◆✖❬❸➆✒➄✸❙❆◗♦➅❸⑧➞❘✶❫⑦◗✶❱✒❘❄◗♦❴❦✽✘✽✚✲✺❶➨➳✶➳❃✷✮❶✥❲❛❧✘✲❪✷ ❢❀❤❛❤❃❶✒✲✑☛▼✦❆❇✘✿❄✾✶✾❀✉❑✩✪❊✘❋❛✻❸❇✖❉❖③♥➤✄↔✜⑧ ✘ ✒✔✓✘✲

✝ ❷✌✞⑤♠❸●✘✽✘✦ ✓✾✄✮⑦✹✯✲ ✴✶✲❑✷ s❑●✘✦❸✧✪✾q❊✘❇❛✇✄❽❦✦❆✾q✉❑✾⑤✉❑✩✪❵❑✩✪✻❆✩✪❇❛❊❦✻✖✕✤✄✾✟✗❣✾❀✿❄✫★●✘✾♦✦q✽✔❇❛●✘✦❸❇❛❽✘✫★✾♦❊✘✩✪✦❈✧✪✾q✽❦✧✬●❦✻❈❋❛✦❄✤✖❊✒✉ ✿❄❇❛✇❹✇✄●✘❊②✉❑✩✪❵❑✩✬✻★✾♦●✘✦❸✾♦❊❑✫❆✦❆✾✉❑✾♦●❩✈①❊✘❇✸✇✄❽✘✦❆✾♦✻➁✾♦❊❑✫❆✩✪✾♦✦★✻❀✲✳➇❑◆✖➄❑➅♦❱✒❚❃P✚➨❛◗☛❲❳❚❏❙✌❨ ✚◗✶❬✄❚❏❙❜❫✙✘♦➄✘◗❁④♦❴✘❵❛❇✸✧❜✲ ❶✘❶❛❴❣❢❀➵❃❶❞❥❦❴❛✽✘✽✜✲✼➳ ❶❁✷ ✭ ➳✒✲

❝❛➉

Page 39: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✝ ➳ ✞⑤✰✚✤❃✇ ✓✾✥✮❜➊✄✲✵✴♦✲❏✷➦➭✥❇✸✫❆✾✥✻❆●❦✦❖✧❅✤❸✧✪✩✬✇❹✩✪✫❆✾✳✉❑●✄❊✘❇✸✇✄❽✘✦❆✾✥✉❑✾❿✉❩✩✬❵❑✩✪✻❆✩✪❇✸❊✘✻✎✉✘✤❃❊✘✻➁✧❂✤❸✦★✾❀✿★➍✘✾♦✦❍✿★➍✘✾q✉❑●✄✽❦✧✬●❦✻✳❋❛✦❄✤✖❊✒✉✄✿❄❇✸✇②✇✄●✘❊q✉❑✩✪❵❑✩✪✻❆✾♦●❦✦✾♦❊❑✫❆✦★✾⑤✉❑✾♦●❩✈①❊✘❇✸✇✄❽✘✦❆✾♦✻➁✾♦❊❑✫❆✩✪✾♦✦★✻❀✲➁▲❖◆✖❬❸➆✘❙❆◗❁④✂✕✗✖✥◗♦❱✒➨❃➄✸④☛➨✸◗✯P ✘ ③♥❘❄❚❛➨✛✚◗♦❬✯❫⑦◗q➨✸◗❄④♥⑧➞❘✶❫⑦◗✶❱✒❘❄◗❄④♦❴✘❵✸❇❛✧❜✲✸➼❈➐❜➼⑤❴✜❢❀➵❃❶❞⑩✘❴✸✽✘✽✚✲✔❧ ✭✸❡❏✷❩❧✸❡❛❷❦✲

✝ ❲✌✞q➝❖✤❃✧✬✧ ✓✾♦✾♥✮✗✌❈✲✵✴✶✲✸✷t③♥P ✣❃◆❃➅♦❫✪❙✌❨❞❬✄◗✳➆✔➅❍◆✸➈❍❚✸➈♦❫ P↕❫✪④❄❙❆◗✳➆✘◆✖➄❑➅qP✙✘ ✚◗ ✜❪❚❃P↕➄✘❚❏❙❜❫⑦◆✖❱➦➨❃➄②④♦❫ ✣✖❱✒◗q➨ ✘ ➄❑❱❳➨✛✚◗❁❙❆◗♦➅♦❬✯❫❅❱✒❚❃❱❑❙ ✪✠✮✢✪➫◗♦❱ ✘✶➄✘❚❏④♦❫ ✕❜④♦❫❅❬❸➆✒P✬◗➆✒➅ ✚◗❀❘✶❫✪④♦❫⑦◆✖❱❦✲✸✷t➜➯✾♦✻❆✾❀✤❃✦❍✿★➍➦✦★✾♦✽✒❇✸✦❆✫❏❴✒➊q➜❸r✜➲✣✢♥❴ ✎➯❊✘✩✪❵❛✾♦✦★✻❆✩✪✫ ✓✾⑤✉❩✾✣✢✥✤❃✾♦❊✚❴✜❢❀❤❛❤✸⑩✘✲

✝ ✭✌✞q➝❖✤❃✧✬✧ ✓✾♦✾❹✮ ✌❸✲✵✴♦✲✜✷ ➃ ✜✖❚✖P ➄✘❚❏❙❜❫⑦◆✖❱➫➨✖➄➂④♦❫ ✣✖❱✒◗➦➨ ✘ ➄❑❱➫➨✛✚◗❁❙❯◗✶➅♦❬✯❫❅❱✒❚✖❱❩❙➯❝✂✮❻❝✁❚✖❱✒❚❃P ✍❏④❀◗➦◗✶❱➣❬✄◆ ✍❛◗✶❱✘❱✒◗✶✲▼✷ ➜➯✾♦✻❆✾❀✤❃✦❍✿★➍➣✦★✾♦✽✔❇❛✦❆✫❏❴

➊q➜❸r✜➲✣✢♥❴✞✎✥❊✘✩✪❵✸✾♦✦❆✻★✩✬✫ ✓✾⑤✉❑✾q✢✥✤✖✾✶❊✚❴✚❢❏❤❛❤❛⑩❦✲

❷❛❷

Page 40: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✞ ✠ ✆ ✓ ✞ ✏✑☛ ✁ ✠★� ✞✡✠ ✆ ✁ ☛☞✞✡✓✑✕ ✞ ✝✁� ☛ ✓✑✡ ✁◆✄✄✂ ✏ ✡☞✄ ✁☞✁✒✞✵✄✲�✆☎✭✆ ✁✮✁✒☛ ✞✡✓✞✕

✝ ✓✟✞✡✠◆✩☞☛✔✢☎✥✌✠◆✩✎✍✑✏✚✺✢✒✠✥ ❋✁▲◆①✬❈●❍❁❱✪▲◆❏▼✐❅❚✽❖✡✏✭✵❞◗✎❴✁❤ ✵✷■✽❋❃■ ✴ ❣✽❤◆❚❴①❲❈●❋✁▲❳■ ✶

❁ ◗✲❋✲❈ ✜ ♠ ✳ ➭✼➭ ★✥ ❱▼◗✲❡✑❡✞■✽❍✷✐⑤❴✁✐●✱✲❍✌✣❈❩❨☎✣❈●❍▼▲✇❙ ❪ ❇✁✐✩✕❩■✘❦ ✯✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶

➸✥➍❦✾❭✤❃✧✬❋✸❇❛✦★✩✬✫★➍✘✇➟✉❑✾✶✻❍✿❄✦★✩✬❽✔✾❀✉➂➍✘✾✶✦❆✾✄✾❄✈✘✫❆✾✶❊✒✉❑✻q✫★➍✘✾❭✤❃✧✪❋❛❇❛✦★✩✪✫❆➍✘✇ ✫★❇ ✾✒❊✒✉➦✤❃✧✬✧✜✽✒❇✸✧✪■❞❊❦❇❛✇②✩❅✤❃✧✒✻★❇❛✧✪●✘✫❆✩✪❇✸❊✘✻❈❇❃❉✉❑✩ ✗➞✾♦✦★✾♦❊❑✫❆✩❅✤✖✧✘✤❃❊✒✉q✉❑✩ ✗❣✾♦✦❆✾♦❊✔✿❄✾✥✾✶✵✸●✒✤✖✫★✩✪❇❛❊✘✻▼✫❆➍✔✤✖✫✚➀✥✤✖✻▼❋✸✩✬❵✸✾♦❊q✩✪❊ ✝ ❶❛❴✖❝✔✞✘✫❆❇♥✇②❇✸✦❆✾▼❋❛✾♦❊❦✾♦✦❍✤❃✧✘❇❛✽✔✾♦✦❍✤❃✫❆❇✸✦❆✻❀✲▼➐❜✫▼✤✖✧✪✻❆❇✫❍✤✖➠✸✾♦✻❈✤☛✇②❇❛✦★✾❈✾✔✓①✿❁✩✬✾✶❊❞✫♥✤✖✽✘✽❦✦❆❇❞✤✸✿★➍②✫❆➍✔✤✖✫❈✤❏❵❛❇✸✩❅✉❑✻❖●❦✻❆✩✪❊✘❋✄●✘❊✒✉❩✾♦✫❆✾♦✦★✇②✩✪❊✘✾❀✉➛✿❄❇❑✾✔✓①✿❁✩✬✾✶❊❞✫★✻❀✲➔➸✥➍✘✩✪✻✥✻❆●✘✇❹✇①✤✖✦★■✩✬✻➁❽✒✤❃✻❆✾❀✉➛❇✸❊ ✝ ➳ ✞❆✲✏ ❈●❏✖✕ ❴❃❈ ■ ✐❃❈✰❤✇❨✌❚✽❖ ❙❀❇❃■✽❍❁■✬❙✰❏✷❈●❍♣▲❳❱♣❏▼▲✇❙ ❩ ■✽❋❃❨ ✍ ④ ✕ ✥ ✠ ✯ ✥ ✕ ✥ ✠ ✯ ■✗✕ q ❤ ▲◆❋✲❈❩■✽❍❜❈●❋❃❨✁❚✬❡ ❚✬❍❀❣✲❇✁▲❳❱♣❡☛❚✽❖✘✕ ✥ ✠ ✯ ✇ ➢❋✲❈❂♣ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱ ❣✲❍✷❈❩❱▼❈●❋✁❏✷❈❩❨ ▲❢❋ ✥ ★ ✯ ❏✷❇❃■✽❏✟✐❃❋❃❨✲❱t■✘❤r❤✮❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱ ❚✽❖✲❇✲❚✬❡ ❚❲❉✬❈●❋✲❈●❚✬◗❃❱ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ❚✽❖❃❏✷❇✲❈❖②❚✬❍✷❡ ✍ ☛♦✤ ❩ ♠ ❚✽❖ ❋✲❚✬❋✲❇✲❚❲❡ ❚✬❉✬❈●❋✲❈●❚✬◗❃❱ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ❚✽❖ ❏❀❇✲❈✛❖❘❚❲❍✷❡ ✍ ☛♦✤ ⑧ ■✽❋❃❨❜❚✽❖ ❣❃■✽❍❁■✽❡✑❈●❏✷❍▼▲✇❙☎❋✲❚✬❋✲❇✲❚✬❡ ❚✬❉❲❈●❋✲❈●❚✬◗❃❱❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✛❚✽❖t❏✷❇✲❈✉❖②❚✬❍✷❡ ✍ ☛❊✤➅➄ ❑❵ ❃✺✹ ✥ ❵ ⑧ ❵ ✇t❆✛❇✲❈ ❈●❋❃❨✁❚❲❡ ❚✬❍✷❣✲❇✁▲✇❱▼❡✞❱ ✍ ◗✲❋❃❨✁❈●❍❝❙✰❚✬❋❃❱✪▲✇❨✁❈●❍❁■✽❏▼▲◆❚✬❋❪▲◆❋♥❏✷❇✲❈✉❖②❚✽❤r❤◆❚➍♣ ▲❢❋✲❉■✽❍✷❈❝❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤✇❱✕▲❢❋ ❚✬❋✲❈❝❚✽❖t❏✷❇✲❈✉❖②❚✽❤r❤❢❚✒♣✛▲◆❋✲❉P❚✬❣❃❈●❍✰■✽❏✷❚✬❍❁❱ ♠ ■❑❋❃❨❯♣✛▲◆❏✷❇✄❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱✛▲◆❋✙✕ ✥ ✠ ✯ ④✚ ❏✷❇✲❈ ❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤ ❚✬❣❃❈●❍❁■❑❏✷❚✬❍❍❼ ❨✁❈❄✐❃❋✲❈❩❨☎❴✁✐ ❼ ⑧ ✴ ✠ ✶t✤ ❾ ⑧ ❜ ❾ ✠ ❝

✚ ❏✷❇✲❈ ❨❲▲✚✙ ❈●❍❀❈●❋❃❙✰❈ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍✓✦③❨✁❈❄✐❃❋✲❈❩❨☎❴✁✐ ✦ ⑧ ✴ ✠ ✶t✤ ⑧ ✴ ✠ ❧✓✳ ✶ ✵ ⑧ ✴ ✠ ✶❞❝✚ ❏✷❇✲❈✹✑✘q✼❨❲▲r❤❳■❑❏▼▲◆❚✬❋ ❚✬❣✺❈●❍❁■✽❏✷❚❲❍✁✛ ◗❃❱▼❈❩❨ ❖❘❚❲❍ ✑✘q✼❨❲▲✚✙ ❈●❍❀❈●❋❃❙✰❈❅❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱❯■❑❋❃❨ ❨✁❈❄✐❃❋✲❈❩❨ ❴✁✐✜✛ ⑧ ✴ ✠ ✶ ✤ ⑧ ✴ ✑✍✠ ✶ ✇✴ ❢✼❋❅❏✷❇✁▲✇❱✉❙●■✬❱▼❈ ♠ ✑✆✢✣✕ ♠ ▲✇❱✛❋✲❚✬❏ ✕●❈●❍✷❚✞■✽❋❃❨❪❋✲❚✬❏✿■❊❍✷❚✁❚✬❏✿❚✽❖ ◗✲❋✁▲◆❏▼✐✼✇ ✶❆✛❇✲❈❪▲❢❋✁❏✷❈●❍✷❈❩❱♣❏❅❚✽❖ ❏❀❇✲❈✄❋✲❈❂♣☛■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ▲✇❱P❏✺♣✛❚✽❖❘❚❑❤❳❨✂✇ ✱ ▲◆❍❁❱♣❏ ♠ ❋ ◗✲❡✑❈●❍✷❚✬◗❃❱❅■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡✞❱ ❋✲❈●❈❩❨ ❏✷❚ ❱▼❚✽❤◆①✬❈✌❇✲❚✬q❡ ❚✬❉❲❈●❋✲❈●❚✬◗❃❱ ♠ ❋✲❚✬❋✲❇✲❚❲❡ ❚✬❉✬❈●❋✲❈●❚✬◗❃❱❜❚✬❍❊❣❃■✽❍✰■✽❡ ❈●❏✷❍▼▲✇❙✑❋✲❚✬❋✲❇✲❚✬❡ ❚❲❉✬❈●❋✲❈●❚✬◗❃❱❜❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱❜▲◆❋✤✕ ✥ ✠ ✯ ■✬❱❊❱▼◗✎❴✲❣✲❍✷❚✼❴✁❤◆❈●❡✞❱❂✇s ❡❃■✽❡ ❣✁❤◆❈❩❱✉■✽❍✷❈ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡✞❱✕❏✷❚❫✐❃❋❃❨♥■❴❤ ❤t❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ♠ ❇ ✐✁❣❃❈●❍❀❈❄❡✮❣✺❚✬❋✲❈●❋ ❏♣▲❳■❴❤ ♠ ❉✬❈●❚✬❡ ❈●❏❀❍▼▲✇❙✉❚✬❍ ✏ ▲❢❚❲◗✲①✬▲r❤r❤r▲❳■❑❋ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋❃❱ ♠❏✷❚❜❣❃❈●❍▼❖②❚✬❍✷❡ ▲◆❋❃❨✁❈❄✐❃❋✁▲◆❏✷❈ ❚✬❍✛❨✁❈❄✐❃❋✁▲◆❏✷❈❝❇ ✐✁❣❃❈●❍❀❉✬❈●❚✬❡ ❈●❏✷❍♣▲❳❙❝❱♣◗✲❡ ❡✞■✽❏▼▲◆❚✬❋ ♠ ❏✷❚❜❖✠■❲❙✰❏✷❚✬❍▼▲✛✕●❈✛❤r▲◆❋✲❈❩■✽❍✿❚✬❣✺❈●❍❁■✽❏✷❚❲❍❁❱ ♠ ❈●❏✰❙✒✇ ✴ ❣✬❈●❈❖②❚✬❍✉▲◆❋❃❱▼❏❁■✽❋❃❙✰❈ ✥ ✁ ♠ ➛ ♠ ✜ ♠✲❇✽✯ ✇ ✶ ❣✬❈❩❙✰❚✬❋❃❨ ♠ ❏❀❇✲❈♦■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡ ❏❀❇❃■✽❏✿▲✇❱❜❨✁❈❩❱✷❙✰❍▼▲ ❴❃❈❩❨ ❇✲❈●❍✷❈❊❇❃■✬❱✕❤◆❚✒♣ ❈●❍ ❙✰❚❲❡ ❣✁❤◆❈❄❡ ▲◆❏▼✐✌❏✷❇❃■✽❋❏✷❇✲❈ ◗❃❱▼◗❃■✘❤ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡✞❱ ♠ ❏✷❇❃■✽❏✞■❑❍✷❈♥❚✽❖②❏✷❈●❋➤❴❃■✬❱♣❈❩❨ ❚✬❋ ◗✲❋❃❨✁❈●❏✷❈●❍❀❡❊▲◆❋✲❈❩❨ ❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❁❱❂✇✖❆✛❇✲❈✌■✽❣✲❣✲❍✷❚ ■✬❙❀❇ ❇✲❈●❍✷❈❪▲❳❱❏✷❚❧✐❃❋❃❨ ■✌❨✁❈●❉✬❍✷❈●❈☎❴✺❚✬◗✲❋❃❨ ❚✬❋ ❏✷❇✲❈❅❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱❊❏❀❚✡❴✺❈♥❙✰❚✬❡ ❣✲◗✲❏✷❈❩❨ ♠ ■✽❋❃❨ ❋✲❈❄❡✮❏ ✐❃❋❃❨ ❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❩❱❊❏❀❚ ❙✰❚❲❡ ❣✲◗✲❏✷❈❏✷❇✲❈ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱✿❚✽❖t❏✷❇✲❈ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋❃❱✿❈ � ❙❀▲◆❈●❋✁❏▼❤◆✐✼✇ ❆ ❇✲❈❝❣✲❍✷❚✼❴✁❤◆❈●❡❭♣ ▲❢❏❀❇♥◗✲❋❃❨✁❈●❏✷❈●❍✷❡♦▲❢❋✲❈❩❨ ❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❁❱✉■✽❍▼▲✇❱▼❈❩❱◗♣✛▲◆❏✷❇①✬❈●❍✷✐ ❙✰❚✬❋❃❙❀▲✇❱▼❈♥❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱❊❇❃■✘①❲▲◆❋✲❉❦❇✁▲◆❉✬❇✓❨✁❈●❉✬❍❀❈●❈♥❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱❂✇ ➢ ❤❢❏❀❇✲❚✬◗✲❉✬❇ ❏✷❇✲❈❅❋✁◗✲❡❫❴❃❈●❍❊❚✽❖ ❙✰❚ ❈ � ❙❀▲◆❈●❋✁❏❁❱❊❏✷❚→❴✺❈❨✁❈●❏✷❈●❍✷❡♦▲❢❋✲❈❩❨❪▲✇❱✛❇✁▲◆❉✬❇ ♠ ❏✷❇✲❈❝❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❩❱✿❏✷❇❃■❑❏ ■✽❍✷❈✉❖②❚✬◗✲❋❃❨❯❴✁✐✞❏✷❇✲❈❝❋✲❈❂♣ ■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ▲◆❋ ✥ ★ ✯ ■✽❍❀❈❝❚✽❖ ❱♣❡✞■✘❤r❤ ❚✬❍❁❨✁❈●❍❆✇❆✛❇✲❈✉▲✇❨✁❈❩■♦▲❳❱✕❏✷❚❊①❲▲❢❈❂♣ ❏✷❇✲❈ ❱▼❣❃■❲❙✰❈✁✕ ✥ ✠ ✯ ■✬❱✕■❯❱♣◗✎❴❃❱▼❣❃■✬❙✰❈ ❚❑❖ ■❊◗✲❋✁◗❃❱▼◗❃■✘❤t❱▼❣❃■✬❙✰❈❝❚✽❖ ❖❘❚❲❍✷❡✞■✘❤ ❣❃❚✒♣✛❈●❍✿❱▼❈●❍▼▲◆❈❩❱ ♠ ■✽❋❃❨❏✷❚ ❈●❡❫❴✺❈❩❨P❏✷❇✲❈❯❱▼❣❃■❲❙✰❈❝❚✽❖ ❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤ ❱♣❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱✛▲◆❋✁❏✷❚✞■ ❱♣❣❃■✬❙✰❈❝❚✽❖ ❖❘❚✬❍❀❡✞■✘❤ ❣❃❚✒♣✛❈●❍ ❱▼❈●❍▼▲◆❈❩❱✿❱♣❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱❂✇

❊✔✁✽✸ ✓✦✥⑧⑨ ✠ ✏ ✌ ☛ ✳ ✕❂⑨✳✍✒✗ ✻✏ ❈●❏ ✴✔✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ❴✺❈❯■ ❱♣❈❩❬✬◗✲❈●❋❃❙✰❈❜❚✽❖ ❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤✇❱ ❱✷■❑❏▼▲✇❱✪❖❘✐❲▲◆❋✲❉✞❏❀❇✲❈✉❖❘❚✽❤r❤◆❚✒♣✛▲◆❋✲❉ ❙✰❚❲❋❃❨❲▲❢❏♣▲❢❚❲❋❃❱ ④✴ ✂ ✳ ✶ ❨✁❈●❉ ✧ ✩ ✤ ⑥ ♠ ♣✿❇✁▲✇❙✷❇ ❡✞■✒❦✬❈❩❱ ✴✫✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ■✝❴❃■❲❱✪▲✇❱✿❚✽❖✬✕ ✥ ✠ ✯❲❝✴ ✂❍✦ ✶ ✧ ✩ ❂ ✧ ❑ ■✬❱✿❱▼❚✁❚✬❋♥■✬❱ ⑥ ❨ ■ ❝ ❷✬❶

Page 41: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✴ ✂❍➛ ✶ ❏✷❇✲❈●❍✷❈❝❈❄❡✁▲❳❱♣❏❁❱ ✴ ❥ ❘ ③ ✶ ✢✁� ❛ ♠ ❥ ✞ ❩ ♠ ❥ ✞ ③ ♠ ■✽❋❃❨❪❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱✾❈ ❵ ✢✣✕ ✥ ⑥ ✯ ❱▼◗❃❙❀❇❅❏✷❇❃■✽❏ ❖❘❚✬❍✿■✘❤r❤ ⑥✍ ✧ ✩ ✤ ✂⑤❵ ❃☎✄ ❈ ❵ ✴ ⑥ ✶ ✧ ✩❴✸ ❵ ❘♣✛▲◆❏✷❇❂❈ ✄ ■✽❋❃❨ ❈ ✂ ❏✺♣✛❚ ❋✲❚✬❋✲q ✕●❈●❍✷❚P❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ♠ ■✽❋❃❨ ✧ ✩ ✤ ❩ ♣✿❇✲❈●❋ ⑥ ❨❬❩ ✇✏ ❈●❏ ✴✝✆ ✩ ✶ ✩ ★ ✪ ❴❃❈ ❏❀❇✲❈ ❨✁◗❃■✘❤☞❴❃■✬❱✪▲✇❱✕❚✽❖t❏✷❇✲❈ ✕ ✥ ✠ ✯ q✸❴❃■❲❱✪▲✇❱ ✴✌✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ✇❽④ ✐❅❨✁❈❄✐❃❋✁▲◆❏▼▲◆❚✬❋ ♠ ✆ ✩ ✴✔✧ ❑ ✶t✤✱✰ ✩❈➀ ❑ ■✽❋❃❨

✧ ✩ ✧ ❑ ✤ ⑤✭ ★ ✪ ✆ ✭ ✴✫✧ ✩ ✧ ❑ ✶ ✧ ✭ ❄➢ ❱✞■❦❙✰❚❲❋❃❱▼❈❩❬✬◗✲❈●❋❃❙✰❈✌❚✽❖ ✴ ✂➉✦ ✶❁♠ ❙✰❚❲❡ ❣✲◗✲❏▼▲◆❋✲❉ ❡ ❚✲❨✁◗✁❤❢❚ ✧ ✩ ■✽❋❃❨ ❙✰❚❲❋❃❱✪▲✇❨✁❈●❍▼▲◆❋✲❉ ❨✁❈●❉✬❍✷❈●❈❩❱✑✐✬▲◆❈✰❤✇❨✲❱ ✆ ✭ ✴✔✧ ✩ ✧ ❑ ✶P✤ ❩♣✿❇✲❈●❋ ⑦ ❨ ⑥ ✇➓❣✽▲❢❡♦▲ ❤✇■✽❍♣❤❢✐ ♠ ✆ ✭ ✴✔✧ ✩ ✧ ❑ ✶t✤ ❩ ♣✿❇✲❈●❋ ⑦ ❨ ■ ✇➋❢✼❏✛❖②❚✽❤r❤◆❚➍♣✉❱✿❏✷❇❃■❑❏✆ ✭ ✴✔✧ ✩ ✧ ❑ ✶☎✤ ❩ ♣✿❇✲❈●❋ ⑦ ❨ ❡✞■❆❡ ✴ ⑥ ❘ ■ ✶ ❚❲❍ ⑥ ❧ ■ ❨ ⑦ ❄❆✛❇✲❈✿❋✲❈❄❡✲❏ ❱▼❏✷❈●❣♦▲❳❱ ❏✷❚ ❙✰❚✬❋❃❱✪▲✇❨✁❈●❍ ❖❘❚✬❍❀❡✞■✘❤✲❣❃❚✒♣✛❈●❍ ❱▼❈●❍▼▲◆❈❩❱ ④ ❤◆❈●❏✟✞ ✴ ✠ ✶t✤➅➄ ✯✩✣❃✁❄ ✢ ✩ ✧ ✩ ✴ ✠ ✶ ❨✁❈●❋✲❚✬❏✷❈✿■✉❖②❚✬❍✷❡P■✘❤✣❱♣❈●❍▼▲◆❈❩❱ ♠■✽❋❃❨ ✕ ✥◆✥ ✴✌✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ✯◆✯ ❏✷❇✲❈❝①✬❈❩❙✰❏❀❚✬❍✿❱▼❣❃■✬❙✰❈ ❚❑❖ ■✘❤r❤ ❱▼◗❃❙❀❇♥❱▼❈●❍▼▲◆❈❩❱❂✇ ✏ ❈●❏ ✥ ✩ ❴❃❈❜❏✷❇✲❈✉❤r▲❢❋✲❈❩■❑❍✿❖②❚✬❍✷❡✞❱☎❚✽①✬❈●❍ ✴✌✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪❱▼◗❃❙❀❇✌❏✷❇❃■✽❏ ✥ ✩ ✴ ✞ ✶✛✤ ✢ ✩ ✇❝❆✛❇✲❈●❋ ✕ ✥❳✥ ✴ ✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ✯◆✯ ▲✇❱❝■☞✕ q✼■✘❤◆❉✬❈❂❴✲❍❁■✑❖②❚✬❍✉❏✷❈●❍✷❡❫♣✛▲✇❱▼❈❊❱▼◗✲❡ ■✽❋❃❨ ❚✬◗✲❏✷❈●❍✉❣✲❍✷❚✲❨✁◗❃❙✰❏ ♠■✽❋❃❨✑❖②❚✬❍✿❏✷❇✲❈✉❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉ ▲◆❋✲❋✲❈●❍✉❣✲❍✷❚✮❨✁◗❃❙✰❏✞✂❄ ✤ ✯⑤✭✥❃✁❄

✠✡ ⑤✩✼➀ ❑ ✹✮✭ ✹ ✩✽✸ ❑ ✥ ✩ ✴ ✞ ✶ ✥ ❑ ✴ ❄ ✶ ✆ ✭ ✴✫✧ ✩ ✧ ❑ ✶☞☛✌ ✧ ✭ ❄❆✛❇❃■✽❋✎❦✲❱✛❏✷❚ ✴ ✂❍➛ ✶❁♠ ❏✷❇✲❈❜❚✬❣❃❈●❍✰■✽❏✷❚✬❍ ✍ ▲✇❱✕❈❄❡✮❏❀❈●❋❃❨✁❈❩❨❅❏✷❚✎✍ ❚✬❋✣✕ ✥◆✥ ✴✌✧ ✩ ✴ ✠ ✶❀✶ ✩ ★✒✪ ✯◆✯ ❴ ✐❅❏❀❇✲❈✉❖❘❚✽❤r❤◆❚✒♣✛▲◆❋✲❉✞❍❀◗✁❤❢❈ ④✍✏✞ ✤ ✯⑤✩✍❃✁❄ ✪ ✫✑✄⑤❵ ❃✺✫ ✂ ❈ ✫ ❵ ✴ ⑥ ❧ ✍ ✶✝✥ ✩✽✸ ❵ ✴ ✞ ✶ ✢ ✧ ✩ ❄✞✕❚➍♣ ♠ ❖②❚✬❍ ■❑❋ ✐P❉✽▲◆①✬❈●❋ ⑧ ✢✣✕ ✥◆✥ ✴✌✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ✯◆✯✼♠ ✍ ☛❊✤ ⑧ ▲✇❱✿❈❩❬❲◗✁▲◆①❴■✘❤◆❈●❋✁❏❝❏✷❚✫✑✄⑤❵ ❃✺✫ ✂ ❈ ✫ ❵ ✴ ⑥ ❧ ✍ ✶ ✥ ✩✽✸ ❵ ✴ ☛✲✶t✤ ✆ ✩ ✴ ⑧ ✶✴ ✳ ✶❖②❚✬❍ ■✘❤r❤ ⑥ ✢✓✒ ✴ ♣✛▲◆❏✷❇ ✥ ✭ ✤ ❩ ♣✿❇✲❈●❋ ⑦ ❨❬❩ ✶ ✇❆✛❇✲❈ ❨✁❈●❉✬❍❀❈●❈✝❴❃❚❲◗✲❋❃❨♥■✽❋❃❨P❏✷❇✲❈❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❖❘❚✽❤r❤◆❚✒♣✖❖②❍✷❚✬❡③❏✷❇✲❈✉❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉✞❏✷❇✲❈●❚❲❍✷❈●❡✞❱ ✴ ❱♣❈●❈ ✥ ★ ✯②✶ ✇✙✝✚✟✛✢✜✤✣✂✛✎✥ ✳ ★✄✂✬✭✶✷✴✍ ☛❊✤ ⑧ ➏ ✫✢✭✶✵✺✭ ☛ ✹✼✻⑧❹ ⑧ ✹✼✵✺✭◗❸❖❁✼✲✴➒✒✻✔❁✼❃❫❉➔✹✼✲ ✽ ➡ ✩✬✫✢✭❆✻❨✁❈●❉ ☛ ✞✕✔ ✤ ❡✞■❆❡✉❭ ✵ ③ ✵ ✳ ❘ ❨✁❈●❉ ⑧ ✵ ③ ❘ ⑥ ✢✖�♥✽❂✰✳❺❂✫☎✷➔✫✢✹✼✷ ❈ ✂ ✴ ⑥ ✶t✤ ❩ ❛ ❄✙✝✚✟✛✢✜✤✣✂✛✎✥✧✦✔★✄✂✬✭✶✷ ✔ ❀➟✭➉❹✼✭ ❑✖✻✔✭❄❹❥✹✒✽❍❉➔✻➩✷➔✫✢✭❽❸✂✵❇✭❆➞✶❉➔❁✼✰❈✽❍✷➔✫✢✭❄❁✼✵✺✭✶❃ ➡ ➜✯✽❄✽ ✰✳❃❫✭ ✔ ✕ ❩ ➡ ✩✬✫✢✭❆✻ ✤ ✿ ❁❈✵➑✹✼✻✔➒➋✿ ❁❈✵❞❃❫✹✼✲❸❖❁❈➏✤✭✶✵❥✽❂✭✶✵❄❉➔✭❂✽ ☛ ✢ ✕ ✥❳✥ ✴ ✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪ ✯◆✯ ✤ ✷➔✫✢✭✖✿❂❁✼✲➔✲✴❁✼➏✤❉❀✻✳❅❯✹✼✵✺✭ ✭ ✢✶✰✳❉➔➞✶✹✼✲✴✭✶✻⑧✷▲➣✴ ✳ ✶ ✷➔✫✢✭❽✿ ❁✼✵❄❃❫✹✼✲✾❸❖❁✼➏✤✭❆✵➉✽ ✭❆✵❞❉➔✭❂✽ ☛ ❉●✽✝✹❥❸✎❁✼✲✴➒✒✻✔❁✼❃❫❉➔✹✼✲✂✽❂❁✼✲✴✰✢✷✸❉➔❁✼✻→❁✺✿✫✍ ☛✑✤ ⑧✘✗✴ ✦ ✶ ✷➔✫✢✭ ✥ ✩ ✴ ☛✣✶✑✙ ✽❍✽❂✹✼✷✸❉●✽❀✿❂➒⑤✭ ✢✶✰✳✹✼✷✸❉➔❁✼✻ ✘ ✳ ✤➑✿❂❁✼✵ ⑥ ✞✕✔ ❧ ③ ✹✼✻⑧❹ ✥ ✩ ✴ ☛✲✶ ✤ ❩ ✿ ❁✼✵ ⑥ ❨✕✔ ➡❷❛❝

Page 42: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☛❃☎✄ ⑨✡✌✔✓ ✥ ✆✂✏✒☛ ✍ ✄ ✞❆✛❇✲❈❝❉✬❚✁■✘❤ ▲❳❱✕❏✷❚ ✐❃❋❃❨♥■ ❴❃■✬❱✪▲✇❱✛❖②❚✬❍✛❏✷❇✲❈❊■✥�✞❋✲❈ ❱▼❣❃■✬❙✰❈❝❚❑❖ ①✬❈❩❙✰❏❀❚✬❍❁❱ ➂ ✢ ✕✁� ✫✑✄❃✸ ✂ ✸✺✹ ❏✷❇❃■✽❏✿❱✷■❑❏▼▲✇❱✪❖❘✐✫☎✄⑤❵ ❃✺✫ ✂ ❈ ✫ ❵ ✴ ⑥ ❧ ✍ ✶❈➂ ✩❴✸ ❵ ✴ ☛✣✶t✤ ✆ ✩ ✴ ⑧ ✶ ❄✴ ✦ ✶❅ ❖ ❙✰❚✬◗✲❍❁❱▼❈ ♠ ❏❀❇✲❈ ❨❲▲❢❍❀❈❩❙✰❏▼▲◆❚✬❋♥❚✽❖ ❏✷❇✲❈ ■✥�✞❋✲❈ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋✄❱▼❣❃■✬❙✰❈✉▲✇❱✛❉❑▲❢①❲❈●❋❤❴✁✐ ①✬❈❩❙✰❏✷❚✬❍✰❱ ❍❊❏✷❇❃■✽❏✿❙●■✽❋❃❙✰❈✰❤ ❏✷❇✲❈✉❤◆❈✰❖❘❏✿❇❃■❑❋❃❨✁q❱✪▲✇❨✁❈✼✇✛❆✛❇✲❈❝①✬❈❩❙✰❏✷❚✬❍✰❱ ➂ ■✽❋❃❨ ❍❊❍✷❈●❣✲❍✷❈❩❱▼❈●❋✁❏✉❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱✛▲◆❋✄✕ ✥ ✠ ✯ ❨✁❈●❋✲❚✬❏❀❈❩❨❯❴ ✐

❿ ✴ ➂ ❘ ⑧ ✶ ✤ � ✫✑✄❃✸ ✂⑤✩✍❃✁❄ ➂ ✩ ✧ ✩ ■✽❋❃❨ ☞ ✴ ❍ ✶t✤ � ✫✑✄❃✸ ✂⑤✩✍❃✁❄ ❍ ✩ ✧ ✩ ❍✷❈❩❱▼❣✺❈❩❙✰❏▼▲◆①✬❈✰❤◆✐✼✇❆✛❇✲❈✞❱♣❈●❏ ❚✽❖ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼▲◆❈❩❱✄✂ ✤ ❭ ⑥ ✢ ✒ ❂✲❈ ✄ ✴ ⑥ ✶t✤ ❩ ❛ ■✽❋❃❨ ❏✷❇✲❈ ❱♣❈●❏✆☎ ✤ ❭ ❩ ❘ ❄❩❄✘❄ ❘ ❥ ✵ ✳ ❛✾❆✝✂ ❣✁❤✇■✘✐ ■✽❋▲◆❡ ❣❃❚❲❍✷❏❁■✽❋✁❏ ❍ ✡❚✽❤◆❈✼✇ ❆✛❇✲❈❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❣✲❍✷❚✲❙✰❈●❈❩❨✲❱➉❴ ✐P▲◆❏✷❈●❍❁■❑❏▼▲◆①✬❈✰❤◆✐✄❙✰❚✬❡ ❣✲◗✲❏♣▲❢❋✲❉❅❏❀❇✲❈❯❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱✉❚❑❖ ❏✷❇✲❈ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋❃❱❂✇s ■❲❙✷❇❦❏♣▲❢❡✑❈✞■♥❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❜▲✇❱❝❋✲❚❲❏❝❖②◗✁❤ ❤◆✐ ❨✁❈●❏❀❈●❍✷❡❊▲◆❋✲❈❩❨❶❴✁✐✌❈❩❬✬◗❃■❑❏▼▲◆❚✬❋ ✴ ✦ ✶ ❚✬❍✉▲◆❏❁❱✉❤◆❈✰❖②❏❊❇❃■✽❋❃❨✁q✼❱✪▲✇❨✁❈ ♠ ▲▲✇★❈✼✇ ❖②❚✬❍❝❈❩■✬❙❀❇▲◆❋ ❏❀❈●❉✬❈●❍✛▲◆❋✞☎ ♠ ■❜❋✲❈❂♣ ❣❃■✽❍❁■❑❡ ❈●❏✷❈●❍✛▲✇❱✿■✬❨✲❨✁❈❩❨ ♠ ■✘❤◆❚✬❋✲❉⑤♣✛▲◆❏✷❇✌■✽❋❅❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❅❏✷❚❊❉✬◗❃■✽❍❁■❑❋ ❏✷❈●❈ ❙✰❚❲❋❃❱✪▲✇❱▼❏✷❈●❋❃❙✰✐☎❴❃❈●❏✺♣✛❈●❈●❋❏✷❇✲❈❝❈✰❤◆❈●❡ ❈●❋✁❏❁❱✕❚✽❖ ❏❀❇✲❈❥❴❃■✬❱✪▲✇❱✿◗✲❋❃❨✁❈●❍❝❙✰❚✬❋❃❱▼❏❀❍✷◗❃❙✰❏▼▲◆❚✬❋✬✇❆✛❇✲❈ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡③❡✞■✘▲◆❋✁❏❁■✘▲◆❋❃❱✿■❜❤r▲✇❱▼❏✉❚✽❖ ①✬❈❩❙✰❏❀❚✬❍❁❱ ✕ ♠ ■ ❤ ▲✇❱▼❏✉❚✽❖ ▲◆❋❃❨✁❈●❏✷❈●❍✷❡❊▲◆❋❃■✽❏✷❈❩❱✠✟ ♠ ■ ❤r▲✇❱▼❏✉❚✽❖ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱☛✡❦■✽❋❃❨■✽❋ ■❲❨✲❨❲▲❢❏♣▲❢❚❲❋❃■✘❤ ①✬❈❩❙✰❏❀❚✬❍ ➂ ✇ ❆ ❇✲❈ ①✬❈❩❙✰❏✷❚✬❍✰❱✕▲❢❋ ✕ ■✘❤◆❡ ❚ ❱▼❏✉❖②❚✬❍✷❡ ■❯❴❃■✬❱❞▲❳❱❜❚✽❖✛❏✷❇✲❈✞❨❲▲◆❍✷❈❩❙✰❏▼▲◆❚✬❋ ❱▼❣❃■✬❙✰❈✑❚✽❖ ❏✷❇✲❈P■✥�✞❋✲❈❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❦❱▼❈●❏✕❖②❚✬❍ ❏❀❇✲❈ ❇✲❚✬❡ ❚❲❉✬❈●❋✲❈●❚✬◗❃❱✉❈❩❬❲◗❃■✽❏▼▲◆❚✬❋✬✇➑❢✪❋❃❨✁❈●❈❩❨ ♠ ❏✷❇✲❈ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋❃❱❝■✽❍✷❈❝❤r▲◆❋✲❈❩■✽❍ ❙✰❚✬❡❫❴✁▲◆❋❃■✽❏▼▲◆❚✬❋❃❱✉❚❑❖ ❏✷❇✲❈●❡❍✷◗✁❤◆❈❩❨ ❴✁✐❦❏✷❇✲❈P❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱❜▲◆❋☞✡✤✇❦❆ ❇✲❈✞①✬❈❩❙✰❏❀❚✬❍ ➂ ❏✰■✒❦✬❈❩❱❝❏❀❇✲❈✞❋✲❚✬❋✲❇✲❚❲❡ ❚✬❉✬❈●❋✲❈●❚✬◗❃❱❜❣❃■✽❍❀❏❯❚❑❖ ❏❀❇✲❈❅❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❦▲◆❋✁❏✷❚■✬❙●❙✰❚✬◗✲❋✁❏✶✇ ❆ ❇✲❈ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱✕❏✷❇✲❈✉❖②❚✽❤r❤❢❚✒♣✛▲◆❋✲❉ ④✴ ✳ ✶ ❱▼❈●❏✣✕ ♠ ✟ ♠ ✡❦■✽❋❃❨ ➂ ❏✷❚❊❈●❡ ❣✲❏▼✐✑❤ ▲✇❱▼❏✰❱✿❚✬❍✕①✬❈❩❙✰❏✷❚✬❍❁❱ ❝✴ ✦ ✶ ❖❘❚✬❍✛❈❩■✬❙❀❇ ⑥ ❖❘❍❀❚✬❡ ❩ ❏❀❚ ✔ ✵ ❥ ❧ ③ ♠ ❣❃❈●❍▼❖②❚✬❍✷❡ ❣✬❏✷❈●❣❤➛❫♣✕❇✲❈●❋ ⑥ ✁✢✌☎ ♠ ❚✬❍✯❣✬❏✷❈●❣ ★ ♣✿❇✲❈●❋ ⑥ ✢✌☎ ♠ ❏✷❇✲❈●❋❉✬❚❊❏✷❚☎❣✬❏✷❈●❣ ✁ ❝✴ ➛ ✶ ✴ ✭✺❅✒✷✸✭✶✻✎✽❂❉➔❁✼✻ ✽ ✷✸✭➃❸ ✶ ❈❄❡✲❏✷❈●❋❃❨ ■✘❤r❤ ①✬❈❩❙✰❏✷❚❲❍❁❱❁❍✤✢ ✕ ✴ ❍✷❈❩❱♣❣✬✇ ➂ ✶ ❴ ✐ ◗❃❱✪▲◆❋✲❉ ❏✷❇✲❈♥■✽❣✲❣✲❍✷❚✬❣✲❍♣▲❳■❑❏✷❈P▲◆❋❃❱▼❏❁■✽❋❃❙✰❈❅❚✽❖❈❩❬✬◗❃■✽❏♣▲❢❚❲❋ ✴ ✦ ✶ ❚✬❍✛▲◆❏❁❱☎❤◆❈✰❖②❏ ❇❃■❑❋❃❨✁q✼❱✪▲✇❨✁❈ ❝✴ ★ ✶ ✴ ✽ ❉➔✻✢❅❈✰✢✲✴✹✼✵❄❉➔✷✸➒⑤✽❂✷✸✭✺❸ ✶ ❈❄❡✮❏✷❈●❋❃❨ ■✘❤r❤ ①✬❈❩❙✰❏✷❚✬❍ ❍✄✢ ✕✦■✽❋❃❨ ➂ ❴✁✐ ❩ ♠ ❏✷❇✲❈●❋ ■✬❨✲❨✌❏✷❇✲❈❊①✬❈❩❙✰❏✷❚❲❍ ✥ ❩ ❘ ❄❩❄✘❄ ❘ ❩ ❘ ✳ ✯ ✴ ❚✽❖❤❢❈●❋✲❉❲❏✷❇ ⑥ ❧ ✳ ✶ ❏❀❚✤✕ ♠ ■❲❨✲❨❅❏✷❇✲❈✉▲◆❋❃❨✁❈●❏✷❈●❍✷❡♦▲❢❋❃■❑❏✷❈✒✢ ✩ ❏❀❚ ❏✷❇✲❈✉❤r▲✇❱▼❏✍✟ ♠ ■✽❋❃❨✪✐❃❋❃■✘❤r❤◆✐✄■✬❨✲❨❪❈❩❬✬◗❃■❑❏▼▲◆❚✬❋ ✴ ✦ ✶ ❖②❚✬❍❏✷❇✲❈✿▲◆❋❃❨✁❈❄❡ ⑥ ✵ ❥ ✴ ♣✕❇✲❈●❋✞❋✲❚✬❋✲q②❋✲❈●❉✁■✽❏▼▲◆①✬❈ ✶❁♠ ♣✕❇✲❈●❍✷❈❝❈❩■✬❙❀❇ ➂ ✈ ❇❃■✬❱❽❴❃❈●❈●❋ ❍✷❈●❣✁❤✇■✬❙✰❈❩❨☎❴✁✐ ❏✷❇✲❈ ❱♣◗✲❡ ✢✤❍ ✈ ❚✽①✬❈●❍■✘❤r❤ ❣❃■✘▲◆❍❁❱ ✴ ✢ ❘ ❍ ✶ ✢ ✴ ✟ ❘ ✕ ✶ ❏✷❇❃■❑❏ ❇❃■✘①✬❈❥❴✺❈●❈●❋❦■✬❨✲❨✁❈❩❨✑▲◆❋✄■❊❣✲❍✷❈●①❲▲◆❚✬◗❃❱✉❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼✐♥❱▼❏✷❈●❣ ❝✴ ✁ ✶ ❤❢❈●❏ ✴ ✢ ✭ ❘ ❍ ✭ ✶ ❴✺❈❝❏✷❇✲❈✉❣❃■✘▲◆❍❁❱✿■✬❨✲❨✁❈❩❨✑▲◆❋✁❏✷❚ ✴ ✟ ❘ ✕ ✶ ❨✁◗✲❍▼▲◆❋✲❉✞❱❞▲❢❋✲❉❲◗✁❤❳■❑❍▼▲◆❏❞✐♥❱♣❏✷❈●❣❃❱✛■✽❋❃❨✞✡ ✴ ⑧ ✶ ❨✁❈●❋✲❚❲❏✷❈❝❏✷❇✲❈◗✐❃❋❃■✘❤❤ ▲✇❱▼❏✛❚✽❖ ❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱ ❙✰❚❲❡ ❣✲◗✲❏✷❈❩❨❯❴✁✐ ❏✷❇✲❈✉❣✲❍✷❈●①✬▲◆❚✬◗❃❱ ❣✲❍✷❚✮❙✰❈❩❱❀❱ ❝ ❣❃❈●❍▼❖②❚✬❍✷❡ ❏✷❇✲❈✕❖❘❚❑❤ ❤◆❚✒♣✛▲◆❋✲❉ ■✬❙✰❏▼▲◆❚✬❋ ♠ ■✬❙●❙✰❚✬❍✰❨❲▲❢❋✲❉❏✷❚❊❏✷❇✲❈❝❏▼✐ ❣✺❈ ❚✽❖ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❧❴❃❈✰▲◆❋✲❉❅❱▼❚✽❤◆①✬❈❩❨ ④✚ ✫✢❁✼❃❫❁❞❅❈✭✶✻✔✭❄❁✼✰❈✽ ④ ❱▼❚✽❤◆①✬❈ ❏❀❇✲❈✞❱▼✐✲❱▼❏✷❈●❡ ▲◆❋ ❏❀❇✲❈✹✢ ✭ ➫ ❱❝❙✰❚✬❡ ❣✺❚ ❱▼❈❩❨✌❚❑❖ ❏❀❇✲❈ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱✎✡ ✴ ⑧ ✶ ■❑❋❃❨✌❏✷❇✲❈❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱ ➄ ✭ ✢ ✭ ✆ ✩ ✴ ☞ ✴ ❍ ✭ ✶❀✶♥✤ ❩ ♠ ❖❘❚❲❍ ✔ ❨ ⑥ ✞ ✔ ✵ ❥ ❧ ③ ♠ ■✽❋❃❨ ❍✷❈●❏❀◗✲❍✷❋✖❏✷❇✲❈♥❉✬❈●❋✲❈●❍✰■✘❤❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋ ☛♦✤➅➄ ✭ ✢ ✭ ☞ ✴ ❍ ✭ ✶❞❝✚ ✻✔❁✼✻✾✫✢❁✼❃❫❁❞❅❈✭✶✻✔✭❄❁✼✰❈✽ ④ ❱▼❚❑❤❢①❲❈ ❏✷❇✲❈✞❱▼✐✲❱▼❏✷❈●❡ ▲◆❋ ❏✷❇✲❈✟✢ ✭ ➫ ❱❜❙✰❚✬❡ ❣❃❚✁❱▼❈❩❨✌❚✽❖✿❏✷❇✲❈ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✏✡ ✴ ⑧ ✶ ■✽❋❃❨❏✷❇✲❈❝❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱ ➄ ✭ ✢ ✭ ✆ ✩ ✴ ☞ ✴ ❍ ✭ ✶✷✶t✤ ✵ ✆ ✩ ✴ ❿ ✴ ➂✬❘ ⑧ ✶✷✶✰♠ ❖❘❚✬❍ ✔ ❨ ⑥ ✞✕✔ ✵ ❥ ❧ ③ ♠ ■✽❋❃❨P❍✷❈●❏❀◗✲❍✷❋❅❏✷❇✲❈❉✬❈●❋✲❈●❍❁■✘❤ ❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋ ☛✑✤ ➄ ✭ ✢ ✭ ☞ ✴ ❍ ✭ ✶ ❧ ❿ ✴ ➂ ❘ ⑧ ✶❞❝✚ ❸❖✹✼✵✺✹✼❃❫✭✶✷✸✵❄❉➔❺❬✻✔❁❈✻✎✫✢❁✼❃❫❁❄❅✼✭✶✻⑧✭❞❁❈✰✼✽ ④ ❱▼❚✽❤◆①✬❈ ❏✷❇✲❈ ❱♣✐✮❱▼❏❀❈●❡ ▲◆❋ ❏✷❇✲❈ ✢ ✭ ➫ ❱❦■✽❋❃❨ ✥ ❵ ➫ ❱✌❙✰❚✬❡ ❣✺❚ ❱▼❈❩❨ ❚✽❖❏✷❇✲❈ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱☛✡ ✴ ➄ ❑❵ ❃✺✹ ✥ ❵ ⑧ ❵ ✶ ■✽❋❃❨❪❏✷❇✲❈❝❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱ ➄ ✭ ✢ ✭ ✆ ✩ ✴ ☞ ✴ ❍ ✭ ✶✷✶ ✤ ✵ ✆ ✩ ✴ ❿ ✴ ➂✬❘ ➄ ❑❵ ❃✺✹ ✥ ❵ ⑧ ❵ ✶✷✶✷♠❖❘❚✬❍ ✔ ❨ ⑥ ✞✕✔ ✵ ❥ ❧ ③ ♠ ■✽❋❃❨✑❍✷❈●❏✷◗✲❍✷❋✑❏✷❇✲❈✿❉✬❈●❋✲❈●❍❁■❴❤ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤ ❱▼❚❑❤❢◗✲❏♣▲❢❚❲❋ ☛♦✤ ➄ ✭ ✢ ✭ ☞ ✴ ❍ ✭ ✶ ❧❿ ✴ ➂✬❘❞➄ ❑❵ ❃✺✹ ✥ ❵ ⑧ ❵ ✶ ✇

✑✬✁☎✄ ✄✑✆✂☛ ✳ ⑨ ✆ ⑩❍✍ ✄ ⑨ ✠ ✌✔✕ ☛ ✕ ✴✔✧ ✩ ✴ ✠ ✶✷✶ ✩✩★✒✪❆✛❇✲❈t❣✲❍✷❈●①❲▲◆❚✬◗❃❱ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❈●❋❃❨✲❱✂❴✁✐ ❱▼❚✽❤◆①✬▲◆❋✲❉❝■ ❤ ▲◆❋✲❈❩■✽❍ ❱♣✐✮❱▼❏❀❈●❡ ❏✷❇❃■✽❏ ❙✰❚✬❋❃❱✪▲✇❱▼❏✰❱ ❚✽❖❃■✽❏ ❡ ❚ ❱♣❏ ✫ ✵ ❥ ❧ ③ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱▲◆❋ ■❑❏ ❡ ❚ ❱♣❏ ✫ ✵ ❥ ✴ ❍✷❈❩❱♣❣✬✇ ✫ ✵ ❥ ❧ ■ ▲◆❋ ❏❀❇✲❈✞❣❃■✽❍✰■✽❡ ❈●❏✷❍▼▲✇❙ ❙●■❲❱▼❈ ✶ ①✽■✽❍▼▲✇■✒❴✁❤◆❈❩❱ ♠ ♣✿❇✲❈●❍❀❈ ✫ ▲❳❱❜❏✷❇✲❈P❋✁◗✲❡ ❴✺❈●❍ ❚✽❖❷❩❷

Page 43: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼▲◆❈❩❱➉❴✺❈●❏❇♣✛❈●❈●❋ ✵ ❥✦■❑❋❃❨ ✔ ✵ ❥ ❧ ③ ✇ ❆✛❇✲❈●❍✷❈✰❖②❚✬❍✷❈ ♠ ■✘①✬❚✽▲✇❨❲▲◆❋✲❉✞❱✪▲◆❋✲❉✬◗✁❤✇■✽❍♣▲❢❏♣▲❢❈❩❱✕❤◆❈❩❱✷❱♣❈●❋❃❱✿❏✷❇✲❈❝❙✰❚✬❡ ❣✁❤◆❈❄❡✁▲◆❏❞✐✼✇✏ ❈●❏ ✍ ✤♥➄ ✩ ✭❳❃✁❄ ① ✭ ✴ ✠ ✶✁� ✩ ♠ ♣✿❇✲❈●❍✷❈ � ▲✇❱✕❈✰▲❢❏❀❇✲❈●❍❝❚✽❖➋❼ ♠ ✦ ❚❲❍ ✛ ♠ ■✽❋❃❨✑❤◆❈●❏ ❾ ✤ ❡✞■❆❡ ❭✄✂●❂✆☎ ⑦ ✆ ➆ ✴ ① ✭ ✶ ✁✤ ❩ ❛✢✇✛❆✛❇✲❈❖②❚✽❤r❤❢❚✒♣✛▲◆❋✲❉❅❙✷❇✲❚❑▲❳❙✰❈❩❱ ❖②❚✬❍✿❏✷❇✲❈ ✧ ✩ ➫ ❱✛❱✷■✽❏♣▲❳❱❞❖❘✐❅❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱ ✴ ✂ ✳✞✝ ✂➉➛ ✶ ✇✚ ❹✼❉ ✟➉✭✶✵✺✭✶✻⑧✷✸❉❀✹✼✲⑧❺❞✹✘✽ ✭ ④ ✧ ✩ ✤ ✴ ✠ ✵ ❫ ✶ ✩ ❜ ⑥ q ♠ ❖❘❚❲❍ ❫ ❱▼◗❃❙❀❇P❏✷❇❃■✽❏ ① ✩ ✴ ❫ ✶ ✁✤ ❩ ❝ ♣ ▲❢❏❀❇✞❏✷❇✁▲✇❱❽❴❃■✬❱✪▲✇❱ ♠ ❋✲❚ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼✐❙●■✽❋❅❚✮❙●❙✰◗✲❍ ♠ ❥ ✤ ✡ ♠ ③ ✤ ❾ ♠ ■✽❋❃❨❈ ❵ ✴ ⑥ ✶t✤ ✲⑤➆ ❃✁❄ ✪ ⑥ ❧ ✍

✂ ✢ ✆ ➆ ✴ ① ➆ ✫ ❵ ✶❞❝✚ ❹✼❉ ✟➉✭✶✵✺✭✶✻⑧❺❞✭❥❺❄✹✒✽❂✭ ④ ✧ ✩ ✤ ❚ ❂ ✫✎◆✩ ❱ ♠ ❖②❚✬❍✿❫ P ❡✞■❆❡ ❭ ⑥ ✢✓✒ ❂ ① ✩ ✴ ⑥ ✶t✤ ❩ ❛ ❝ ♣✛▲◆❏✷❇❅❏❀❇✁▲❳❱➓❴❃■✬❱✪▲✇❱ ♠ ❋✲❚✞❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼✐❙●■✽❋❅❚✮❙●❙✰◗✲❍ ♠ ❥ ✤ ✡ ♠ ③ ✤ ❾ ♠ ■✽❋❃❨

❈ ❵ ✴ ⑥ ✶☎✤ ✩⑤✭❳❃✁❄ ✲⑤➆ ❃✁❄ ✪✲⑥ ❧ ✍✂ ✢ ✪ ✂✍ ❧ ⑦ ✢ ✆ ➆ ✴ ① ✭ ✶❞❝

✚ ✑ ☎✺❹✼❉ ✟❍✭✶✵✺✭✶✻⑧❺❞✭ ❺❞✹✘✽ ✭ ④ ✧ ✩ ✵ ✠ ✩ ❝ ♣✛▲◆❏✷❇ ❏✷❇✁▲✇❱✖❴❃■✬❱✪▲✇❱ ♠ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼✐✄❙●■✽❋❅❚✲❙●❙✰◗✲❍ ♠ ❴✲◗✲❏ ❥ ✤ ❩ ♠ ③ ✤ ❾ ♠ ■✽❋❃❨❈ ❵ ✴ ⑥ ✶ ✤ ✩⑤✭✥❃✁❄ ✑ ✩✽✭ ✆ ❵ ✴ ① ✭ ✶ ❄✠☞✁☛✡✟✆✑✏❈✞ ✌✔✓ ✻ ✆ ✂❫⑨ ✏ ✕❂⑨ ✏✒☛ ⑨✎✕⑤✕ ✆ ✓✸✗✂✍ ☛●✆ ✆✬✕❢✼❋♥❙✰❚❲❋❃❙❀❤❢◗❃❱❞▲❢❚❲❋ ♠ ▲◆❏ ❱▼❇✲❚✬◗✁❤✇❨❯❴❃❈❝❋✲❚❲❏✷❈❩❨ ❏❀❇❃■✽❏✛❏✷❇✲❈ ■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡③❏✷❇❃■❑❏ ❇❃■✬❱❽❴❃❈●❈●❋✌❨❲▲✇❱✷❙✰◗❃❱✷❱▼❈❩❨❅❙●■✽❋♥■❴❤❳❱♣❚ ❴✺❈❝◗❃❱▼❈❩❨P❏✷❚❙✰❚✬❡ ❣✲◗✲❏❀❈ ✴ ■P❨✁❈❩❱✷❙✰❍▼▲◆❣✲❏▼▲◆❚✬❋❦❚❑❖ ✶ ❖②❚✬❍✷❡✞■✘❤ ❣✺❚➍♣✛❈●❍❝❱▼❈●❍▼▲◆❈❩❱❝❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱✕▲◆❋ ✴✫✧ ✩ ✴ ✠ ✶✷✶ ✩ ★ ✪ ✇➑❢✼❋❃❨✁❈●❈❩❨ ♠ ❤◆❈●❏✌☞ ✤ ❡P■❆❡ ✴ ✂ ✶ ✇❆✛❇✲❈●❋✖❍✷◗✲❋✲❋✁▲◆❋✲❉ ❏❀❇✲❈♥❤◆❚✁❚✬❣✖❚✽❖ ❏✷❇✲❈❦■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ❖❘❚✬❍ ⑥ ✤ ❩ ❘ ❄✘❄❩❄ ❘ ☞ ■✽❋❃❨✖❙✰❚✬❡ ❣✲◗✲❏▼▲◆❋✲❉ ❏✷❇✲❈✂☞ ✴ ❍ ✶ ❖❘❚❲❍✰❍ ✢ ✕✐❲▲❢❈✰❤✇❨✲❱ ❏✷❇✲❈ ❱▼❈●❏❝❚✽❖ ■✘❤r❤ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ① ✢ ✕ ✥ ✠ ✯ ❚✽❖ ❨✁❈●❉✬❍✷❈●❈♦❤❢❈❩❱❀❱✉❏✷❇❃■✽❋♥❚❲❍❝❈❩❬✬◗❃■✘❤t❏✷❚✍☞ ❱▼◗❃❙❀❇✌❏✷❇❃■✽❏ ✍ ① ✴ ✠ ✶✛✤ ⑧❡ ❚✲❨✁◗✁❤◆❚ ✧✏✎ ✸✺✹ ✴ ✠ ✶ ✇ ❢✼❏❀❈●❍❁■✽❏▼▲◆❋✲❉❊▲◆❋✳✐❃❋✁▲◆❏✷❈✰❤◆✐♥❡✞■❑❋ ✐ ❏♣▲❢❡✑❈❩❱✿❏✷❇✲❈❝❈❄❡✲❏✷❈●❋❃❱✪▲◆❚✬❋♥❱♣❏✷❈●❣ ✴ ❴✁✐✞◗❃❱✪▲◆❋✲❉ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ✴ ✦ ✶✷✶ ✐✬▲◆❈✰❤✇❨✲❱■❜❖②❚✬❍✷❡✞■❴❤ ❣✺❚✒♣ ❈●❍✿❱▼❈●❍♣▲❢❈❩❱✕❏✷❇❃■✽❏ ▲❳❱✕■ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋✬✇✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛

✝ ❶✟✞q✹❈❽❦✦❍✤✖✇❹❇✖❵➣✮❜s❣✲▼✹⑤✲✵✴✶✲✜✷ ☛▼✦★❇❛❽✘✧✪✾♦✇❹✻⑤✩✪❊❾✿❄❇❛✇❹✽✘●✘✫❆✾✶✦❭✤❃✧✬❋✸✾♦❽✘✦❄✤➂✫❆➍✒✤❃✫❭✤❃✦❆✾❳✿❄❇✸❊✘❊✘✾❀✿❁✫❆✾❀✉❾➀✥✩✪✫★➍➥✤ ✻❆✾❏✤✖✦❍✿★➍❾❉✌❇❛✦✯✽✒❇✸✧✬■❑❊✘❇✸✇②✩❅✤✖✧✻❆❇✸✧✪●✘✫❆✩✪❇❛❊❦✻q❇✖❉♥✧✬✩✪❊✘✾❏✤✖✦✄✉❑✩ ✗➞✾♦✦★✾♦❊❑✫❆✩❅✤✖✧❈✤❃❊✒✉➣✉❩✩ ✗❣✾♦✦★✾♦❊✒✿❄✾➦✾✛✵❛●✔✤✖✫❆✩✪❇✸❊✘✻❀✲➔❲❳◆❏④❀❘❄◆✒✑✔✓✚❱✘❫ ✜❪◗✶➅❄④♦❫✪❙✡✍❻▲❖◆✖❬❸➆✒➄✸❙✖✕❈❲❳❚❪❙⑦❨✗✕⑤▲ ✍❛➈❄◗✶➅♦❱✒◗❁❙✘✕ ❴❊✘➽❩❷❦❴✚❢❀❤✸➵❛❤❦❴❛✽✘✽✜✲✤✭❩❷❏✷✤✭❛❧❦✲✸✷✺➸▼✦❍✤❃❊✘✻❆✧❜✲✸❉⑦✦★❇❛✇ ➝➔✾♦✻❆✫★❊✚✲✒❺➛❇✸✻❆➠✸❇✖❵➞✲❑●❦❊✘✩✪❵➞✲✘s❩✾♦✦❀✲❦➼❈➝✼➝❈■✘✿★➍✘✩✪✻❆✧❜✲❑✇➛✤✖✫❀✲✸➠❑✩✪❽✒✾♦✦★❊✘✾♦✫❏✲ ❷✘❴✯❲✜✭❏✷✤✭❛❷✘✲

✝ ❝✌✞q✹❈❽❦✦❍✤✖✇❹❇✖❵➂✮✱s❣✲▼✹✯✲ ✴✶✲❣✷ ➜❸✤✖✫★✩✬❇✸❊✒✤✖✧➔✻❆❇❛✧✪●✘✫★✩✪❇❛❊✘✻q❇❃❉❈✧✪✩✬❊❦✾❀✤✖✦⑤✉❩✩ ✗❣✾♦✦★✾♦❊❑✫❆✩❅✤✖✧✥✤✖❊✒✉➋✉❑✩ ✗➞✾✶✦❆✾♦❊✒✿❁✾①✾✛✵❛●✔✤✖✫❆✩✪❇✸❊✘✻⑤➀✥✩✪✫★➍❻✽✒❇✸✧✬■❑❊✘❇✸✇②✩❅✤✖✧✿❄❇❑✾✔✓①✿❄✩✪✾♦❊❑✫★✻❀✲✙✓❣⑧✘⑧ ✖ ▲❖◆✖❬❸➆✒➄✸❙❆❚❏❙❜❫⑦◆✖❱✔❚✖P❦❲ ❚❪❙⑦❨✘◗♦❬✄❚❏❙❜❫⑦❘❁④❿❚✖❱✒➨✣❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫✌❘❍❚❃P✘➡➔❨ ✍❏④♦❫⑦❘❁④❁❴✸❵❛❇✸✧❜✲❪❝✸➉✘❴✖❊❦➽ ❶❩❶✸❴✘❢❀❤✸➵❛❤❦❴✖✽✘✽✚✲✬❶✣✭✬❶✘❶❄✷❶✮✭✸❝❛❷❦✲✖✷❻➸▼✦❍✤✖❊❦✻❆✧❅✤✖✫★✩✬❇✸❊②❇❃❉✎✫❆➍❦✾✛✚✔➍❑●✘✦★❊✒✤✖✧✜❵❑■❩✿★➍✘✩✪✻★✧✬✩✪✫★✾♦✧✗✑ ❊❦❇❛✩✔✇①✤✖✫★✾♦✇①✤❃✫❆✩✪➠❑✩❑✩✚✇①✤❃✫❆✾♦✇➛✤✖✫★✩❂✿★➍✘✾✶✻❍✿★➠❛❇✸✩ ✾✒✭♦✩✪➠❑✩❜✲

✝ ❷✌✞q✹❈❽❦✦❍✤✖✇❹❇✖❵✄✮✱s⑨✲❛✹✯✲ ✴➔✤✖❊✒✉ ☛✚✾✶✫❆➠❛❇✖❵✢✜✻★✾♦➠➛✮✱❺❻✲✵✴✶✲✖✷ ✥✜✩✪❊✒✉❑✩✪❊✘❋q✤❃✧✬✧✁✣✶➒❜➍❞■❑✽✔✾♦✦❆❋✸✾♦❇❛✇❹✾♦✫❆✦★✩❅✿✥✻❆❇✸✧✪●✘✫❆✩✪❇❛❊❦✻✳❇✖❉✤✣✶➒❆✉❑✩ ✗➞✾✶✦❆✾♦❊✒✿❁✾❿✾✛✵❛●✔✤✖✫❆✩✪❇✸❊✘✻❀✲➐❜❊⑤✰⑨✾❀✿❄✧✪✾♦✦❍✿✣✮ ✌❸✲✵✴✎✤❃❊✒✉☛➸✥➍✘✩✪❽✒❇✸❊✄✮⑦➑✔✲❏➲❭✲✵✴▼✮✌✾❀✉❑✩✪✫❆❇✸✦❆✻❄✴♦❴✦✥⑨◆❃➅♦❬❭❚❃P✖➆✘◆✒✑❖◗✶➅✳④❀◗✶➅♦❫⑦◗❁④➯❚❃❱✒➨✯❚✖P ✣❛◗❏➈♦➅❄❚✖❫⑦❘✥❘❄◆✖❬✄➈✶❫❅❱✒❚❏❙❆◆✖➅✶❫⑦❘❄④♦✲❏✽✘✽✚✲❲❶❄✷✮❶❏❷✘✲❁✷✎✥❊❦✩✬❵✸✾♦✦❆✻★✩✪✫ ✓✾q✉❑✾q❺➦✤✖✦★❊✘✾❄➒❜✧❅✤❏➒❜➝❖✤✖✧✪✧ ✓✾♦✾❛❴❣❢❏❤❛❤❛⑩❦✲ ☛ ✦❆❇✘✿❄✾♦✾❀✉❩✩✬❊❦❋❛✻qs ✥✚✢➁✹ ✑✵➉ ❲✘✲

✝ ➳ ✞q✹❈❽❦✦❍✤✖✇❹❇✖❵✯✮✱s❑✾♦✦★❋❛✾♦✩❣✹✯✲✵✴♦❴✞✌✳✦★❇❛❊✘✻★✫❆✾♦✩✪❊➦✮❜❺➦✤✖❊❑●✘✾✶✧❂✴✶❴❞✤❃❊✒✉ ☛✜✾♦✫❆➠✸❇✖❵✢✜✻❆✾♦➠➛✮❜❺➦✤✖✦★➠❛❇❞✴✶✲❏✷★✧✥❱❹➡➎◆❃P ✍✖❱✒◆❃❬⑤❫⑦❚❃P✘⑧❣◆✖P↕➄✸❙❜❫⑦◆✖❱❩④✣◆❜⑥➯➢✎❫❅❱✔◗❍❚❃➅✧▼➆❩◗✶➅❍❚❪❙❯◆❃➅✯➃ ✘✶➄❩❚❪❙✱❫✌◆✖❱❑④♦✲✜✷ ➸▼✾❀✿★➍✘❊❦✩❂✿✶✤✖✧✥➜✥✾♦✽✔❇❛✦★✫⑤❊ ➽ ❷❩❷❪➒ ➳ ✭❛❧✘❴✜➐❜❊✘✻★✫❆✩✪✫❆●✘✫★✾➛❇✖❉❿❺➦✤❃✫❆➍✘✾♦✇➛✤✖✫★✩❂✿❁✻❀❴ ☛▼➍❑■❞✻★✩❅✿❄✻②✤✖❊✒✉❻❺ ✾❀✿★➍✒✤✖❊✘✩❅✿❄✻❏❴✎✥❊❦✩✬❵✸✾♦✦❆✻★✩✪✫❜■✄❇✖❉❖✰★✧❄●❦❽✘✧ ✧♦✤✖❊✒✤❦✲❞s❩✧✬❇✖❵✸✾♦❊✘✩❅✤✘✲✪❴✖✹❸✽✘✦❆✩✪✧➁❢❀❤❛❤✸⑩✘✲✁❶✮✭☛✽✒✤✖❋✸✾♦✻❀✲

✝ ❲✌✞✍✌➔✦❆❇❛❊❦✻❆✫❆✾✶✩✬❊➺✮✱❺❻✲✵✴✚✤❃❊✒✉ ☛✜✾♦✫❆➠✸❇✖❵✢✜✻★✾♦➠✯✮✱❺❻✲✵✴✶✲❄✷ ✠❸❊ ✠❸✦❆✾➁✦❆✩✪❊✘❋❛✻❏❴❏✧✬✩✪❊✘✾❏✤✖✦❣❇❛✽✔✾♦✦❄✤✖✫❆❇✸✦❆✻✳✤✖❊✔✉✥❉❜✤❛✿❄✫★❇❛✦❆✩✪✻❄✤✖✫❆✩✪❇✸❊✚✲❏➡❖➅❍◆✤✣✖➅❍❚✖❬✯❬✯❫❅➅❍◆ ✜❪❚❃❱✘❫⑦◗✶❴❊ ➽ ❶✸❴✚❢❀❤✸❤✖❶✔❴❛✽✘✽✜✲✘❝❛❡❏✷✒➳✶➳✔✲✸✷✺✹❸✧✬✻★❇❭✤❏❵❛✤❃✩✪✧❂✤❃❽✘✧✪✾❈✤✖✻❈➜➯✾♦✻❆✾❀✤❃✦❍✿★➍❳➜➯✾♦✽✒❇✸✦❆✫❈❝✸❷❛❷✘❴❑➐❜❊❩❉⑦❇❛✦★✇①✤✖✫★✩✪➠➞❴✸r▼➸❈♣✩✚✫✪●✘✦❆✩❅✿★➍✚✲

✝ ✭✌✞⑤➊♥❇✸✻❆✽✔✾♦✦♥✮✱➜☛✲❑➩➫✩✪✧✬✧✪✩❅✤✖✇②✴✶✲❏✷➣♠❈✾❏✿❄✩✪✻❆✩✪❇❛❊❹✽✘✦❆❇✘✿❄✾❀✉❩●✘✦❆✾☛❉⑦❇❛✦➁✩✪❊✒✉❑✾✿✾✔❊✘✩✪✫❆✾♥➍❑■❞✽✔✾♦✦★❋❛✾♦❇✸✇②✾♦✫★✦❆✩❅✿❸✻❆●✘✇❹✇①✤✖✫★✩✪❇❛❊✚✲✸➡❖➅❄◆❀❘❄◗❄◗❄➨✖❫❅❱✞✣❏④⑤◆❜⑥♥❙✌❨❩◗➤✣❚❪❙✱❫✌◆✖❱✒❚❃P✘③❿❘❄❚❛➨✸◗♦❬ ✍①◆❯⑥❸⑧➞❘♦❫✌◗♦❱✒❘❄◗❁④☛✓❣⑧❑③q❴❑❵❛❇✸✧❜✲✘❡ ❲✘❴❑❊❦➽✬❶❛❴✘➑❑✤✖❊❑●✒✤❃✦❆■➦❢❀❤✸✐❛➵❦❴❑✽✘✽✚✲✒➳❞❷❪✷➍➳❑❝✘✲

✝ ❡✌✞⑤s❑✩✪❊✘❋✸✾♦✦q✮❜❺➛✩❅✿❆➍✔✤✖✾♦✧ ✥➁✲✵✴♦✲❦✷ ✰⑨✩✪❇❛●✘❵❑✩✪✧✪✧✬✩❅✤❃❊②✻❆❇✸✧✪●✘✫❆✩✪❇❛❊❦✻❈❇✖❉➁✧✬✩✪❊✘✾❏✤✖✦❿✉❩✩ ✗❣✾♦✦★✾♦❊❑✫❆✩❅✤✖✧▼✾✶✵✸●✒✤❃✫❆✩✪❇❛❊✘✻❸➀✥✩✪✫❆➍❻✰❣✩✪❇❛●✘❵❑✩✪✧✪✧✪✩❂✤❃❊②✿❄❇❑✾✔✓①✿❄✩✪✾♦❊❑✫❆✻❏✲➇❑◆✖➄❑➅♦❱✒❚❃P✚◆❜⑥♥⑧ ✍✖❬❭➈❄◆✖P ❫⑦❘➺▲❖◆✖❬❸➆✒➄✸❙❯❚❪❙✱❫✌◆✖❱✘❴❦❵❛❇❛✧❜✲✁❶❩❶✸❴❣❢❀❤❛❤❦❢❛❴❑✽✘✽✜✲✘❝ ❲✬❶❁✷❩❝✸❡❩❷✘✲

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Page 44: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✆✑✏ ✒✟✞✡✠ ☛✪✝ ✁ ✓✞☛ ✌ ✆✞✏ ✡☞✄ ☛ ✝ ✁ ✠✁� ✁ ✓ ☛ ✏✞✆ ✠☞✁☞✁✒☛☞✞✡✓✑✕ ✞✞✝✠✟ ☛✾✁ ✡☞✄✑✄✵✡ ✓✵✁ � ✞✄✂❏✡✮✄✎�✜✡✮✄✒☛ ✡✮✕

✒ ✢ ✓✫✙✆☎✞✝✂✩✠✟ ✓✫✙◆✙❢❱✞➉✦☎✯s➛ ♠ ❣✬❏✷❍❁■✬❱✺❴✺❚✬◗✲❍✷❉▼✉❈❩❙✰❈●❡❫❴❃❈●❍ ✳ ✦ ♠ ✳ ➭✼➭ ★✥ ❱♣◗✲❡ ❡✞■✽❍✷✐✪❴ ✐☎④☎❍✷◗✲❋✲❚❤❣ ■❴❤❢①✁✐ ✯✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶

♠❸✩✪❵❛✾✶✦❆❋❛✾✶❊❞✫☛✻❆✾♦✦★✩✬✾✶✻❭✤❃✦❆✩✪✻❆✾❹❊✒✤✖✫★●✘✦❍✤❃✧✬✧✪■➦✩✪❊❻✇➛✤✖❊❑■➦✉❑✩ ✗➞✾♦✦★✾♦❊❑✫❭✿❁❇❛❊❑✫❆✾❄✈✘✫★✻❀✲➦➸✥➍❦✩✬✻☛✫❍✤✖✧✪➠❻✉❑✾♦✻❄✿❄✦❆✩✪❽✔✾♦✻✄✇②✩ ✈✘✾❀✉✻❆■❑✇✄❽✒❇✸✧✪✩❂✿❍➒✱❊❑●✘✇✄✾♦✦★✩❅✿♦✤✖✧❣✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇②✻➁✫❆❇①✉❩✾❀✤✖✧▼➀✥✩✪✫❆➍➦✫★➍✘✾♦✻★✾⑤✻★✾♦✦❆✩✪✾♦✻q➀✥➍❦✾♦❊➦✫❆➍❦✾♦■❳✤✖✦★✩✪✻❆✾♥❉⑦✦★❇❛✇✆✧✪✩✬❊❦✾❀✤✖✦♥✉❑✩ ✗➞✾♦✦❯➒✾♦❊❑✫❆✩❅✤✖✧❣✾✶✵✸●✒✤❃✫❆✩✪❇❛❊❦✻❀✲

⑥ ✆⑧✍ ✏✶✆ �➋✗ ✳ ✍ ☛ ✆ ✆➢ ❱✪▲◆❡ ❣✁❤◆❈✌❈❄❡✣■❑❡ ❣✁❤◆❈✄❚❑❖ ■ ❨❲▲◆①✬❈●❍✷❉✬❈●❋✁❏✞❋✁◗✲❡ ❈●❍▼▲✇❙●■✘❤ ❱▼❈●❍▼▲◆❈❩❱✑▲✇❱✑❚✼❴✲❏❁■✘▲◆❋✲❈❩❨➤♣✕❇✲❈●❋ ❱♣◗✲❡ ❡❊▲◆❋✲❉ ■ ❆ ■❩✐❲❤◆❚✬❍✞❱▼❈●❍♣▲❢❈❩❱❚✬◗✲❏❁❱❞▲❳❨✁❈❪▲◆❏❁❱✞❙❀▲◆❍❁❙❀❤◆❈✌❚✽❖ ❙✰❚✬❋✁①✬❈●❍✷❉✬❈●❋❃❙✰❈✼✇ ✔ ❚✬❍✷❈P①❲▲❢❚❑❤❢❈●❋✁❏♥❨❲▲◆①✬❈●❍✷❉✬❈●❋❃❙✰❈ ▲✇❱✑❈●❋❃❙✰❚✬◗✲❋ ❏❀❈●❍✷❈❩❨➤♣✿❇✲❈●❋✖❱▼❚✽❤◆①❲▲❢❋✲❉ ■ ❤ ▲◆❋✲❈❩■✽❍❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❅❤r▲ ❦✬❈ ❏❀❇✲❈❯st◗✁❤◆❈●❍✉❈❩❬✬◗❃■❑❏▼▲◆❚✬❋ ✠ ❛ ☛ ✎ ❧ ☛♦✤ ✠❴✁✐ ■✽❋❅◗✲❋❃❨✁❈●❏❀❈●❍✷❡❊▲◆❋❃■✽❏✷❈❊❙✰❚ ❈ � ❙❀▲◆❈●❋✁❏❝❡ ❈●❏✷❇✲❚✲❨✂✇ ❆✛❇✲❈❝❣✺❚➍♣✛❈●❍ ❱♣❈●❍▼▲◆❈❩❱✿❚✬❋✲❈❝❚❈❴✲❏❁■✘▲◆❋❃❱☎▲✇❱✿❏❀❇✲❈ st◗✁❤◆❈●❍ ❱♣❈●❍▼▲◆❈❩❱⑤✩✪✩✁❄ ✴ ✵❝✳ ✶ ✩ ⑥ q ✠ ✩✽✸✺✹ ❘♣✿❇✁▲✇❙❀❇❦❇❃■✬❱ ■P❍✰■✬❨❲▲◆◗❃❱❝❚✽❖✿❙✰❚✬❋ ①❲❈●❍✷❉✬❈●❋❃❙✰❈❊❈❩❬✬◗❃■❴❤ ❏✷❚ ❩ ✇❊❆✛❇✁▲✇❱❝❣✲❍✷❚✼❴✁❤◆❈●❡ ■✘❤✇❱▼❚♥❚✲❙●❙✰◗✲❍❁❱✉▲◆❋❦❋✲❚❲❋✲q ❤ ▲◆❋✲❈❩■✽❍ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ♠ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍✛❣❃❈●❍✷❏✷◗✲❍➟❴❃■✽❏▼▲◆❚✬❋❃❱ ♠ ❨❲▲✚✙ ❈●❍✷❈●❋❃❙✰❈ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ♠ ❚✬❍✛■✬❱▼✐✁❡ ❣✲❏✷❚✬❏▼▲✇❙✛■✽❋❃■✘❤◆✐✲❱✪▲✇❱ ✴ ❈✼✇★❉✔✇ ♠ ❴✁✐❊❏✷❇✲❈ ✏ ■❑❣✁❤❳■❲❙✰❈❡ ❈●❏✷❇✲❚✲❨ ✶ ✇❆✛❇✲❈ ④☎❚✬❍❀❈✰❤❢q▲❻ ▲❢❏❀❏♥❏✷❇✲❈●❚✬❍❀❈●❡ ❱▼❏❁■✽❏✷❈❩❱P❏❀❇❃■✽❏♥■✽❋✁✐ ❣❃❚✒♣✛❈●❍♥❱▼❈●❍▼▲◆❈❩❱❪❚✬❋ ■✽❋ ✐✖❱▼❈❩❙✰❏✷❚✬❍❅❚❑❖✝✐❃❋✁▲◆❏✷❈ ❚✬❣❃❈●❋✁▲◆❋✲❉ ▲◆❋ ❏✷❇✲❈❙✰❚✬❡ ❣✁❤◆❈❄❡♥❣✁❤✇■✽❋✲❈❜▲✇❱✿❏❀❇✲❈ ■✬❱▼✐✁❡ ❣✲❏✷❚✬❏▼▲✇❙✉❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋✌❚✽❖ ■❜❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❤♣✿❇✁▲✇❙❀❇❅▲✇❱✉■✽❋❃■✘❤◆✐ ❏♣▲❳❙ ▲◆❋✄❏❀❇✲❈ ❱▼❈❩❙✰❏✷❚✬❍✶✇❸✂✿❚✒♣✛❈●①✬❈●❍ ♠❏✷❇✁▲✇❱ ■✽❋❃■❴❤❢✐✁❏▼▲✇❙✑❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ▲✇❱❜❖✠■❑❍ ❖②❍✷❚✬❡ ❴✺❈✰▲❢❋✲❉ ◗✲❋✁▲✇❬✬◗✲❈✰❤◆✐ ❨✁❈●❏✷❈●❍❀❡❊▲◆❋✲❈❩❨ ♠ ♣✿❇✁▲✇❙✷❇ ❡✞■✘❦✬❈❩❱❜❋ ◗✲❡ ❈●❍♣▲❳❙●■❴❤ ❈●①❴■✘❤◆◗❃■✽❏♣▲❢❚❲❋❇✲❚✬❣✺❈✰❤❢❈❩❱❀❱❂✇ ❢✼❋ ❏✷❇✲❈ ❙✰❚✬❋ ❏❀❈❄❡✮❏❅❚✽❖✞❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤❯❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱❪❏✷❇✲❈ ❱✪▲◆❏✷◗❃■✽❏♣▲❢❚❲❋✖▲✇❱❅❡❊◗❃❙✷❇ ❴❃❈●❏✷❏✷❈●❍❧❴❃❈❩❙●■✽◗❃❱♣❈ ❚✽❖❊❏✷❇✲❈❖②❚✽❤r❤❢❚✒♣✛▲◆❋✲❉P❍✷❈❩❱▼◗✁❤◆❏✶✇✙✝✚✟✛✢✜✤✣✂✛✎✥ ✳ ★✄✂✬✭✶✷✕✁ ✴ ✠ ❘❳☛ ❄ ❘ ❄❩❄❩❄ ❘✥☛ ✩ ✶ ❀➨✭☎✹❈✻➅✹❈✻✔✹✼✲✴➒✒✷✸❉❀❺✯✿ ✰✳✻✔❺❆✷✸❉❀❁❈✻❬❁✺✿ ⑥ ❧ ✦ ➞✶✹✼✵❄❉❀✹✟❀❂✲✴✭❂✽☎✹✼✻✔❹ ✡⑧ ✢☛✡ ✥◆✥ ✠ ✯◆✯ ✹✿❂❁✼✵❞❃❫✹✼✲⑧❸✎❁✼➏✤✭✶✵ ✽❂✭✶✵❄❉❀✭ ✽✝✽❂❁✼✲✴✰✢✷✸❉➔❁✼✻❶❁➃✿ ✁ ✴ ✠ ❘✥☛✔❘ ❄❩❄●❄ ❘✥☛ P❢✩✣❘ ✶✿✤ ❩ ➡ ✩✬✫✢✭✶✻➝✷➔✫✢✭✶✵✺✭⑤✭ ❅➍❉●✽ ✷➔✽❫✹❤✵✺✭❞✹❈✲☞✻⑧✰✢❃❇❀➟✭✶✵ ⑦ P♥❩ ✽❂✰✢❺ ✫✷➔✫✢✹✼✷✾✿ ❁❈✵❍✹✼✲➔✲✂❁❄❸❖✭❆✻☎✽❂✭❞❺❆✷✸❁✼✵➟✽ ✞ ➏✤❉❀✷➔✫☎➞✶✭❆✵❞✷✸✭ ❅ ✹✼✷✤✷➔✫✢✭❫❁✼✵❄❉✴❅✼❉➔✻ ✤ ❁❄❸❖✭❆✻✔❉➔✻✢❅ ❨ ✪ ❜ ⑦ ✹✼✻⑧❹❫✽❂❃ ✹❈✲❀✲✂✭✶✻⑧❁✼✰✒❅✒✫➩✵✺✹✼❹✼❉➔✰❈✽ ✤ ✷➔✫✢✭❆✵✺✭✭✺❅✒❉ ✽❂✷➔✽✝✹➉✿❂✰✢✻⑧❺✶✷✸❉➔❁✼✻ ⑧ ➏ ✫✢❉❀❺ ✫❤❉ ✽✝✹❯✽❂❁✼✲✴✰✳✷✸❉❀❁✼✻➝❁✺✿ ✷➔✫✢✭✪❹✼❉ ✟➉✭✶✵✺✭✶✻⑧✷✸❉❀✹✼✲✟✭✣✢❆✰✢✹✼✷✸❉➔❁✼✻✄✁ ✴ ✠ ❘✥☛✔❘ ❄●❄❩❄ ❘❳☛ Pr✩✍❘ ✶☎✤ ❩ ✹✒✽❂➒➍❃◗❸✑✷✸❁❈✷✸❉❀❺✷✸❁ ✡⑧ ❁✼✻✪✞ ➡❆✛❇✁◗❃❱✛❏✷❇✲❈❜❡✞■✘▲◆❋♥❋✁◗✲❡ ❈●❍▼▲✇❙●■✘❤ ❣✲❍❀❚✼❴✁❤◆❈●❡ ▲❳❱✕❏✷❚ ❨✁❈●①❲▲❳❱♣❈❯❏❀❈❩❙✷❇✲❋✁▲✇❬❲◗✲❈❩❱✉❏✷❇❃■✽❏✖♣✛▲r❤r❤ ❱▼◗✲❡③❏✷❇✲❈❊❨❲▲❢①❲❈●❍✷❉✬❈●❋✁❏ ❱▼❈●❍▼▲◆❈❩❱✕❋✲❚✬❏❏✷❚❦①✽■✘❤◆◗✲❈❩❱P❚✽❖ ■✽❋ ✐ ■❑❋❃■✘❤◆✐ ❏▼▲✇❙ ❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋ ■✬❱♣✐ ❡ ❣✲❏❀❚✬❏▼▲✇❙P❏✷❚✌▲◆❏ ♠ ❴✲◗✲❏P❏✷❚❦①✽■✘❤◆◗✲❈❩❱P❚✽❖ ❏❀❇✲❈✄■✬❙✰❏✷◗❃■❴❤ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋✖❚✽❖❝❏✷❇✲❈❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋✄❙✰❚✬❍❀❍✷❈❩❱▼❣❃❚❲❋❃❨❲▲❢❋✲❉P❏✷❚❊▲◆❏✶✇ ❷ ❲

Page 45: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❊✔✁✁� ✓●⑨ ✞ ⑨ ✆⑧✍❂✌ ✏ ✱ ✞ ⑨✳✍ ✄✑✆ � ✕❆ ❚♦❙✰❚❲❡ ❣✲◗✲❏✷❈❝❏✷❇✲❈ ❱▼◗✲❡ ❚✽❖ ■❊❙✰❚✬❋✁①✬❈●❍✷❉❲❈●❋ ❏✛❣❃❚✒♣✛❈●❍ ❱▼❈●❍♣▲❢❈❩❱ ➄ ✩ ❫ ✩ ✠ ✩ ❚✬◗✲❏✰❱✪▲✇❨✁❈❝▲◆❏❁❱✿❙❀▲◆❍❁❙❀❤◆❈❊❚✽❖ ❙✰❚✬❋✁①✬❈●❍✷❉❲❈●❋❃❙✰❈ ♠ ❚✬❋✲❈✐❃❍❁❱▼❏❊❇❃■✬❱❜❏✷❚❦❨✁❈❄✐❃❋✲❈✌■♥❣❃■❑❏✷❇ ❙✰❚❲❋✲❋✲❈❩❙✰❏▼▲◆❋✲❉ ❏✷❇✲❈P❚✬❍▼▲◆❉✽▲◆❋ ❏✷❚✌❏✷❇✲❈✞❣✺❚✽▲◆❋ ❏✪♣✿❇✲❈●❍✷❈❅❏✷❇✲❈❅❱▼◗✲❡ ▲✇❱ ❨✁❈❩❱✪▲◆❍✷❈❩❨✂✇ ➢ ❴❃■❲❱✪▲✇❙❱▼◗✎❴✲❣✲❍✷❚❈❴✁❤❢❈●❡ ▲✇❱✉❏✷❇❃■✽❏❝❚✽❖ ❱▼◗✲❡✑❡❊▲◆❋✲❉♥■✘❤◆❚✬❋✲❉♥■P❍❁■✘✐❅❚✬❍▼▲◆❉✽▲◆❋❃■✽❏▼▲◆❋✲❉♥■✽❏❝❏❀❇✲❈❯❚❲❍▼▲◆❉✽▲◆❋ ■❑❋❃❨✄■✘①✬❚❑▲❳❨❲▲◆❋✲❉✌❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼▲◆❈❩❱❝❚✽❖❏✷❇✲❈✉❖②◗✲❋❃❙✰❏▼▲◆❚✬❋✬✇ ✏✺▲◆❋❃❨✁❈✰❤✄✂❚❑❖ ❉ ■✘①✬❈❝■ ❱✪▲◆❡ ❣✁❤◆❈❫♣✿■❩✐✑❚✽❖ ❨✁❚❑▲❢❋✲❉P❏✷❇✁▲✇❱✖❴✁✐ ❙✰❚❲❡ ❣✲◗✲❏▼▲◆❋✲❉✞❏❀❇✁▲❳❱✕①❴■❴❤❢◗✲❈❊■✬❱✛❏✷❇✲❈✉❤r▲◆❡❊▲◆❏❝❚✽❖❫ ❄ ❧ ❤r▲◆❡✈✆☎ ❄ ⑤✩✪✩✺✹ ❫ ✩ ✠ ✩ ✉ ✫ ✈ ✩ ✏ ✑✖✒ ✩ ❄✝✖❇✲❈●❋ ❏✷❇✲❈✛❱▼❈●❍▼▲◆❈❩❱ ▲✇❱ ❙✰❚❲❋ ①✬❈●❍❀❉✬❈●❋ ❏ ■✽❏ ✠ ♠ ❏✷❇✲❈☎❍✷❈❩❱▼◗✁❤◆❏ ▲✇❱ ❏✷❇✲❈✛❱▼◗✲❡ ❚✽❖❃❏❀❇✲❈ ❱▼❈●❍▼▲◆❈❩❱❂✇t❆✛❇✁▲✇❱ ❏✷❈❩❙❀❇✲❋✁▲❳❬❲◗✲❈✖♣✿■✬❱ ❉✬❈●❋✲❈●❍❁■❴❤ ▲✛✕●❈❩❨❴✁✐✺✂✉■✽❍❁❨✁✐P❏✷❚✞❱▼◗✲❡ ❨❲▲❢①❲❈●❍✷❉✬❈●❋✁❏ ❱▼❈●❍▼▲◆❈❩❱✕❚✽❖ ❏❀❇✲❈ ❱✷■✽❡ ❈❝❏▼✐✁❣❃❈ ■✬❱✛❏❀❇✲❈ st◗✁❤◆❈●❍ ❱♣❈●❍▼▲◆❈❩❱ ♠ ❴✁✐❅❙✰❚✬❡ ❣✲◗✲❏▼▲◆❋✲❉❫ ❄ ❧ ❫ ✹ ✠ ❧ ❫ ❛ ✠ ❛ ❧ ❤r▲◆❡✈✝☎ ❄ ⑤✩✪✩ ❋ ❫ ✩ ✠ ✩ ✉ ✫ ✈ ✏ ✑✓✒ ✩ ✏ ✑✓✒✆✏ ✑✖✒ ✩ ❄✴ ✳ ✶✥ ❋✁❖❘❚✬❍❀❏✷◗✲❋❃■✽❏✷❈✰❤◆✐ ♠ ❏✷❇✁▲✇❱✕❏✷❈❩❙❀❇✲❋✁▲❳❬❲◗✲❈❯❨✁❚✁❈❩❱✕❋✲❚✬❏➑❴❃❈●❇❃■✘①✬❈❝①❲❈●❍✷✐➩♣✛❈✰❤r❤ ❋✁◗✲❡ ❈●❍▼▲✇❙●■✘❤r❤◆✐✼✇❆✛❇✲❈✞❱❞▲❢❡✑❣✁❤❢❈❩❱♣❏❯❈ �❅❙❀▲❢❈●❋✁❏❊❏✷❈❩❙❀❇✲❋✁▲❳❬❲◗✲❈P❏✷❚✄❨✁❈❩■✘❤s♣ ▲❢❏❀❇ ❨❲▲◆①✬❈●❍✷❉❲❈●❋ ❏❊❱▼❈●❍▼▲◆❈❩❱❜❚✽❖ ❏✷❇✲❈✑❏❞✐✁❣❃❈✑❚✽❖✿❏✷❇✲❈✞st◗✁❤◆❈●❍ ❱▼❈●❍▼▲◆❈❩❱ ▲❳❱❙●■✘❤r❤◆❈❩❨➤✽❂✰✳❃ ❃❫✹✼✷✸❉➔❁✼✻➤✷✸❁❧✷➔✫✢✭☎✲✴✭❞✹✒✽❂✷✖✷✸✭✶✵❄❃❫✇❇✱✲❚✬❍✉▲◆❋❃❱▼❏❁■❑❋❃❙✰❈ ♠ ❏✷❇✲❈❊①❴■❴❤❢◗✲❈❩❱❜❚✽❖✛❏✷❇✲❈ ❱▼◗❃❙●❙✰❈❩❱✷❱✪▲◆①✬❈P❏✷❈●❍✷❡P❱✉❚✽❖ ❏✷❇✲❈ s ◗✁❤❢❈●❍❱▼❈●❍▼▲◆❈❩❱✉■✽❏✷✠ ✤ ✳ ❜ ✳ ❩ ■✽❍✷❈❄ ✳ ❩✼❩✼❩✼❩❈❩ ❘ ✵ ❄ ❩ ✳ ❩❈❩✼❩✒❩ ❘ ❄ ❩✼❩ ✦ ❩✼❩❈❩ ❘ ✵ ❄ ❩✒❩✼❩ ❇ ❩✼❩ ❘ ❄ ❩➍❩❈❩ ✦ ★ ❩ ❘ ✵ ❄ ❩✼❩❈❩ ✳ ✦ ❩ ❘ ❄ ❩✼❩✼❩✼❩ ✜ ✦ ❘ ✵ ❄ ❩✼❩✒❩✼❩ ✁ ❩ ❘ ❄ ❩❈❩✼❩✒❩ ★ ❩ ❘ ✵ ❄ ❩❈❩➍❩❈❩ ➛ ❇✎❘❄ ❩✼❩✼❩✼❩ ➛ ❇✎❘ ✵ ❄ ❩✼❩✼❩✼❩ ★ ❩ ❘ ❄ ❩✼❩✒❩✼❩ ★ ✾✎❘ ✵ ❄ ❩✼❩❈❩✼❩ ❇ ✦ ❘ ❄ ❩✒❩✼❩✼❩ ✾✭✜✳❘ ✵ ❄ ❩✼❩✼❩ ✳ ➛ ✳ ❘ ❄ ❩❈❩✼❩ ✦ ❩ ➭✎❘ ✵ ❄ ❩❈❩➍❩ ➛ ✁ ❇✎❘ ❄ ❩✼❩✒❩ ❇ ★ ❩ ❘ ✵ ❄ ❩✒❩ ✳ ✦ ✳ ❇ ❄❆✛❇✲❈ ■✘❴❃❱▼❚✽❤◆◗✲❏✷❈✉①❴■✘❤◆◗✲❈✉❚✽❖ ❏✷❇✲❈✿❏✷❈●❍✷❡P❱✟✐❃❍❁❱▼❏ ❨✁❈❩❙✰❍❀❈❩■✬❱▼❈ ♠ ❏❀❇✲❈●❋✞❍✷❈❩■❲❙✷❇✲❈❩❱☎■✉❡❊▲◆❋✁▲❢❡❊◗✲❡ ■❑❏ ❩ ✇ ❩✼❩✼❩❈❩ ➛ ❇✲♠ ■✽❋❃❨❊❈●①✬❈●❋✁❏✷◗❃■✘❤r❤◆✐▲◆❋❃❙✰❍✷❈❩■✬❱▼❈ ❏✷❚ ▲◆❋✳✐❃❋✁▲❢❏▼✐✼✇ ④ ✐ ❱▼◗✲❡✑❡❊▲◆❋✲❉ ❏✷❇✲❈❩❱▼❈❦❏✷❈●❍❀❡✞❱P◗✲❣ ❏✷❚ ❏✷❇✲❈ ❱▼❡P■✘❤r❤❢❈❩❱♣❏♥❚✬❋✲❈ ♠ ❚✬❋✲❈✌❉✬❈●❏❁❱P❏❀❇✲❈❦❋ ◗✲❡✑❈●❍▼▲✇❙●■✘❤①❴■❴❤❢◗✲❈ ❩ ❄ ❩ ➭ ✳ ✁✍★✒✁ ❇ ➛✼✦ ❩✼❩ ♠ ♣✿❇✁▲✇❙✷❇ ▲✇❱ ①✬❈●❍❀✐ ❙❀❤◆❚ ❱▼❈❅❏❀❚❦❏✷❇✲❈❅①❴■❴❤❢◗✲❈✌❚✽❖❝❏✷❇✲❈♥❙✰❚✬❍❀❍✷❈❩❱▼❣❃❚❲❋❃❨❲▲❢❋✲❉❧✿❂✰✢✻⑧❺✶✷✸❉➔❁✼✻✓❱♣❚✽❤◆◗✲❏▼▲◆❚✬❋ ❚✽❖❏✷❇✲❈♥❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ♠ ❋❃■✽❡ ❈✰❤◆✐ ❩ ❄ ❩ ➭ ✳ ✁ ❇ ➛✼➛✼➛✼➛ ➭ ★ ✇ ✥ ❱✪▲◆❋✲❉ ■❦❙✰❚❲❋ ①✬❈●❍❀❉✬❈●❋ ❏❜▲◆❋✁❏✷❈●❉✬❍❁■✘❤✿❍✷❈●❣✲❍❀❈❩❱▼❈●❋ ❏✰■✽❏▼▲◆❚✬❋ ❖②❚✬❍❏✷❇✲❈✞s ◗✁❤◆❈●❍❯❱▼❈●❍▼▲◆❈❩❱ ♠ ▲◆❏❝▲✇❱ ❋✲❚✬❏❯❨❲▲ � ❙✰◗✁❤◆❏❊❏✷❚♥❱▼❇✲❚✒♣ ✴ ❱▼❈●❈ ✥ ✁ ✯②✶ ❏✷❇❃■✽❏❝❏✷❇✲❈✑❈●❍✷❍✷❚✬❍❝❡✞■❲❨✁❈⑤❴ ✐ ❏✷❍✷◗✲❋❃❙●■✽❏♣▲❢❋✲❉ ❏✷❇✁▲✇❱ ❱▼❈●❍♣▲❢❈❩❱■✽❏✑▲◆❏❁❱❊❤◆❈❩■✬❱♣❏✞❏✷❈●❍❀❡ ▲✇❱P❈❄❡✲❣❃❚✬❋✲❈●❋✁❏▼▲✇■✘❤r❤◆✐ ❱♣❡✞■✘❤r❤ ✴ ♣✛▲◆❏✷❇ ❍✷❈❩❱♣❣❃❈❩❙✰❏❅❏✷❚ ✳ ❜ ✠ ✶ ✇ ❆✛❇✁▲✇❱ ❣✲❍❀❚✬❣❃❈●❍✷❏▼✐ ▲✇❱❅■✬❙✰❏✷◗❃■❴❤ ❤◆✐ ❡❯◗❃❙❀❇❡ ❚✬❍❀❈ ❉✬❈●❋✲❈●❍✰■✘❤ ✴ ❱▼❈●❈➉❴❃❈✰❤◆❚✒♣ ✶ ✇☎❆✛❇✲❈ ❨✁❍❁■❆♣➑❴❃■✬❙➟❦ ❚✽❖ ❏❀❇✁▲❳❱✕❉✬❚✁❚✮❨✑❣✲❍✷❈❩❙❀▲✇❱✪▲◆❚✬❋ ▲✇❱✛❏✷❇✲❈✉▲◆❡ ❣✺❚ ❱✷❱✪▲ ❴✁▲r❤r▲❢❏▼✐ ❚✽❖ ❚✼❴✲❏❁■❴▲❢❋✁▲◆❋✲❉❅■✽❋■✽❍➨❴✁▲◆❏✷❍✰■✽❍✷✐✉❣✲❍✷❈❩❙❀▲✇❱✪▲◆❚✬❋❫❴ ✐❝❏✷❇✁▲✇❱ ❡ ❈●❏✷❇✲❚✲❨✂✇ ❆✛❇✁▲✇❱ ▲✇❱ ❏✷❚◗❴❃❈✿❙✰❚✬❋✁❏✷❍❁■✬❱▼❏❀❈❩❨➑♣✛▲◆❏✷❇❜❏✷❇✲❈ ❨❲▲◆❍✷❈❩❙✰❏t❱▼◗✲❡ ❡P■✽❏▼▲◆❚✬❋ ❚❑❖✣❙✰❚✬❋✁①✬❈●❍✷❉❲❈●❋ ❏❣❃❚✒♣✛❈●❍t❱▼❈●❍▼▲◆❈❩❱ ♠ ♣✕❇✲❈●❍✷❈✛❏✷❇✲❈ ❏✷❈●❍❀❡✞❱ ❉❲❈●❋✲❈●❍❁■✘❤r❤◆✐✝✐❃❍✰❱▼❏ ▲◆❋❃❙✰❍✷❈❩■❲❱▼❈➑❴❃❈✰❖②❚✬❍✷❈✿❨✁❈❩❙✰❍✷❈❩■❲❱✪▲◆❋✲❉❝❏✷❚ ❩ ♠ ❴✲◗✲❏t❋ ◗✲❡ ❈●❍❀❚✬◗❃❱ ❏❀❈●❍✷❡✞❱ ■✽❍✷❈❋✲❈❩❙✰❈❩❱✷❱✷■❑❍✷✐❅❏✷❚ ❚✼❴✲❏✰■✘▲◆❋✄■✑❉✬❚ ❚✲❨❅❣✲❍❀❈❩❙❀▲❳❱❞▲❢❚❲❋✬✇ ➢ ❱ ■ ❙✰❚❲❋❃❱▼❈❩❬✬◗✲❈●❋❃❙✰❈ ♠ ❡P■✽❋ ✐❅❏❀❈❩❙✷❇✲❋✁▲✇❬❲◗✲❈❩❱✉❏✷❚✞❙✰❚✬❋✁①✬❈●❍✷❏✛❖②❍✷❚✬❡ ①❴■✽❍▼▲◆❚✬◗❃❱❍✷❈●❣✲❍✷❈❩❱♣❈●❋ ❏❁■❑❏▼▲◆❚✬❋❃❱✛❚✽❖ ■❜❖②◗✲❋❃❙✰❏▼▲◆❚✬❋♥❏✷❚ ■ ❨❲▲◆①✬❈●❍❀❉✬❈●❋ ❏❝❱▼❈●❍▼▲◆❈❩❱✛❇❃■✘①✬❈❥❴✺❈●❈●❋❦❨✁❈●①✬❈✰❤◆❚✬❣❃❈❩❨ ✥ ➛ ✯ ✇�✂✁✟✞ ⑨✳⑦ ✏ ⑨✭✱ ✌✔✕ ✱ ✞✼✻ ✍ ✆ ✍ ☛✆✳ ✕✡✠☞☛ ✆✂✏ ⑨✎✓❽✍ ✏ ✌ ✆ ✕ ⑩ ✆✑✏❈✞ ✠

⑦❅ ✕✒✗ ✞ ✞ ✌ ✠ ☛ ✓ ☛ ✍❳✱➢ ❉✬❚ ❚✲❨ ❖②❍❁■✽❡ ❈❂♣✛❚✬❍➨❦ ❏✷❚❦■✬❙●❙✰❚✬◗✲❋✁❏❊❖❘❚❲❍ ❏✷❇✲❈❅❋✁▲✇❙✰❈❤❴✺❈●❇❃■❩①❲▲◆❚✬◗✲❍P❚✽❖ ❙✰❚❲❡ ❡ ❚✬❋ ❨❲▲◆①✬❈●❍✷❉✬❈●❋✁❏ ❱♣❈●❍▼▲◆❈❩❱❊▲✇❱❊❣✲❍✷❚✽①❲▲✇❨✁❈❩❨❴✁✐✍✌➑✭❆➞✶✵✺✭✶➒→✹✒✽❂➒✒❃◗❸✑✷✸❁✼✷✸❉➔❺❂✽❂✇ ➢ ✌➑✭✶➞✶✵✺✭❆➒☎✽❂✭✶✵❄❉❀✭ ✽❊▲❳❱✑■❅❣❃❚✒♣✛❈●❍❯❱♣❈●❍▼▲◆❈❩❱✝♣✕❇✲❚ ❱▼❈✞❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱❂➫ ❉✬❍✷❚✒♣✿❏✷❇✌▲✇❱ ❴❃❚❲◗✲❋❃❨✁❈❩❨❴✁✐ ❵ ✴ ⑥ q ✶ ✹ ❖▼✭ ❥ ✩ ♠ ❖②❚✬❍❊❱▼❚✬❡ ❈✪✐✎❡✮❈❩❨➤❵ ❘ ❥ ❘ ⑦ P ❩ ✇ ❑ ❈●① ❍✷❈●✐ ■✬❱▼✐✁❡ ❣✲❏✷❚✬❏▼▲✇❙✑❈❄❡✮❣❃■❑❋❃❱✪▲◆❚✬❋❃❱ ■✽❍✷❈ ❑ ❈●①✁❍✷❈●✐ ❱▼❈●❍▼▲◆❈❩❱❜❖②❚✬❍♣✿❇✁▲✇❙❀❇♥❏✷❇✲❈❝❍✷❈●❡P■✘▲◆❋❃❨✁❈●❍✿❏✷❈●❍✷❡③❱✷■✽❏♣▲❳❱❇✐❃❈❩❱✿❏✷❇✲❈❝❱✷■✽❡✑❈❝❏❞✐✁❣❃❈❝❚❑❖☞❴❃❚✬◗✲❋❃❨✂✇ ✔ ❚✬❍✷❈✉❣✲❍✷❈❩❙❀▲✇❱▼❈✰❤◆✐ ♠ ♣✛❈ ❇❃■✘①✬❈❝❏✷❇✲❈✉❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉✔✇

✍ ✛✏✎✪✆✒✑ ✆ ➌ ✆➔✜✓✑ ✳ ★ ✏ ❈●❏ ⑦ ❴✺❈ ■❝❣✺❚ ❱✪▲◆❏▼▲◆①✬❈✉❍✷❈❩■✘❤ ❋✁◗✲❡❫❴❃❈●❍✛■✽❋❃❨❜❤◆❈●❏✣✞♥❴✺❈ ■✽❋✑❚✬❣❃❈●❋❅❱▼❈❩❙✰❏✷❚✬❍❽♣✛▲◆❏✷❇ ①✬❈●❍❀❏✷❈❄❡ ❩ ✇ ✏ ❈●❏ ⑧❴❃❈ ■✽❋❦■✽❋❃■❴❤❢✐✁❏▼▲✇❙ ❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋✄❚❲❋ ✞✪✇❝❆✛❇✲❈❜❖❘❚✬❍❀❡✞■✘❤ ❣✺❚➍♣✛❈●❍❝❱▼❈●❍▼▲◆❈❩❱ ✡⑧ ✤ ➄ ✩ ✩ ❄ ❫ ✩ ✠ ✩ ▲✇❱✔✌➑✭❆➞✶✵✺✭✶➒❯✹✒✽❂➒➍❃◗❸✑✷✸❁❈✷✸❉❀❺❯✷✸❁ ⑧❁✺✿✝❁✼✵✺❹✼✭❆✵✍☞ ✤ ✳ ❜ ⑦ ❁❈✻✤✞ ▲r❖ ❖②❚✬❍✿■✘❤r❤ ❙✰❚✬❡ ❣❃■❲❙✰❏ ❱♣◗✎❴✲q✼❱▼❈❩❙✰❏✷❚✬❍❁❱ ✢ ❚✽❖✭✞ ■❑❋❃❨❊❖②❚✬❍ ■✘❤r❤ ⑥ ✢✓✒ ♠ ❏✷❇✲❈●❍❀❈❝❈❄❡ ▲✇❱▼❏❍❵✖✕ P❬❩■✽❋❃❨❅❥ ✕ P❬❩ ❱▼◗❃❙✷❇❅❏❀❇❃■✽❏❂ ✠ ❂ ✫ ✩ ✗✗✗✗✗ ⑧ ✴ ✠ ✶ ✵ ✩❲✫❃✹⑤

②✺❃✁❄ ❫ ② ✠ ② ✗✗✗✗✗ ❨ ❵ ✕ ✴ ⑥ q ✶ ✹✶❖▼✭ ❥ ✩ ✕ ❘ ✘ ✠✣✢✔✢ ❘ ✠ ✁✤ ❩❷ ✭

Page 46: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

④☎✐❤❣✬❏♣▲❢❍♣❤ ▲◆❋✲❉✔➫ ❱✕❖❘❚✬❍❀❡❯◗✁❤✇■ ♠ ❏✷❍✷◗✲❋❃❙●■✽❏▼▲◆❋✲❉❅■ ❑ ❈●①✁❍✷❈●✐❅■✬❱▼✐✁❡ ❣✲❏✷❚✬❏♣▲❳❙✉❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋✌❚✽❖t❚✬❍❁❨✁❈●❍ ✳ ❜ ⑦ ❏✷❚ ❏❀❇✲❈❝❤◆❈❩■✬❱▼❏✿❏❀❈●❍✷❡❉✽▲◆①✬❈❩❱❊■✽❋ ❈❄❡✮❣✺❚✬❋✲❈●❋✁❏▼▲✇■✘❤r❤❢✐✖❱▼❡✞■✘❤r❤✛❈●❍✷❍✷❚✬❍ ✴ ▲◆❋ ✳ ❜ ✠ ✭ ✶ ✇✄❆✛❇✁▲✇❱❜▲✇❱❊❚❲❋✲❈✞❚✽❖✉❏✷❇✲❈ ❖✼■✬❙✰❈●❏❁❱ ❚✽❖ ❏✷❇✲❈✑▲◆❋ ❏❀❈●❍✷❈❩❱▼❏❊❚✽❖ ❑ ❈●① ❍✷❈●✐■✬❱▼✐✁❡ ❣✲❏✷❚❲❏▼▲✇❙●❱❂✇ ➢ ❋✲❚❲❏✷❇✲❈●❍ ❙✰❍❀◗❃❙❀▲❳■❴❤ ❣✲❍✷❚❲❣❃❈●❍✷❏▼✐ ♠ ❨✁◗✲❈ ❏✷❚✽✝ ■✽❏❁❱♣❚✬❋ ♠ ▲✇❱✿❏❀❇❃■✽❏✿❏✷❇✲❈●❍✷❈ ▲✇❱❝■✽❏✿❡ ❚ ❱♣❏✿❚✬❋✲❈ ■✽❋❃■✘❤◆✐✁❏▼▲✇❙✉❖②◗✲❋❃❙✰q❏▼▲◆❚✬❋ ⑧ ❑ ❈●① ❍✷❈●✐♥■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙❝❚❑❖ ❚✬❍❁❨✁❈●❍ ✳ ❜ ⑦ ❏❀❚✞■✞❱♣❈●❍▼▲◆❈❩❱ ✡⑧ ❚✬❋❦■✞❱♣❈❩❙✰❏✷❚✬❍✿❚✽❖ ❚❲❣❃❈●❋✁▲◆❋✲❉❅❤✇■✽❍✷❉❲❈●❍ ❏✷❇❃■❑❋ ✪ ❜ ⑦ ✇✿❆ ❇✁▲❳❱❣✲❍✷❚✽①❲▲❳❨✁❈❩❱✕❏✷❇✲❈❝◗✲❋✁▲✇❬❲◗✲❈●❋✲❈❩❱✷❱✉❋✲❈❩❙✰❈❩❱✷❱✷■✽❍❀✐ ❖②❚✬❍✿❋✁◗✲❡ ❈●❍▼▲✇❙●■✘❤ ❙✰❚❲❡ ❣✲◗✲❏❁■✽❏▼▲◆❚✬❋❃❱➓❴❃■✬❱▼❈❩❨❅❚❲❋❅❏✷❇✲❈ ❱▼❈●❍▼▲◆❈❩❱✉■✘❤◆❚✬❋✲❈✼✇✝ ▲◆❏✷❇❊❏✷❇✲❈✿❱✷■✽❡ ❈☎❇ ✐✁❣❃❚✬❏❀❇✲❈❩❱▼❈❩❱t■✬❱ ▲◆❋ ❆✛❇✲❈●❚✬❍✷❈●❡ ✳ ♠ ■✽❋❊❚✽❤✇❨❜❏✷❇✲❈●❚✬❍✷❈●❡ ❚❑❖ ✔✄■❴▲ ❤r❤◆❈●❏ ❱♣❏❁■✽❏✷❈❩❱ ❏✷❇❃■✽❏ ❏✷❇✲❈●❍✷❈✛❈❄❡✁▲❳❱♣❏❁❱ ⑦ P❩ ❱▼◗❃❙❀❇ ❏✷❇❃■✽❏ ✡⑧ ▲✇❱☎■ ❑ ❈●①✁❍✷❈●✐❊❱▼❈●❍▼▲◆❈❩❱t❚✽❖ ❚✬❍✰❨✁❈●❍ ✳ ❜ ⑦ ✇t❆✛❇✁▲✇❱t❍✷❈❩❱♣◗✁❤❢❏ ▲✇❱t◗❃❱▼❈✰❖②◗✁❤❃▲◆❋❅❙✰❚✬❋✍✵❞◗✲❋❃❙✰❏♣▲❢❚❲❋⑤♣✛▲◆❏✷❇✞■❜❙✰❚✬◗✲❋ ❏❀❈●❍✷❣❃■✽❍✷❏❚✽❖✿❆✛❇✲❈●❚✬❍✷❈●❡ ✳ ❨✁◗✲❈ ❏✷❚❤❻✿■✽❡♦▲❳❱❜■✽❋❃❨ ❣✽▲ ❴✲◗✲✐ ■➇♣✿❇✁▲✇❙✷❇ ❱♣❏❁■✽❏✷❈❩❱✉❏✷❇❃■❑❏✉▲ ❖ ✡⑧ ▲✇❱ ❑ ❈●①✁❍✷❈●✐✌❚✽❖✛❚✬❍❁❨✁❈●❍ ✳ ❜ ⑦ ❏✷❇✲❈●❋ ❏✷❇✲❈●❍✷❈❈❄❡✁▲❳❱♣❏❁❱ ⑦ ✎ ✕⑦ ❱▼◗❃❙✷❇✑❏✷❇❃■✽❏ ❖②❚✬❍ ■✽❋✁✐❯❱♣❈❩❙✰❏✷❚✬❍ ✞ ♣ ▲❢❏❀❇ ①✬❈●❍✷❏✷❈❄❡ ❩ ♠ ❚❲❣❃❈●❋✁▲◆❋✲❉ ❨ ✪ ❜ ⑦ ✎ ■✽❋❃❨P❱▼◗✁� ❙❀▲◆❈●❋ ❏♣❤❢✐P❱▼❡✞■✘❤r❤ ❍✰■✬❨❲▲◆◗❃❱ ♠❏✷❇✲❈●❍✷❈✕❈❄❡ ▲✇❱▼❏❁❱✛■ ❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋ ⑧ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋P❏✷❚❜❏✷❇✲❈ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋✪♣✿❇✁▲✇❙✷❇✑▲✇❱ ❑ ❈●① ❍❀❈●✐♦■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✛❚✽❖ ❚✬❍✰❨✁❈●❍ ⑦❏✷❚ ✡⑧ ✇✝❪☎❚✬❡❫❴✁▲❢❋✁▲◆❋✲❉ ❏✷❇✲❈❩❱▼❈ ❏✺♣✛❚P❍✷❈❩❱▼◗✁❤◆❏❁❱✉❈❄❡✲❣✁❤❳■❴▲❢❋❃❱✯♣✿❇✁✐♥❱▼◗✲❡ ❡❊▲◆❋✲❉❅❏✷❚P❏✷❇✲❈❜❤◆❈❩■✬❱▼❏❝❏✷❈●❍✷❡ ▲✇❱❝■ ❉❲❚ ❚✲❨ ❡ ❈●❏✷❇✲❚✲❨❅❖②❚✬❍❖②❚✬❍✷❡✞■✘❤ ❱▼❈●❍♣▲❢❈❩❱✉❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱✕❚✽❖ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤t❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱❂✇❢②❖ ✡⑧ ✤➅➄ ❫ ✩ ✠ ✩ ▲✇❱✿■ ❑ ❈●① ❍✷❈●✐❅❱▼❈●❍▼▲◆❈❩❱✕❚✽❖t❚✬❍❁❨✁❈●❍ ✳ ❜ ⑦ ♠ ❏❀❇✲❈●❋❅▲◆❏❁❱✁�➑❁✼✵✺✭✶✲✟✷✸✵❇✹❈✻✎✽➔✿ ❁✼✵❄❃ ❁✺✿❫❉❀✻⑧❹✼✭✺❅ ⑦ ▲✇❱✿❨✁❈❄✐❃❋✲❈❩❨✌■✬❱✴ ✡✄ ✭ ✡⑧ ✶ ✴✄✂ ✶t✤ ⑤✩ ✩ ❄

❫ ✩☎ ✴ ✳✛❧ ⑥ ❜ ⑦ ✶ ✂ ✩ ❄✱✲❚❲❍ ⑦ ✤ ✳ ♠ ❏✷❇✁▲✇❱❊❙✰❚✬❍✷❍❀❈❩❱▼❣❃❚✬❋❃❨✲❱❜❏✷❚✌❨❲▲◆①✬▲✇❨❲▲◆❋✲❉ ❏❀❇✲❈ ⑥ q②❏✷❇ ❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❫❴ ✐ ⑥ q ✇♥s ❱▼❏♣▲❢❡P■✽❏✷❈❩❱❜❚✬❋❦❏✷❇✲❈❅❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱❱▼❇✲❚✒♣ ❏✷❇❃■❑❏ ❏❀❇✁▲❳❱✕❏✷❍❁■❑❋❃❱✪❖❘❚❲❍✷❡ ▲❳❱✕■✽❋♥■✽❋❃■✘❤◆✐✁❏▼▲✇❙✉❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ✛ ✴✄✂ ✶ ✇ ❆ ❇✲❈●❋P▲ ❖ ❏❀❇✲❈ ✏ ■✽❣✁❤✇■✬❙✰❈❊❏✷❍❁■✽❋❃❱❞❖❘❚✬❍❀❡✈❚✽❖ ▲◆❋❃❨✁❈❄❡ ⑦

⑧ ✴ ✠ ✶t✤ ✆✲

⑦✛ ✴✄✂ ✶ ✉ ✫✞✝ ❙ ❖ ❂ ❙ ✂ ✭ ✫❃✹ ❾✟✂❙✰❚✬❋✁①✬❈●❍✷❉✬❈❩❱ ♠ ▲◆❏✿▲✇❱❝❙●■✘❤r❤◆❈❩❨ ❏✷❇✲❈❯❱▼◗✲❡ ❚✽❖ ✡⑧ ▲◆❋✌❏✷❇✲❈❯❨❲▲◆❍✷❈❩❙✰❏▼▲◆❚✬❋ ❾ ♠ ♣✿❇✲❈●❍✷❈ ❾ ▲✇❱ ■ ❱♣❏✷❍❁■✘▲◆❉✬❇✁❏✛❤r▲◆❋✲❈❊❖❘❍❀❚✬❡ ❩ ❏✷❚❊▲◆❋✳✐❃❋✁▲◆❏❞✐✼✇❆✛❇✲❈ ❱▼❈●❍▼▲◆❈❩❱ ✡⑧ ▲✇❱✉❏✷❇✲❈●❋❦❱✷■❴▲❳❨ ❏✷❚❯❴❃❈ ⑦ ☎❲✽ ✰✳❃❫❃ ✹✟❀❂✲✴✭⑤❉➔✻❶✷➔✫✢✭❯❹✼❉❀✵✺✭❄❺✶✷✸❉➔❁✼✻ ❾ ✇ ❆✛❇✲❈❊❙✰❚✬❋✁①✬❈●❍✷❉✬❈●❋❃❙✰❈❊❚✽❖ ❏✷❇✁▲✇❱✕▲◆❋✁❏✷❈●❉✬❍❁■✘❤ ▲❳❱❍✷❈✰❤✇■✽❏✷❈❩❨❪❏✷❚P❏✷❇✲❈ ❉✬❍❀❚➍♣✕❏✷❇✞❚❑❖ ✛ ■✽❏✛▲◆❋✳✐❃❋✁▲◆❏▼✐✼✇❍❢✪❏✿▲✇❱✕❈❩■✬❱▼✐❅❏✷❚P❱▼❈●❈ ❏✷❇❃■❑❏ ❏✷❇✲❈❊❆ ■✘✐❲❤◆❚✬❍ ❱▼❈●❍▼▲◆❈❩❱✉❚✽❖ ⑧ ▲✇❱✉❣✲❍✷❈❩❙❀▲✇❱▼❈✰❤◆✐ ✡⑧ ❱▼❚❏✷❇❃■✽❏✕❏✷❇✁▲✇❱✉❣✲❍✷❚✮❙✰❈❩❱❀❱✿✐❲▲◆❈✰❤❳❨✲❱❝■P❙✰❚✬❋✁①✬❈●❍✷❉✬❈●❋✁❏✿❍✷❈●❣✲❍❀❈❩❱▼❈●❋ ❏✰■✽❏▼▲◆❚✬❋❅❖②❚✬❍ ✡⑧ ✇✿❆✛❇✲❈ ❱▼◗✲❡ ❇✲❚✒♣✛❈●①✬❈●❍ ❨✁❈●❣❃❈●❋❃❨✲❱✉❚❲❋♥❏✷❇✲❈❜❣❃■✽❏✷❇❚✽❖ ▲◆❋ ❏✷❈●❉❲❍❁■✽❏▼▲◆❚✬❋ ❾ ♠ ▲❢❋ ❏✷❇✲❈ ❱✷■✽❡✑❈❥♣ ■✘✐ ■✽❋♥■✽❋❃■❴❤❢✐✁❏▼▲✇❙ ❙✰❚❲❋ ❏▼▲◆❋✁◗❃■✽❏▼▲◆❚✬❋✌❨✁❈●❣❃❈●❋❃❨✲❱✕❚✬❋♥■❊❣❃■✽❏✷❇✬✇☎❆✛❇✁▲✇❱✿❨✁❈●❣❃❈●❋❃❨✁❈●❋❃❙✰✐❪▲❳❱❍✷❈✰❤✇■✽❏✷❈❩❨❪❏✷❚❊❏✷❇✲❈✄✂✑✷✸❁ ✌➍✭❂✽✖❸⑧✫✢✭✶✻⑧❁✼❃❫✭✶✻✔❁❈✻✔✇✞✕◗✲❡ ❈●❍▼▲✇❙●■✘❤r❤◆✐ ♠ ▲❢❋ ❏✷❇✲❈ ❙●■✬❱▼❈❝❚❑❖ ❙✰❚✬❋✁①✬❈●❍✷❉❲❈●❋❃❙✰❈ ♠ ❏✷❇✲❈❝❣✲❍✷❚✼❴✁❤◆❈●❡ ▲✇❱✛❍✷❈❩❨✁◗❃❙✰❈❩❨ ❏✷❚ ✐❃❋❃❨❲▲◆❋✲❉ ⑦ ■✽❋❃❨❅❙✰❚✬❡ ❣✲◗✲❏▼▲◆❋✲❉P❏✷❇✲❈■✽❋❃■✘❤◆✐✁❏▼▲✇❙✿❙✰❚✬❋✁❏▼▲◆❋ ◗❃■❑❏▼▲◆❚✬❋ ❚✽❖ ✛ ✇ ❢✪❋ ❏✷❇✲❈ ❙●■✬❱♣❈ ❚❑❖ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱ ❚✽❖ ✲✴❉➔✻✔✭❄✹✼✵ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤❃❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ♠ ❏✷❇✁▲✇❱ ❙✰❚✬❡ ❣✲◗✲❏✰■✽❏▼▲◆❚✬❋▲✇❱ ❱✪▲◆❡ ❣✁❤r▲✴✐❃❈❩❨✪❴ ✐❊❋✲❚✬❏▼▲✇❙❀▲◆❋✲❉ ❏❀❇❃■✽❏ ⑦ ❙●■✽❋✪❴❃❈ ❨✁❈❩❨✁◗❃❙✰❈❩❨❜❖②❍✷❚✬❡ ❏❀❇✲❈ ❱❞❤❢❚❲❣❃❈❩❱t❚❑❖ ■ ✞✕❈❂♣✿❏✷❚✬❋❊❣❃❚❑❤❢✐✁❉✬❚✬❋ ■✬❱❀❱▼❚✮❙❀▲✇■✽❏❀❈❩❨❫♣✛▲◆❏✷❇❏✷❇✲❈❊❤r▲◆❋✲❈❩■✽❍ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ■✽❋❃❨ ❏✷❇❃■✽❏ ✛ ❱❀■✽❏▼▲✇❱❲✐❃❈❩❱ ■✑❤r▲◆❋✲❈❩■✽❍ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋ ❨✁❈●❍▼▲◆①✬❈❩❨✌❖②❚✬❍✷❡P■✘❤r❤❢✐❖②❍✷❚✬❡ ❏❀❇❃■✽❏ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❨➝❴✁✐ ✡⑧ ✇ ❆ ❇✲❈●❍✷❈✰❖❘❚❲❍✷❈❊▲◆❏❁❱❊❆ ■✘✐❲❤◆❚✬❍❯❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱❯❱❀■✽❏▼▲✇❱✪❖②✐ ■ ❙✰❚✬❡ ❣✲◗✲❏❁■✘❴✁❤❢❈✑❤r▲◆❋✲❈❩■✽❍ ❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈♣✿❇✁▲✇❙❀❇ ❙●■✽❋✪❴❃❈✉◗❃❱▼❈❩❨ ❏❀❚❝❚✼❴✲❏❁■✘▲◆❋ ❡✞■❑❋ ✐ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱☎❈ � ❙❀▲◆❈●❋✁❏▼❤◆✐✼✇✱④☎❈❩❱✪▲✇❨✁❈❩❱ ♠ ❏✷❇✲❈✕❣❃❚ ❱✷❱❞▲ ❴✁❤◆❈ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍♣▲❢❏♣▲❢❈❩❱ ❚✽❖ ✛ ■✽❍✷❈❤◆❚✮❙●■❑❏✷❈❩❨❅■✽❏✛❏✷❇✲❈ ✕●❈●❍✷❚✁❈❩❱✛❚✽❖ ❏❀❇✲❈✿❤◆❈❩■✬❨❲▲◆❋✲❉❅❙✰❚ ❈ � ❙❀▲◆❈●❋✁❏ ❚❑❖ ❏✷❇✲❈✉❤r▲◆❋✲❈❩■✽❍ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋P▲◆❏ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❱ ♠ ❱♣❚ ❏✷❇❃■✽❏▲◆❏t▲✇❱t❣✺❚ ❱✷❱✪▲ ❴✁❤◆❈✉❏✷❚ ❙✰❚✬❡ ❣✲◗✲❏✷❈✕❏✷❇✲❈ ❙✰❚✬❋✁❏▼▲◆❋ ◗❃■❑❏▼▲◆❚✬❋✞■✘❤◆❚✬❋✲❉❊■✉❣❃■✽❏✷❇⑤♣✿❇✁▲✇❙❀❇✞■✘①✬❚✽▲✇❨✲❱t❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼▲◆❈❩❱ ♠ ♣✛▲◆❏✷❇✞■➉❦✁❋✲❚➍♣ ❤❢❈❩❨✁❉❲❈❚✽❖ ❏✷❇✲❈❜❈❄❡✣■❲❙✰❏ ❍❁■❲❨❲▲❢◗❃❱✉❚❑❖ ❙✰❚✬❋ ①❲❈●❍✷❉✬❈●❋❃❙✰❈ ❚❑❖ ❏✷❇✲❈❊❣❃❚✒♣✛❈●❍ ❱▼❈●❍▼▲◆❈❩❱✉❚✬❋✲❈❜▲✇❱❝❙✰❚✬❡ ❣✲◗✲❏▼▲◆❋✲❉✔✇✉❆✛❇✁▲✇❱✉❣✲❍✷❚✲❙✰❈❩❱✷❱❝❙●■✽❋✄■❴❤❳❱♣❚➩❴✺❈■✽❣✲❣✁❤r▲◆❈❩❨❅❏✷❚❜❏✷❇✲❈❝❨❲▲❢①❲❈●❍✷❉✬❈●❋✁❏ ❱▼❈●❍▼▲◆❈❩❱☎❏✷❇❃■✽❏✛❚✲❙●❙✰◗✲❍ ■❲❱ ❣❃■❑❍✷❏ ❚✽❖ ❏✷❇✲❈ ■❲❱▼✐ ❡✑❣✲❏✷❚✬❏▼▲✇❙✕❈❄❡✮❣❃■✽❋❃❱❞▲❢❚❲❋❅❚✽❖ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱✛❚✽❖ ❤ ▲◆❋✲❈❩■✽❍❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ■❑❏ ■✽❋❊▲◆❍✷❍✷❈●❉✬◗✁❤✇■✽❍✛❱✪▲◆❋✲❉✬◗✁❤✇■✽❍✛❣❃❚✽▲◆❋✁❏ ♠ ❴✁✐ ✐❃❍❁❱▼❏ ❙✰❚✬❡✑❣✲◗✲❏▼▲◆❋✲❉❯■✉❤r▲◆❋✲❈❩■✽❍✿❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❱✷■✽❏♣▲❳❱❇✐❃❈❩❨☎❴✁✐✞❏✷❇✲❈❩❱♣❈ ❱▼❈●❍▼▲◆❈❩❱❂✇

✑✬✁✡✠ ✗ ✓●✍ ☛ ✕✘✗ ✞ ✞ ✌ ✠☞☛ ✓ ☛ ✍✥✱✞✕❚✬❏✿■✘❤r❤ ❱▼❚✽❤◆◗✲❏▼▲◆❚✬❋❃❱✛❚❑❖ ❤r▲◆❋✲❈❩■✽❍❝❨❲▲ ✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✕■✽❍✷❈ ⑦ q✼❱▼◗✲❡ ❡P■✒❴✁❤◆❈❝❖②❚✬❍✿❱▼❚✬❡ ❈ ⑦ ✇ ❅ ❋✲❈ ❍❀❈❩■✬❱▼❚✬❋✑❖❘❚❲❍✿❏✷❇✁▲✇❱▲✇❱✿❏❀❇❃■✽❏✛❏✷❇✲❈❝❚✬❍❁❨✁❈●❍✿❚❑❖ ❉✬❍❀❚➍♣✕❏✷❇✞❚❑❖ ■✽❋✄■❑❋❃■✘❤◆✐ ❏▼▲✇❙✕❖②◗✲❋❃❙✰❏▼▲◆❚✬❋✄■❑❏✛▲◆❋✳✐❃❋✁▲❢❏▼✐P▲✇❱✕❍✷❈✰❤✇■✽❏✷❈❩❨❅❏❀❚❯❏❀❇✲❈❝❉✬❍✷❚✒♣✿❏✷❇P❚✽❖ ▲❢❏✰❱✿❆ ■✘✐❲❤◆❚✬❍❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱❊■✽❏❝❏❀❇✲❈ ❚✬❍▼▲◆❉✽▲◆❋✬✇✞❆ ❇ ◗❃❱✯❴ ✐✌■✬❨✲❨❲▲◆❋✲❉ ■ ✳ q✼❱▼◗✲❡ ❡✞■✒❴✁❤◆❈❅■✽❋❃❨✌■❤✦✽q✼❱♣◗✲❡ ❡✞■✒❴✁❤◆❈✞❨❲▲◆①✬❈●❍✷❉❲❈●❋ ❏❊❱▼❈●❍▼▲◆❈❩❱ ♠ ❚✬❋✲❈❚✼❴✲❏❁■❴▲❢❋❃❱❊■✌❱▼❈●❍▼▲◆❈❩❱ ♣✿❇✁▲✇❙❀❇ ▲❳❱ ❑ ❈●①✁❍✷❈●✐❦❚✽❖✿❚✬❍❁❨✁❈●❍ ✳ ♠ ❴✲◗✲❏❊❏✷❇✲❈P❉✬❍✷❚✒♣✿❏✷❇ ■✽❏❝▲◆❋✳✐❃❋✁▲◆❏▼✐ ❚✽❖✛▲❢❏✰❱ ④☎❚✬❍❀❈✰❤ ❏❀❍❁■✽❋❃❱✪❖②❚✬❍✷❡☛❚✽❖❤◆❈●①✬❈✰❤ ✳ ▲✇❱t❈❄❡✲❣❃❚✬❋✲❈●❋✁❏▼▲✇■✘❤ ❚✽❖ ❚✬❍❁❨✁❈●❍s✦✎✇t❆✛❇✁▲✇❱ ❤◆❈❩■✬❨✲❱t❏❀❚ ❏✷❇✲❈ ❙✰❚❲❋❃❱✪▲✇❨✁❈●❍❁■✽❏▼▲◆❚✬❋P❚✽❖ ■ ❡ ❚✬❍✷❈✛❉✬❈●❋✲❈●❍✰■✘❤ ❙❀❤✇■✬❱✷❱ ❚✽❖ ❨❲▲◆①✬❈●❍✷❉✬❈●❋✁❏❱▼❈●❍▼▲◆❈❩❱❂✇ ❷❛❡

Page 47: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✍ ✛✏✎✪✆✒✑ ✆ ➌ ✆➔✜✓✑❶✦✔★ ✏ ❈●❏ ⑦ ✹ ❘ ❄❩❄✘❄ ❘ ⑦ ✩ ❴✺❈ ❍✷❈❩■✘❤ ❋✁◗✲❡❫❴❃❈●❍❁❱❝❱♣◗❃❙✷❇❦❏❀❇❃■✽❏ ⑦ ✹ P ↔❆↔✶↔ P ⑦✩ P ❩ ■❑❋❃❨ ❤◆❈●❏ ❾ ❴❃❈P■✑❤ ▲◆❋✲❈❖②❍✷❚✬❡ ❩ ❏✷❚P▲◆❋✳✐❃❋✁▲❢❏▼✐✼✇ ➢ ❖❘❚✬❍❀❡✞■✘❤t❣❃❚✒♣✛❈●❍ ❱▼❈●❍▼▲◆❈❩❱ ✡⑧ ✴ ✠ ✶ ▲✇❱ ✴ ⑦ ✹ ❘ ❄❩❄✘❄ ❘ ⑦ ✩ ✶ ☎▲✽❂✰✢❃❫❃❫✹✹❀ ✲❊✭❯❉➔✻ ✷➔✫✢✭❯❹✼❉➔✵✺✭❞❺❆✷✸❉❀❁✼✻ ❾ ▲r❖✿❏✷❇✲❈●❍✷❈❈❄❡✁▲❳❱♣❏❁❱❊■♥❣✺❚ ❱✪▲◆❏▼▲◆①✬❈P▲◆❋✁❏✷❈●❉✬❈●❍ ■ ❱▼◗❃❙❀❇ ❏❀❇❃■✽❏ ✡⑧ ✴ ✠ ✹✶❖ ❑ ✶ ▲✇❱❊■✌❱▼◗✲❡ ❚✽❖✌✡♥❱▼❈●❍♣▲❢❈❩❱ ✡⑧ ✹ ❘ ❄❩❄✘❄ ❘ ✡⑧ ✩ ♠ ❈❩■✬❙❀❇ ✡⑧ ❵ ❴❃❈✰▲◆❋✲❉ ⑦ ❵ ❜ ■❱▼◗✲❡ ❡P■✒❴✁❤◆❈❝▲◆❋♥❏✷❇✲❈ ❨❲▲◆❍✷❈❩❙✰❏♣▲❢❚❲❋ ❾ ✇➢ ❍✷❈❩❱▼◗✁❤◆❏✉❚✽❖ ❁ ◗✲❍➨❦❴■❑❏✿▲✇❱✉❏✷❇❃■✽❏✯✂ ■✽❍✰❨✁✐✑➫ ❱✕❱▼◗✲❡ ❡✞■✽❏♣▲❢❚❲❋❅❏✷❈❩❙✷❇✲❋✁▲✇❬❲◗✲❈ ✴ ✳ ✶ ♣✛▲r❤r❤ ❱▼◗✲❡☛■✽❋✁✐✞❡❊◗✁❤◆❏▼▲✇❱▼◗✲❡ ❡✞■✘❴✁❤❢❈ ❱▼❈●❍♣▲❢❈❩❱♣✛▲◆❏✷❇✲❚✬◗✲❏✕❇❃■❩①❲▲◆❋✲❉✞❏❀❚ ❦✁❋✲❚✒♣ ⑦ ✹ ❘ ❄✘❄❩❄ ❘ ⑦ ✩ ✇❆✛❇✲❈✕❖❘❚❑❤ ❤◆❚✒♣✛▲◆❋✲❉❊❍✷❈❩❙✰❈●❋✁❏ ❏❀❇✲❈●❚✬❍✷❈●❡③❨✁◗✲❈ ❏❀❚ ④☎❍❁■❲■✒❦✮❱♣❡✞■❝❨✁❈●❡ ❚✬❋❃❱▼❏❀❍❁■✽❏✷❈❩❱ ❏✷❇✲❈ ❍❀❈✰❤❢❈●①✽■✽❋❃❙✰❈ ❚❑❖ ❡❊◗✁❤◆❏▼▲✇❱▼◗✲❡ ❡P■✒❴✁▲r❤ ▲◆❏▼✐✼✇✙✝✚✟✛✢✜✤✣✂✛✎✥✧✦✔★✄✂✬✭✶✷✕✁ ✴ ✠ ❘❳☛ ❄ ❘ ❄❩❄❩❄ ❘✥☛ ✩ ✶ ❀➨✭☎✹❈✻➅✹❈✻✔✹✼✲✴➒✒✷✸❉❀❺✯✿ ✰✳✻✔❺❆✷✸❉❀❁❈✻❬❁✺✿ ⑥ ❧ ✦ ➞✶✹✼✵❄❉❀✹✟❀❂✲✴✭❂✽☎✹✼✻✔❹ ✡⑧ ✢☛✡ ✥◆✥ ✠ ✯◆✯ ✹✿❂❁✼✵❞❃❫✹✼✲⑧❸✎❁✼➏✤✭✶✵ ✽❂✭✶✵❄❉❀✭ ✽✝✽❂❁✼✲✴✰✢✷✸❉➔❁✼✻ ❁✺✿✆✁ ✴ ✠ ❘❳☛⑧❘ ❄✘❄●❄ ❘✥☛ P❢✩✣❘ ✶✿✤ ❩ ➡ ✂✬✭✶✷ ⑦ ✹ P ↔❆↔✶↔ P ⑦

✩ P ❩ ❀➟✭❯✷➔✫✢✭❥❸✎❁✒✽❂❉❀✷✸❉➔➞✶✭❫✽❂✲✴❁❄❸❖✭ ✽❁✺✿☎✷➔✫✢✭→✹✒✽❄✽ ❁❆❺✶❉➔✹✼✷✸✭❞❹✁� ✭❆➏✤✷✸❁✼✻→❸✎❁✼✲✴➒ ❅❈❁✼✻ ➡ ✩✬✫✢✭❆✻ ✡⑧ ❉ ✽ ✴ ⑦ ✹ ❘ ❄✘❄❩❄ ❘ ⑦ ✩ ✶ ✽❂✰✳❃ ❃❫✹✹❀ ✲✴✭❤❉➔✻❬✭✶➞❆✭✶✵❄➒❶❹✼❉➔✵✺✭❞❺❆✷✸❉❀❁✼✻ ❾ ✤ ✭✺❅✒❺❞✭➃❸✑✷❸❖❁✘✽❞✽❂❉ ❀ ✲✴➒ ✹✓❑✖✻✔❉➔✷✸✭✝✻⑧✰✢❃❇❀➟✭✶✵❥❁✺✿✝✷➔✫✢✭❆❃ ➡④☎❍❁■✬■✒❦✲❱▼❡✞■✾➫ ❱☎❣✲❍✷❚ ❚❑❖ ◗❃❱▼❈❩❱ ✣s ❙●■✘❤r❤◆❈✼➫ ❱✕❏✷❇✲❈●❚✬❍✷✐P❚✽❖ ■✬❙●❙✰❈✰❤◆❈●❍✷❚✬q✼❱▼◗✲❡ ❡P■✒❴✁▲r❤ ▲◆❏▼✐✼✇❢✼❋P❏✷❇✲❈✛❤r▲◆❋✲❈❩■✽❍✿❙●■✬❱▼❈ ♠ ■ ❏✷❈❩❙✷❇✲❋✁▲✇❬❲◗✲❈ ❨✁◗✲❈✉❏✷❚❫④ ■❴❤❳❱♣❈●❍ ❡✞■✒❦❲❈❩❱ ▲◆❏✛❣❃❚ ❱✷❱❞▲ ❴✁❤◆❈❝❏✷❚ ❙✰❚❲❡ ❣✲◗✲❏✷❈✉❏✷❇✲❈ ❱▼◗✲❡↕❴ ✐ ❙✰❚✬❡ ❣✲◗✲❏♣▲❢❋✲❉❱▼◗❃❙●❙✰❈❩❱✷❱❞▲❢①❲❈ ④☎❚✬❍❀❈✰❤ ❏✷❍✰■✽❋❃❱✪❖②❚✬❍✷❡✞❱✛❚❑❖ ▲◆❋❃❨❲▲✇❙✰❈❩❱✄✂ ➆ ❍✷❈✰❤✇■✽❏❀❈❩❨♥❏❀❚ ❏✷❇✲❈ ⑦ ❵❲➫ ❱➑❴✁✐ ✳ ❜ ⑦ ➆ ✤ ✳ ❜ ✂ ✹ ❧ ↔✶↔❆↔ ❧✖✳ ❜ ✂ ➆ ■✽❋❃❨ ❏✷❇✲❈●❋❍✷❈❩❙✰❚✽①✬❈●❍▼▲◆❋✲❉P❏✷❇✲❈✉❖②◗✲❋❃❙✰❏▼▲◆❚✬❋→❴ ✐❅❙✰❚✬❡ ❣✲◗✲❏▼▲◆❋✲❉❅❏✷❇✲❈ ❙✰❚❲❍✷❍✷❈❩❱▼❣✺❚✬❋❃❨❲▲◆❋✲❉❀✏ ■✽❣✁❤✇■✬❙✰❈❊❏✷❍❁■✽❋❃❱❞❖❘❚✬❍❀❡✞❱☎❚✽❖ ❚❲❍❁❨✁❈●❍☎✂ ➆ ▲◆❋♥❍✷❈●①❲❈●❍❁❱▼❈❚✬❍❁❨✁❈●❍❆✇ ➢ ❏❊❈❩■✬❙❀❇ ❱▼❏✷❈●❣ ♠ ❈❄❡✣■❲❙✰❏ ❤r▲◆❋✲❈❩■✽❍❅❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤✉❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱ ❙●■✽❋➤❴❃❈♥❙✰❚❲❡ ❣✲◗✲❏✷❈❩❨ ❖②❚✬❍❊❏✷❇✲❈❅①❴■✽❍♣▲❢❚❲◗❃❱ ❆ ■✘✐❲❤◆❚✬❍❱▼❈●❍▼▲◆❈❩❱✉■✽❋❃❨P❈❄❡❃■✬❙✰❏✛❤r▲◆❋✲❈❩■✽❍❝❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❩❱ ❖②❚✬❍✛❏✷❇✲❈✰▲◆❍ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱❂✇✄✝✆ ✆ ✳ ✓ ✗✬✕ ☛●✆ ✆✞✕◗✲❡ ❈●❍▼▲✇❙●■✘❤r❤◆✐ ♠ ❏✷❇✲❈✄❨❲▲ � ❙✰◗✁❤◆❏▼✐ ▲✇❱P❏✷❇❃■✽❏ ❈❩■✬❙❀❇ ❤◆❈●①✬❈✰❤ ❚❑❖❝▲❢❋✁❏✷❈●❉✬❍✰■✽❏▼▲◆❚✬❋ ▲✇❱P❏▼▲◆❡ ❈✄❙✰❚✬❋❃❱♣◗✲❡❊▲◆❋✲❉✓■✽❋❃❨ ▲❢❋❃❨✁◗❃❙✰❈❩❱ ■❣✲❍✷❈❩❙❀▲✇❱✪▲◆❚✬❋✌❤◆❚ ❱❀❱❂✇ ➢ ❏✉❏✷❇✲❈❜❡ ❚✬❡ ❈●❋✁❏ ♠ ❏✷❇✁▲✇❱✉❣✲❍✷❚✮❙✰❈❩❱❀❱✛▲✇❱❝❱▼❏▼▲r❤r❤t❤✇■✽❍✷❉✬❈✰❤◆✐❪▲❢❋✁❏✷❈●❍❁■❲❙✰❏▼▲◆①✬❈ ♠ ❋✲❚❲❏❁■✒❴✁❤◆✐♥❏✷❇✲❈❊❙✷❇✲❚❑▲❳❙✰❈❊❚✽❖ ❣❃■❑❏✷❇❃❱❚✽❖ ▲◆❋ ❏✷❈●❉❲❍❁■✽❏▼▲◆❚✬❋♥■✽❏✕❈❩■✬❙✷❇♥❱♣❏✷❈●❣✬✇✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛

✝ ❶ ✞ ✌➁✤✖✧✪✻❆✾♦✦➯✮⑦➩❻✾♦✦★❊✘✾♦✦❍✴✶✲❏✷ ✥➞➅❄◆✖❬ ➏❿❫ ✜❪◗✶➅✗✣❛◗♦❱❩❙✚➡➎◆ ✑❖◗♦➅➁⑧❣◗♦➅♦❫✌◗❄④➁❙❯◆➁③♥❱✒❚❃P ✍❏❙❜❫⑦❘✙✥❣➄❑❱✒❘❁❙✱❫⑦◆❃❱❑④♦✲❏✷②s❑✽✘✦❆✩✪❊✘❋✸✾♦✦❜➒❜➝✳✾♦✦★✧❅✤✖❋✒❴❦❢❀❤❛❤❃❶✒❴❃➢⑨◗❄❘❁❙✱➄❑➅❍◗➤✣◆❪❙❯◗❁④q❫❅❱➛❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄④♦❴❦❵❛❇❛✧❜✲✁❶❳❲✸❧❛❝✘✲

✝ ❝ ✞ ✌➔✦❍✤❛✤❃➠❑✻❆✇①✤ ✮✗✌❈✲▼✰✳✲❣➑✔✲✵✴♦✲⑨✷ ❺➛●✘✧✪✫❆✩✪✻★●✘✇②✇➛✤✖❽✘✩ ✧✬✩ ✫❜■②❇❃❉❖❉⑦❇✸✦❆✇➛✤✖✧▼✽✒❇✖➀➁✾♦✦q✻★✾♦✦❆✩✪✾♦✻✯✻❆❇✸✧✪●✘✫❆✩✪❇❛❊❦✻q❇✖❉✥❊✘❇❛❊❦✧✬✩✪❊✘✾❏✤✖✦♥✇②✾♦✦★❇❛✇❹❇❛✦❆✽❦➍✘✩❅✿✉❑✩ ✗❣✾♦✦❆✾♦❊❑✫★✩❂✤❃✧✚✾✶✵✸●✒✤❃✫❆✩✪❇❛❊❦✻❀✲✘③♥❱✘❱✒❚❃P✬◗❁④❭➨❛◗☛P ✘ ✆♦❱❑④❄❙❜❫✪❙✱➄✸❙✫✥✚◆✖➄❑➅♦❫✌◗♦➅♦❴✸❵❛❇✸✧❜✲✒➳❞❝✘❴❑❊ ➽ ❷✘❴✚❢❏❤❛❤✸➙✘❴✸✽✘✽✚✲✯❲✬❶❏❡❏✷✯❲❂➳❞❷❦✲

✝ ❷ ✞✣♠❸✩✪❊✘❋❛✧✪✾♥✮✱➜➯❇❛❽✔✾♦✦❆✫✔✌❸✲ ✴✶✲✸✷❳③♥④✎✍✖❬❈➆❦❙❯◆❪❙✱❫✌❘❸➃✞✝❄➆❩❚❃❱❑④♦❫⑦◆✖❱❑④✁↔✜❨✘◗♦❫ ➅✥➏✣◗✶➅♦❫ ✜✖❚❏❙❜❫⑦◆❃❱ ❚❃❱✒➨✟✆♦❱❩❙❯◗✶➅❜➆✒➅❄◗❄❙❆❚❏❙❜❫⑦◆❃❱✘✲✖✷➂✹❿✿♦✤✸✉❑✾♦✇②✩❅✿ ☛▼✦★✾♦✻❆✻❏❴

✰❣❇✸❊✒✉❑❇✸❊✚❴✘➭✥✾♦➀ ➲➁❇❛✦❆➠❣❴❣❢❏❤❛✐❛➾❦✲✝ ➳ ✞✣♣❈✤❃✦❍✉❑■ ✮✱➊✄✲✘♣☛✲✵✴♦✲❑✷❾➏❿❫ ✜❪◗✶➅✗✣❛◗♦❱❩❙❖⑧➞◗✶➅♦❫⑦◗❁④♦✲✸✷ ✠➯✈❑❉⑦❇✸✦❍✉ ✎✥❊✘✩✪❵✸✾♦✦❆✻★✩✬✫❜■ ☛ ✦❆✾♦✻★✻❀❴▼❢❀❤❃❶❞✐✘✲✝ ❲ ✞ ✠❸✧✪❵❛✾♦✦♥✮✗✥❖✲❦➩ ✲❑➑✒✲✵✴✶✲✸✷ ③♥④✎✍✖❬❈➆❦❙❯◆❪❙✱❫✌❘❄④q❚✖❱✒➨➺⑧❛➆✘◗❄❘♦❫⑦❚❃P✁✥❣➄❑❱✒❘❄❙❜❫⑦◆❃❱❑④♦✲❑✷❻✹❿✿♦✤✸✉❑✾♦✇②✩❅✿ ☛▼✦❆✾♦✻★✻❀❴▼❢❀❤✸✐✖❶✔✲✝ ✭ ✞✣➜❈✤❃✇②✩✪✻✜✮⑦➑✒✲ ➒ ☛▼✲✵✴❣✤✖❊✒✉♥s❑✩✪❽✘●✘■❑✤❸✮❅➲✄✲ ✴✶✲❄✷⑤♣✥●❦➠❞●❦➍✒✤✖✦❄✤❈✉❑❇✸✇①✤✖✩✪❊✘✻❣✤✖❊✔✉✥❉✌●✘❊✒✉✘✤❃✇②✾♦❊❑✫❍✤❃✧✖✾❄✈✘✩✪✻❆✫❆✾✶❊✒✿❄✾✥✤✖❊✒✉♥●❦❊✘✩✻✵❛●❦✾♦❊✘✾♦✻★✻✎✫★➍✘✾♦❇✸✦❆✾♦✇❹✻

❉⑦❇✸✦❈✤✖✻❆■❑✇❹✽✘✫❆❇✸✫❆✩❅✿➁✻❆❇✸✧✬●❦✫❆✩✪❇❛❊✘✻✥❇❃❉ ➊♥✾✶❵❞✦★✾♦■➛✫❜■❑✽✒✾❛✲✘③✣④✎✍✖❬❈➆❦❙❯◆❪❙✱❫⑦❘❸③♥❱✒❚❃P ✍❏④♦❫✪④♦❴❑❵❛❇✸✧✱✲✘❝❦❴❣❢❀❤✸➵❛❤✘❴✸✽✘✽✚✲✁❷❛➉❪✷❩➉❂➳✔✲✝ ❡ ✞✣➜❈✤❃✇②✩✪✻q✮✌➑✒✲ ➒ ☛▼✲ ✴☛✤✖❊✒✉❻s❑✩✪❽✘●❦■❞✤ ✮❅➲✄✲ ✴✶✲✔✷➌✹ ❊✘✾♦➀ ✽❦✦❆❇❑❇✖❉❈❇❃❉➎✇✄●✘✧✪✫★✩✬✻★●✘✇②✇②✤❏✫★✩✪✧✬✩ ✫❜■②❇❃❉✥❉⑦❇❛✦★✇①✤✖✧✜✻❆❇✸✧✬●❦✫❆✩✪❇❛❊✘✻☛❇✖❉✥❊✘❇❛❊❻✧✪✩✪❊✘✾❀✤❃✦

✇②✾✶✦❆❇❛✇❹❇❛✦★✽✘➍✘✩❅✿✥✉❑✩ ✗➞✾✶✦❆✾♦❊❑✫❆✩❅✤❃✧✚✾✶✵✸●✒✤❃✫❆✩✪❇❛❊✘✻❏✲✘③♥❱✘❱✒❚❃P✬◗❁④☛➨✸◗qP✙✘ ✆♦❱❩④❍❙❜❫✪❙❜➄✸❙✫✥⑨◆❃➄❑➅♦❫⑦◗✶➅♦❴❑❵❛❇✸✧✱✲❆➳✶➳✔❴❑❊ ➽ ❷❦❴❣❢❀❤✸❤✖❶✒❴❑✽❦✽✚✲✘❧✬❶✘❶❄✷❩❧ ➳❞❧❦✲✝ ❧ ✞✣➜❈✤❃✇②✩✪✻✳✮✌➑❛✾❀✤❃❊❑➒ ☛▼✩✪✾♦✦❆✦★✾❀✴♦✲❃✷❳⑧ ✚◗✶➅♦❫⑦◗❁④❈➨✖❫ ✜✖◗♦➅ ✣❃◗✶❱❑❙❆◗❄④❿◗❁❙✚❙✌❨ ✚◗❏◆✖➅✶❫⑦◗❄④❈❚❏④✎✍✖❬❸➆✘❙❆◆❏❙❜❫✙✘✶➄❩◗❁④♦✲✖✷①s❩❇❩✿❁✩ ✓✾✶✫ ✓✾❿❺ ✤✖✫❆➍✔✓✾♦✇①✤❃✫❆✩✻✵✸●✘✾❖✉❑✾ ✥❦✦❍✤❃❊✒✿❄✾❛❴

❢❀❤✸❤❛➾❦❴✔➡➎❚✖❱✒◆❃➅❍❚❃❬❭❚❪④☛◗❁❙➁⑧✏✍✖❱❑❙✌❨✡✠◗❁④✶◗❁④♦❴✘❵✸❇❛✧❜✲✲❶❀❝❲❶❛✲✝ ➉ ✞❿➸✥➍✘❇✸✇①✤✖❊❦❊➦✮⑦➑✸✾❀✤✖❊✔✴♦✲❑✷➫➜✥✾♦✻★❇❛✇❹✇①✤✖✫★✩↕❇✸❊❭✉❑✾✶✻❈✻ ✓✾✶✦❆✩✪✾♦✻❸❉⑦❇❛✦★✇②✾♦✧✪✧✪✾♦✻❏✲❞s❑❇✸✧✪●✘✫❆✩✪❇❛❊❦✻❈✉✒✑ ✓✾✶✵✸●✒✤✖✫★✩✬❇✸❊✘✻❈✉❑✩ ✗ ✓✾♦✦❆✾♦❊❑✫★✩✬✾✶✧✬✧✪✾♦✻❸✧✪✩✬❊✔✓✾❀✤✖✩✪✦❆✾✶✻❈✉❑●

✻❆✾❏✿❄❇❛❊✒✉❹❇✸✦❍✉❑✦★✾❿✉✘✤❃❊✘✻✳✧✪✾❈✿★➍✒✤✖✇❹✽❭✿❄❇✸✇②✽✘✧✪✾❄✈✘✾❈✤❃●✄❵❛❇❛✩✪✻★✩✬❊✔✤✖❋❛✾✥✉❑✾✥✻★✩✬❊❦❋❛●✘✧❅✤✖✦★✩✪✫ ✓✾♦✻✳✩✪✦★✦ ✓✾♦❋✸●✘✧✪✩☞✕✾✶✦❆✾♦✻❏✲✔➤❿➄❑❬❭◗✶➅♦❫✪④❀❘❁❨❩◗➯❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫☞☛❪❴❵❛❇✸✧❜✲✯❲❛❧✘❴❑❊ ➽ ❲✘❴✚❢❏❤❛❤✍✌✘❴✸✽✘✽✚✲✯❲❛❷✘❷❏✷✯❲❩❷ ❲❦✲

✝ ❶❀❷ ✞❿➸✥➍✘❇✸✇①✤✖❊❦❊ ✮✌➑❛✾❀✤❃❊✒✴♦✲➎✷ ☛▼✦★❇✘✿ ✓✾❀✉✛✓✾♦✻ ❉⑦❇✸✦❆✇②✾✶✧✬✻✄✾✶✫①❊❑●✘✇ ✓✾♦✦❆✩✻✵✸●✘✾♦✻➛✉❑✾➂✻❆❇❛✇❹✇①✤❃✫❆✩✪❇❛❊➣✉❑✾➂✻ ✓✾✶✦❆✩✪✾♦✻➦✻★❇❛✧✪●✘✫❆✩✪❇✸❊✘✻①✉✒✑✙✓✾✶✵✸●✒✤❃✫❆✩✪❇❛❊❦✻✉❑✩ ✗ ✓✾♦✦❆✾♦❊❑✫★✩✬✾✶✧✬✧✪✾♦✻❏✲❦✷ ☛▼✦★✾♦✽✘✦★✩✬❊❑✫❏❴✘✹❈✽❦✦❆✩✪✧✳❢❀❤✸❤✖❶✒✲

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Page 48: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�☎✞✡✠ ✞ ✓ ✞✵✏✑☛✪✝ �✝✆✑✕■✁☎✡✮✏ ✕✎✁ ✓✞☛ ✍ ✆ ✁✒✞✵✏✑✁✮✁✒☛ ✝ �❇✄✒✞ ✞✞✝✷✕ ✞✞✝✂✁ ☛✑✡ ✓ ✁✒☛ ✁✒☛ ✡✮✕

✄ ✞✆☎✢✠✬✝☎✢✒✞ ✗ ✛✟✞✞✝✡✠☞☛ ✓✟✠❢◗✞❍❻➓❢ ➢ ■✽❋❃❨ ✣s ❙✰❚✽❤◆❈ ✯ ❚❑❤❢✐✁❏✷❈❩❙❀❇✲❋✁▲✇❬✬◗✲❈❅ ❙✰❏❀❚✼❴❃❈●❍❥➛ ♠ ✳ ➭❈➭ ★✥ ❱♣◗✲❡ ❡✞■✽❍✷✐✪❴ ✐☎④☎❍✷◗✲❋✲❚❤❣ ■❴❤❢①✁✐ ✯

✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶♠✯✲✁✚✔✾♦✩✪✧✪❽✒✾✶✦❆❋❛✾✶✦q➍✒✤✖✻♥✻★➍✘❇✖➀✥❊❳➍❦❇✖➀ ✇①✤❃❊❑■①✿❄❇✸✇✄❽✘✩✪❊✒✤✖✫★❇❛✦❆✩❅✤❃✧❣✩❂✉❩✾♦❊❑✫❆✩✪✫❆✩✪✾♦✻♥✩✪❊❑❵❛❇❛✧✪❵❑✩✪❊✘❋✯✻❆✽✔✾❀✿❄✩❅✤✖✧▼❉✌●✘❊✒✿❄✫★✩✬❇✸❊✘✻

✿♦✤✖❊❹❽✒✾❸✽✘✦❆❇✖❵✸✾❀✉✄●✘✻★✩✪❊✘❋⑤✫★➍✘✾❈✫★➍✘✾♦❇✸✦❆■②❇❃❉✚➍✘❇❛✧✪❇✸❊✘❇❛✇❹✩❂✿ ✻❆✾✶✵✸●✘✾♦❊✔✿❄✾♦✻q✤✖❊✒✉❭❉⑦●✘❊✒✿❁✫❆✩✪❇❛❊✘✻❏✲✚➸✥➍❦✩✬✻➁➀➁❇❛✦❆➠✄✽❦✦❆✾♦✻★✾♦❊❑✫❆✻❿✤❋❛✾♦❊✘✾✶✦❍✤✖✧▼✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇②✩❅✿❖✤❃✽✘✽✘✦★❇❞✤❛✿★➍➛✫❆❇✯✫❆➍❦✾q✇✄●✘✧✪✫❆✩✪❵❛✤✖✦★✩❅✤❏✫❆✾❈✿♦✤❃✻❆✾❛❴❦✫❆❇❛❋✸✾♦✫❆➍❦✾♦✦❈➀✥✩✪✫❆➍➦✤❃❊②✩✪✇②✽✘✧✪✾♦✇❹✾♦❊❑✫❍✤❃✫❆✩✪❇❛❊✚✲

⑥ ✆⑧✍ ✏✶✆ �➋✗ ✳ ✍ ☛ ✆ ✆❣✬❣❃❈❩■✘❦✬▲◆❋✲❉ ▲❢❋✁❖②❚✬❍✷❡P■✘❤r❤❢✐ ♠ ▼❫✇✍✌❃❈✰▲r❤ ❴❃❈●❍❀❉✬❈●❍❅❇❃■✬❱ ❨✁❈❄✐❃❋✲❈❩❨ ❇✲❚✽❤◆❚✬❋✲❚✬❡❊▲✇❙P❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱♦▲◆❋ ✥ ✳ ❩ ✯ ■✬❱❜❏✷❇✲❚ ❱♣❈P❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱❚✽❖✿❚✬❋✲❈P❚✬❍❯❱♣❈●①✬❈●❍❁■✘❤✛①❴■✽❍▼▲✇■✒❴✁❤◆❈❩❱ ❱❀■✽❏▼▲✇❱✪❖②✐✬▲◆❋✲❉ ❱▼◗✁�❅❙❀▲❢❈●❋✁❏▼❤◆✐ ❡✞■✽❋✁✐ ✲✴❉➔✻✔✭❄✹✼✵P❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱ ✴ ❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤✛❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱❜❚✬❍❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈✿❍✷❈✰❤✇■✽❏▼▲◆❚✬❋❃❱ ✶ ♣ ▲❢❏❀❇❯❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱ ❱▼❚❝❏✷❇❃■❑❏ ❏✷❇✲❈●✐❊■✽❍✷❈✿❙✰❚✬❡ ❣✁❤◆❈●❏✷❈✰❤◆✐ ❨✁❈●❏✷❈●❍✷❡♦▲❢❋✲❈❩❨ ❴ ✐❊■◗✐❃❋✁▲❢❏❀❈❋✁◗✲❡ ❴✺❈●❍ ❚✽❖✿▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱P■✽❋❃❨ ■✡✐❃❋✁▲❢❏❀❈❅❋ ◗✲❡❫❴❃❈●❍✑❚✽❖ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤❝❙✰❚ ❈ � ❙❀▲◆❈●❋✁❏❁❱❂✇ ❆✛❇✲❈♥❱▼❏❀◗❃❨✁✐ ❚✽❖✉❏✷❇✲❈❩❱▼❈❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱✉▲✇❱❜❡ ❚✬❏▼▲◆①✽■✽❏✷❈❩❨❧❴ ✐✌❏✷❇✲❈✰▲◆❍❜❣❃❈●❍✷①✽■✬❱✪▲◆①✬❈●❋✲❈❩❱✷❱ ▲◆❋ ❙✰❚❲❡ ❴✁▲◆❋❃■✽❏❀❚✬❍▼▲✇❙●❱ ■✽❋❃❨ ❱▼❣❃❈❩❙❀▲✇■✘❤☎❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱❜❏✷❇✲❈●❚❲❍✷✐✼✇ ❆✛❇✲❈❙❀❤✇■✬❱✷❱✛❚❑❖ ❇✲❚✽❤◆❚✬❋✲❚❲❡❊▲✇❙✉❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱✿❈●❋✍✵▼❚✽✐✮❱✛❙❀❤◆❚ ❱▼◗✲❍❀❈ ❣✲❍✷❚✬❣✺❈●❍✷❏▼▲◆❈❩❱✕❏✷❇❃■✽❏✛❡✞■✒❦✬❈✉▲◆❏✿❣✺❚ ❱✷❱✪▲ ❴✁❤◆❈❊❏✷❚ ❙✰❚✬❋❃❱▼❏✷❍❀◗❃❙✰❏✿❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱❱✷■✽❏♣▲❳❱❇✐❃❈❩❨❶❴✁✐ ■❅❣❃■❑❍✷❏▼▲✇❙✰◗✁❤✇■✽❍❜❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋ ❖②❍✷❚✬❡ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱❊❱✷■❑❏▼▲✇❱❲✐❃❈❩❨❶❴✁✐ ❱✪▲◆❡ ❣✁❤◆❈●❍❜❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱❂✇✌❆✛❇✲❈❩❱▼❈P❚✬❣❃❈●❍❁■❑❏✷❚✬❍❁❱❙●■✽❋⑤❴✺❈ ❈❄❡✲❣✁❤◆❚✽▲◆❏✷❈❩❨❯❴✁✐❯❡P■✽❋ ✐❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡P❱❂✇ ❢✼❋P❣❃■✽❍✷❏▼▲✇❙✰◗✁❤✇■✽❍ ♠ ❱▼❈●❍▼▲◆❈❩❱☎❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❃❱t❚❑❖ ❇✲❚❑❤❢❚❲❋✲❚✬❡❊▲✇❙✛❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❅❙●■✽❋⑤❴✺❈❙✰❚✬❡ ❣✲◗✲❏❀❈❩❨❅❈ � ❙❀▲◆❈●❋✁❏▼❤◆✐♥■✽❋❃❨♥■✬❱♣✐ ❡ ❣✲❏❀❚✬❏▼▲✇❙✉❈❩❱▼❏▼▲◆❡✞■✽❏❀❈❩❱✛❍✷❈✰❤✇■✽❏✷❈❩❨❪❏✷❚❊❏✷❇✲❈●❡ ❙●■❑❋☎❴❃❈❯❨✁❈●❍♣▲❢①❲❈❩❨P❖②❍✷❚✬❡③❏✷❇✲❈❝❚❲❣❃❈●❍❁■✽❏❀❚✬❍❁❱❂✇➢ ①❲❈●❍✷✐P▲◆❡ ❣❃❚✬❍❀❏❁■✽❋✁❏ ❱▼❣✺❈❩❙❀▲✇■✘❤ ❙❀❤✇■✬❱✷❱✉❚✽❖✛❇✲❚✽❤◆❚✬❋✲❚✬❡❊▲✇❙ ❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋❃❱✕▲❳❱ ❖❘❚❲❍✷❡ ❈❩❨☎❴✁✐♥■✘❤◆❉✬❈❂❴✲❍❁■❴▲❳❙❯❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱ ♠ ❖❘❚✬❍➉♣✿❇✁▲✇❙❀❇✐❃❋❃❨❲▲◆❋✲❉❦■♥❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍✉▲✇❱❜❏✷❇✲❈⑤❴✺❈❩❱▼❏✝❦✁❋✲❚✒♣✿❋ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ❏✷❚♥❙✰❚❲❡ ❣✲◗✲❏✷❈✞❱▼❈●❍♣▲❢❈❩❱❜❈❄❡✲❣❃■✽❋❃❱✪▲◆❚✬❋❃❱ ❚✽❖✛❤❳■❑❍✷❉✬❈❚✬❍❁❨✁❈●❍❆✇✱✲❚❲❍ ❏✷❇✲❈ ❱✪▲◆❋✲❉✽❤◆❈❝①✽■✽❍▼▲✇■✒❴✁❤◆❈❯❙●■✬❱♣❈ ♠ ❏❀❇✲❈ ❅➃✿ ✰✳✻❅❣❃■✬❙➟❦❴■✽❉❲❈ ✥✿❇❑✯ ❣✲❍❀❚❴①❲▲✇❨✁❈❩❱ ❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱ ❏✷❇❃■✽❏✿❙✰❚✬❋❃❱▼❏✷❍❀◗❃❙✰❏ ❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❝❚✬❍❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍✰❱❝❱✷■✽❏▼▲✇❱❲✐❃❈❩❨→❴✁✐✌❇✲❚✽❤◆❚✬❋✲❚✬❡❊▲✇❙P❱▼❈❩❬❲◗✲❈●❋❃❙✰❈❩❱ ❚❲❍✉❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋❃❱❜■✽❋❃❨✌❏✷❇✁◗❃❱❝❣✲❍❀❚❴①❲❈ ❖②❚✬❍✷❡❊◗✁❤❀➧❥✇✲✱✲❚✬❍▲◆❋❃❱▼❏❁■✽❋❃❙✰❈ ♠ ❪ ■✬❱❀❱✪▲◆❋✁▲ ➫ ❱☎▲✇❨✁❈●❋ ❏▼▲◆❏▼✐❅❚✬❋❅❏✷❇✲❈❁✱ ▲ ❴❃❚✬❋❃■✬❙●❙❀▲ ❋ ◗✲❡❫❴❃❈●❍✰❱➁ ✩❴✸ ❛ ➁ ✩ ✵ ➁ ❛✩✽✸✺✹ ✤ ✴ ✵❝✳ ✶ ✩ ❘▲✇❱✿❣✲❍❀❚❴①❲❈❩❨❯❴ ✐♥❙✰❚✬❡✑❣✲◗✲❏▼▲◆❋✲❉ ■❜❤r▲◆❋✲❈❩■✽❍✉❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈ ❱✷■❑❏▼▲✇❱❲✐❃❈❩❨☎❴✁✐✞❏❀❇✲❈❝❤◆❈✰❖❘❏❀q②❇❃■✽❋❃❨♥❱✪▲✇❨✁❈ ♠ ❱▼❏✰■✽❍✷❏▼▲◆❋✲❉❜❖❘❍❀❚✬❡③❏✷❇✲❈ ❤ ▲◆❋✲❈❩■✽❍❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈✞❱✷■✽❏▼▲✇❱❲✐❃❈❩❨➲❴ ✐ ❏✷❇✲❈❇✱ ▲ ❴✺❚✬❋❃■✬❙●❙❀▲✛❋ ◗✲❡❫❴❃❈●❍✰❱❂✇①✂✕❈●❍✷❈❜▲✇❱❝❏✷❇✲❈❫❦❲▲◆❋❃❨✌❚✽❖ ❣✲❍❀❚ ❚✽❖☎❖❘❚❲❍❍♣✿❇✁▲✇❙❀❇ ❅✺✿❂✰✳✻❦❣✲❍✷❚✽①❲▲❳❨✁❈❩❱❏✷❚✁❚✽❤✇❱ ④ ❿ ✩ ✤ ➁ ✩❴✸ ❛ ➁ ✩ ✵ ➁ ❛✩✽✸✺✹ ✤ ➁ ❛✩ ❧ ➁ ✩ ➁ ✩❴✸✺✹ ✵ ➁ ❛✩❴✸✺✹❿ ✩✽✸✺✹ ✤ ➁ ❛✩❴✸✺✹ ❧ ➁ ✩❴✸✺✹ ➁ ✩✽✸ ❛ ✵ ➁ ❛✩✽✸ ❛ ✤ ➁ ❛✩❴✸✺✹ ✵ ➁ ✩❴✸✺✹ ➁ ✩ ✵ ➁ ❛✩ ✤ ✵ ❿ ✩ ❄❢✼❏ ▲✇❱❝❏✷❇✲❈●❋ ❱♣◗✁� ❙❀▲◆❈●❋ ❏❜❏✷❚♥❙✷❇✲❈❩❙➟❦✌❏✷❇❃■✽❏ ✴ ✵❝✳ ✶ ✩ ■✘❤✇❱▼❚✄❱❀■✽❏▼▲✇❱❲✐❃❈❩❱❝❏❀❇✁▲❳❱ ❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈P■✽❋❃❨✌❏✷❇❃■✽❏ ■ ✐❃❋✁▲◆❏✷❈ ❋✁◗✲❡ ❴✺❈●❍ ❚✽❖▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚❲❋❃❨❲▲❢❏♣▲❢❚❲❋❃❱✉❡✞■✽❏❁❙❀❇✬✇ ❷❛➉

Page 49: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❅ ❍❀❈ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍ ✫ ✴ ✠ ✶ ✰ ✴ ✠ ✶ ➢ ❙✰❏▼▲◆❚✬❋❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✽❏▼▲◆❚✬❋ ✠ ✳ ⑧ ✴ ✠ ✶✁�✥ ⑧ ✎ ✴ ✠ ✶❱♣❇✁▲ ❖②❏ ✠ ❧✓✳ ❩ ⑧ ✴ ✠ ✶✁�✥ ⑧ ✴ ✠ ❧ ✳ ✶❨❲▲✚✙ ❈●❍✷❈●❋❃❙✰❈ ✠ ❧✓✳ ✳ ⑧ ✴ ✠ ✶✁�✥ ⑧ ✴ ✠ ❧ ✳ ✶ ✵ ⑧ ✴ ✠ ✶✑✘q✼❨❲▲r❤❳■❑❏▼▲◆❚✬❋ ✑✍✠ ❩ ⑧ ✴ ✠ ✶✁�✥ ⑧ ✴ ✑✍✠ ✶✑✘q✼❨❲▲ ✙ ❈●❍✷❈●❋✁❏▼▲✇■✽❏▼▲◆❚✬❋ ✑✍✠ ✳ ⑧ ✴ ✠ ✶✁�✥ ✥ ⑧ ✴ ✑✍✠ ✶ ✵ ⑧ ✴ ✠ ✶✼✯ ❜ ✥ ✴ ✑ ✵ ✳ ✶ ✠ ✯✔✌■✽❇✁❤◆❈●❍▼▲✇■✽❋ ❚✬❣❃❈●❍❁■❑❏✷❚✬❍ ✠ ② ❩ ⑧ ✴ ✠ ✶✁�✥ ⑧ ✴ ✠ ② ✶✙ ✖ ✒ ✘✼✛✂✁✎★❝s ❡✣■❑❡ ❣✁❤◆❈❩❱✛❚✽❖ ❅ ❍✷❈ ❚✬❣✺❈●❍❁■✽❏✷❚❲❍❁❱❢✼❋ ❚❲❋✲❈❅①❴■✽❍▼▲✇■✒❴✁❤◆❈ ♠ ❏✷❇✲❈❅■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡✞❱❜❖②❚✬❍ ❨❲▲ ✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✑■✽❋❃❨ ❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❅❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✑■✽❍✷❈♥■✘❤ ♣✿■✘✐✮❱①✬❈●❍✷✐♥❱❞▲❢❡♦▲ ❤✇■✽❍ ■❑❋❃❨♥❙●■✽❋→❴❃❈❜❣✲❍✷❚✒✐❃❏❁■✘❴✁❤❢✐ ❈❄❡✮❣✲❍❀❈❩❱✷❱▼❈❩❨❅◗❃❱❞▲❢❋✲❉❅❏❀❇✲❈ ①✬❚✲❙●■✒❴✲◗✁❤✇■✽❍✷✐ ❚✽❖ ☞➑✵✺✭⑤❁ ❸❖✭✶✵✺✹✼✷✸❁❈✵➨✽ ✥ ✁ ✯ ✇✿❆✛❇✲❈❩❱▼❈❊■✽❍✷❈❨✁❈❄✐❃❋✲❈❩❨ ❚✽①✬❈●❍✿■ ✐❃❈✰❤✇❨✣✕ ✴ ✠ ✶ ❴ ✐❅■ ❙✰❚✬❡ ❡❊◗✲❏❁■❑❏▼▲◆❚✬❋✞❍❀◗✁❤❢❈

� ✠ ✤ ✫ ✴ ✠ ✶ � ❧ ✰ ✴ ✠ ✶❞❘✴ ✳ ✶♣✿❇✲❈●❍✷❈ ✫ ▲✇❱✉■ ❍♣▲❢❋✲❉P❈●❋❃❨✁❚✬❡ ❚❲❍✷❣✲❇✁▲✇❱▼❡☛❚✽❖✬✕ ✴ ✠ ✶ ■✽❋❃❨ ✰ ▲✇❱❝■❊①✬❈❩❙✰❏✷❚❲❍✷q✼❱▼❣❃■✬❙✰❈❜❈●❋❃❨✁❚✬❡ ❚✬❍✷❣✲❇✁▲✇❱▼❡☛❚❑❖✑✕ ✴ ✠ ✶ ✇✿❆ ■✘❴✁❤❢❈ ✳❉✽▲◆①✬❈❩❱✿■❯❤ ▲✇❱▼❏✉❚✽❖ ▲◆❡ ❣❃❚✬❍❀❏❁■✽❋✁❏✿❈❄❡✣■❑❡ ❣✁❤◆❈❩❱❂✇❢✼❋❅❱▼❈●①✬❈●❍✰■✘❤ ①✽■✽❍▼▲✇■✒❴✁❤◆❈❩❱ ♠ ■ ❇✲❚✽❤◆❚✬❋✲❚✬❡❊▲✇❙✕❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ▲✇❱✛❨✁❈❄✐❃❋✲❈❩❨❯❴✁✐✞❱▼❈●①✬❈●❍❁■❴❤ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍✰❱ ■✽❋❃❨❊❡✑❚ ❱▼❏ ❚❑❖ ❏✷❇✲❈ ❙❀❤◆❚ ❱▼◗✲❍❀❈❣✲❍✷❚✬❣✺❈●❍✷❏▼▲◆❈❩❱✿❱▼❏♣▲ ❤r❤ ❇✲❚✽❤✇❨✂✇❽❢✼❋❅■✬❨✲❨❲▲◆❏▼▲◆❚✬❋ ♠ ❇✲❚✽❤◆❚✬❋✲❚✬❡❊✐❊▲✇❱✛❚❑❖❘❏✷❈●❋P❣✲❍✷❈❩❱▼❈●❍❀①✬❈❩❨⑤❴✁✐✞❱▼❣✺❈❩❙❀▲✇■✘❤r▲✘✕❩■❑❏▼▲◆❚✬❋ ❝ ❴ ✐P❨✁❈❄✐❃❋✁▲❢❏❀❈❯■✽❋❃❨♦▲◆❋✲q❨✁❈❄✐❃❋✁▲◆❏✷❈✿❱▼◗✲❡ ❡✞■❑❏▼▲◆❚✬❋ ✴ ❖②❚✬❍ ❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❩❱ ✶ ❚✬❍ ▲◆❋✁❏✷❈●❉✬❍❁■❑❏▼▲◆❚✬❋ ✴ ❖②❚✬❍ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱ ✶ ✇➁✂✿❚✒♣✛❈●①✬❈●❍ ♠ ❡P■✒❦✬▲◆❋✲❉✉❏✷❇✲❈❙✰❚✬❍✷❍❀❈❩❱▼❣❃❚✬❋❃❨❲▲◆❋✲❉❊❙✰❚✬❋❃❱▼❏✷❍✷◗❃❙✰❏♣▲❢❚❲❋ ❚✽❖ ❚❲❣❃❈●❍❁■✽❏❀❚✬❍❁❱ ❈❄❡✲❣✁❤ ▲✇❙❀▲◆❏☎▲✇❱t❡ ❚✬❍❀❈ ❨❲▲ � ❙✰◗✁❤◆❏✶✇ ✝ ▲r❤r❖ ■✽❋❃❨ ✌❃❈✰▲r❤ ❴❃❈●❍❀❉✬❈●❍ ✥➯➭✘✯ ❇❃■❩①❲❈ ❉❑▲❢①❲❈●❋❈ � ❙❀▲◆❈●❋✁❏♦■❴❤❢❉❲❚✬❍▼▲◆❏✷❇✲❡✞❱ ❖②❚✬❍❯❱▼❚❲❡ ❈✞❚❑❖ ❏❀❇✲❈❩❱▼❈✞❚❲❣❃❈●❍❁■✽❏♣▲❢❚❲❋❃❱❝▲◆❋ ❏✷❇✲❈❧✫✢➒➟❸❖✭✶✵✸❅❈✭❞❁✼❃❫✭❆✷✸✵❞❉➔❺❅■✽❋❃❨❦❏❀❇✲❈ ✑ ☎▲✫✳➒➨❸✎✭✶✵✸❅✼✭❄❁✼❃❫✭✶✷✸✵❄❉➔❺❙●■✬❱▼❈ ✴ ❤ ▲◆❋✲❈❩■✽❍✕❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❩❱✛❚❲❍ ✑✘q②❍✷❈❩❙✰◗✲❍❀❍✷❈●❋❃❙✰❈❩❱✿❚❑❖ ❚✬❍❁❨✁❈●❍ ✳ ❚✬❋❅■❊❱▼❈❩❬❲◗✲❈●❋❃❙✰❈ ❚✬❍✛❚✬❋❅❏✷❇✲❈❝❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱✕❚✽❖ ■❊❱▼❈●❍♣▲❢❈❩❱ ✶ ✇✞ ✇❃❆ ■✘❦❴■✘✐ ■✽❡✞■ ✥✚✜✬♠ ✾✽✯ ❇❃■✬❱✿◗❃❱♣❈❩❨ ❑ ❍ ✂❚✼❴✲❋✲❈●❍❍❴❃■❲❱▼❈❩❱✛❚✽❖ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤ ♠ ❨❲▲ ✙ ❈●❍✷❈●❋❃❙✰❈ ■✽❋❃❨ ✑✘q✼❨❲▲ ✙ ❈●❍✷❈●❋❃❙✰❈❊❚✬❣✺❈●❍❁■✽❏✷❚❲❍❁❱✛❏✷❚❡✞■✒❦❲❈♦■❑❋❦❈❄❡✮❣✁❤r▲✇❙❀▲◆❏✞❙✰❚✬❋❃❱▼❏❀❍✷◗❃❙✰❏▼▲◆❚✬❋ ❚✽❖ ❚✬❣✺❈●❍❁■✽❏✷❚❲❍❁❱✕▲◆❋ ❏✷❇✲❈✑❉✬❈●❋✲❈●❍❁■✘❤ ✴ ❋✲❚✬❋✲q②❇✁✐ ❣✺❈●❍✷❉✬❈●❚✬❡ ❈●❏❀❍▼▲✇❙ ✶ ❙●■✬❱▼❈✼✇P❆✛❇✁▲✇❱✉▲✇❱ ✴ ■✽❏❤◆❈❩■✬❱▼❏✿❣❃■❑❍✷❏▼❤◆✐ ✶ ▲❢❡✑❣✁❤❢❈●❡✑❈●❋ ❏✷❈❩❨❪▲◆❋♥❇✁▲✇❱✕❣✲❍✷❚✬❉✬❍✰■✽❡✞❱✄✂✝✹✼✻❦■✽❋❃❨✆☎→✹✼❺❞✹❈✰✢✲✴✹✼➒✖✿❂❁✼✵✞✝✫☎✺❃ ❁❆❹✼✰✳✲❊✭ ✽ ✇❆✛❇✲❈ ■❴▲❢❡ ❚✽❖ ❏❀❇✁▲❳❱❽♣✛❚✬❍➨❦✉▲✇❱☎❏✷❚ ■✽❏❀❏❁■✬❙➟❦ ❡❊◗✁❤◆❏▼▲◆①❴■✽❍▼▲✇■✽❏❀❈✿❇✲❚✽❤◆❚✬❋✲❚✬❡❊✐❊①✬▲✇■ ❅ ❍✷❈✿❚✬❣✺❈●❍❁■✽❏✷❚✬❍✰❱t■✽❋❃❨❊❋✲❚✬❋✲q✼❙✰❚✬❡✑❡❯◗✲❏✰■✽❏▼▲◆①✬❈❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋➤❴✁✐ ❑ ❍ ✂❚✼❴✲❋✲❈●❍❥❴❃■✬❱▼❈❩❱ ❚✬❍ ■❅❱✺❦✬❈❂♣ ①✬❈●❍✰❱✪▲◆❚✬❋❦❚✽❖✛❏✷❇✲❈✞st◗❃❙❀❤r▲✇❨✁❈❩■✽❋ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ✥ ✳ ♠ ✦ ✯ ✇❊❆✛❇✁▲✇❱✉▲✇❱✉▲◆❡ ❣✁❤◆❈●q❡ ❈●❋✁❏✷❈❩❨✑▲◆❋ ✱✖✇✂❪☎❇ ✐✭✕❩■✒❦✂➫ ❱✄☎ ❅✺✿❂✰✳✻♥❣❃■✬❙➟❦❴■❑❉✬❈ ✹ ♣✕❍▼▲◆❏✷❏✷❈●❋P▲◆❋✬✔✄■❑❣✁❤❢❈✼✇❊✔✁✔� ✓ ☛ ✞➲☛ ✆✑✌✎✍ ☛●✆ ✆♥✌ ✆ � ☛ �✟⑨✳✌✔✓❀✕

☞➑✵✺✭❍✹❈✲ ❅❈✭✫❀ ✵❇✹✘✽ ▲◆❋❊❏✷❇✲❈✿◗✲❋✁▲◆①❴■❑❍▼▲✇■✽❏✷❈ ❙●■✬❱♣❈ ■❑❍✷❈✿■✘❤◆❉✬❈❂❴✲❍❁■✬❱ ✕ ✏ ✠ ❘✞� ✒ ♣✿❇✲❈●❍✷❈ ✕ ▲✇❱☎■✉❍▼▲◆❋✲❉ ■✽❋❃❨✴✠ ■✽❋❃❨ � ■❑❍✷❈✛❍✷❈✰❤✇■✽❏✷❈❩❨❴✁✐ ✴ ✳ ✶ ✇t❆✛❇✲❈❝❡❊◗✁❤❢❏♣▲❢①✽■✽❍▼▲✇■✽❏✷❈ ❙●■✬❱♣❈✉▲❳❱✕❚✼❴✲❏❁■❴▲❢❋✲❈❩❨❅■❲❱✛❏✷❇✲❈ ❏❀❈●❋❃❱▼❚✬❍✛❣✲❍✷❚✲❨✁◗❃❙✰❏ ✕ ✏ ✠ ✹ ❘✄� ✹ ✒✠✟ ↔❆↔✶↔ ✟ ✕ ✏ ✠ ✩ ❘✄� ✩ ✒ ✇❆✛❇✲❈❜❈❄❡✣■✽❡✑❣✁❤❢❈❊❚✽❖✡✏ ❈●❉✬❈●❋❃❨✁❍❀❈❯❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤✇❱✕▲ ❤r❤◆◗❃❱▼❏✷❍✰■✽❏✷❈❩❱❝■P❱✪▲◆❡ ❣✁❤◆❈❯◗❃❱♣❈❯❚❑❖ ❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋✬✇ ✏ ❈●❉✬❈●❋❃❨✁❍❀❈❯❣✺❚✽❤◆✐ ❋✲❚❲q❡❊▲✇■✘❤✇❱✉❱✷■✽❏▼▲✇❱✪❖②✐✞❏❀❇✲❈✉❖❘❚✽❤r❤◆❚✒♣✛▲◆❋✲❉✞❏❀❇✲❍✷❈●❈ ❨✁❈●❣❃❈●❋❃❨✁❈●❋✁❏❝❍✷❈✰❤✇■✽❏▼▲◆❚✬❋❃❱ ④✴ ✳ ✵ ✠ ❛ ✶ ✧ ✎ ✎✩ ✴ ✠ ✶ ✵ ✦✯✠ ✧ ✎✩ ✴ ✠ ✶ ❧ ⑥ ✴ ⑥ ❧✓✳ ✶ ✧ ✩ ✴ ✠ ✶t✤ ❩ ❘✴ ✦ ✶ ✴ ⑥ ❧ ✦ ✶ ✧ ✩✽✸ ❛ ✴ ✠ ✶ ✵ ✴ ✦ ⑥ ❧ ➛ ✶ ✠ ✧ ✩✽✸✺✹ ✴ ✠ ✶ ❧ ✴ ⑥ ❧✓✳ ✶ ✧ ✩ ✴ ✠ ✶t✤ ❩ ❘✴ ➛ ✶ ✴ ✳ ✵ ✠ ❛ ✶ ✧ ✎✩✽✸✺✹ ✴ ✠ ✶ ❧ ✴ ⑥ ❧ ✳ ✶ ✠ ✧ ✩✽✸✺✹ ✴ ✠ ✶ ✵ ✴ ⑥ ❧✓✳ ✶ ✧ ✩ ✴ ✠ ✶t✤ ❩ ❄✴ ★ ✶➢ ❋ ✐❦❚❑❖ ❏❀❇✲❈❩❱▼❈✞❍❀❈✰❤❳■❑❏▼▲◆❚✬❋❃❱ ❙●■✽❋ ❴❃❈❅❨✁❈❩❨✁◗❃❙✰❈❩❨ ❖②❍✷❚✬❡ ❏✷❇✲❈✞❚❲❏✷❇✲❈●❍ ❚✬❋✲❈❩❱ ✇ ✂✕❈●❍✷❈✑▲❳❱❜❇✲❚✒♣✡☎ ❅➃✿ ✰✳✻ ❙●■✽❋ ❴❃❈P◗❃❱▼❈❩❨ ❏✷❚❣✲❍✷❚✽①✬❈ ✴ ➛ ✶ ❖❘❍❀❚✬❡ ✴ ✦ ✶ ■✽❋❃❨ ✴ ★ ✶ ✇☎❆✛❇✲❈❯❙✰❚✬❡✑❣✲◗✲❏❁■✽❏▼▲◆❚✬❋✌❙✰❚✬❋❃❱✪▲✇❱▼❏❁❱☎▲◆❋❦❨✁❈❄✐❃❋✁▲◆❋✲❉♥■ ❱▼◗✁▲◆❏❁■✒❴✁❤◆❈ ❅ ❍✷❈❊■✘❤◆❉✬❈❂❴✲❍❁■ ♠ ■✑❣✲❍✷❚✬❣✺❈●❍❏✷❈●❍✷❡ ❚✬❍❁❨✁❈●❍▼▲◆❋✲❉ ❚✬❋❅❏❀❇✲❈ ①❴■❑❍▼▲✇■✒❴✁❤◆❈❩❱ ♠ ■❑❋❃❨P❏✷❇✲❈●❋✄❙✰❚✬❡✑❣✲◗✲❏▼▲◆❋✲❉✞■ ❑ ❍ ✂❚✼❴✲❋✲❈●❍➑❴❃■✬❱✪▲✇❱◗♣✛▲◆❏✷❇❅❍✷❈❩❱▼❣✺❈❩❙✰❏ ❏❀❚ ❏✷❇✁▲✇❱✛❚✬❍❁❨✁❈●❍❆✇✹ ✹❸❵❛✤✖✩✪✧❅✤✖❽✘✧✪✾❈❽❑■➛✤✖❊✘❇✸❊❞■❑✇❹❇❛●✘✻▼❉✌✫❆✽➛❇❛❊☞☛✍✌✏✎✒✑✔✓✖✕✘✗✙✓✛✚✜✑✢☛✍✗✤✣✦✥★✧✍✩✙✥★✪✬✫✏✭✍✗✯✮✍✰✯✱✬✲★✌✙✳✴✫✍✚✍✵✏✶✘✮✷✫✛✎✘✗✯✮✏✶✏✗✯✚✛✸✹✳✷✫★✺✍✶✍☛✏✻✬✕q❇✸✦❿✤✖✫✥✫★➍✘✾ ✎❈➜❸✰✼ ✌✍✌✷✎✁✣✽✫✍✫✏✾✬✾✍✾✘✿✏✗✘✮✘✲✷❀✜✑✔✓❁✕✘✗✙✓✷✚✠✑❂☛✍✗✯✫✍❃✍✮✖✸✍❄✹✓✖✕❅✚★✌✘✮✏✗❅✓✍✲✏✳✛✿✏❆✙✓✖❄✬✗✘✚✏✗✍❇✬✫✏✾✍✾✬✾✘✫✴✎✯✗✘✮✏✶✍✗✬✚✛✸✹✳✷✫✷✺✏✶✍☛✷✻✍✕✚✲

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Page 50: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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�✑✁➇✄ ✏ ⑨✢✌✎✍ ☛ ⑦✂⑨❤✍❂⑨✎✓ ⑨✎✕ ✳✘✆ ✻ ☛ ✆ ✥✙ ❁✼✲✴❁✼✻✔❁✼❃❫❉➔❺➩❉➔❹✼✭❄✹✼✲ ✽❊❖❘❚❲❍✷❡ ■✽❋ ▲◆❡ ❣❃❚✬❍❀❏❁■✽❋✁❏ ❙❀❤❳■❲❱✷❱❜❚✽❖ ▲✇❨✁❈❩■✘❤✇❱❜❚✽❖ ❚❲❣❃❈●❍❁■✽❏❀❚✬❍❁❱❂✇❫❢✪❋❦❏✷❇✲❈❩❱▼❈❊▲✇❨✁❈❩■✘❤✇❱ ♠ ▲◆❏❝▲✇❱ ❣❃❚ ❱✷❱❞▲ ❴✁❤◆❈❏✷❚ ❈✰❤ ▲◆❡❊▲◆❋❃■✽❏❀❈ ✹✼✻⑧➒✌❚✽❖✿❏✷❇✲❈✞①✽■✽❍▼▲✇■✒❴✁❤◆❈❩❱❂✇ ❆✛❇✁▲✇❱ ❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋ ▲✇❱ ■✽❣✲❣✁❤r▲◆❈❩❨➤❴✁✐ ❺❆✵✺✭❞✹✼✷✸❉➔➞✶✭❧✷✸✭✶✲✴✭❂✽❂❺❄❁❄❸✑❉➔✻✢❅ ✥ ✳❲✳ ✯ ❏✷❚ ❏✷❇✲❈❙✰❚✬❡ ❣✲◗✲❏✰■✽❏▼▲◆❚✬❋P❚✽❖ ❨✁❈❄✐❃❋✁▲◆❏✷❈❝▲◆❋✁❏✷❈●❉✬❍❁■❴❤❳❱ ❚✬❍✿❱▼◗✲❡✞❱❂✇ ❆ ❇✲❈✿▲✇❨✁❈❩■♦▲❳❱ ❏✷❇❃■✽❏t▲r❖ ⑧ ▲❳❱✕■✽❋✲❋✁▲◆❇✁▲ ❤✇■✽❏❀❈❩❨❤❴✁✐✞■❜❇✲❚✽❤◆❚✬❋✲❚✬❡♦▲❳❙ ▲✇❨✁❈❩■✘❤❚✽❖ ✕ ✏ ✠ ❘✄� ✒ ■✽❋❃❨ ▲r❖ ❏✷❇✲❈ � ✭ ⑧ ➫ ❱ ✴ ⑦ ✕ ❩ ✶ ①❴■❑❋✁▲❳❱♣❇✞■✽❏ ❏✷❇✲❈✖❴❃❚✬❍❁❨✁❈●❍ �✵◗ ❚✽❖ ■✉❱▼◗✁▲◆❏❁■✒❴✁❤◆❈ ❨✁❚❲❡✞■✘▲◆❋ ◗❝♠ ❏✷❇✲❈●❋ ■✽❋❊❚✬❣❃❈●❍✰■✽❏✷❚✬❍■✽❋✲❋✁▲◆❇✁▲r❤✇■✽❏▼▲◆❋✲❉ � ✫✺✹❘ ⑧ ✴ ❏✷❇✲❈ ❨✁❈❄✐❃❋✁▲◆❏✷❈✞❱▼◗✲❡ ❚✬❍✉▲◆❋ ❏❀❈●❉✬❍❁■✘❤ ✶ ▲❳❱ ❚✼❴✲❏❁■✘▲◆❋✲❈❩❨❧❴✁✐☎✐❃❍❁❱▼❏✉❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❋✲❉✬✠✬✇❝❆✛❇✁▲✇❱❝✐❲▲◆❈✰❤❳❨✲❱❜■✽❋❚✬❣✺❈●❍❁■✽❏✷❚✬❍✖♣✿❇✁▲✇❙❀❇✄❙●■✽❋❧❴❃❈❜❍✷❈❂♣✿❍▼▲◆❏✷❏✷❈●❋ � ❥ ✴ � ✶ ❧ ③ ❱♣◗❃❙✷❇ ❏✷❇❃■✽❏✥ � ↔❩❥ ✴ � ✶✼✯ ✴ ⑧ ✶ ❧ ③ ✴ ⑧ ✶☎✤ ❩ ❄❆✛❇✲❈●❋✞■❑❣✲❣✁❤❢✐❲▲◆❋✲❉ � ✫✺✹❘ ✴ ▲▲✇★❈✼✇ ♠ ❱▼◗✲❡ ❡♦▲❢❋✲❉❜❚✬❍t▲◆❋✁❏✷❈●❉✬❍❁■❑❏▼▲◆❋✲❉❝❚❴①❲❈●❍t❏✷❇✲❈ ❨✁❚✬❡✞■❴▲❢❋ ✶ ❉✽▲◆①✬❈❩❱ ❥ ✴ � ✶ ✴ ⑧ ✶ ❂ ❙ ❘ ❧ � ✫❃✹❘ ③ ✴ ⑧ ✶☎✤ ❩ ♠♣✿❇✲❈●❍✷❈❅❏❀❇✲❈❅❇ ✐✁❣❃❚✬❏❀❇✲❈❩❱▼❈❩❱❊❈●❋❃❱▼◗✲❍✷❈❩❱♦❏✷❇❃■✽❏❊❏✷❇✲❈✪✐❃❍❁❱▼❏ ❣❃■✽❍❀❏ ✴ ❏✷❇✲❈ ❱♣◗✲❡ ❚✬❍❜▲◆❋ ❏✷❈●❉❲❍❁■✘❤ ■✽❏❊❏✷❇✲❈☎❴❃❚❲◗✲❋❃❨✲■✽❍✷✐ ✶ ▲✇❱✴✕●❈●❍❀❚✔✇❣✽▲◆❋❃❙✰❈ ③ ❨✁❚✁❈❩❱✛❋✲❚✬❏✉❙✰❚✬❋ ❏✰■✘▲◆❋❀✠P▲◆❏ ❙✰❚❲❡ ❡❊◗✲❏✷❈❩❱✖♣✛▲◆❏✷❇ � ✫❃✹ ■✽❋❃❨P▲✇❱✕❏✷❇✲❈ ❨✁❈❩❱✪▲◆❍✷❈❩❨❅❚❲❣❃❈●❍❁■✽❏❀❚✬❍✶✇➢ ❱t■✽❋❊❈❄❡✣■✽❡✑❣✁❤❢❈ ♠ ♣✛❈ ❙✰❚✬❡ ❣✲◗✲❏❀❈ ■❝❱♣✐✮❱▼❏❀❈●❡ ❚✽❖ ❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤❃❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱☎❱✷■✽❏▼▲✇❱❲✐❃❈❩❨ ❴✁✐ ❏✷❇✲❈✛❉✬❈●❋✲❈●❍✰■✽❏▼▲◆❋✲❉✉❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋❚✽❖t❏✷❇✲❈ ✏ ❈●❉✬❈●❋❃❨✁❍❀❈ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ➁ ✴ ✠ ❘❳❁✁✶t✤ ⑤✩ ✩ ❄ ✧ ✩ ✴ ✠ ✶❱❁ ✩❱▼❏❁■❑❍✷❏▼▲◆❋✲❉❅❖②❍✷❚✬❡ ✴ ✦ ✶ ■❑❋❃❨ ✴ ➛ ✶ ✇♥❆✛❇✲❈♥❱▼❏❀❈●❣❃❱❝❏✷❚→❴❃❈P❣❃❈●❍♣❖❘❚✬❍❀❡ ❈❩❨ ■❑❍✷❈ ④ ✘ ❉ ✤♥❙✰❍✷❈❩■✽❏▼▲◆❚✬❋ ❚✽❖✿❏✷❇✲❈ ❅ ❍✷❈♥■✘❤◆❉✬❈❂❴✲❍❁■❯❚ ✤❱ ✏ ⑥ ❘ ✞ ✩ ✒ ✟ ❱ ✏ ✠ ❘✞� ❂ ✒ ✟ ❱ ✏✶❁✎❘✄� ✙ ✒ ❝ ✘ ❉➔❉ ✤✄❨✁❈●❏✷❈●❍❀❡❊▲◆❋❃■✽❏▼▲◆❚✬❋✖❚✽❖ ❚✬❣✺❈●❍❁■✽❏✷❚✬❍✰❱ ■✽❋✲❋✁▲◆❇✁▲r❤❳■❑❏▼▲◆❋✲❉ ✧ ✩ ✴ ✠ ✶◗❁ ✩ ▲◆❋❲❚ ❝ ✘ ❉➔❉❀❉ ✤❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋✌❚✽❖ ⑥ ❝ ✘ ❉➔➞✖✤❝❤◆❈✰❖②❏ ❨❲▲◆①❲▲❳❱❞▲❢❚❲❋✡❴✁✐✖✞ ✩ ✵ ✳ ✇✥✂✕❈●❍✷❈❝▲✇❱✕❏✷❇✲❈ ❙✰❚✬❍✷❍✷❈❩❱♣❣❃❚✬❋❃❨❲▲◆❋✲❉✆☎ ❅✺✿❂✰✳✻✄❱▼❈❩❱❀❱✪▲◆❚✬❋ ④❳✡✠✹✍✡✠✰★✚✗✎✞✚✠▲✁☎✄✦✒✔❋✤❃✦✕☎✢✝❃✦✕☎✢✝❨✤✥✂✁✸❨✡❩✹✱✽✆✽❩✻✱✎✭✼✠✝❩✰★❬✁✣✄✖✒✔✢✤✓✦✕✣❨✚❈✻✢✤❨✡❅✜★✪✕✘✲✻★✵❅✰❨✝✥✪✁

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Page 51: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✷✽❇✖✁✣✄✟✱✡✠✻✞✹✺✵✆✟✞✽✗❉✠✹✞▲✏✘�✦✕✘☞✽✠✻✓✧✗❉✠✻✍✧✄✦✒✤✒✩★✤✥✦✕✧✒✔✢✝✓✖✕✘✲✜★✂✕☎✢✝❨✤✥✝✥✦✕ ✺✵☛✻✓✵✴✶✁✍✎❏❭✁✣✄✟✍✎❏✵☛✤✫✽✙✟✫✯✏✾❳✚✠✻✍✚✠✜★✚✗✟✞✡✠✤❩✻✱✵✙ ✺❍✠✤✫✝❩✰❨✎★✪✕✣✷✽❇▲✕✣✞✽☛✻✱✟✿✚✆✤☞✎❑▲✏✘✞✽☛✻✱✵✙✹✆✌★✼☛✟☞❂✕✽✒❀✓✦✕✔★✪✕✣❨✟✥✵✴✤✴❍◆

➂ ❏ ④ ✤ ✥ ❼ ❛❂ ✵ ✠ ❛ ❼ ❛❂ ✵ ✦✯✠✔❼ ❂ ❧ ❁ ❛ ❼ ❛✙ ❧ ✦ ❁ ❼ ✙ ❘❳❁ ✵ ✠ ✞ ✩ ❧ ✞ ❛✩ ❼ ✙ ✵ ✦ ❁ ✠ ✞ ✩ ❼ ✙ ❧ ❁ ❛ ❼ ✙ ❘✥❁ ❼ ✙ ✵ ⑥ ✯✺❍☛✰✿✖✏✮■✟✆✝☞✤☞❉✠✤■✻✱✦✕ ✫ ✁ ❏✵✫✯✏ ✲✌★❉✄✵❄ ✕✧✒✔✍✟❏❬✒ ❄ ✥✖✕✣✍✎❏❭✒✣❇✻✥✝✥✼✴❍✕✧✒✔✢✝✓✖✕❀✢✝❨✝✥✼✴❍◆✥ ✴ ✳✛✵ ✠ ❛ ✶ ❼ ❛❂ ✵ ✦❊✠✔❼ ❂ ❧ ✦ ❁ ❼ ✙ ❧ ❁ ❛ ❼ ❛✙ ❘ ✴ ✳✛✵ ✦ ❁ ✠ ❧ ❁ ❛ ✶ ❼ ✙ ❧ ❁ ✵ ✠ ✯❆✛❇✁▲✇❱P▲✇❱ ■ ❱▼✐✮❱♣❏✷❈●❡ ❚✽❖✞❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❨ ❴ ✐✖❏✷❇✲❈✌❉✬❈●❋✲❈●❍❁■❑❏▼▲◆❋✲❉ ❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ❚✽❖❊❏✷❇✲❈✮✏ ❈●❉✬❈●❋❃❨✁❍❀❈❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱❂✇❊❆✛❇✲❈❫♣✿❇✲❚✽❤◆❈ ❙✰❚✬❡ ❣✲◗✲❏✰■✽❏▼▲◆❚✬❋ ▲✇❱✉❣❃❈●❍▼❖②❚✬❍✷❡ ❈❩❨❪▲◆❋ ✦✎✇ ✳ ❱❂✇✉❚✬❋❦■✽▼✉❈❩❙ ➢ ❤◆❣✲❇❃■✎✇ ❆ ❇✲❈♦❱♣✐✮❱▼❏❀❈●❡ ❙●■✽❋→❴✺❈❖②◗✲❍✷❏✷❇✲❈●❍ ❱❞▲❢❡✑❣✁❤ ▲✴✐❃❈❩❨➇❴ ✐✞■❑❋✲❚✬❏✷❇✲❈●❍ ❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋❅❏❀❚ ✐❲▲❢❈✰❤✇❨❅■✽❋✑❚✬❣❃❈●❍❁■❑❏✷❚✬❍ ❚❑❖ ❱♣❈❩❙✰❚✬❋❃❨ ❚❲❍❁❨✁❈●❍t▲◆❋☎❼ ❂ ❚❲❋✁❤❢✐✼✇✞✱✲❍✷❚✬❡ ❏✷❇✲❈■✒❴✺❚❴①❲❈ ❱▼✐✲❱▼❏✷❈●❡ ■❜❱▼✐✁❡ ❴✺❚✽❤r▲✇❙ ❱▼❚❑❤❢①❲❈●❍ ❚✽❖ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱☎❙●■✽❋❯❴❃❈✿◗❃❱▼❈❩❨✑❏✷❚✯✐❃❋❃❨ ❏✷❇✲❈◗♣ ❈✰❤r❤◆q✸❦✁❋✲❚➍♣✕❋ ❖②❚✬❍✷❡❊◗✁❤✇■⑤✩ ✩ ❄ ✧ ✩ ✴ ✠ ✶❱❁ ✩ ✤ ✳✫ ✳✿✵ ✦✯✠ ❁ ❧ ❁ ❛ ❄✄✝✆ ✆ ✳ ✓ ✗✬✕ ☛●✆ ✆❆✛❇✁▲✇❱❝■✽❣✲❣✲❍✷❚✁■✬❙✷❇❪▲✇❱ ❱▼◗❃❱❀❙✰❈●❣✲❏▼▲ ❴✁❤❢❈P❏✷❚P❋ ◗✲❡✑❈●❍✷❚✬◗❃❱✉■✽❣✲❣✁❤r▲❳❙●■❑❏▼▲◆❚✬❋❃❱ ♠ ❈❄❡✲❏✷❈●❋❃❱✪▲◆❚✬❋❃❱❝■❑❋❃❨P▲◆❡ ❣✲❍✷❚✽①✬❈●❡ ❈●❋✁❏❁❱❂✇ ➢ ❣✲❣✁❤r▲✇❙●■✽q❏▼▲◆❚✬❋❃❱ ❏✷❚ ✑✘q✼❙✰❚✬❡ ❣✲◗✲❏❁■❑❏▼▲◆❚✬❋❃❱ ❤◆❚ ❚✼❦❊❣✲❍✷❚❲❡❊▲✇❱✪▲◆❋✲❉ ❝ ❪ ❚❲❡❯❏❀❈●❏✶➫ ❱ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ✥ ★ ✯ ❏✷❚❝❙✰❚✬❡ ❣✲◗✲❏✷❈✛❏✷❇✲❈✿❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❱✷■✽❏♣▲❳❱❇✐❃❈❩❨❯❴ ✐✞■❑❋ ■✘❤◆❉✬❈❂❴✲❍✰■✘▲✇❙✕❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋♥❙●■❑❋➩❴✺❈❝❉✬❈●❋✲❈●❍❁■✘❤r▲✛✕●❈❩❨P❏✷❚ ❱▼❚✬❡ ❈✉❈❄❡✲❏✷❈●❋ ❏ ❝ ■❜❣✲❍✷❚✬❉✬❍✰■✽❡✈❇❃■✽❋❃❨❲❤r▲◆❋✲❉P❚✬❣❃❈●❍❁■❑❏✷❚✬❍❁❱■✽❋❃❨❪▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱ ❱❞▲❢❡❊◗✁❤◆❏❁■✽❋✲❈●❚❲◗❃❱✪❤◆✐ ❙✰❚❲◗✁❤❳❨❧❴✺❈●❋✲❈❄✐❃❏✉❖❘❍✷❚❲❡ ❏✷❇✲❈❜▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱ ❏✷❚ ■✘①✬❚❑▲❳❨ ❤◆❈●❏✷❏▼▲◆❋✲❉❅❏✷❇✲❈❚✬❍❁❨✁❈●❍✰❱ ❚✽❖ ❏✷❇✲❈✛❚✬❣❃❈●❍❁■❑❏✷❚✬❍❁❱ ❉✬❍❀❚➍♣ ❏❀❚ ❚❝❡❊◗❃❙❀❇♦■❑❋❃❨❊❏✷❇✁◗❃❱ ❙✰❚✬◗✁❤✇❨❊❏✷◗✲❍❀❋❊▲◆❋ ❏✷❚❊■✽❋❊❈ � ❙❀▲◆❈●❋ ❏☎❖②❚✬❍✷❡❊◗✁❤❀➧ ❣✲❍✷❚✽①✬❈●❍ ❝ ❙✰❚✬❡ ❣✲◗✲q❏❁■✽❏♣▲❢❚❲❋❅❚✽❖ ❑ ❍ ✂❚✼❴✲❋✲❈●❍➑❴❃■❲❱▼❈❩❱✿❙✰❚✬◗✁❤✇❨☎❴✺❈❯❱▼❣✺❈●❈❩❨✁❈❩❨ ◗✲❣♥◗❃❱✪▲◆❋✲❉❅■❊❋✲❚✬❋✲q✼❙✰❚✬❡ ❡❊◗✲❏❁■❑❏▼▲◆①✬❈ ■✽❋❃■✘❤◆❚✬❉✬◗✲❈❝❚❑❖ ❏✷❍✰■✬❙✰❈✉❤r▲ ❖②❏▼▲◆❋✲❉P❚✬❍❱✪▲◆❡ ❣✁❤◆❈✉❉✬❈●❋✲❈●❍❁■✘❤r▲✛✕❩■✽❏▼▲◆❚✬❋❃❱☎❚✽❖ ❏✷❇✲❈ ✱ ❑ ✏ ✔ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ♠ ❈●❏❁❙✒✇✥✂✕❚✬❣❃❈✰❖②◗✁❤r❤❢✐ ♠ ■✘❤r❤ ❚✽❖ ❏✷❇✁▲✇❱✤♣✛▲r❤r❤ ■✽❣✲❣✺❈❩■✽❍t▲◆❋●✱✖✇✳❪ ❇✁✐✩✕❩■✒❦✂➫ ❱❏✷❇✲❈❩❱✪▲✇❱❂✇

✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛✝ ❶ ✞✣✢➁➍❑■❑✭❀✤✖➠✄✮✗✥✘✦ ✓✾❀✉✛✓✾♦✦★✩❅✿♦✴♦✲❃✷✄✂q◆✖P✪◆✖❱✒◆❃❬⑤❫⑦❘➎⑧✏✍❏④❄❙❯◗✶❬☛④➯❚❃❱✒➨❈③♥➄✸❙❆◆✖❬✄❚❏❙❜❫⑦❘➁➡➁➅❍◆❏◆❜⑥❄④➎◆❯⑥✞✆❀➨✸◗♦❱❑❙❜❫✪❙❜❫⑦◗❁④❁✲✶✷①➜➯✾♦✻❆✾❀✤❃✦❍✿★➍②➜✥✾✶✽✒❇✸✦❆✫▼❊✘➽❛❝❩❷✸❡✬❶✸❴

➐❜❊✘✻★✫❆✩✪✫❆●✘✫♥➭❈✤❃✫❆✩✪❇❛❊✒✤❃✧➞✉❩✾✣➜➯✾❀✿★➍✘✾♦✦❄✿❆➍❦✾⑤✾♦❊ ➐❜❊❑❉⑦❇❛✦★✇①✤❃✫❆✩✻✵✸●✘✾✥✾♦✫✥✾♦❊➛✹❈●❦✫❆❇❛✇➛✤✖✫★✩ ✵✸●✘✾✸❴ ✠♥✿❄✫★❇❛❽✔✾♦✦✄❢❀❤❛❤❃❶✒✲✝ ❝ ✞✣✢➁➍❑■❑✭❀✤✖➠➋✮ ✥❦✦ ✓✾❀✉✛✓✾♦✦❆✩❅✿♦✴✯✤✖❊✒✉➂s✘✤❃✧✬❵❑■❻✮✗✌✳✦★●✘❊✘❇❑✴♦✲⑨✷ ➭➯❇❛❊❑➒❆✿❄❇✸✇②✇✄●✘✫❄✤✖✫❆✩✪❵✸✾❿✾✶✧✬✩✪✇❹✩✬❊✔✤✖✫❆✩✪❇✸❊②✩✪❊ ✠❸✦★✾①✤✖✧✪❋✸✾♦❽✘✦❍✤❃✻♥✽✘✦❆❇✖❵✸✾♦✻q✇✄●✘✧✪✫❆✩ ➒

❵❛✤✖✦★✩❅✤✖✫❆✾♥➍✘❇✸✧✪❇❛❊✘❇✸✇②✩❅✿✳✩❅✉❑✾✶❊❞✫★✩✪✫❆✩✪✾♦✻❀✲✸✷➣➐❜❊➛✽✘✦★✾♦✽✒✤❃✦❍✤✖✫★✩✪❇❛❊✚❴❣❢❏❤❛❤❛⑩❦✲✝ ❷ ✞✣✢➁❇❛➍❦❊➛✮☞☛▼✲❛❺❻✲✵✴✶✲❏✷☛✥❣➅❍◗❄◗ ✖➎❫ ❱✞✣❀④❿❚❃❱✒➨➛↔✜❨❩◗✶❫❅➅✛✖➎◗✶P✬❚❪❙✱❫✌◆✖❱❑④♦✲❃✷①✹❿✿✶✤❛✉❑✾♦✇❹✩❅✿ ☛▼✦★✾♦✻❆✻❏❴✚❢❏❤❛✐✘❢✸❴✸➢⑨◆❃❱✒➨❛◆❃❱➛❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫⑦❘❄❚❃P✘⑧➞◆❏❘✶❫⑦◗❄❙✡✍

❲❳◆✖❱✒◆✤✣✖➅❍❚❄➆❦❨❛④♦✲✝ ➳ ✞✣✢➁❇❛✇✄✫★✾♦✫✯✮✱✰➔✲ ✴✶✲✔✷ ✢✥✤❃✧❂✿❁●✘✧✳✽✘✦❄✤✖✫❆✩✻✵✸●✘✾②✉❑✾✶✻❭✿❄❇❑✾✔✓①✿❁✩✬✾✶❊❞✫★✻❭✉❩✾✄➸❈✤❏■❞✧✪❇✸✦✣✉ ✑ ●❦❊✘✾✯❉⑦❇❛❊✔✿❄✫❆✩✪❇❛❊❻✤✖✧✪❋ ✓✾♦❽✘✦❆✩✻✵✸●✘✾❛✲ ➢ ✘ ➃❖❱❩④✶◗✶❫ ✣✖❱✒◗✶❬❭◗✶❱❑❙

❲❳❚❏❙✌❨ ✚◗✶❬❭❚❪❙✱❫ ✘♦➄✘◗✶❴✘❵❛❇✸✧❜✲✲❶❀❷✘❴❣❢❏❤❛❥❃❶✒❴✸✽✘✽✚✲✒❝✜✭❛❡❪✷❩❝❛❡✸❷✘✲✝ ❲ ✞ ✠❸✦❆✾❾✮✡✠❈■❑✻★✫❆✾♦✩✪❊✒✴✶✲✥✷ ➸✥➍✘✾✶❇❛✦❆■➳❇✖❉⑤❊✘❇✸❊❑➒❆✿❄❇❛✇❹✇✄●✘✫❍✤❃✫❆✩✪❵✖✾➛✽✒❇✸✧✬■❑❊✘❇✸✇②✩❅✤✖✧ ✻❀✲✳③♥❱✘❱✔❚✖P✵④➣◆❜⑥ ❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫✌❘❄④♦❴❸❵❛❇❛✧❜✲t❷❂➳✔❴q❢❀❤✸➾❛➾❦❴

✽✘✽✚✲❈➳❞❧✸❷❏✷ ❲✸❷❛❧❦✲✝ ✭ ✞✣s✘✤❃✧✬❵❑■ ✮ ✌➔✦❆●✘❊✘❇❑✴♥✤✖❊✒✉ ✚✔✩✪✇②✇❹✾♦✦❆✇➛✤✖❊✘❊❹✮☞☛▼✤✖●❦✧❂✴✶✲❑✷ ➊❸❉⑦●❦❊✚➧✥✤✄❺➦✤✖✽✘✧✪✾q✽✔✤❛✿★➠❛✤✖❋✸✾❈❉✌❇❛✦❈✫★➍✘✾q✇➛✤✖❊✘✩✪✽✘●✘✧❅✤❃✫❆✩✪❇❛❊✄❇❃❉ ❋✸✾♦❊✘✾♦✦❄✤✖✫★✩✬❊❦❋

✤✖❊✔✉➂➍✘❇❛✧✪❇❛❊❦❇❛✇②✩❅✿➯❉⑦●✘❊✔✿❄✫❆✩✪❇❛❊❦✻q✩✪❊❳❇✸❊✘✾✄❵❛✤✖✦★✩❂✤❃❽✘✧✪✾❛✲✚③✯▲▼❲ ↔✔➅❍❚✖❱❩④✶❚✸❘❄❙❜❫⑦◆❃❱❑④➺◆❃❱❻❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄❚✖P➔⑧➞◆❜⑥❄❙✖✑❖❚❃➅❍◗✶❴❣❵❛❇✸✧✱✲❣❝✸❷✘❴✜❊ ➽ ❝❦❴❢❀❤✸❤✖❶✔❴❑✽✘✽✚✲✲❶✮✭✘❷❏✷✲❶❀❡❛❡❦✲

✝ ❡ ✞❿➸✳✤✖➠❛✤❏■❑✤✖✇①✤☛✮❜➭✥❇❛❽❦●✘➠❑✩❂✴✶✲❑✷ ➊♥✦✞✪❇❛❽✘❊✘✾✶✦❈❽✒✤❃✻❆✩✪✻❀❴❦✩✬❊❑✫★✾♦❋❛✦❄✤✖✫❆✩✪❇✸❊ ✤❃❊✒✉❹✫❆✦❄✤✖❊✘✻❄✿❄✾♦❊✒✉❑✾✶❊❞✫❄✤✖✧▼❉✌●✘❊✒✿❄✫★✩✬❇✸❊✘✻❀✲✔➐❜❊➂⑧✏✍✖❬✄➈❄◆✖P↕❫✌❘✄❚✖❱✒➨➛❚✖P ✣❃◗✤✕➈✶➅❍❚✖❫✌❘⑤❘❄◆✖❬❸➆✒➄✸❙❆❚❏❙❜❫⑦◆✖❱❦✲✘✹❈✢✥❺❻❴❑✽✘✽✜✲❃❶❳❲✸❝❏✷✲❶❳❲ ✭❦✲❏✷➫❢❀❤❛❤✍✌✘✲✆☛▼✦★❇✘✿❄✾♦✾❀✉❑✩✪❊✘❋✸✻❈➐❆s✘s❩✹❈✢ ✑ ➉✸❷✘❴✘→❸■❛❇✸✫❆❇✔✲

✝ ❧ ✞❿➸✳✤✖➠❛✤❏■❑✤✖✇①✤✣✮✱➭➯❇❛❽✘●✘➠❑✩❅✴♦✲❃✷❳✹❸❊①✤✖✽❦✽✘✦❆❇❑✤❛✿★➍➛✫❆❇✯✫❆➍✘✾❸✭♦✾♦✦❆❇✄✦★✾❀✿❄❇✸❋❛❊✘✩✪✫❆✩✪❇✸❊②✽✘✦★❇❛❽✘✧✪✾♦✇ ❽❑■ ✌➔●✒✿★➍❑❽✒✾♦✦★❋❛✾♦✦♥✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇❳✲✘➇❑◆✖➄❑➅♦❱✒❚❃P◆❜⑥✣⑧✏✍✖❬❭➈❄◆❃P↕❫⑦❘➺▲❖◆✖❬❸➆✒➄✸❙❆❚❏❙❜❫⑦◆✖❱✘❴❦❵❛❇✸✧✱✲✁❶➨➳✔❴❣❢❀❤✸❤❛➙✘❴❑✽❦✽✚✲✘❝ ✭ ❲❏✷❩❝✸❧❛❝❦✲

✝ ➉ ✞❿➩➫✩✪✧ ❉❖✮❜♣✥✾♦✦★❽✒✾♦✦★✫qs❣✲✵✴❖✤❃❊✒✉ ✚✔✾♦✩✪✧✬❽✔✾♦✦★❋❛✾♦✦☛✮✱♠❸❇❛✦★❇❛❊✒✴✶✲✸✷✺✹❸❊❳✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇②✩✬✿➁✽❦✦❆❇❑❇✖❉▼✫❆➍✘✾♦❇✸✦❆■❹❉⑦❇✸✦❖➍❑■❑✽✒✾✶✦❆❋❛✾✶❇❛✇②✾✶✫❆✦❆✩❅✿☛✮⑦❇✸✦❍✉❑✩✪❊✒✤❃✦❆■✤✖❊✔✉ ✻ ✣ ✽❞✴➁✇✄●✘✧✪✫★✩✬✻★●✘✇✆☎✖✩✪❊✸✫❆✾♦❋✸✦❍✤✖✧❦✩❂✉❩✾♦❊❑✫❆✩✪✫❆✩✪✾♦✻❏✲ ✆♦❱ ✜❪◗✶❱❑❙❜❫⑦◆✖❱✒◗❁④q❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄❚❛◗✶❴❑❵❛❇❛✧❜✲✲❶❏❷❛❧✘❴✔❢❀❤✸❤❛➙❦❴❑✽✘✽✚✲✯❲❛❡ ❲❏✷✤✭❩❷❩❷❦✲

✝ ❶❀❷ ✞✛✚✔✾♦✩✪✧✪❽✒✾✶✦❆❋❛✾✶✦♥✮✱♠❸❇❛✦★❇❛❊✒✴✶✲✖✷➦✹ ➍✘❇❛✧✪❇❛❊❦❇❛✇②✩❅✿▼✻★■❑✻❆✫❆✾✶✇②✻✥✤✖✽✘✽✘✦★❇❞✤✸✿❆➍❹✫❆❇q✻★✽✒✾❏✿❄✩❅✤✖✧✔❉⑦●✘❊✔✿❄✫❆✩✪❇❛❊❦✻❖✩❅✉❑✾♦❊❑✫★✩✬✫★✩✪✾♦✻❀✲❣➇❑◆✖➄❑➅♦❱✒❚❃P✚◆❜⑥✯▲❖◆✖❬❸➆✒➄ ✕❙❆❚❏❙❜❫⑦◆✖❱✒❚❃P✎❚❃❱✒➨✯③✥➆❛➆✔P↕❫⑦◗❄➨☛❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄④♦❴❦❵❛❇❛✧❜✲✽❷❛❝❦❴❑❊ ➽ ❷❦❴❣❢❀❤❛❤✍✌✘❴❑✽✘✽✜✲✬❷❛❝✬❶❁✷❑❷✜✭❛❧✘✲

✝ ❶❩❶ ✞✛✚✔✾♦✩✪✧✪❽✒✾✶✦❆❋❛✾✶✦②✮❜♠❈❇✸✦❆❇✸❊✒✴♦✲❦✷ ➸✥➍✘✾✄✇❹✾♦✫❆➍✘❇✘✉➛❇❃❉➯✿❁✦❆✾❀✤❃✫❆✩✪❵❛✾✯✫❆✾♦✧✪✾♦✻❄✿❄❇❛✽❦✩✬❊❦❋✒✲❖➇❑◆✖➄❑➅♦❱✔❚✖P❖◆❯⑥✯⑧✏✍✖❬❭➈❄◆❃P↕❫⑦❘ ▲❖◆✖❬❸➆✒➄✸❙❯❚❪❙✱❫✌◆✖❱✘❴❣❵✸❇❛✧❜✲ ❶❩❶✸❴❢❀❤✸❤✘❢✸❴❑✽✘✽✚✲✲❶❀➉ ❲❏✷✘❝❛❷❂➳✔✲

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Page 52: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✏ ✞ ✄ ✁ ✁ ✓✑☛ � ✁◆✕ ✆ ✌✎✞✵✏✑✏✞✆✭✁☎✡☞✄ � ✄✒✞ ✞✞✝✷✕ ✞✞✝ �✂✁◆✄ ✁✒☛ ✁✒☛☞✞✡✓ ✁ ✓✞☛✁�✭☞ ✁ ☛✑✡ ✓ ✁✒☛ ✁✒☛ ✡✮✕

☛✔✢☎✥ ✢ ✞✖☛ ✓✄✂✟✧✪✢❻✖❢➨❣✎❪ ✏✺▲◆❋✁✕ ♠ ➢ ◗❃❱▼❏✷❍▼▲✇■❅ ❙✰❏❀❚✼❴❃❈●❍❥➛ ♠ ✳ ➭❈➭ ★✥ ❱♣◗✲❡ ❡✞■✽❍✷✐✪❴ ✐☎④☎❍✷◗✲❋✲❚❤❣ ■❴❤❢①✁✐ ✯

❊⑧✁ ☛ ☛ ✆ ✆✬✞❶☛ ✌✔✓◗✌ ✆ � ✄ ✱ ✻ ⑨ ✏ ✥✔⑨ ✆✬✞ ⑨✳✍ ✏➍☛✆✳☎☛ �✬⑨✝✆✔✍ ☛ ✍ ☛ ⑨✎✕✆☎❳✑ ✤ ✳ ✝④ ▲◆❋✲❚✬❡❊▲✇■✘❤t▲✇❨✁❈●❋ ❏♣▲❢❏♣▲❢❈❩❱❊■✽❍❀❈❝▲✇❨✁❈●❋ ❏♣▲❢❏♣▲❢❈❩❱ ♣✿❇✁▲✇❙❀❇ ▲❢❋✁①✬❚✽❤◆①✬❈✪❴✁▲❢❋✲❚❲❡❊▲✇■✘❤ ❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❁❱ ❤ ▲ ❦✬❈✑❏✷❇✲❈❝❖✼■✽❡ ❚✬◗❃❱✌✂✂✹✼✹✼✲ ✽❂❺❂✫✟✞✰✳✷➔❋❉➔❹✼✭✶✻⑧✷✸❉❀✷✸➒✼➣ ✩⑤✭❳❃✁❄ ❚ ✩ ✭ ❱ ❚ ❂ ✭ ❱ ❚✡✠ ✭ ❱❚ ❂ ✸ ✠ ✸ ✙ ✸✁✩✭ ❱ ❚ ✙ ✸✲✭✭ ❱ ✤ ❚ ❂ ✸ ✙ ✸✁✩✩ ❱ ❚✡✠ ✸ ✙ ✸✁✩✩ ❱❚ ✙ ✸✁✩✩ ❱ ❚ ❂ ✸ ✠ ✸ ✙ ✸✁✩✩ ❱ ❄✴ ✳ ✶❆ ■✒❴✁❤◆❈❩❱ ❤ ▲ ❦✬❈ ✥ ➛ ✯ ❤ ▲✇❱▼❏✛❱▼❈●①✬❈●❍❁■❴❤✮❇✁◗✲❋❃❨✁❍✷❈❩❨❊❱▼◗❃❙❀❇ ▲✇❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱❂✇◗❣✽▲❢❋❃❙✰❈◗❴✁▲❢❋✲❚❲❡❊▲✇■✘❤ ❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❁❱☎❱✷■✽❏▼▲✇❱✪❖②✐ ❡✞■❑❋ ✐❝❍✷❈✰❤✇■✽❏♣▲❢❚❲❋❃❱ ♠❏✷❇✲❈✉❈❄❡✮❣✲❍❀❈❩❱✷❱✪▲◆❚✬❋P❚✬❋✞❏❀❇✲❈✿❤◆❈✰❖②❏✷q②❇❃■✽❋❃❨P❱✪▲✇❨✁❈❝❡✞■✘✐♦■❑❣✲❣❃❈❩■✽❍✛◗✲❋❃❨✁❈●❍✛❋ ◗✲❡✑❈●❍✷❚✬◗❃❱✛❨❲▲✇❱▼❉✬◗✁▲✇❱▼❈❩❱ ♠ ♣✕❇✁▲❳❙❀❇P❡✞■✒❦✬❈❩❱ ▲◆❏ ❨❲▲ � ❙✰◗✁❤◆❏❏✷❚✉❤◆❚✲❙●■✽❏✷❈✛▲◆❏t▲◆❋✞❱♣◗❃❙✷❇ ❏✰■✒❴✁❤◆❈❩❱ ✴ ❚✬❍t❏❀❚✿▲◆❡ ❣✁❤◆❈●❡ ❈●❋✁❏✛❏❁■✒❴✁❤◆❈✛❤◆❚ ❚❈❦ ◗✲❣✑▲◆❋✞■❝❙✰❚✬❡ ❣✲◗✲❏✷❈●❍✛■✘❤◆❉✬❈❂❴✲❍❁■❝❱▼✐✲❱▼❏✷❈●❡ ✶ ✇✥✂✿❚✒♣✛❈●①✬❈●❍ ♠ ■❱▼❚✬❍❀❏ ❚✽❖✬✻✔❁✼✵❄❃❫✹✼✲➨✿❂❁✼✵❄❃✖❖②❚✽❤r❤◆❚➍♣✉❱ ❖②❍✷❚✬❡ ❏❀❇✲❈t❚✼❴❃❱▼❈●❍✷①✽■✽❏▼▲◆❚✬❋ ❏❀❇❃■✽❏ ▲◆❋❊❡✞■✽❋✁✐✿▲✇❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱ ♣✛▲◆❏✷❇❝❤◆❈✰❖②❏✷q②❇❃■✽❋❃❨ ❱❞▲❳❨✁❈ ➄ ✭ ⑧ ✴ ⑦ ✶✷♠❏✷❇✲❈✉❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ⑧ ✴ ⑦ ✶ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❱ ⑧ ✴ ⑦ ❧ ✳ ✶⑧ ✴ ⑦ ✶ ✢❤➁ ✴ ⑦ ✶❞❘✴ ✦ ✶❖②❚✬❍ ❱▼❚✬❡ ❈❊❱▼◗✁▲◆❏❁■✒❴✁❤◆❈✪✐❃❈✰❤❳❨ ❚✽❖ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱✝➁❫✇❊❆✛❇ ◗❃❱ ⑧ ▲✇❱❝❙✰❚✬❡✑❣✁❤❢❈●❏❀❈✰❤❢✐ ❨✁❈●❏✷❈●❍✷❡❊▲◆❋✲❈❩❨→❴✁✐ ⑧ ✴ ❩ ✶ ■❑❋❃❨✄■P❍✰■✽❏▼▲◆❚✬❋❃■✘❤❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ♠ ❖②❚✬❍✝♣✿❇✁▲✇❙❀❇ ■ ❋✲❚✬❍✷❡✞■✘❤t❖②❚✬❍✷❡ ▲✇❱ ■✘①❴■✘▲r❤✇■✒❴✁❤◆❈✼✇ ➢ ❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ⑧ ❱✷■❑❏▼▲✇❱✪❖❘✐❲▲◆❋✲❉✌❏✷❇✁▲✇❱ ❣✲❍❀❚✬❣❃❈●❍✷❏▼✐✌▲✇❱❊❙●■✘❤r❤◆❈❩❨ ■✫✢➒➟❸❖✭❆✵✸❅✼✭❄❁✼❃❫✭✶✷✸✵❄❉❀❺❫✷✸✭✶✵❄❃❫✇✤❢✼❋✌■ ❱▼◗✁▲◆❏❁■✒❴✁❤◆❈❊■✘❤◆❉✬❈❂❴✲❍❁■✘▲✇❙❜❈❄❡✮❏❀❈●❋❃❱✪▲◆❚✬❋ ♠ ⑧ ✴ ⑦ ✶ ❙●■✽❋☎❴✺❈ ❡✞■❲❨✁❈❝❈❄❡✮❣✁❤r▲✇❙❀▲◆❏ ④⑧ ✴ ⑦ ✶t✤ ✴ ❫ ✹ ✶ ✭ ↔✶↔❆↔ ✴ ❫ ❑ ✶ ✭✴ ❏ ✹ ✶ ✭ ↔✶↔❆↔ ✴ ❏ ✩ ✶ ✭ ❁ ✭⑦ q ⑧ ✴ ❩ ✶❞❘♣✿❇✲❈●❍✷❈ ✴ ❫ ✶ ✭ ✤ ❫ ✴ ❫ ❧ ✳ ✶ ↔✶↔❆↔ ✴ ❫ ❧ ⑦ ✵ ✳ ✶ ❨✁❈●❋✲❚✬❏✷❈❩❱✕❏✷❇✲❈❝❍▼▲✇❱✪▲◆❋✲❉✑❖✠■❲❙✰❏✷❚✬❍▼▲✇■✘❤▲✇ ❆✛❇✲❈ ❱♣◗✲❡ ❚✽❖ ⑧ ✴ ♣✿❇✲❈●❋ ⑧ ✴ ❩ ✶t✤ ✳ ✶ ▲❳❱◗❃❱▼◗❃■✘❤r❤◆✐✄❙●■❴❤ ❤◆❈❩❨❪❏✷❇✲❈⑤✫✢➒➟❸✎✭✶✵✸❅✼✭❄❁✼❃❫✭✶✷✸✵❄❉❀❺ ✽❂✭✶✵❄❉❀✭ ✽❥♣✛▲◆❏✷❇❅❏✷❇✲❈❝❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉ ❋✲❚✬❏❁■✽❏♣▲❢❚❲❋❑ ➁ ✩ ⑨ ❫ ✹ ❘ ❄❩❄✘❄ ❘ ❫ ❑❏ ✹ ❘ ❄❩❄✘❄ ❘ ❏ ✩ ✗✗✗✗ ❁ ⑩ ✤ ✯⑤✭❳❃✁❄ ⑧ ✴

⑦ ✶ ❄➢ ❙●❙✰❚✬❍❁❨❲▲◆❋✲❉❊❏✷❚ ❑ ✇✬s◗✇ ➢ ❋❃❨✁❍✷❈❂♣✉❱ ♠ ❆❂④☎✐ ◗❃❱✪▲◆❋✲❉❊❇ ✐✁❣❃❈●❍❀❉✬❈●❚✬❡ ❈●❏✷❍♣▲❳❙✕❱▼❈●❍▼▲◆❈❩❱☎❚✬❋✲❈ ❙●■✽❋ ❍❀❈❩❨✁◗❃❙✰❈ ★✒✁ ❩ ❚✽❖ ❏✷❇✲❈ ✁ ✜✯✜ ❈●❋✁❏✷❍▼▲◆❈❩❱▲◆❋ ❑ ❚✬◗✁❤✇❨✂➫ ❱✛❏❁■✒❴✁❤◆❈❜❏✷❚⑤➛✼✦❊❈●❋✁❏✷❍▼▲◆❈❩❱❂✇ ❈❦❆ ❇ ◗❃❱☎❖②❚✬❍✛▲◆❋❃❱▼❏✰■✽❋❃❙✰❈ ♠ ❏✷❇✲❈✪❣ ■✬■✘❤✇❱✷❙❀❇ ✂◗✲❏✗✕✉▲✇❨✁❈●❋ ❏▼▲◆❏▼✐P▲✇❱✿❚❈❴✲❏❁■✘▲◆❋✲❈❩❨♥■✬❱❋ ➁ ❛ ⑨ ✵ ✠ ❘ ✵ ☛⑧❘ ✵ ⑥❁ ❧✓✳ ❘ ✵ ✠ ✵ ☛ ✵ ❁ ✵ ⑥ ✗✗✗✗ ✳●⑩ ✤ ✴ ✠ ❧ ❁ ❧ ✳ ✶ ✩ ✴ ☛ ❧ ❁ ❧ ✳ ✶ ✩✴ ❁ ❧✓✳ ✶ ✩ ✴ ✠ ❧ ☛ ❧ ❁ ❧ ✳ ✶ ✩ ❄❑ ▲◆①✬❈●❋♥■❯❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋→➁ ✴ ⑥ ❘ ⑦ ✶ ❇✁✐✁❣❃❈●❍✷❉✬❈●❚❲❡ ❈●❏✷❍▼▲✇❙✉▲◆❋❧❴❃❚✬❏✷❇❅❣❃■❑❍❁■✽❡ ❈●❏✷❈●❍✰❱ ♠ ❣✁❤❢◗❃❱✉■❊❏✷❈❩❙❀❇✲❋✁▲✇❙●■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋ ✴ ❇✲❚✽❤◆❚✬❋✲q❚✬❡❊✐ ✶❁♠ ▼❫✇ ✌❃❈✰▲r❤ ❴❃❈●❍✷❉❲❈●❍ ❉ ■✘①✬❈✉■✽❋♥■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❏✷❚ ❙✰❚✬❡✑❣✲◗✲❏✷❈ ■ ❤ ▲◆❋✲❈❩■✽❍✉❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❨❯❴✁✐ ❏✷❇✲❈ ❨✁❈❄✐❃❋✁▲◆❏✷❈❊❱▼◗✲❡♣✛▲◆❏✷❇❦❍❀❈❩❱▼❣❃❈❩❙✰❏❜❏✷❚❅❚✬❋✲❈ ❚✽❖✛❏✷❇✲❈❊❣❃■✽❍❁■✽❡✑❈●❏✷❈●❍❁❱❂✇ ❆✛❇✲❈❊❏✷❈❩❙❀❇✲❋✁▲✇❬✬◗✲❈✑▲✇❱❥❴❃■✬❱♣❈❩❨✌❚✬❋❬❺❆✵❇✭❄✹✼✷✸❉➔➞✶✭❯✷✸✭✶✲✴✭❂✽❂❺❄❁❄❸✑❉➔✻✢❅ ✥ ✳✬✳ ✯ ♣✿❇✁▲✇❙❀❇➳❴❷

Page 53: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

■✽❣✲❣✁❤r▲◆❈❩❱t❏✷❚❝■ ❤❳■❑❍✷❉✬❈●❍t❙✰❚✬❋ ❏❀❈❄❡✮❏ ❚✽❖❃❇✲❚✽❤◆❚✬❋✲❚✬❡♦▲❳❙ ▲❳❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱❂✇ ❆ ❚❝❙✰❚✬❡ ❣✲◗✲❏✷❈ ➄ ✭ ➁ ✩❈➀ ✭ ❖②❍✷❚✬❡ ■✖✐❃❍✰❱▼❏✷q②❚✬❍❁❨✁❈●❍ ❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❤r▲ ❦✬❈ ✴ ✦ ✶ ▲◆❋ ⑥ ■✽❋❃❨♥■❊❱▼❈❩❙✰❚❲❋❃❨❅❚✬❋✲❈ ▲❢❋ ⑦ ♠ ❏✷❇✲❈❝▲✇❨✁❈❩■♦▲❳❱ ❏✷❚✞❨✁❈●❏✷❈●❍✷❡♦▲❢❋✲❈❊■❊❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❯❱✷■✽❏♣▲❳❱❇✐❃❈❩❨☎❴✁✐ ➁ ✩✼➀ ✭ ♣✿❇✲❈●❍❀❈ ⑦❨✁❚✁❈❩❱✿❋✲❚✬❏✿■✽❣✲❣✺❈❩■✽❍❫❉❀✻❧✷➔✫✢✭⑤❺❄❁✶✭✁�❬❺❆❉❀✭❆✻✔✷➔✽❂✇✬❢✪❋♥❏✷❇✲❈ ❙●■✬❱♣❈ ❚✽❖ ❏❀❇✲❈⑤❣ ■✬■✘❤✇❱✷❙❀❇ ✂◗✲❏✗✕✉▲✇❨✁❈●❋✁❏▼▲◆❏❞✐ ♠ ❏✷❇✁▲✇❱✕❉✽▲◆①✬❈❩❱✮✘✪✼✷♥❷ ✷✄✂✸✴❄✮✘✪✼✷ ❶ ✷✆☎❇✷✄✝❊✷✆✂❛✴

❋✞ ✩✽✸ ❋ ➀ ✭✰✸✺✹✟ ✮✘✪ ✷ ❶ ✷✄☎❇✷✆✝❊✷✠✂✸✴ ❛ ✡ ✝ ✮☛☎ ✷☞✝☎✷✄✂ ✷❾❝★✪✼✷❀❲❛✴❁✮✱❝ ✪ ✷✄✂ ✷ ❲❛✴ ✟ ❝❑✮✘✪✼✷❾❝❛✴❁✮✘✪✼✷♥❷❛✴☞✞✌✞ ✩✽✸ ❛ ➀ ✭❁✸✺✹✷❾✮✾✪ ✷➣❝ ✟ ✝❛✴❁✮✘✪ ✷➋❝ ✟ ☎✔✴✍✞ ✩✽✸ ❛ ➀ ✭ ✎✷❾✮✘✪ ✷ ❶ ✷✄☎❇✷✆✝❊✷✠✂✸✴ ✝ ✮✘✪✼✷➣❝✸✴❄✮✾✪ ✷❾❝ ✷✆☎ ✷✠✝❊✷➣❝✏✂❛✴❄✮✾✪ ✷➣❝ ✷✄☎❇✷☞✝☎✷✄✂❛✴✑✞ ✩✽✸✺✹✺➀ ✭❁✸✺✹✷❾✮✾✪ ✷➣❝✸✴❄✮✱❝ ✪ ❛ ✷✄✭ ✪ ✷❾❝ ✪✒✂ ✟ ☎ ❛ ✟ ☎✓✂ ✟ ✝✔✂☎✷✌❷✏✂ ✟ ✝ ❛ ✷❀❲✸✴✍✞ ✩❴✸✺✹✺➀ ✭ ✞✟ ✮✘✪ ✷ ❶❀✴❁✮✘✪✼✷ ❝✸✴❄✮✾✪ ✷☞✝✫✷☞✂ ✷ ❶❀✴❄✮✾✪ ✷✄☎❇✷☞✂ ✷ ❶❀✴✍✞ ✩❈➀ ✭ ✱ ❷✖✕

✴ ➛ ✶❢✼❋✖❏✷❇✲❈✌❇✲❚✽❤◆❚✬❋✲❚❲❡❊▲✇❙♥◗✲❋✁▲◆①✬❈●❍✰❱▼❈ ♠ ❱▼◗❃❙❀❇ ■✽❋✖❈✰❤r▲❢❡♦▲❢❋❃■❑❏▼▲◆❚✬❋✖▲✇❱❅■✘❤ ♣✿■❩✐✲❱✑❣❃❚ ❱✷❱❞▲ ❴✁❤◆❈✼✇✈❆ ❇✲❈ ■✘❴❃❚✽①✬❈❅▲✇❨✁❈●❋✁❏▼▲◆❏▼✐ ▲✇❱P❏✷❇✲❈●❋❍✷❈❂♣✿❍♣▲❢❏❀❏✷❈●❋

✮✁☎ ✷☞✝☎✷✄✂ ✷ ✪ ✷ ❶❀✴ ❋ ✮✾✪ ✷✄✂ ✷♥❷✸✴✍✞ ✩❴✸ ❋ ➀ ✭✟ ✮☛☎❇✷✄✝❊✷✆✂☎✷✲✪ ✷ ❶❏✴ ❛ ✮✮✁✂ ❛ ✷☞☎✗✂ ✷ ❶❀❷✏✂ ✷✆✝✏✂☎✷❧➳✔✪✒✂ ✷☞☎✗✝❊✷ ❶➟➳✔✪❇✷✌❷✏✝☎✷ ✪✒✝❊✷ ❶❀❡✖✷ ✪✒☎ ✷♥❷✔☎ ✷✄❷ ✪ ❛ ✴✍✞ ✩✽✸ ❛ ➀ ✭✷➥✮☛☎❇✷✄✝❊✷✆✂☎✷✲✪ ✷ ❶❏✴❄✮✘✪✼✷❾❝❛✴✖✮✮❜❝✔☎✓✂ ✷➣❝✔☎✓✝☎✷➋❝★✪✒☎❇✷➇➳✘☎❇✷➋❝✔✂ ❛ ✷❾➉✔✂ ✷❀❲ ✪✒✂ ✷✌❷★✪ ❛ ✷❾➉ ✷❦❶❀❷ ✪ ✷❧➳✙✝ ✷ ❝✏✝✔✂❊✷➣❝★✪✒✝✸✴✍✞ ✩❴✸✺✹✺➀ ✭✟ ✮✘✪ ✷➋❝❛✴❄✮✾✪ ✷ ❶❏✴❄✮✘✪✼✷❦❶ ✷✄☎❇✷☞✂❛✴❁✮✘✪ ✷❦❶ ✷✄✝❊✷✠✂✸✴✍✞ ✩✼➀ ✭ ✱✛✚ ✩✼➀ ✭✰✸✺✹ ✟ ✚ ✩✼➀ ✭✏✜

✴ ★ ✶♣✛▲◆❏✷❇ ✁ ✩❈➀ ✭ ✤ ✴ ✠ ❧ ☛ ❧ ❁ ❧ ⑥ ❧ ✦ ✶ ✴ ✠ ❧ ☛ ❧ ❁ ❧ ⑥ ❧ ✳ ✶❁✥ ✴ ✠ ❧ ☛ ❧ ❁ ❧ ⑥ ❧ ➛ ✶ ✴ ⑥ ❧ ❁ ❧ ➛ ✶ ➁ ✩✽✸ ❋ ➀ ✭✵ ✴ ❁ ❛ ❧ ★ ⑥ ❁ ❧✖✳ ❩ ❁ ❧ ✠ ❁ ❧ ✦ ⑥ ❛ ❧✖✳ ❩ ⑥ ❧ ✁ ✠ ❧ ✳ ➛ ❧ ✦ ⑥ ✠ ❧ ✦ ⑥ ☛ ❧ ☛✭❁ ❧ ✁ ☛✲✶ ➁ ✩✽✸ ❛ ➀ ✭❧ ✴ ⑥ ❧ ✦ ✶ ✴ ✦ ❁ ❧ ✦ ❧ ⑥ ❧ ✠ ❧ ☛✣✶ ➁ ✩❴✸✺✹✺➀ ✭ ✯ ❄✴ ✁ ✶✞✕❚➍♣ ❱▼◗✲❡ ❡♦▲❢❋✲❉☎♣ ▲❢❏❀❇❦❍✷❈❩❱▼❣✺❈❩❙✰❏❝❏✷❚ ⑦ ❱▼❇✲❚✒♣ ❱✕❏✷❇❃■✽❏✉❏✷❇✲❈❜❤◆❈✰❖❘❏❀q②❇❃■✽❋❃❨❦❱✪▲✇❨✁❈ ❚✽❖ ✴ ★ ✶ ▲✇❱✉❏✷❇✲❈ ❨✁❈❩❱✪▲◆❍✷❈❩❨ ❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❊❖②❚✬❍❏✷❇✲❈ ❱▼◗✲❡❧✇ ✥ ❱❞▲❢❋✲❉✟✔ ✇ ✯ ❈●❏➨❦✬❚✽①✣✢❱▼❈❂❦✂➫ ❱ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ✥✚✜❩✯✪♠ ▲◆❏✛▲✇❱✕❏✷❇✲❈●❋♥❣✺❚ ❱✷❱✪▲ ❴✁❤◆❈❊❏✷❚ ✐❃❋❃❨❅❏✷❇✲❈❝❍♣▲❢❉❲❇ ❏✷q②❇❃■❑❋❃❨♥❱✪▲✇❨✁❈ ❚❑❖ ✴ ✳ ✶ ✇✂ ✇ ✝ ▲r❤r❖ ■✽❋❃❨✴▼❫✇ ✌❃❈✰▲r❤ ❴❃❈●❍✷❉✬❈●❍t❇❃■✘①✬❈✛❨✁❈❩❱✪▲◆❉✬❋✲❈❩❨ ■ ✿❂✹✒✽❂✷ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ✴ ■✬❱ ❚✬❣✲❣✺❚ ❱▼❈❩❨❝❏❀❚ ❉✬❈●❋✲❈●❍✰■✘❤ ❋✲❚✬❋✲q✼❙✰❚✬❡✑❡❯◗✲❏✰■✽❏▼▲◆①✬❈❈✰❤r▲◆❡❊▲◆❋❃■✽❏▼▲◆❚✬❋ ✶ ❏✷❚ ❙✰❚✬❡ ❣✲◗✲❏❀❈✿❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈❩❱ ❚✽❖ ❏❀❇✲❈ ❏▼✐✁❣❃❈ ✴ ➛ ✶ ❖②❚✬❍t❏✷❈●❍❀❡❊▲◆❋❃■✽❏▼▲◆❋✲❉ ❇✁✐ ❣✺❈●❍✷❉✬❈●❚✬❡✑❈●❏✷❍▼▲✇❙✛❱▼◗✲❡ ❡✞■✽❏♣▲❢❚❲❋✞■✽❋❃❨❡❊◗✁❤◆❏▼▲◆q✼❱▼◗✲❡ ❡✞■✽❏♣▲❢❚❲❋ ✥➯➭✽✯ ✇ ❆✛❇✲❈ ■✽❋❃■❴❤❢❚❲❉✬❚✬◗❃❱ ❚✽❖✗✁ ✩✼➀ ✭ ▲◆❋ ✴ ✁ ✶ ▲❳❱☎❙●■✘❤r❤◆❈❩❨✞■✪❺❞✭❆✵❞✷✸❉ ❑✱❺❄✹✼✷✸✭✿❚❑❖ ❏✷❇✲❈✿❙✰❚✬❡ ❣✲◗✲❏✰■✽❏▼▲◆❚✬❋ ♠ ❱❞▲❢❋❃❙✰❈✕▲◆❏❡✞■✒❦❲❈❩❱ ✴ ★ ✶ ❈❩■✬❱▼✐ ❏❀❚❯❙❀❇✲❈❩❙➨❦⑤❴✁✐ ❡ ❈●❍❀❈ ❍❁■❑❏▼▲◆❚✬❋❃■✘❤❃❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❅❡✞■❑❋✁▲❢❣✲◗✁❤✇■✽❏♣▲❢❚❲❋❃❱❂✇ ❆ ❇✁▲❳❱✛■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ❇❃■✬❱❽❴❃❈●❈●❋♥■✽❏ ❤❢❈❩■❲❱▼❏❣❃■✽❍✷❏♣▲❳■❴❤ ❤◆✐P▲◆❡ ❣✁❤◆❈●❡ ❈●❋✁❏✷❈❩❨P▲◆❋ ✔✄■❑❣✁❤❢❈❥❴✁✐✟▼❫✇ ✌✺❈✰▲ ❤ ❴✺❈●❍✷❉✬❈●❍ ✥ ✳ ❩ ✯ ■✽❋❃❨❅❆❥✇✒✤✉❚✁❚✬❍✷❋✳♣✛▲◆❋❃❨✁❈●❍ ✥ ★ ✯ ■✽❋❃❨✑▲◆❋ ✔✄■❑❏✷❇✲❈●❡✞■✽❏▼▲✇❙●■❴✁✐ ✯ ✇✵✯t■✽◗✁❤◆❈ ■✽❋❃❨✬✔ ✇✬❣ ❙❀❇✲❚✬❍✷❋ ✥ ✁ ✯ ✇ ❢✼❏❝❇❃■❲❱✉❏✷❇✲❈❊❈❄❡✮❏✷❍✰■✞■✬❨✁①✽■✽❋✁❏❁■✽❉✬❈❊❏✷❇❃■✽❏✉❏✷❇✲❈❊❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❊▲◆❏❝❍✷❈●❏✷◗✲❍✷❋❃❱✕▲◆❋❃❱▼❏✷❈❩■❲❨❚✽❖ ✴ ➛ ✶ ▲✇❱✿❚❑❖ ❚✬❍❁❨✁❈●❍ ✳ ✇ �✑✁ ✑ ❅➨☛ �✬⑨✝✆✔✍ ☛ ✍ ☛ ⑨✎✕➢ ❋❃■✽❏❀◗✲❍❁■✘❤ ❉❲❈●❋✲❈●❍❁■✘❤r▲✛✕❩■✽❏▼▲◆❚✬❋❅❚✽❖ ❇✁✐✁❣❃❈●❍✷❉✬❈●❚❲❡ ❈●❏✷❍▼▲✇❙ ▲❳❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱ ▲❳❱☎❣✲❍✷❚✽①❲▲✇❨✁❈❩❨❯❴ ✐✹✑✘q②❇✁✐ ❣✺❈●❍✷❉✬❈●❚✬❡✑❈●❏✷❍▼▲✇❙✕▲✇❨✁❈●❋ ❏▼▲◆❏▼▲◆❈❩❱❂✇❢✼❋✖❏✷❇✁▲✇❱❅❙✰❚✬❋✁❏✷❈❄❡✲❏ ♠ ❍♣▲❳❱❞▲❢❋✲❉ ❖✼■✬❙✰❏✷❚❲❍▼▲✇■✘❤✇❱❅■✽❍✷❈♥❍❀❈●❣✁❤❳■❲❙✰❈❩❨ ❴ ✐ ✴ ❫ ✶ ✩ ✤ ✴ ✳❊✵ ❫ ✶ ✴ ✳ ✵ ❫✭✑ ✶ ↔❆↔✶↔ ✴ ✳❜✵ ❫✩✑ ✩❲✫❃✹ ✶❁♠ ⑥ q ❴✺❈●q❙✰❚✬❡ ❈❩❱ ✴ ✑ ✶ ✩ ❜ ✴ ✳ ✵ ✑ ✶ ✩ ■✽❋❃❨ ❏✷❇✲❈⑤❴✁▲◆❋✲❚✬❡❊▲✇■✘❤✿❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❁❱✯❴❃❈❩❙✰❚✬❡ ❈✑❏✷❇✲❈✒✑❩q✸❴✁▲◆❋✲❚✬❡♦▲❳■❴❤ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱ ❚✬❍ ❑ ■❑◗❃❱✷❱✪▲✇■✽❋❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱

r ⑥ ⑦ t ✤ ✴ ✑ ✶ ✩✴ ✑ ✶ ✭ ✴ ✑ ✶ ✩❲✫✮✭ ❘ ❩✄✞ ⑦✞ ⑥ ❄❆✛❇✲❈ ❙❀❤✇■✬❱❀❱✪▲✇❙●■✘❤ ❙✰❚✬◗✲❋✁❏✷❈●❍✷❣❃■✽❍✷❏t❚❑❖ ❏✷❇✲❈❩❱▼❈✛❋✁◗✲❡❫❴❃❈●❍❁❱ ❚✬❍ ▲✇❨✁❈●❋ ❏▼▲◆❏▼▲◆❈❩❱ ▲◆❋ ①❲❚✽❤◆①✬▲◆❋✲❉ ❏❀❇✲❈●❡ ▲❳❱ ❚✼❴✲❏❁■✘▲◆❋✲❈❩❨❫❴✁✐❝❤◆❈●❏✷❏♣▲❢❋✲❉✴✑✉❏✷❈●❋❃❨❏✷❚ ✳ ✇ ✏✺▲ ❦✬❈❫❴✁▲◆❋✲❚✬❡❊▲✇■✘❤ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏❁❱ ♠ ❏✷❇✲❈ ❑ ■✽◗❃❱❀❱✪▲✇■✽❋♥❣✺❚✽❤◆✐ ❋✲❚✬❡♦▲❳■❴❤❳❱✉❇❃■✘①✬❈❜❋✁▲✇❙✰❈♦❙✰❚❲❡ ❴✁▲◆❋❃■✽❏❀❚✬❍▼▲✇■✘❤ ▲◆❋✁❏✷❈●❍✷❣✲❍✷❈●❏❁■❑❏▼▲◆❚✬❋❃❱■✽❋❃❨P❣✲❍✷❚❲❣❃❈●❍✷❏▼▲◆❈❩❱ ✴ ❱▼❈●❈ ✥ ✦ ✯②✶ ✇ ➳✶➳

Page 54: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➢ ✑✘q②❇✁✐ ❣✺❈●❍✷❉✬❈●❚✬❡✑❈●❏✷❍▼▲✇❙❜❏✷❈●❍✷❡ ▲❳❱❝■✑❖②◗✲❋❃❙✰❏▼▲◆❚✬❋ ⑧ ✴ ⑦ ✶ ❱▼◗❃❙✷❇✌❏✷❇❃■❑❏ ⑧ ✴ ⑦ ❧ ✳ ✶ ❜ ⑧ ✴ ⑦ ✶ ▲✇❱❝■P❍❁■✽❏♣▲❢❚❲❋❃■✘❤ ❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❦❚✽❖ ✑■✽❋❃❨✄✑ ✭ ✇✖❆✛❇✲❈ ❏✷❈❩❙✷❇✲❋✁▲✇❬❲◗✲❈❩❱P❚✽❖ ✝ ▲r❤r❖❯■✽❋❃❨ ✌❃❈✰▲r❤ ❴✺❈●❍✷❉✬❈●❍❅❈❄❡✲❏✷❈●❋❃❨ ❏❀❚✮✑✘q②❇ ✐✁❣❃❈●❍✷❉❲❈●❚✬❡ ❈●❏✷❍▼▲✇❙ ▲❳❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱ ✥➯➭✘✯ ■✽❋❃❨ ■✔✌■✽❏✷❇✲❈●❡✞■❑❏▼▲✇❙●■❊▲◆❡ ❣✁❤◆❈●❡ ❈●❋✁❏❁■✽❏▼▲◆❚✬❋ ▲❳❱❜■✘①❴■✘▲r❤✇■✒❴✁❤◆❈ ✥✿✾✽✯ ✇ ✱✣❚✬❍✉▲◆❋❃❱▼❏❁■✽❋❃❙✰❈ ♠ ❏❀❇✲❈ ❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉❅▲✇❨✁❈●❋ ❏♣▲❢❏▼✐ ▲✇❱✉❈❩❬✬◗✁▲◆①✽■✘❤◆❈●❋ ❏❊❏✷❚❏✷❇✲❈ ✑✘q✸❴✁▲◆❋✲❚✬❡❊▲✇■✘❤t❏✷❇✲❈●❚✬❍✷❈●❡ ④ ✩⑤✭❳❃✺✫✁✩ ✑ ✴ ❙ ❍ ✶ r ✦ ⑥⑥ ❧ ⑦❈t ✠ ✭✉✤ ✴ ✵ ✠ ✶ ✩ ✴ ✵ ✑ ❜ ✠ ✶ ✩ ❄✴ ❇✁✶✏ ❈●❏✿❏❀❇✲❈❯❱▼◗✲❡ ❡P■✽❋❃❨❯❴❃❈ ⑧ ✩❈➀ ✭ ♠ ♣✿❇✁▲✇❙❀❇✄❱✷■✽❏♣▲❳❱❇✐❃❈❩❱⑧ ✩✼➀ ✭✰✸✺✹⑧ ✩✼➀ ✭ ✤ ✠ ✑ ✭ ✵ ✑ ✩✳✿✵ ✑ ✩❴✸✲✭✰✸✺✹ ❘ ⑧ ✩✽✸✺✹✺➀ ✭⑧ ✩✼➀ ✭ ✤ ✴ ✳✿✵ ✑ ❛ ✩❴✸✺✹ ✶ ✴ ✳✿✵ ✑ ❛ ✩✽✸ ❛ ✶ ✑ ✭✴ ✑ ✭ ✵ ✑ ✩✽✸✺✹ ✶ ✴ ✳✿✵ ✑ ✩✽✸✲✭❁✸✺✹ ✶ ❄❆✛❇✲❈●❋✌▲◆❏ ❙●■✽❋➝❴❃❈❜❖❘❚❲◗✲❋❃❨✌❏✷❇❃■✽❏ ⑧ ✩✼➀ ✭ ■✘❤✇❱▼❚♥❱❀■✽❏▼▲✇❱❲✐❃❈❩❱✉❏✷❇✲❈❊❖②❚✽❤r❤◆❚✒♣✛▲◆❋✲❉♥❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈⑤♣✿❇✲❈●❍✷❈ ⑦ ❨✁❚ ❈❩❱ ❋✲❚✬❏ ■✽❣✲❣✺❈❩■✽❍✉▲◆❋❏✷❇✲❈ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏✰❱ ④ ✑ ✩✽✸✺✹♣⑧ ✩✼➀ ✭✰✸ ❛ ❧ ✠ ✴ ✳☎❧ ✑ ❛ ✩❴✸✺✹ ✶ ⑧ ✩✼➀ ✭✰✸✺✹ ❧ ✠ ❛ ✑ ✩ ⑧ ✩❈➀ ✭ ✵ ✠ ⑧ ✩✽✸✺✹❇➀ ✭✰✸✺✹ ✤ ❩ ❄❆✛❇✁▲✇❱ ▲❳❱ ❏✷❇✲❈●❋♥❍✷❈❂♣✕❍▼▲◆❏✷❏✷❈●❋♥■✬❱✠ ⑧ ✩❴✸✺✹✺➀ ✭ ✵ ✴ ✠ ❛ ✑ ✩ ❧ ✠ ✑ ❛ ✩❴✸✺✹ ❧ ✠ ❧ ✑ ✩✽✸✺✹ ✶ ⑧ ✩❈➀ ✭ ✤ ➂ ✩❈➀ ✭❁✸✺✹ ✵ ➂ ✩❈➀ ✭ ❘✴ ✜✬✶♣✛▲◆❏✷❇✌❙✰❈●❍✷❏▼▲✴✐ ❙●■✽❏✷❈ ➂ ✩✼➀ ✭ ✤ ✠ ⑧ ✩✽✸✺✹❇➀ ✭ ✵ ✑ ✩❴✸✺✹✷⑧ ✩❈➀ ✭❁✸✺✹ ✵ ✠ ✑ ✴ ✑ ❛ ✩ ❧ ✑ ✩ ❧✖✳ ✶ ⑧ ✩✼➀ ✭ ❄✱✲❍❀❚✬❡③❏✷❇✁▲✇❱✕❖②❚✽❤r❤❢❚✒♣ ❱✕❏✷❇❃■✽❏✕❏✷❇✲❈❝❤◆❈✰❖②❏✷q②❇❃■✽❋❃❨✌❱✪▲✇❨✁❈❊❚✽❖ ✴ ✜✬✶ ❉❑▲❢①❲❈❩❱ ■❊❍❀❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈ ❱✷■✽❏▼▲✇❱❲✐❃❈❩❨❧❴✁✐❅❏✷❇✲❈❯❱♣◗✲❡❤✇➉❣✽▲◆❋❃❙✰❈ ❏✷❇✁▲✇❱❍✷❈❩❙✰◗✲❍✷❍❀❈●❋❃❙✰❈❝▲✇❱✿❚❑❖ ❚✬❍✰❨✁❈●❍ ✳ ♠ ❱▼❚✽❤◆①❲▲❢❋✲❉✑▲◆❏✛▲✇❱✿❈❩■❲❱▼✐ ■❑❋❃❨❅❏✷❇✁▲✇❱✛✐❲▲◆❈✰❤❳❨✲❱✉❏❀❇✲❈❝❍▼▲◆❉✬❇ ❏❀q②❇❃■✽❋❃❨♥❱✪▲✇❨✁❈❜❚✽❖ ✴ ❇✁✶ ✇❢✼❏✉▲✇❱ ❋✲❚✬❏ ❨❲▲ � ❙✰◗✁❤◆❏❊❏✷❚❅❱▼❈●❈ ❏✷❇❃■❑❏✿❤r▲◆❡ ✩ ☎ ✯ ✥ ❛ ✩✩✽✸✲✭ ✯t✤ ✳ ❜ ✴ ✑ ✶ ✯ ✇ ✞✕❚✒♣ ♠ ❏❁■✒❦❲▲◆❋✲❉❅❏✷❇✲❈❜❤r▲❢❡♦▲❢❏ ▲◆❋ ✴ ❇✁✶❁♠ ❙❀❇❃■✽❋✲❉✽▲◆❋✲❉❀✑▲◆❋ ❏❀❚✹✑ ❛ ■✽❋❃❨✟✠ ▲◆❋ ❏✷❚✟✑ ❁ ✐❲▲❢❈✰❤✇❨✲❱✉❏✷❇✲❈✉❖✼■✽❡ ❚❲◗❃❱✁�✎✹✼❺❄❁✹❀❂❉✤✷✸✵❄❉ ❸✑✲✴✭★☎ ❸✂✵❇❁❆❹✼✰✳❺✶✷➑❉➔❹✼✭✶✻⑧✷✸❉❀✷✸➒✼➣✯⑤✭✥❃✺✫ ✯ ✑ ✭ ❍ ❁ ✭ ✤ ✯✂✩✍❃✁❄ ✴ ✳✛✵ ✑ ❛ ✩❴✸ ❛ ✶ ✴ ✳ ❧ ❁ ✑ ❛ ✩✽✸✺✹ ✶ ✴ ✳ ❧ ✑ ❛ ✩❴✸✺✹❁ ✶ ❄✴ ✾✁✶

✑✬✁✛✥ ✌ ✏ ✍ ☛ ✍ ☛●✆ ✆ ☛ �✬⑨✝✆✔✍ ☛ ✍ ☛ ⑨✎✕❆✛❇✲❈●❍✷❈✑▲✇❱❊■✄❱♣❏✷❍✷❚✬❋✲❉✌❙✰❚✬❋✲❋✲❈❩❙✰❏▼▲◆❚✬❋➤❴❃❈●❏✺♣✛❈●❈●❋ ▲❳❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱ ■✒❴✺❚✬◗✲❏❊❣❃■✽❍✷❏▼▲◆❏▼▲◆❚✬❋❃❱❊■✽❋❃❨ ✑✘q✼❙●■✘❤✇❙✰◗✁❤◆◗❃❱❂✇ ✱✣❚✬❍❝▲◆❋❃❱▼❏❁■❑❋❃❙✰❈❏✷❇✲❈✟✑✘q✸❴✁▲❢❋✲❚❲❡❊▲✇■✘❤ ❙✰❚✁❈ � ❙❀▲◆❈●❋ ❏ ✥ � ✸ ✎✎ ✯ ▲✇❱❊❏✷❇✲❈P❉✬❈●❋✲❈●❍❁■✽❏♣▲❢❋✲❉ ❖❘◗✲❋❃❙✰❏▼▲◆❚✬❋ ✴ ▲❢❋ ❏✷❇✲❈❅①✽■✽❍▼▲✇■✒❴✁❤◆❈❀✑ ✶ ❚❑❖ ❏✷❇✲❈P❋ ◗✲❡❫❴❃❈●❍❊❚✽❖❣❃■✽❍✷❏♣▲❢❏♣▲❢❚❲❋❃❱✿❚✽❖ ⑥ ▲◆❋✁❏✷❚✞■✽❏✿❡✑❚ ❱▼❏ ☞ ❣❃■✽❍✷❏❁❱ ♠ ❈❩■✬❙❀❇ ✞ ✔ ✇✑✯ ❍✷❚✼❴❃■✒❴✁❤◆✐❅❏✷❇✲❈❝❡ ❚✁❱▼❏✛❖✼■✽❡ ❚✬◗❃❱✛❣❃■❑❍✷❏▼▲◆❏▼▲◆❚✬❋❅▲✇❨✁❈●❋✁❏▼▲◆❏▼▲◆❈❩❱✕▲◆❋❏✷❇✁▲✇❱✉❙●■✽❏✷❈●❉✬❚✬❍❀✐✞■✽❍✷❈❝❏✷❇✲❈❫➐✖❁❞❅❈✭✶✵➟✽✣☎❲➐✱✹✼❃❫✹✼✻⑧✰☎✄❂✹✼✻→❉❀❹❈✭✶✻✔✷✸❉➔✷✸❉➔✭❂✽ ♠ ■❑❋❅❈❄❡✣■✽❡✑❣✁❤❢❈❜❚✽❖✤♣✿❇✁▲✇❙✷❇❪▲❳❱✳✛❧ ✯⑤✭✥❃✺✹ ✑ ✭ ❍✴ ✳✿✵ ✑ ✶ ✴ ✳✛✵ ✑ ❛ ✶ ↔✶↔❆↔ ✴ ✳✿✵ ✑ ✭ ✶ ✤ ✯✂

❑ ❃✁❄ ✳✴ ✳✛✵ ✑ ✭ ❑ ✸✺✹ ✶ ✴ ✳✛✵ ✑ ✭ ❑ ✸ ✫ ✶ ❄✴ ➭✁✶❢✼❏✉▲✇❱ ❈❩■✬❱▼✐✌❏✷❚❅❱▼❈●❈ ❏✷❇❃■✽❏❝❏❀❇✲❈❯❍♣▲❢❉❲❇ ❏✷q②❇❃■❑❋❃❨❦❱✪▲✇❨✁❈❊▲✇❱❝❏✷❇✲❈✑❉✬❈●❋✲❈●❍❁■✽❏▼▲◆❋✲❉P❖②◗✲❋❃❙✰❏▼▲◆❚✬❋❦❚✽❖✛❣❃■✽❍✷❏▼▲◆❏▼▲◆❚✬❋❃❱ ▲◆❋ ❏✷❚❅❣❃■❑❍✷❏❁❱✉❈❩❬❲◗❃■✘❤❏✷❚ ✳ ❚✬❍ ★ ❡✑❚✮❨ ✁ ✇☎❢✪❏❯❏❀◗✲❍✷❋❃❱❝❚✬◗✲❏❊❏✷❇❃■❑❏ ❏✷❇✲❈✑❤◆❈✰❖❘❏✷q②❇❃■❑❋❃❨ ❱✪▲✇❨✁❈♥❙●■✽❋ ❴❃❈P❍✷❈❩■✬❨ ■✬❱ ❏✷❇✲❈✞❉❲❈●❋✲❈●❍❁■✽❏▼▲◆❋✲❉ ❖❘◗✲❋❃❙✰❏♣▲❢❚❲❋ ❚✽❖❣❃■✽❍✷❏♣▲❢❏♣▲❢❚❲❋❃❱ ▲◆❋ ❏❀❚❝❣❃■✽❍✷❏❁❱ ♣✛▲◆❏✷❇✑❡❊▲◆❋✁▲❢❡P■✘❤ ❨❲▲✚✙ ❈●❍✷❈●❋❃❙✰❈❥✦ ✴ ❱▼❈●❈ ✥ ✦ ✯②✶ ✇ ❆ ❇✁▲❳❱ ▲✇❨✁❈●❋ ❏▼▲◆❏▼✐ ❱▼❏❁■✽❏❀❈❩❱ ❏✷❇❃■✽❏t❏✷❇✲❈❩❱▼❈✛❋✁◗✲❡❫❴❃❈●❍❁❱☎■✽❍✷❈▲✇❨✁❈●❋ ❏♣▲❳❙●■❴❤ ✇ ✱✣❚✬❍✛▲◆❋❃❱▼❏❁■❑❋❃❙✰❈ ♠ ❏✷❇✲❈❊❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏✉❚✽❖ ✑ ✹✶❄ ▲✇❱ ❇ ❚✬❋❤❴✺❚✬❏✷❇♥❱✪▲✇❨✁❈❩❱ ♠ ❙✰❚✬❍✷❍❀❈❩❱▼❣❃❚✬❋❃❨❲▲◆❋✲❉❅❏✷❚ ✴ ✳ ❩ ✶❁♠ ✴ ✳ ♠➯➭✮✶❁♠ ✴ ✦ ♠✿✾✁✶✰♠✴ ➛ ♠✘✜✬✶ ✴ ★ ♠✿❇✁✶✰♠ ✴ ✳ ♠ ➛ ♠✿❇✮✶ ❚✬❋❅❏✷❇✲❈ ❤◆❈✰❖❘❏❝■✽❋❃❨ ✴ ✳ ✹✶❄ ✶✰♠ ✴ ✳ ✮ ❘ ★ ✶❁♠ ✴ ✳ ❛ ❘ ★ ❛ ✶❁♠ ✴ ✳ ✫ ❘❳❇✮✶❁♠ ✴ ✳ ♠➯➭✁✶✰♠ ✴ ★ ♠✿❇✁✶ ❚✬❋♥❏✷❇✲❈❝❍♣▲❢❉❲❇ ❏ ✴ ❈❄❡✲❣❃❚✬❋✲❈●❋✁❏❨✁❈●❋✲❚✬❏▼▲◆❋✲❉P❍✷❈●❣❃❈●❏♣▲❢❏♣▲❢❚❲❋ ✶ ✇▼❫✇☞✌❃❈✰▲r❤ ❴❃❈●❍❀❉✬❈●❍ ❇❃■✬❱✕◗❃❱▼❈❩❨ ❇✁▲✇❱❝■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❏✷❚ ❣✲❍❀❚❴①❲❈ ✴ ➭✁✶ ❴ ✐❅❣✲❍✷❚✽①❲▲◆❋✲❉✞❏✷❇✲❈ ❖❘❚❑❤ ❤◆❚✒♣✛▲◆❋✲❉❯✐❃❋✁▲◆❏✷❈❊①✬❈●❍❁❱✪▲◆❚✬❋❦❨✁◗✲❈❊❏✷❚❑ ✇ ➢ ❋❃❨✁❍✷❈❂♣ ❱ ④ ⑤ ✭ ✑ ✭ ❍✴ ✑ ✶ ✭ ✴ ✑ ✶ ✩❲✫✮✭ ✤ ⑤ ✭ ✴ ✵❝✳ ✶ ✭ ✑ P ✭ ✭ ❍ ✫✮✭✥❘✛❖ ❛✴ ✑ ✶ ✩✬✫✲✭ ✴ ✑ ✶ ✩❴✸✲✭ ❄✴ ✳ ❩ ✶ ➳✣❲

Page 55: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✏ ❈●❏✷❏♣▲❢❋✲❉ ⑥ ❏✷❈●❋❃❨❪❏✷❚❊▲◆❋✳✐❃❋✁▲◆❏▼✐✄■✽❋❃❨❪❡✞■✒❦❲▲❢❋✲❉✑◗❃❱▼❈ ❚✽❖ ❁ ■✬❙✰❚❈❴✁▲ ➫ ❱✛▲✇❨✁❈●❋✁❏▼▲◆❏❞✐ ✴ ✾✁✶ ✐❲▲❢❈✰❤✇❨✲❱ ✴ ➭✮✶ ✇❈✂✕❚➍♣✛❈●①✬❈●❍ ♠ ■✬❱☎▲◆❋♥❡P■✽❋ ✐❚✬❏✷❇✲❈●❍✉▲◆❋❃❱▼❏✰■✽❋❃❙✰❈❩❱ ♠ ❏❀❇✲❈✒✝ ✌❃q②❏✷❈❩❙❀❇✲❋✁▲❳❬❲◗✲❈ ✴ ❖②❚✬❍ ✝ ▲r❤r❖✁� ✌❃❈✰▲r❤ ❴❃❈●❍❀❉✬❈●❍ ✶ ✐✬▲◆❈✰❤✇❨✲❱❊■P❍✷❈❩❙✰◗✲❍✷❍✷❈●❋❃❙✰❈✪♣✿❇✲❚ ❱▼❈❊❚✬❍❁❨✁❈●❍✉▲✇❱ ❋✲❚✬❏❡❊▲◆❋✁▲◆❡✞■✘❤ ✴ ❇✲❈●❍❀❈ ✁ ▲◆❋❃❱▼❏❀❈❩■✬❨✌❚✽❖✱✦ ✶ ✇ ✞✕❚✬❏❝❚✬❋✁❤◆✐❪▲❳❱✕▲◆❏❜❋✲❚✬❏ ❡P■✽❏✷❇✲❈●❡✞■✽❏♣▲❳❙●■❴❤ ❤◆✐❦■✽❈❩❱▼❏❀❇✲❈●❏▼▲✇❙ ♠ ❴✲◗✲❏✉▲❢❏❝❉❲❈●❋✲❈●❍❁■✘❤r❤◆✐♥❤◆❈❩■✬❨✲❱❏✷❚✞❙✰❚❲❡ ❣✲◗✲❏❁■✽❏▼▲◆❚✬❋❃❱ ❏✷❇❃■✽❏✛❍✷❈❩❬❲◗✁▲❢❍❀❈ ❡❊◗❃❙✷❇❅❡✑❚✬❍✷❈❝❡ ❈●❡ ❚❲❍✷✐ ■❑❋❃❨❅❙✰❚✬❡ ❣✲◗✲❏✷❈●❍✿❏♣▲❢❡✑❈ ❏✷❇❃■✽❋❅❋✲❈❩❙✰❈❩❱❀❱✷■✽❍✷✐✼✇✯ ✇✑✯t■✽◗✁❤◆❈✼➫ ❱❫❦❲❈●✐ ❚✼❴❃❱♣❈●❍✷①❴■✽❏♣▲❢❚❲❋ ✥✿❇✘✯ ▲✇❱✑❏✷❇❃■✽❏ ❀ ➒❶✷✸✹✍✌➍❉➔✻✢❅➝✹✼❹✼➞❆✹✼✻✔✷✸✹✶❅❈✭❶❁✺✿❤✷➔✫✢✭❧✽❂➒✒❃ ❃❫✭❆✷✸✵❞➒❶❉➔✻ ✷➔✫✢✭❧✽ ✰✳❃❫❃❫✹✼✻✔❹✒✽❁✺✿ ✘ ✳ ❩ ✤ ✘ ✹✼✻✔❹ ❁✺✿❶❃❫✹✼✻✔➒➤❁✼✷➔✫✳✭✶✵→✽❂❉❀❃❫❉➔✲✴✹✼✵❤❉➔❹✼✭✶✻⑧✷✸❉❀✷✸❉➔✭❂✽✝✤ ✷➔✫✳✭➤❁✼✵✺❹✼✭✶✵→❁✺✿❶✷➔✫✢✭ ✭✣✢❆✰✢✹❈✷✸❉❀❁✼✻ ❁✹❀ ✷✸✹✼❉❀✻⑧✭❞❹ ❀❂➒➤✷➔✫✢✭ ✠✄✂✴☎✹✼✲ ❅✼❁❈✵❞❉➔✷➔✫✢❃ ❀➨✭❄❺❞❁❈❃ ✭ ✽❤❃❫❉❀✻⑧❉❀❃❫✹✼✲✆☎ ❆✛❇✁◗❃❱❊❖②❚✬❍✞❱▼◗✲❡P❱⑤♣✛▲◆❏✷❇✖❈●①✬❈●❋✖❱▼◗✲❡ ❡✞■❑❋❃❨ ⑧ ✴ ⑦ ✶✰♠ ❏✷❇✲❈❅▲✇❨✁❈❩■ ▲✇❱P❏✷❚❦❏✷❍❀✐ ❱▼◗✲❡ q❡❊▲◆❋✲❉ ✴ ⑧ ✴ ⑦ ✶ ❧ ⑧ ✴ ✵ ⑦ ✶✷✶ ❜ ✦❜▲◆❋❃❱▼❏❀❈❩■✬❨✂✇ ❆✛❇✁▲✇❱ ❤❢❈❩■❲❨✲❱✿❏✷❚❊❏✷❇✲❈ ❖❘❚❑❤ ❤◆❚✒♣✛▲◆❋✲❉P❏✷❇✲❍✷❈●❈●q ❤r▲◆❋✲❈❯❣✲❍❀❚ ❚✽❖t❚✽❖ ✴ ➭✁✶ ✇✙✝✚✟✛✢✜✤✣✂✛✎✥ ✳ ★✪✩✬✫✢✭✯➐✱❁❄❅✼✭✶✵➟✽ ☎▲➐✱✹❈❃ ✹❈✻✔✰ ✄ ✹✼✻→❉➔❹✼✭✶✻⑧✷✸❉❀✷✸➒

✯⑤✭❳❃✁❄ ✑ ✭ ❍✴ ✑ ✶ ✭ ✤ ✳✴ ✑ ✶ ✯⑤ ✭ ✴ ✵❝✳ ✶ ✭ ✑ P ✭ ✭ ❍ ✫✮✭✥❘✛❖ ❛❉●✽✝✷➔✫✢✭❫✲❊❉➔❃❫❉❀✷❽➏ ✫✢✭✶✻ ⑥✦✥ ✧ ❁✺✿ ⑤ ✭ ✦✯✑ ✭ ❍✴ ✑ ✶ ✭ ✴ ✑ ✶ ✩❲✫✮✭ ✤ ⑤ ✭ ✴ ✵❝✳ ✶ ✭ ✑ P ✭ ✭ ❍ ✫✮✭✥❘✛❖ ❛ ✴ ✳☎❧ ✑ ✭ ✶✴ ✑ ✶ ✩✬✫✲✭ ✴ ✑ ✶ ✩❴✸✲✭ ❄✴ ✳✬✳ ✶

✦ ✻❧✹✼❹✼❹✼❉➔✷✸❉❀❁❈✻ ✤ ❀➟❁✼✷➔✫❯✽ ❉➔❹✼✭ ✽✝❁✺✿ ✘ ✳✬✳ ✤⑤✽ ✹✼✷✸❉●✽➔✿ ➒❫✷➔✫✢✭⑤✵✺✭❄❺✶✰✳✵❞✵✺✭❆✻✔❺❄✭✴ ✳✛✵ ✑ ✩✁✶ ❯ ✩ ✤ ✴ ✳✛❧ ✑ ✵ ✑ ✩ ❧ ✑ ❛ ✩❲✫❃✹▼✶ ❯ ✩❲✫❃✹ ❧ ✑ ❯ ✩✬✫ ❛ ❄➈❍✣✎✜☞✜ ✎✾★✕❆✛❇✲❈❝▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱ ❯ ❄ ✤ ✦P■✽❋❃❨ ❯ ✹ ✤ ✦ ✴ ✳✛❧ ✑ ✶ ❜ ✴ ✳ ✵ ✑ ✶ ■✽❍❀❈❝❈❩■✬❱✪▲r❤◆✐✄❱▼❈●❈●❋✌❏✷❚ ❇✲❚❑❤❳❨❪❖②❚✬❍➑❴✺❚✬❏✷❇❱✪▲✇❨✁❈❩❱❂✇ ❆ ❇✲❈❝❣✲❍✷❚ ❚❑❖ ❏✷❇❃■✽❏✖❴❃❚❲❏✷❇ ❱❞▲❳❨✁❈❩❱✕❱✷■✽❏▼▲✇❱✪❖②✐ ❏✷❇✲❈❝❍✷❈❩❙✰◗✲❍❀❍✷❈●❋❃❙✰❈❝❍✷❈✰❤✇■✽❏▼▲◆❚✬❋P▲✇❱☎❈❩■✬❱▼✐P❚✬❋❃❙✰❈✉❉✽▲◆①✬❈●❋❅❏✷❇✲❈✰▲◆❍ ❙✰❈●❍✷❏▼▲✴✐ ❙●■✽❏❀❈❩❱ ④✵ ✑ ❛ ✩✬✫❃✹ ✴ ✳✛✵ ✑ ✩✬✫✲✭ ✶ ■✽❋❃❨✟✑ ❛ ✩❴✸ ❋ ✭ ✴ ✳✿✵ ✑ ✩✬✫✮✭ ✶ ❜ ✴ ✳☎❧ ✑ ✭ ✶ ✇✠☛✡✌☞✎✍✌✡✌✏✒✑✔✓✖✕✘✗✚✙✜✛

✝ ❶ ✞❿✹❈❽❦✦❍✤✖✇❹❇✖❵✯✮✱s❣✲✖✹✯✲✵✴✎✤❃❊✒✉ ☛✚✾✶✫❆➠❛❇✖❵✢✜✻★✾♦➠✄✮✱❺t✲ ✴✶✲❏✷ ✥✜✩✪❊✒✉❑✩✪❊✘❋❿✤❃✧✪✧ ✣✶➒❜➍❑■❑✽✒✾♦✦★❋❛✾♦❇✸✇②✾♦✫★✦❆✩❅✿➔✻❆❇❛✧✪●✘✫★✩✪❇❛❊✘✻▼❇✖❉✁✣✶➒❯✉❑✩ ✗❣✾♦✦❆✾✶❊✒✿❄✾❈✾✛✵❛●✔✤✖✫❆✩✪❇✸❊✘✻❀✲➐❜❊❻✰❣✾❀✿❄✧✪✾♦✦❄✿✄✮✗✌❈✲✵✴♥✤✖❊✔✉➛➸✥➍✘✩✪❽✒❇✸❊❻✮⑦➑✔✲❦➲❭✲✵✴♥✮✌✾❀✉❑✩✪✫❆❇✸✦❆✻❍✴✶❴ ✥✚◆✖➅♦❬✄❚✖P❦➆❩◆ ✑❖◗♦➅☛④❀◗♦➅✶❫⑦◗❄④✄❚✖❱✒➨➛❚✖P ✣❃◗❏➈✶➅❍❚✖❫✌❘✄❘❍◆❃❬❭➈✶❫❅❱✒❚❪❙❯◆❃➅♦❫⑦❘❁④♦✲✒✽❦✽✚✲❃❶❁✷❶❀❷❦✲✸✷ ✎➯❊✘✩✪❵❛✾♦✦★✻❆✩✪✫ ✓✾✯✉❑✾q❺➦✤✖✦★❊✘✾❄➒❜✧❂✤❪➒✱➝➁✤✖✧✪✧ ✓✾♦✾❛❴❣❢❀❤✸❤❛⑩❦✲ ☛▼✦★❇✘✿❄✾♦✾❀✉❑✩✪❊✘❋✸✻❿s ✥✜✢➁✹✍✑✵➉ ❲❦✲

✝ ❝ ✞❿✹❈❊✔✉❑✦❆✾♦➀✥✻➺✮✱➊♥✾♦❇✸✦❆❋✸✾②r✥✲✵✴♦✲❦✷ ↔✜❨❩◗➛↔✜❨✘◗❍◆❃➅✎✍➦◆❜⑥☛➡➎❚✖➅❁❙✱❫✪❙❜❫⑦◆❃❱❑④♦✲✘✷ ✹♥✉✘✉❑✩✪✻❆❇✸❊❑➒❜➩❻✾♦✻❆✧✪✾♦■❑❴❣➜✥✾❀✤✸✉❑✩✪❊✘❋✒❴❣❺➦✤❃✻❆✻❍✤✸✿★➍❞●❦✻❆✾♦✫★✫❆✻❀❴➁❢❀❤✸✐❛❥❦❴➃❖❱✒❘✔✍❛❘✶P✬◆❄➆✘◗❄➨✖❫⑦❚➛◆❯⑥♥❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫⑦❘❁④⑤❚✖❱✒➨❹❫✪❙✌④➎③➯➆❛➆✔P↕❫⑦❘❄❚❏❙❜❫⑦◆❃❱❑④♦❴❑❵❛❇❛✧❜✲✘❝❦✲

✝ ❷ ✞✣➊♥❇✸●✘✧❅✉❹✮✱♣✥✾✶❊✘✦❆■❹➩➣✤❛✉❑✻★➀❖❇✸✦❆✫❆➍✔✴♦✲❏✷➫▲❖◆✖❬✄➈✶❫❅❱✒❚❏❙❆◆✖➅✶❫⑦❚✖P ✆❀➨✸◗♦❱❑❙❜❫✪❙❜❫⑦◗❁④✞✝❖❚☛④❄❙❆❚✖❱✒➨✸❚✖➅❍➨❃❫✠✟❀◗❄➨☛④✶◗❁❙➎◆❯⑥✥❙❆❚❛➈✶P✬◗❁④❿P↕❫❂④❍❙❜❫❅❱✞✣☛✡✌☞✍☞✄➈✶❫❅❱✒◆✖❬✯❫⑦❚❃P❘❄◆❀◗✏✎➫❘♦❫✌◗♦❱❑❙➁④♦➄❑❬⑤❬✄❚❏❙❜❫⑦◆✖❱❩④❁✲❩✷t❺ ❇❛✦❆❋❑✤✖❊❑✫❆❇✖➀✥❊✜❴❑➩ ✲❑➝❖✤✘✲✪❴✔❢❀❤✸✐❛➙✘❴✸✦❆✾✶❵❞✩✪✻★✾❀✉➛✾❀✉❑✩✪✫★✩✬❇✸❊✚✲

✝ ➳ ✞✣→❸❇❑❇❛✦❆❊❑➀✥✩✪❊✒✉❑✾✶✦♥✮⑦➸▼❇❛✇ ♣q✲✵✴✶✲✸✷ ✠❸❊ ✚✔✾✶✩✬✧✪❽✔✾♦✦❆❋✸✾♦✦ ✑ ✻♥✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍✘✇ ✤✖❊✒✉❹✩✪✫❆✻ ✣✶➒❆✤✖❊✒✤❃✧✬❇✸❋❛●✘✾✸✲➞➇❑◆✖➄❑➅♦❱✔❚✖P✚◆❜⑥➺▲❖◆✖❬❸➆✒➄✸❙❯❚❪❙✱❫✌◆✖❱✒❚❃P✚❚✖❱✒➨③✥➆✸➆✒P ❫⑦◗❄➨✯❲❳❚❏❙✌❨❩◗✶❬❭❚❪❙✱❫✌❘❄④♦❴✘❵✸❇❛✧❜✲❆➳❞❧✘❴❣❢❏❤❛❤✸➾✘❴✸✽✘✽✚✲✒➉❲❶❄✷✲❶❩❶❩❶✸✲

✝ ❲ ✞ ☛▼✤✖●✘✧✪✾❹✮☞☛▼✲✵✴♥✤✖❊✒✉➂s✘✿★➍✘❇✸✦❆❊➋✮✱❺❻✲✵✴♦✲➞✷ ✹✞❺ ✤✖✫❆➍❦✾♦✇①✤❃✫❆✩❅✿♦✤✄❵✸✾♦✦❆✻★✩✪❇❛❊➂❇✖❉ ✚✔✾♦✩✪✧✬❽✔✾♦✦★❋❛✾♦✦ ✑ ✻✯✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍✘✇ ❉⑦❇✸✦❿✽❦✦❆❇✖❵❑✩✪❊✘❋②❽✘✩✪❊✘❇✸✇②✩❅✤✖✧✿❄❇❑✾✔✓①✿❄✩✪✾♦❊❑✫❸✩❂✉❩✾♦❊❑✫❆✩✪✫❆✩✪✾♦✻❏✲✎➇❑◆✖➄❑➅♦❱✒❚❃P✚◆❜⑥♥⑧ ✍✖❬❭➈❄◆✖P ❫⑦❘➺▲❖◆✖❬❸➆✒➄✸❙❯❚❪❙✱❫✌◆✖❱✘❴✜❢❀❤❛❤✸⑩✘✲❃✷✺➸▼❇②✤❃✽✘✽✒✾❏✤✖✦❀✲

✝ ✭ ✞ ☛▼✤✖●✘✧✪✾✄✮✡☛✜✾♦✫❆✾♦✦❄✴♦✲✔✷➫s❑➍✘❇✸✦❆✫❿✤❃❊✒✉❹✾❀✤✖✻★■❳✿❄❇✸✇②✽✘●✘✫★✾♦✦✥✽✘✦★❇❞❇❃❉⑦✻❈❇❃❉✳✫❆➍✘✾⑤➜➯❇❛❋✸✾♦✦❆✻❯➒❯➜❸✤✖✇①✤❃❊❑●✶✧♦✤✖❊✄✩❅✉❑✾✶❊❞✫★✩✪✫❆✩✪✾♦✻❈✤✖❊✔✉➛❇✖❉✳✩❅✉❑✾♦❊❑✫❆✩✪✫★✩✬✾✶✻❇✖❉✳✻★✩✬✇❹✩✪✧❂✤❃✦▼✫❜■❞✽✔✾❛✲➁↔✜❨❩◗✣➃❖P✬◗❄❘❁❙✱➅❄◆✖❱✘❫⑦❘☛➇❞◆❃➄❑➅♦❱✒❚✖P▼◆❜⑥✄▲❖◆❃❬❭➈✶❫❅❱✒❚❪❙❯◆❃➅♦❫⑦❘❁④♦❴❑❵❛❇❛✧❜✲✁❶❛❴❑❊ ➽ ❶❀❷❦❴❣❢❀❤❛❤❃❶✒❴✸✽✘✽✚✲✺❶❄✷❩➉❦✲

✝ ❡ ✞ ☛✜✾♦✫❆➠✸❇✖❵✢✜✻❆✾♦➠➛✮❜❺➦✤✖✦★➠❛❇❞✴✶✲❏✷①♣✥■❑✽✔✾♦✦❆❋✸✾♦❇❛✇❹✾♦✫❆✦★✩❅✿➁✻❆❇❛✧✪●✘✫★✩✪❇❛❊✘✻▼❇✖❉❣✧✪✩✪❊✘✾❀✤✖✦▼✦★✾❀✿❄●✘✦★✦❆✾♦❊✒✿❁✾❀✻✥➀✥✩✪✫❆➍✄✽✔❇❛✧✪■❑❊✘❇✸✇②✩❅✤✖✧❛✿❄❇❑✾✔✓①✿❁✩✬✾✶❊❞✫★✻❀✲❣➇❑◆✖➄❑➅ ✕❱✒❚❃P✎◆❜⑥✣⑧✏✍✖❬❭➈❄◆❃P↕❫⑦❘➺▲❖◆✖❬❸➆✒➄✸❙❆❚❏❙❜❫⑦◆✖❱✘❴❦❵❛❇✸✧✱✲✁❶➨➳✔❴❣❢❀❤✸❤❛➙✘❴❑✽❦✽✚✲✘❝❂➳✽❷❏✷❩❝✜✭❂➳✔✲

✝ ❧ ✞✣➜✥✩✪✾♦✻★✾✯✮⑦✹⑤✲✵✴✶✲✸✷✺✹ ❺➦✤❃✫❆➍✘✾✶✇①✤✖✫★✩❅✿♦✤ ✣✶➒❆✤✖❊✒✤❃✧✬❇✸❋❛●✘✾✥❇❃❉ ✚✔✾♦✩✪✧✪❽✔✾♦✦❆❋✸✾♦✦ ✑ ✻❿✤❃✧✪❋❛❇❛✦★✩✪✫❆➍✘✇➻❉⑦❇✸✦❖✽✘✦★❇✖❵❑✩✬❊❦❋✌✣✶➒❜➍❑■❞✽✔✾♦✦★❋❛✾♦❇✸✇②✾♦✫★✦❆✩❅✿❸✩❂✉❩✾♦❊❑✫❆✩ ➒✫❆✩✪✾♦✻❏✲❑✷➣♠❸✩✬✽❦✧✬❇✸✇①✤❸➸✥➍✘✾♦✻★✩✪✻❀✲✘➐❜❊➛✽✘✦★✾♦✽✒✤❃✦❍✤✖✫★✩✪❇❛❊✚✲

✝ ➉ ✞❿➩➫✩✪✧ ❉❖✮❜♣✥✾♦✦★❽✒✾♦✦★✫qs❣✲✵✴❖✤❃❊✒✉ ✚✔✾♦✩✪✧✬❽✔✾♦✦★❋❛✾♦✦☛✮✱♠❸❇❛✦★❇❛❊✒✴✶✲✸✷✺✹❸❊❳✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇②✩✬✿➁✽❦✦❆❇❑❇✖❉▼✫❆➍✘✾♦❇✸✦❆■❹❉⑦❇✸✦❖➍❑■❑✽✒✾✶✦❆❋❛✾✶❇❛✇②✾✶✫❆✦❆✩❅✿☛✮⑦❇✸✦❍✉❑✩✪❊✒✤❃✦❆■✤✖❊✔✉ ✻ ✣ ✽❞✴➁✇✄●✘✧✪✫★✩✬✻★●✘✇✆☎✖✩✪❊✸✫❆✾♦❋✸✦❍✤✖✧❦✩❂✉❩✾♦❊❑✫❆✩✪✫❆✩✪✾♦✻❏✲ ✆♦❱ ✜❪◗✶❱❑❙❜❫⑦◆✖❱✒◗❁④q❲❳❚❏❙✌❨❩◗✶❬✄❚❏❙❜❫⑦❘❄❚❛◗✶❴❑❵❛❇❛✧❜✲✲❶❏❷❛❧✘❴✔❢❀❤✸❤❛➙❦❴❑✽✘✽✚✲✯❲❛❡ ❲❏✷✤✭❩❷❩❷❦✲

✝ ❶❀❷ ✞✛✚✔✾♦✩✪✧✪❽✒✾✶✦❆❋❛✾✶✦✥✮✱♠❸❇❛✦★❇❛❊✒✴✶✲❄✷⑤✹❾❺➦✤✖✽❦✧✬✾➔✽✘✦❆❇✸❋❛✦❍✤❃✇➫❉✌❇❛✦✚✽❦✦❆❇✖❵❑✩✪❊✘❋✥➍❑■❞✽✔✾♦✦★❋❛✾♦❇✸✇②✾♦✫★✦❆✩❅✿▼✩❅✉❑✾♦❊❑✫❆✩✪✫★✩✬✾✶✻❀✲✸⑧ ✆✒✑➁⑧❞③✣❲✔✓✥➄❑P❅P✬◗❁❙❜❫❅❱✘❴❏❵❛❇✸✧✱✲❏❝ ❲❦❴❊✘➽✽❷✘❴❑➑❛●❦✧✬■➂❢❀❤✸❤✘❢❛❴✸✽✘✽✚✲❈➳✖✷✲❶❁❷✘✲

✝ ❶❩❶ ✞✛✚✔✾♦✩✪✧✪❽✒✾✶✦❆❋❛✾✶✦②✮❜♠❈❇✸✦❆❇✸❊✒✴♦✲❦✷ ➸✥➍✘✾✄✇❹✾♦✫❆➍✘❇✘✉➛❇❃❉➯✿❁✦❆✾❀✤❃✫❆✩✪❵❛✾✯✫❆✾♦✧✪✾♦✻❄✿❄❇❛✽❦✩✬❊❦❋✒✲❖➇❑◆✖➄❑➅♦❱✔❚✖P❖◆❯⑥✯⑧✏✍✖❬❭➈❄◆❃P↕❫⑦❘ ▲❖◆✖❬❸➆✒➄✸❙❯❚❪❙✱❫✌◆✖❱✘❴❣❵✸❇❛✧❜✲ ❶❩❶✸❴❢❀❤✸❤✘❢✸❴❑✽✘✽✚✲✲❶❀➉ ❲❏✷✘❝❛❷❂➳✔✲

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Page 56: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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✟ ✞ ✗ ✓ ✙✂✢ ☛ ☎✢✤✧ ✓ ✬✦✓ ✙✖✕✡✠▲✢✒✞ ✟ ✓❑❍➢▲❑ s ♠ ✣s ❙✰❚✽❤◆❈❝❣✺❚✽❤◆✐ ❏✷❈❩❙❀❇✲❋✁▲✇❬✬◗✲❈ ✴ ✱✲❍❁■❑❋❃❙✰❈ ✶✞✕❚✽①✬❈●❡❫❴❃❈●❍➑✦ ✳ ♠ ✳ ➭✼➭ ★✥ ❱▼◗✲❡✑❡✞■✽❍✷✐⑤❴✁✐●✱✲❍✌✣❈❩❨☎✣❈●❍▼▲✇❙ ❪ ❇✁✐✩✕❩■✘❦ ✯

✳✄☞✵✴✷✶❏✓✖✕✹✸✺✶✹✯✲ ☛✍✓✾♦✧❅✤❛✉✘✤❃❊❑➒❆➊♥✾♦✦❆✇➛✤⑤✉❩✾❀✤✖✧✪✻♥➀✥✩✪✫❆➍➦✾❄✈✘✫★✾♦❊✘✻❆✩✪❇✸❊✘✻♥❇✖❉➎✉❑✩ ✗❣✾♦✦❆✾✶❊❞✫★✩❅✤✖✧▼✦❆✩✪❊✘❋✸✻❈❽❑■➛✻❆❇❛✧✪●✘✫★✩✪❇❛❊✘✻❸❇✖❉❖✻★■❞✻★✫❆✾♦✇❹✻❈❇❃❉

☛✳♠♥r✔✑ ✻❀✲✜➐❜❊②✫❆➍❦✾❿✿♦✤❃✻❆✾♥❇✖❉ ✠♥♠♥r✔✑ ✻❀❴✸✫❆➍✘✾❸✽✘✦❆❇✸❽✘✧✪✾♦✇ ❇❃❉✚✾✶✵✸●✒✤✖✧✪✩✪✫❜■⑤✫★✾♦✻❆✫★✩✪❊✘❋⑤✩✪❊✄✫★➍✘✾❈✾❄✈✘✫★✾♦❊✘✻❆✩✪❇✸❊②✦❆✩✪❊✘❋✯➍✒✤❃✻✳❽✒✾✶✾♦❊✻❆❇❛✧✪❵✸✾❀✉ ✝ ❝❑❴✲❷✌✞❆✲☛➸✥➍✘✾②✤✖●✘✫★➍✘❇❛✦♥❋✸✩✬❵✸✾♦✻q✤✖❊❻✤✖✧✪❋❛❇✸✦❆✩✪✫❆➍❦✇ ❉⑦❇✸✦♥✫❆➍✘✾✄✇❹❇❛✦❆✾☛❋❛✾♦❊✘✾✶✦❍✤✖✧➁✿♦✤✖✻★✾✄❇✖❉ ☛✳♠♥r✔✑ ✻ ✝ ✭✔✞❆✲q➐❜✫☛✩✬✻❽✒✤✖✻★✾❀✉✄❇✸❊✄✫❆➍✘✾❸✫❆➍✘✾♦❇✸✦❆■✄❇❃❉✎✉❑✩ ✗➞✾♦✦★✾♦❊❑✫❆✩❅✤✖✧❣✤✖✧✪❋✸✾♦❽✘✦❍✤❦❴❞✤❃❊✒✉✄✩✪❊✄✽✒✤❃✦❆✫★✩❂✿❁●✘✧❅✤✖✦✳❇✸❊✄✫❆➍✘✾♥✿❄❇❛❊✒✿❁✾♦✽✘✫✥❇✖❉✎✤❃●✘✫❆❇❃➒✱✦★✾❀✉❑●✒✿❁✾❀✉✿❄❇❛➍✘✾✶✦❆✾♦❊❑✫❈✻★✾♦✫❆✻ ✝ ❲❑❴✒❧✔✞❆✲

❊✔✁✼❋ ✗✂✍✶✓ ☛ ✆✂⑨ ✆ ⑩➑✍ ✄ ⑨→✌✔✓✦✥ ✆✑✏✒☛ ✍ ✄☞✞✏ ❈●❏☞☛ ❴✺❈❯❏❀❇✲❈ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤t❍▼▲◆❋✲❉ ⑦ ✥ ✠ ✹ ❘ ❄✘❄❩❄ ❘ ✠ ✩ ✯ ❈●❋❃❨✁❚✒♣✛❈❩❨☎♣✛▲◆❏✷❇✌❏✷❇✲❈❜◗❃❱▼◗❃■✘❤t❣❃■✽❍✷❏▼▲✇■✘❤ ❨✁❈●❍♣▲❢①✽■✽❏▼▲◆①✬❈❩❱ � ❂✍✌ ✇✉❆✛❇✲❈♣✛❚✬❍➨❦❅❨✁❈❩❱✷❙✰❍▼▲ ❴❃❈❩❨ ❇✲❈●❍✷❈❜❉✽▲◆①✬❈❩❱✿■✽❋✌■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❖❘❚✬❍✕❈✥✙ ❈❩❙✰❏♣▲❢①❲❈ ❈❩❬❲◗❃■✘❤r▲❢❏▼✐❅❏✷❈❩❱♣❏▼▲◆❋✲❉ ▲◆❋✄❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤t❈❄❡✮❏✷❈●❋❃❱❞▲❢❚❲❋❃❱✿❚✽❖✎☛❴✁✐♥❱▼❈●❍▼▲◆❈❩❱❝❨✁❈❄✐❃❋✲❈❩❨→❴✁✐♥■✘❤◆❉✬❈❂❴✲❍❁■✘▲✇❙❜❣❃■✽❍✷❏▼▲✇■✘❤ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱❂✇ ✔ ❚✬❍✷❈❜❣✲❍✷❈❩❙❀▲✇❱▼❈✰❤◆✐ ♠ ❤◆❈●❏ ⑧ ❵✬✢ ⑦ ✥◆✥ ✠ ✹ ❘ ❄✘❄❩❄ ❘ ✠ ✩ ✯◆✯❴❃❈ ❖❘❚❲❍✷❡✞■✘❤ ❣❃❚✒♣✛❈●❍✿❱▼❈●❍▼▲◆❈❩❱✉❨✁❈❄✐❃❋✲❈❩❨❤❴✁✐P❈❩❬✬◗❃■✽❏♣▲❢❚❲❋❃❱✛❚✽❖t❏✷❇✲❈❝❖②❚✬❍✷❡✛✑✏ ✴ ✠ ✹ ❘ ❄✘❄❩❄ ❘ ✠ ✩ ❘ ❭ �✓✒ ⑧ ❵✪❛ ✶☎✤ ❩ ❘✴ ✳ ✶❖②❚✬❍ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ✛✑✏❪▲◆❋❬✐❃❋✁▲◆❏✷❈✰❤◆✐✖❡✞■✽❋✁✐ ❨✁❈●❍▼▲◆①❴■✽❏▼▲◆①✬❈❩❱ �✓✒ ⑧ ❵✺✇ ❑ ▲◆①✬❈●❋✖❏✷❇✲❈❩❱♣❈♥❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ✛✁✏❦■✽❋❃❨ ❱❞▲❢❡♦▲ ❤✇■✽❍❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ✧ ✏ ♠ ❏✷❇✲❈ ❣✲❍✷❚✼❴✁❤◆❈●❡ ▲❳❱✑❏✷❚ ❨✁❈❩❙❀▲✇❨✁❈→♣✿❇✲❈●❏✷❇✲❈●❍P❏✷❇✲❈ ⑧ ❵✺➫ ❱ ❱✷■✽❏♣▲❳❱❞❖❘✐ ❏✷❇✲❈❅❈❩❬❲◗❃■✽❏▼▲◆❚✬❋❃❱✑❍✷❈●❣✲❍✷❈❩❱♣❈●❋ ❏✷❈❩❨ ❴ ✐❏✷❇✲❈ ✧ ✏ ➫ ❱ ♠ ■✽❋❃❨P▲◆❋✌❙●■✬❱▼❈❝❏✷❇✲❈●✐❅❨✁❚ ❋✲❚✬❏ ♠ ❏✷❚❊❍✷❈●❏✷◗✲❍✷❋❅❚✬❋✲❈❜❚✽❖t❏✷❇✲❈ ✧ ✏ ➫ ❱☎❏✷❇❃■❑❏✛▲✇❱✛❋✲❚✬❏ ❱✷■❑❏▼▲✇❱❲✐❃❈❩❨✂✇❆✛❇✲❈✌①❲▲❢❈❂♣✕❣❃❚✽▲◆❋✁❏✄■✬❨✁❚✬❣✲❏❀❈❩❨ ❇✲❈●❍✷❈✌▲✇❱P❏✷❚ ❙✰❚✬❋❃❱✪▲✇❨✁❈●❍ ❏✷❇✲❈❅❖②❚✬❍✷❡✞■❴❤ ❣✺❚➍♣✛❈●❍❅❱▼❈●❍▼▲◆❈❩❱ ✧ ✏ ✴ ✠ ✹ ❘ ❄❩❄✘❄ ❘ ✠ ✩ ❘ ❭ �✓✒ ⑧ ❵✪❛ ✶ ■✬❱❈✰❤◆❈●❡ ❈●❋✁❏❁❱❊❚✽❖✿❏✷❇✲❈❅❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤✉❈❄❡✮❏✷❈●❋❃❱❞▲❢❚❲❋ ❚✽❖✔☛ ❴✁✐❦❏✷❇✲❈ ⑧ ❵❇➫ ❱ ✇ ✂✕❚✒♣ ❈●①❲❈●❍ ♠ ❱▼❇✲❈✞❍❀❈❩❬✬◗✁▲◆❍✷❈❩❱ ■❑❋ ■✬❱❀❱▼◗✲❡ ❣✲❏▼▲◆❚✬❋ ❚✬❋❏✷❇✲❈❩❱▼❈❅❣✺❚✒♣ ❈●❍P❱▼❈●❍▼▲◆❈❩❱ ♠ ❋❃■✽❡ ❈✰❤◆✐ ❏❀❇❃■✽❏ ❏✷❇✲❈●✐ ■✽❍✷❈❅❨✁❈❄✐❃❋✲❈❩❨ ❴ ✐ ■ ❺❞❁✼❃◗❸✑✲✴✭❆✷✸✭☎✽❂➒✶✽❂✷✸✭✶❃❫✇ ❢✼❋✁❖②❚✬❍✷❡P■✘❤r❤❢✐ ♠ ■✌❙✰❚✬❡✑❣✁❤❢❈●❏❀❈❱▼✐✲❱▼❏✷❈●❡ ❣✲❍✷❚✽①✬▲✇❨✁❈❩❱❽♣✛▲◆❏✷❇❅❱▼◗✁� ❙❀▲◆❈●❋ ❏♣❤❢✐P❡✞■✽❋✁✐❊❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱✛■✽❋❃❨❜▲◆❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱✿❱♣❚❯■✬❱ ❏✷❚✝❴✺❈ ■✒❴✁❤◆❈✉❏✷❚❯❙✰❚❲❡ ❣✲◗✲❏✷❈✹✼✻⑧➒♥❙✰❚ ❈ �❅❙❀▲❢❈●❋✁❏❝❚✽❖❥✹✼✻✔➒P❚✽❖✛❏✷❇✲❈ ❣✺❚➍♣✛❈●❍ ❱▼❈●❍♣▲❢❈❩❱ ⑧ ❵ ✴ ❱▼❈●❈ ❆✛❇✲❈●❚✬❍✷❈●❡ ✦❯❴❃❈✰❤◆❚✒♣ ✶ ✇❝❆✛❇✲❈ ❱✷■❑❡ ❈ ■✘❤✇❱▼❚♥■✽❣✲❣✁❤r▲◆❈❩❱❝❏✷❚❅■✘❤r❤❱▼❈●❍▼▲◆❈❩❱ ✧ ✏ ✴ ✠ ✹ ❘ ❄✘❄❩❄ ❘ ✠ ✩ ❘ ❭ �✓✒ ⑧ ❵✪❛ ✶ ✇❅❆✛❇✲❈✞■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ❨✁❈❩❙❀▲✇❨✁❈❩❱❫♣✿❇✲❈●❏✷❇✲❈●❍❯✹✼✲➔✲✿❙✰❚ ❈ � ❙❀▲◆❈●❋✁❏❁❱❊■✽❍✷❈✴✕●❈●❍✷❚✔✇✟✔ ❚✬❍✷❈●❚✽①✬❈●❍ ♠■❦❙✰❚✬❡✑❣✁❤❢❈●❏❀❈✄❱▼✐✲❱▼❏✷❈●❡ ❡✞■✒❦❲❈❩❱ ❱▼◗✲❍✷❈❅❏✷❇❃■❑❏ ❏✷❇✲❈♥■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ♣✛▲r❤r❤ ♣✛❚✬❍➨❦ ❖❘❚✬❍P■✽❋ ✐ ❱▼❈●❏ ❚✽❖ ✧ ✏✳➫ ❱ ♠ ❈●①✬❈●❋ ❖②❚✬❍❫❴❃■✬❨❲❤◆✐❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋✲❈❩❨ ❚✬❋✲❈❩❱❂✇ ❑ ▲◆①✬❈●❋♥❏❀❇✲❈ ❱▼❈●❏❬❚✈❚❑❖ ■✘❤r❤ ✧ ✏✳➫ ❱✿■✽❋❃❨❅■❴❤ ❤ ✛✑✏✼➫ ❱ ♠ ❏✷❇✲❈ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ▲✇❱ ④✴ ✳ ✶ ❪ ❚✬❡ ❣✲◗✲❏✷❈❊■✽❋ ✹❈✰✢✷✸❁✼✵✺✭❄❹✼✰✳❺❞✭❄❹❤❺❄❁✒✫✢✭❆✵❇✭❆✻✔✷❽✽❂✭✶✷✔✄✦■✬❱❀❱▼❚✮❙❀▲✇■✽❏❀❈❩❨❅❏✷❚ ❚ ■✽❋❃❨✌■✽❋✌■✬❨✲❨❲▲◆❏▼▲◆❚✬❋❃■✘❤ ❣❃❚❑❤❢✐✁❋✲❚✬❡❊▲✇■✘❤✖✕ ♠❏✷❇✲❈❊❣✲❍✷❚✮❨✁◗❃❙✰❏❜❚✽❖ ■✘❤r❤ ❉➔✻✔❉➔✷✸❉➔✹✼✲ ✽❯■✽❋❃❨ ✽❂✭✺❸✎✹✼✵✺✹✼✻✔✷➔✽❊❚✽❖ ❏❀❇✲❈❯❈✰❤◆❈●❡ ❈●❋✁❏❁❱ ❚✽❖✓✄➉✇ ✴ ❆ ❇✲❈❩❱▼❈❊❋✲❚✬❏▼▲◆❚✬❋❃❱ ■❑❍✷❈ ❨✁❈❄✐❃❋✲❈❩❨❴❃❈✰❤◆❚✒♣✝✇ ✶ ❢✪❋✁❖❘❚❲❍✷❡✞■✘❤r❤◆✐ ♠ ❏✷❇✲❈✌❱▼❈●❏ ✄ ❨✁❈❄✐❃❋✲❈❩❱❪❏✷❇✲❈✄❱❀■✽❡ ❈✄❱♣❈●❍▼▲◆❈❩❱❅■✬❱✸❚ ♠ ◗✲❣✖❏✷❚❦❣❃❚✁❱✷❱✪▲ ❴✁❤◆❈ ❱✪▲◆❋✲❉✬◗✁❤✇■✽❍▼▲◆❏▼▲◆❈❩❱❨✁❈❩❱✷❙✰❍▼▲ ❴❃❈❩❨❧❴✁✐✗✕ ④ ❏✷❇✲❈ ■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡ ❇❃■✬❱ ❏✷❚ ❨✁❈❩❙❀▲❳❨✁❈❫♣✿❇✲❈●❏❀❇✲❈●❍✔✕ ✴ ⑧ ✶t✤ ❩ ✇✴ ✦ ✶ ❆ ❚❊❏✷❇✁▲✇❱✕❈●❋❃❨ ④✚ ▲ ❖✘✕ ✴ ⑧ ✶ ✴ ❩ ✶ ✁✤ ❩ ✴ ✵✺✭✺❅✼✰✳✲✴✹✼✵➑❺❄✹✒✽ ✭ ✶❁♠ ❏✷❇✲❈●❋❅❏✷❇✲❈ ✧ ✏ ✴ ⑧ ✶ ■✽❍✷❈❝■✘❤r❤ ✕●❈●❍❀❚ ▲r❖ ■❑❋❃❨ ❚✬❋✁❤◆✐❊▲r❖ �✙✒ ③ ✴ ⑧ ✶ ✴ ❩ ✶t✤ ❩❖❘❚✬❍✿■ ❙✰❚❲❡ ❣✲◗✲❏❁■✒❴✁❤◆❈❥✐❃❋✁▲◆❏✷❈❊❱▼❈●❏✿❚✽❖ ❨✁❈●❍▼▲◆①❴■❑❏▼▲◆①✬❈❩❱❝■✽❋❃❨❅■✘❤r❤ ③ ✢☎✄ ❝

✚ ❚✬❏✷❇✲❈●❍➨♣✛▲✇❱▼❈ ♠ ❏✷❇✲❈ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡ ▲✇❱ ■❑❣✲❣✁❤ ▲◆❈❩❨✑❍✷❈❩❙✰◗✲❍❁❱✪▲◆①✬❈✰❤◆✐ ❏❀❚❯❨✁❈❩❙❀▲✇❨✁❈❍♣✕❇✲❈●❏✷❇✲❈●❍ ■✘❤r❤ ✧ ✏ ✴ ⑧ ✶ ➫ ❱t■✽❋❃❨✚✕ ✴ ⑧ ✶■✽❍✷❈ ✕●❈●❍✷❚ ❝ ❏✷❇✲❈●❋ ④ ➳❞❡

Page 57: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ▲r❖ ✕ ✴ ⑧ ✶ ✁✤ ❩ ✴ ✽ ✭❆❃ ❉ ☎❇✵✺✭✺❅✼✰✳✲✴✹✼✵❥❺❞✹✘✽ ✭ ✶❁♠ ❏✷❇✲❈❝❣✲❍✷❚✼❴✁❤◆❈●❡ ❍✷❈❩❨✁◗❃❙✰❈❩❱✉■✽❉ ■✘▲◆❋❅❏✷❚ ❏❀❈❩❱▼❏▼▲◆❋✲❉ ✄ ✴ ⑧ ✶☎✤ ❩ ❝✄ ✴ ⑧ ✶ ❙✰❚✬❋✁❏▼▲◆❋✁◗✲❚✬◗❃❱✪❤◆✐❦❨✁❈●❣❃❈●❋❃❨✲❱❊❚✬❋✌❏✷❇✲❈♦▲❢❋✁▲◆❏▼▲✇■✘❤ ❙✰❚✬❋❃❨❲▲◆❏▼▲◆❚✬❋❃❱❜❨✁❈❄✐❃❋✁▲◆❋✲❉ ⑧ ♠ ■✽❋❃❨❦❨✁❈❩❙❀▲✇❱✪▲◆❚✬❋ ▲❳❱❨✁❚✬❋✲❈❥❴✁✐ ❙✰❚✬❡✑❣✲◗✲❏▼▲◆❋✲❉✞■ ❑ ❍✷❚✁❈❂❴✲❋✲❈●❍➑❴❃■✬❱✪▲✇❱☎▲◆❋✌■✽❋❅◗❃❱▼◗❃■✘❤ ❋✲❚✬❋✲q✼❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤ ■✘❤◆❉✬❈❂❴✲❍❁■♦❏✷❚ ✐❃❋❃❨❏✷❇✲❈ ❙❀❤◆❚ ❱▼◗✲❍✷❈❜❚✽❖ ■✽❋♥■✽❣✲❣✲❍✷❚✬❣✲❍♣▲❳■❑❏✷❈ ■✘❤◆❉✬❈❂❴✲❍❁■✘▲✇❙ ①❴■✽❍▼▲◆❈●❏▼✐ ❝� ▲r❖ ❚✬❋✲❈❜❚✽❖ ❏✷❇✲❈ ✧ ✏❈➫ ❱ ♠ ❱❀■❩✐ ✧ ✭ ♠ ▲✇❱✛❋✲❚✬❏ ❙●■✽❋❃❙✰❈✰❤r❤◆❈❩❨ ♠ ❍✷❈●❏✷◗✲❍❀❋❅❏✷❇✲❈❯■✽❋❃❱➃♣ ❈●❍ ✧ ✭ ✴ ⑧ ✶ ✁✤ ❩ ❝� ❚✬❏✷❇✲❈●❍➨♣ ▲❳❱♣❈ ✴ ✽ ❉➔✻✢❅❈✰✢✲✴✹✼✵➉❺❄✹✒✽ ✭ ✶❁♠ ❍❀❈●❏✷◗✲❍✷❋❅❏✷❇✲❈ ■✽❋❃❱➃♣ ❈●❍✕❏✷❇❃■✽❏✿■✘❤r❤ ✧ ✏ ✴ ⑧ ✶ ➫ ❱✛■✽❍✷❈ ✕●❈●❍✷❚✔✇❆ ❈●❍✷❡❊▲◆❋❃■✽❏▼▲◆❚✬❋ ❚✽❖ ❏❀❇✁▲❳❱ ❍✷❈❩❙✰◗✲❍❁❱✪▲◆①✬❈❊■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱✕❈●❋❃❱▼◗✲❍✷❈❩❨➇❴ ✐❅❆✛❇✲❈●❚✬❍✷❈●❡ ✳ ❴❃❈✰❤◆❚✒♣✝✇�✂✁✂✁☎☛☎✄ ⑨ ✏ ⑨ ✆✔✍ ☛ ✌✔✓✖✌✔✓ ✥✔⑨ ✠☞✏ ✌➢ ❱▼◗✁▲◆❏❁■✒❴✁❤◆❈✌❏✷❇✲❈●❚✬❍❀✐ ❏✷❚❶♣✛❚✬❍➨❦ ♣✛▲◆❏✷❇✖❈❩❬✬◗❃■❑❏▼▲◆❚✬❋❃❱❊❤r▲ ❦✬❈ ✴ ✳ ✶ ▲❳❱P❏❀❇✲❈♥❏✷❇✲❈●❚✬❍❀✐ ❚✽❖ ❹❈❉ ✟❍✭❆✵✺✭✶✻✔✷✸❉➔✹✼✲➑✹❈✲ ❅❈✭✫❀ ✵❇✹✝✆ ✁ ♠ ✾✟✞ ✇✯ ❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱ ❤ ▲ ❦✬❈P❏✷❇✲❈ ✧ ✏❈➫ ❱ ■❑❋❃❨❦❏✷❇✲❈✗✛✑✏✼➫ ❱ ■✽❍✷❈P❙●■✘❤r❤❢❈❩❨➝❸✎✹✼✵❄✷✸❉❀✹✼✲❽❹✼❉ ✟❍✭✶✵✺✭✶✻⑧✷✸❉❀✹❈✲⑧❸❖❁✼✲✴➒✒✻✔❁✼❃❫❉➔✹✼✲ ✽ ♠ ▲◆❋ ❱▼❇✲❚✬❍✷❏✯❸❖❹❄❸✤➫ ❱ ♠■✽❋❃❨ ❖❘❚✬❍❀❡ ❏✷❇✲❈ ✵❞❉➔✻✢❅ ❁✺✿⑤❸✎✹✼✵❞✷✸❉➔✹✼✲➉❹✼❉ ✟❍✭✶✵✺✭✶✻⑧✷✸❉❀✹❈✲ ❸❖❁✼✲✴➒✒✻✔❁❈❃ ❉➔✹✼✲ ✽✔✬ ✠ ☛✡✆r❭ �✓✒✩☛ ❵✪❛ ✞ ✇☞✞✕❚✬❏✷❈ ❏✷❇❃■✽❏ ❏❀❇✁▲❳❱P❍♣▲❢❋✲❉ ▲✇❱❅■❙✰❚✬❡ ❡❊◗✲❏❁■❑❏▼▲◆①✬❈ ❍♣▲❢❋✲❉✑▲◆❋❅▲◆❋✳✐❃❋✁▲◆❏✷❈✰❤◆✐✌❡✞■✽❋✁✐❊▲◆❋❃❨✁❈●❏✷❈●❍✷❡❊▲◆❋❃■✽❏✷❈❩❱ ✇▼✕▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ■✘❤◆❉✬❈❂❴✲❍❁■❪❏✷❇✲❈●❚✬❍✷✐ ▲◆❋✁❏✷❍✷❚✲❨✁◗❃❙✰❈❩❱➩❹❈❉ ✟❍✭❆✵✺✭✶✻✔✷✸❉➔✹✼✲✤❉➔❹✼✭❄✹✼✲ ✽ ♠ ▲ ✇ ❈✼✇ ▲✇❨✁❈❩■✘❤✇❱ ❙❀❤◆❚ ❱▼❈❩❨ ◗✲❋❃❨✁❈●❍ ■✘❤r❤ ❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❑q❏▼▲◆❚✬❋❃❱❂✇ ✥ ❱▼◗❃■❴❤t▲❳❨✁❈❩■❴❤❳❱❜■✽❍✷❈ ❙●■✘❤r❤◆❈❩❨❬✹❈✲ ❅❈✭✫❀ ✵❇✹❈❉❀❺❜▲✇❨✁❈❩■✘❤✇❱❂✇❁✱✲❚✬❍❝❉❑▲❢①❲❈●❋✄❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤✇❱ ✧ ❵ ♠ ❏✷❇✲❈ ■✘❤◆❉✬❈❂❴✲❍❁■✘▲✇❙❜▲✇❨✁❈❩■✘❤ ❚✽❖✌✬▲✇❱❝❨✁❈●❋✲❚✬❏✷❈❩❨☞☛ ✧✍✌ ❘ ❄❩❄✘❄ ❘ ✧ ✈✏✎ ♠ ♣✿❇✁▲r❤❢❈✑❏✷❇✲❈ ❨❲▲ ✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤t▲✇❨✁❈❩■✘❤t▲✇❱ ❨✁❈●❋✲❚❲❏✷❈❩❨☞✆ ✧✑✌ ❘ ❄✘❄❩❄ ❘ ✧ ✈ ✞ ✇❥❢✼❋ ❖✼■✬❙✰❏ ♠ ❏✷❇✲❈ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤▲✇❨✁❈❩■✘❤✒✆ ✧ ✌ ❘ ❄❩❄✘❄ ❘ ✧ ✈ ✞ ▲✇❱✛❏✷❇✲❈❯■❴❤❢❉❲❈❂❴✲❍❁■✘▲✇❙✉▲✇❨✁❈❩■✘❤ ❉❲❈●❋✲❈●❍❁■✽❏✷❈❩❨❯❴✁✐♥■✘❤r❤ �✓✒ ✧ ❵✺➫ ❱❂✇❆✛❇✲❈❝❣✲❍✷❚❈❴✁❤❢❈●❡ ❚✽❖ ♣✛❚✬❍➟❦✬▲◆❋✲❉❫♣✛▲◆❏✷❇✓☛❞■✘❤◆❉✬❈❂❴✲❍✰■✘▲✇❙ ✎ ▲✇❨✁❈❩■✘❤✇❱✛▲◆❋♥◗❃❱♣◗❃■✘❤ ❋✲❚✬❋✲q✼❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤t■✘❤◆❉✬❈❂❴✲❍❁■✬❱✛❚❑❖ ❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱▲✇❱❊❱▼❚✽❤◆①✬❈❩❨➝❴ ✐ ❑ ❍❀❚ ❈❂❴✲❋✲❈●❍❫❴❃■✬❱▼❈❩❱❊❙✰❚✬❡✑❣✲◗✲❏❁■✽❏▼▲◆❚✬❋❃❱❂✇❧❣✽▲◆❡❊▲r❤✇■✽❍ ❏✷❚✁❚✽❤✇❱❜❇❃■✘①✬❈⑤❴❃❈●❈●❋ ❨✁❈●①❲❈✰❤❢❚❲❣❃❈❩❨ ▲◆❋ ❏❀❇✲❈ ❨❲▲✚✙ ❈●❍✷❈●❋✁❏▼▲✇■✘❤❙●■✬❱▼❈ ④ ✐❃❍❁❱▼❏ ♠ ■✉❣✲❍✷❚✲❙✰❈❩❱✷❱ ❚✽❖❃❍✷❈❩❨✁◗❃❙✰❏▼▲◆❚✬❋ ❇❃■❲❱✬❴✺❈●❈●❋❊▲◆❋ ❏✷❍❀❚✮❨✁◗❃❙✰❈❩❨ ❴✁✐ ❻☎▲◆❏✷❏✒✆ ✾✔✞▲❝ ❱♣❈❩❙✰❚✬❋❃❨ ♠ ❏✷❇✲❈✛❋✲❚✬❋✲q✼❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤❃❋✲❚✬❏▼▲◆❚✬❋❚✽❖ ❍✷❈❩❨✁◗❃❙✰❈❩❨❯❴❃■✬❱♣❈ ❇❃■✬❱ ▲◆❏❁❱✛❙✰❚✬◗✲❋✁❏✷❈●❍✷❣❃■✽❍❀❏ ■✬❱◗✹✼✰✢✷✸❁✭☎❇✵✺✭❞❹❈✰✢❺❄✭❞❹✪✽❂✭✶✷➔✽ ♠ ▲▲✇★❈✼✇✲❱▼❈●❏❁❱ ♠ ♣✿❇✲❈●❍✷❈✉❈❩■✬❙❀❇✞❈✰❤◆❈●❡ ❈●❋✁❏✛▲✇❱☎❍✷❈❩❨✁◗❃❙✰❈❩❨❯❴ ✐■✘❤r❤ ❚✬❏✷❇✲❈●❍✰❱ ❝ ❏✷❇✁▲◆❍❁❨ ♠ ❱▼✐✭✕●✐ ❉✽▲◆❈❩❱✕☛②▲▲✇★❈✼✇ ❙✰❍▼▲◆❏▼▲✇❙●■✘❤ ❣❃■❴▲❢❍✰❱ ✎ ■✽❋❃❨✌❙✰❚✬❍✷❍✷❈❩❱♣❣❃❚✬❋❃❨❲▲◆❋✲❉ ❣✬q②❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱❊■✽❍✷❈ ■✘❤✇❱▼❚♥❨✁❈❄✐❃❋✲❈❩❨ ▲◆❋❏✷❇✲❈❝❨❲▲✚✙ ❈●❍❀❈●❋ ❏▼▲✇■✘❤ ❙●■✬❱♣❈ ❝ ❤✇■✬❱▼❏ ♠ ❏✷❇✲❈ ■✽❋❃■✘❤◆❚✬❉✬◗✲❈✉❚✽❖ ❑ ❍❀❚ ❈❂❴✲❋✲❈●❍➑❴❃■❲❱▼❈❩❱✛■✽❍✷❈✝❺❄❁✒✫✢✭❆✵❇✭❆✻✔✷ ✽❂✭✶✷➔✽ ♠ ▲▲✇★❈✼✇✲❱▼❈●❏❁❱☎❏✷❇❃■✽❏☎❍✷❈❩❨✁◗❃❙✰❈ ■✘❤r❤❏✷❇✲❈✰▲◆❍ ❣✬q②❣❃❚✽❤◆✐✁❋✲❚✬❡❊▲✇■✘❤✇❱✉❏✷❚ ❩ ✇➢ ❋ ✹❈✰✢✷✸❁✆☎✺✵✺✭❞❹✼✰✳❺❄✭❞❹❧❺❞❁✒✫✳✭✶✵✺✭✶✻⑧✷s✽❂✭✶✷✖✹✒✽❄✽❂❁✶❺✶❉➔✹✼✷✸✭❄❹☎✷✸❁♥■P❱▼❈●❏✗✖ ❚✽❖ ❣ ❨✁❣✬➫ ❱✕▲✇❱❝■✽❋❦■✽◗✲❏✷❚✬q②❍✷❈❩❨✁◗❃❙✰❈❩❨✌❙✰❚✬❇✲❈●❍❀❈●❋ ❏ ❱▼❈●❏✙✘❱▼◗❃❙❀❇ ❏❀❇❃■✽❏✚✆✛✘ ✞✢✜ ✆✛✖ ✞✪♠ ■✽❋❃❨✣✘ ❍✷❈❩❨✁◗❃❙✰❈❩❱✑■✘❤r❤ ❣ ❨✁❣✬➫ ❱ ▲◆❋✡✖✈❏✷❚ ❩ ✇ ❪ ❚✬❡ ❣✲◗✲❏✰■✽❏▼▲◆❚✬❋❃■✘❤r❤◆✐ ♠ ❱▼◗❃❙❀❇ ■✽❋ ■✬❱✷❱▼❚✲❙❀▲✇■✽❏✷❈❩❨❱▼❈●❏ ▲❳❱❜❚✼❴✲❏✰■✘▲◆❋✲❈❩❨❶❴✁✐✌▲◆❋ ❏❀❍✷❚✮❨✁◗❃❙❀▲◆❋✲❉❦❏❀❇✲❈✞❙✰❍▼▲◆❏▼▲✇❙●■✘❤✿❣❃■✘▲◆❍❁❱❜❚✬❋✲❈✞■✘❖②❏✷❈●❍❜❏✷❇✲❈✞❚❲❏✷❇✲❈●❍ ♠ ♣✕❇✁▲ ❤◆❈☎❦✬❈●❈●❣✁▲◆❋✲❉✌❏✷❇✲❈❅❱▼❈●❏ ◗✲❋❃❨✁❈●❍❙✰❚✬❋❃❱▼❏❀❍✷◗❃❙✰❏▼▲◆❚✬❋ ■✽◗✲❏❀❚✬q②❍✷❈❩❨✁◗❃❙✰❈❩❨✂✇ ➢ ❋ ■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ❴✁✐ ✱✖✇✬④☎❚✬◗✁❤r▲◆❈●❍❜▲✇❱❝❉✽▲◆①✬❈●❋✌▲◆❋✤✆✦✥ ♠ ✦ ✞ ✇⑤❪ ❤❳■❲❱✷❱✪▲✇❙●■✘❤ ❋✲❚✁❈●❏✷❇✲❈●❍▼▲✇■✽❋✁▲◆❏▼✐■✽❍✷❉❲◗✲❡ ❈●❋ ❏✰❱✛◗❃❱▼❈❩❨❪▲◆❋✄❏❀❇✲❈❯❙✰❚✬❡ ❡❊◗✲❏❁■❑❏▼▲◆①✬❈ ❙●■✬❱▼❈❜❏✷❚✞❣✲❍❀❚❴①❲❈❝❏✷❈●❍✷❡❊▲◆❋❃■✽❏▼▲◆❚✬❋✌❚✽❖ ■✘❤◆❉✬❚✬❍♣▲❢❏❀❇✲❡✞❱ ❨✁❚P❋✲❚✬❏✉❈❄❡✮❏❀❈●❋❃❨❅❏✷❚P❏✷❇✲❈❨❲▲✚✙ ❈●❍✷❈●❋ ❏♣▲❳■❴❤ ❙●■✬❱♣❈✼✇ ❢✼❋❃❱▼❏✷❈❩■❲❨ ♠ ■✽❋ ❚✬❍✰❨✁❈●❍❊▲✇❱❅❨✁❈❄✐❃❋✲❈❩❨ ❚❲❋✓■✽◗✲❏✷❚❲q②❍✷❈❩❨✁◗❃❙✰❈❩❨ ❙✰❚✬❇✲❈●❍❀❈●❋ ❏❅❱▼❈●❏❁❱ ♠ ■✽❋❃❨ ❏✷❇✲❈❅❖②❚✽❤r❤◆❚➍♣ ▲❢❋✲❉❏✷❇✲❈●❚✬❍❀❈●❡③❈●❋❃❱▼◗✲❍✷❈❩❱✕❏✷❇✲❈❝❏✷❈●❍✷❡♦▲❢❋❃■❑❏▼▲◆❚✬❋♥❚✽❖✤④ ❚❲◗✁❤ ▲◆❈●❍✶➫ ❱ ■✘❤◆❉✬❚❲❍▼▲◆❏✷❇✲❡❤✇✙✝✚✟✛✢✜✤✣✂✛✎✥✧✥✢★✪✩✬✫✢✭❆✵✺✭✝❉●✽✝✻✔❁❯❉❀✻ ❑✱✻✔❉➔✷✸✭✝❹❈✭❞❺❆✵❇✭❄✹✒✽❂❉❀✻✳❅ ✽ ✭ ✢✶✰✳✭✶✻⑧❺❞✭ ❁✺✿ ✹❈✰✢✷✸❁✆☎✺✵✺✭❞❹✼✰✳❺❄✭❞❹❯✽❂✭✶✷➔✽ ➡➢ ❱❯■❴❤❢❍❀❈❩■✬❨✁✐ ❡✑❈●❋ ❏▼▲◆❚✬❋✲❈❩❨ ♠ ❏✷❇✲❈♥■✽◗✲❏❀❇✲❚✬❍✶➫ ❱❜■✘❤◆❉✬❚✬❍▼▲◆❏✷❇✲❡ ▲✇❱ ❙✰❍❀◗❃❙❀▲❳■❴❤ ❤◆✐➤❴❃■✬❱♣❈❩❨ ❚✬❋ ❏❀❇✲❈❅❣❃❚✬❏✷❈●❋✁❏▼▲✇■✘❤ ❙●■✽❋❃❙✰❈✰❤r❤✇■✽❏▼▲◆❚✬❋❚✽❖ ■♥❙✰❈●❍❀❏❁■✘▲◆❋ ❣✺❚✽❤◆✐ ❋✲❚❲❡❊▲✇■✘❤✔✕ ✇✚★✪✩✬✫✕✭✯✮✟✰✱✰✲✮✒♣✪✳✲✴✬✵✷✶✸✫❄✐✹✴✸✳☎✺✻✳☎✮✼✴✹✽✿✾✟❀❁✫✿✴✬✫❂✫❃✶✸✫❃✶☞✺❄✮❅✫❄❡✬❆✸✰✦✾❇✳☎✴✡✩✬✮✒♣❈✺❁✩✸✳❉✽✗❆✹✮❊✰☎❋✸✴✬✮❍●■✳❉✾✔✰✳❉✽❏✳✲✴❑✺❄❀❁✮▲✶✸▼✹◆❖✫❃✶◗P✡★✪✩✬✫❂❋☞✾✔✰❉✽❘✮✷❆✸✰❉✾✔❋❙✾✟✴✣✳✲●✿❆✹✮✼❀❁✺❚✾✟✴✸✺■❀☛✡✮✟✰✲✫❯✳✲✴✡✺❁✩✬✫❱✶✸✫❖❲✹✴✸✳✲✺❘✳✲✮❍✴✝✮✟✭✗✾❳◆❖✮✼●✿❆✸✰✲✫❂✺❁✫❅✽❘❋✬✽❘✺❁✫❂●❅P✷❨✪✫❃◆❂✾❇✰❩✰✺❁✩✹✾✟✺✗❨❬✳✲✺❁✺❃❭❪✽✙❀❁✫❃✶✸▼✹◆❖✺❘✳✲✮❍✴✷❀❁✫❖✰✱✳✲✫❃✽✗✮✼✴❫✾❊✴❳✮✼❀❚✶✸✫❂❀✗✮❍✴✓✺❁✩✬✫❏✳✲✴✹✶✸✫❂✺❁✫❂❀❁●■✳✲✴✹✾✟✺❁✫❃✽ �✙✒✸❴✔❵ P❏★✪✩✬✫❅❛✱❜❚❝✼❞❍❜❃❡❇❍✔❢✡✮✟✭❣✾❯❆◗✶✸❆ ✧ ✳✦✽✺❁✩✬✫✿✩✸✳✲✵❍✩✬✫❃✽✻✺❤✳✲✴✹✶✸✫❂✺❁✫❂❀❄●■✳✲✴✹✾✟✺❁✫✚✺❁✩✹✾✟✺✗✮✬◆❂◆❖▼✬❀❚✽✐✳✲✴✷✳✲✺❃P✚★✪✩✸✳❉✽❏✴✬✮❍✺❘✳✲✮❍✴❫✳✦✽❏✺❁✩✬✫❯✾✟✴✹✾✔✰✲✮❍✵❍▼✬✫❯✮✟✭❣✩✬✫❃✾✼✶✷✺❁✫❂❀❄●✂✽✙✳✲✴☞▼✹✽❘▼✹✾✔✰✏❥✴✬✮❍✴✬❦✏✶✼✳✱❧♠✫❂❀❁✫❂✴✸✺❘✳❉✾✔✰ ❑ ❀❁✮✸✫❂♥✬✴✬✫❂❀✒♥✹✾❍✽❘✫❃✽✪✺❄✩✬✫❂✮❍❀❁❋❍P✑♦✒✮✟♣❤❥✸✺❁✩✬✫❯q❉rsq❉t✉q✈❝❍❛◗✇ ❢ ✮❊✭ ✧ ✳❉✽①✺❁✩✬✫❤◆❖✮❑✫ �✚◆❄✳☎✫❂✴✸✺①✳☎✴ ❍❍②❄③ ✒ ❢❢ ✾✟✴✹✶❯✺❁✩✬✫④ ❜❘⑤▲❝✼❡⑥❝✼r✹t ✞✹❢⑦✮✟✭ ✧ ✳❉✽■✺❁✩✬✫✚◆❖✮❍●✿●✿✮❍✴❫✳☎✴✸✳✲✺❘✳❉✾✔✰✙✮✟✭⑧✾✔✰✱✰✢✶✸✫❂❀❘✳✲⑨❇✾✟✺✻✳☎⑨✼✫❃✽■✮✟✭ ✧ P ✱⑩✳✲✴✹✾✔✰✱✰☎❋❍❥❬✵✟✳✲⑨❍✫❂✴✤✾❶✽❘✫❂✺✸❚❷✮✟✭✢❆❸✶✸❆♠❭❪✽❂❥♣✒❀❘✳✲✺❁✫ ✞✹❹❺✾✟✴✹✶ ✕■❹❻✭✯✮❍❀✗✺❄✩✬✫✂❆✬❀❁✮✬✶✸▼✹◆❖✺❤✮❊✭❣✺❁✩✬✫✂✽✻✫❂❆✹✾✟❀❚✾✟✴✸✺❚✽✗✮❊✭❣✺❁✩✬✫❃✽❘✫❼❆❸✶✸❆♠❭❽✽■✾✟✴✹✶✓✺❄✩✬✫✿❆✬❀❁✮✬✶✸▼✹◆❖✺❤✮✟✭✒✺❁✩✬✫■✳✲✴✸✳✲✺❘✳❉✾✔✰❉✽✾✟✴✹✶✚✽❘✫❂❆✹✾❊❀❚✾✟✴✸✺❚✽✪✮✟✭✑✺❁✩✬✫❃✽❘✫✗❆◗✶✸❆♠❭❽✽✒❀❄✫❃✽❘❆✹✫❃◆❖✺❘✳✲⑨❍✫❖✰✲❋❍P

✑♠❾✂✁✚❿☎✄❣➀✬➁✔➀ ✆s➂ ❿✲➃✹➄✪➀✸➅ ➂ ➀ ✆➇➆ ❿✲➈ ✆➇➆❼➉◗➊➌➋ ➈❸➁✼➍✓➃✹➄❣➎➏➈✬➐■➀✬➁ ➆ ➀✬➁✟❿✲➀ ➆★✪✩✬✫✿✾✟▼✬✺❁✩✬✮✼❀❃❭❽✽✒◆❖❀❁▼✹◆❄✳❉✾✔✰❣✾✼✽❁✽❘▼✬●✿❆✬✺❘✳✲✮❍✴❶✳❉✽✗✺❄✩✹✾✟✺✢✺❄✩✬✫➒➑ ❵ ❭❪✽✗✾✟❀❁✫❤▼✬✴✸✳❉➓✼▼✬✫❖✰✲❋➌✶✸✫❖❲✹✴✬✫❃✶✓♥✸❋❳✽❘❋✬✽❘✺❁✫❂●✂✽①✮✟✭❣➔❬→✗➣✒❭❽✽✙✾✟✴✹✶❲✹✴✸✳✲✺❁✫➒✽✻✫❂✺❚✽✪✮✟✭➏✳✲✴✸✳☎✺✻✳✦✾❇✰✍◆❖✮❍✴✹✶✼✳✲✺❘✳✲✮❍✴✹✽✗✾❊✺❣✺❄✩✬✫✗✮❍❀❘✳✲✵✟✳✲✴♠P

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✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✓☎✓✝✓✔✓✝✓☎✓✝✓✝✓✔✓✝✓✕ ✖✖☎✖✝✖ ✕✖☎✖✝✖✔✖✖☎✖✝✖✔✖✝✖ ✕✖☎✖✝✖✔✖✝✖☎✖ ✕✖☎✖✝✖✔✖✝✖☎✖✝✖ ✕✖☎✖✝✖✔✖✝✖☎✖✝✖✝✖✔✖

✕ ✕

�✘✗✚✙✘✛✢✜✤✣✦✥★✧✗★⑩✮➒♥s✫✪✩✸r✹❞❍❜✔❡❤❝ ④ t✉❝✼q❉❡ ④✫ ✴❯✳☎✴✹✶✸✫❂✺❄✫❂❀❁●■✳✲✴✹✾✟✺❁✫ �✓✒❑❴✔❵ ✳✦✽✔✩✸r✹❞❍❜✔❡❤t✚✬❑❜ ④ t✉❝❍q❉❡ ④ ✮✟✭ ✾✿✽❘✫❂✺✮✭ ✮❊✭ ❆◗✶✸❆♠❭❽✽✪✳✱✭➏✳✲✺✒✳❉✽①✺❁✩✬✫❤✶✸✫❂❀❘✳✲⑨❇✾✟✺✻✳☎⑨✼✫➒✮❊✭ ✺❁✩✬✫✙✰✲✫❃✾❍✶✸✫❂❀

✮✟✭ ✴✬✮❼✫❖✰☎✫❂●❼✫❂✴❑✺✙✮✟✭ ✺❁✩✸✳❉✽✒✽✻✫❂✺❃P ✫ ✴✚✫✰✯ ✾✟●❼❆✸✰☎✫✐✳✲✴✚✺❁✩✬✫❤◆❂✾❍✽❘✫✗♣✒✩✬✫❂✴ ☛ ✠ ✡✪✆✲✱✢✳ ❴❍✞ ✾✟✴✹✶❯♣✪✳✲✺❁✩❅✾❼✽ ✳✲✴✬✵✟✰✲✫✗✭✉▼✬✴✹◆❖✺❘✳✲✮❍✴❳➑❱✳✦✽✵❍❀❚✾❊❆✬✩✸✳✦◆❂✾❇✰❩✰✲❋✓✺❁❀❁✫❃✾❊✺❁✫❃✶❶✮❍✴✵✴⑩✳☎✵✼▼✬❀❁✫✚✥✒✶✢✾❍✽❄✽❘▼✬●✿✫■✺❁✩✬✫❏✰✲✫❃✾❍✶✸✫❂❀❚✽✗✮❊✭ ✺❁✩✬✫■✫❖✰☎✫❂●❼✫❂✴❑✺❚✽✐✮✟✭ ✾❯✽❘✫❂✺✝✭✧✺❄✮✚♥✹✫ �✸✷✑ ➑➏❥ �✤✹✑ �✸✺✠➑➏❥

�✤✻✑ � ✠➑ ❥ �✤✻✑ � ✹✠

➑➏❥ �✤✼✑ �✤✽✠➑➏❥ � ✺✑ �✸✾✠

➑➏❥ � ✺✑ �✿✻✠➑ ❥✪✾✟✴✹✶ �✤✻✠

➑ ☛✉✰❉✾✟❀❁✵✼✫✿✭✉❀❚✾✟●✿✫❃✶✡◆❄✳✲❀❚◆❄✰✲✫❃✽❼✮❍✴✡✺❁✩✬✫❼❲✹✵❍▼✬❀❁✫ ✎ P✡★✪✩✬✫❯✳✲✴✹✶✸✫❂✺❁✫❂❀❄❦●■✳✲✴✹✾✟✺❁✫❃✽①▼✬✴✹✶✸✫❂❀✗✺❁✩✬✫✿✽❘✺❚✾❇✳☎❀❖✽✪✮✟✭❀✭ ✾✟❀❄✫✗✺❁✩✬✫❂✴✷➑❁✳❃❂❄❂❄❂❅✳ � ✷✑ ➑➏❥ � ✠

➑✸✳❄❂❄❂❃❂❆✳ �✤✻✑ � ✠➑➏❥ �✤✽✠

➑✸✳❄❂❃❂❄❂✰✳ �✤✼✑ �✤✽✠➑➏❥ � ✺✠

➑❁✳❃❂❄❂❄❂❅✳ �✸✾✑ � ✺✠➑➏❥

�✸✾✠➑✸✳❄❂❄❂❃❂❇✳ � ✺✑ �✸✾✠

➑➏❥ �✤✼✠➑❁✳❃❂❄❂❃❂❆✳ �✤✽✑ �✤✼✠

➑➏❥ �✤✻✠➑✣☛⑥✽❘●❯✾✔✰✱✰☎✫❂❀✙❆✸✰❉✾✔✳✲✴✷◆❄✳☎❀❖◆❄✰☎✫❃✽①✮❍✴✚✺❁✩✬✫✐❲✹✵❍▼✬❀❁✫ ✎ P❈✝✩✬✫❂✴✡✺❁✩✬✫✚✽❘✫❂✺■✮✟✭⑧✶✸✫❂❀❘✳✲⑨❇✾❊✺❘✳✲⑨❍✫❃✽✿✺❄✩✹✾✟✺✿✾✟❀❁✫❯▼✬✴✹✶✸✫❂❀✿✺❁✩✬✫✚✽❘✺❚✾✔✳✲❀❚✽❏✮✟✭⑧✾✣✽❘✫❂✺✡✭❷✮✟✭✢❆❸✶✸❆♠❭❪✽❏✳❉✽❏❲✹✴✸✳✲✺❁✫❍❥ ✺❄✩✸✳✦✽❼✽❘✫❂✺❏✳✦✽

◆❂✾✔✰✱✰✲✫❃✶✡✾❊❉❃❛●❋ ④ ❜❚❞ ④ ❜✔t✉P❅★✪✩✬✫❼✳✦✶✸✫❃✾ ✳❉✽❏✺❁✩✹✾✟✺■✾❳◆❄✰✲✮❑✽✻✫❃✶➌✽❘✫❂✺■●✂✾■❍❍✫❃✽✙✳✲✺■❆✹✮❑✽❄✽ ✳✲♥✸✰☎✫❍❥❬▼✬✴✹✶✸✫❂❀✿✽❘✮❍●✿✫❯✾❍✽❁✽❘▼✬●✿❆✬✺✻✳☎✮✼✴✹✽❂❥✑✺❁✮❀❁✫❃◆❖▼✬❀❚✽⑥✳☎⑨✼✫❖✰☎❋❯◆❖✮❍●✿❆✬▼✬✺❁✫✒✺❄✩✬✫✒⑨❇✾✔✰✲▼✬✫❃✽✪✾✟✺✑✺❁✩✬✫①✮❍❀❘✳✲✵✟✳✲✴✿✮✟✭ ✾✔✰✱✰➇✶✸✫❂❀✻✳☎⑨✟✾✟✺❘✳✲⑨❍✫❃✽❂❥✸❆✬❀❁✮✟⑨✼✳❉✶✸✫❃✶■✺❁✩✹✾✟✺✑✺❁✩✬✫①⑨❇✾✔✰✲▼✬✫❃✽✪✾✟✺✑✺❁✩✬✫✒✮✼❀❘✳✲✵✟✳✲✴✮✟✭✒✾✔✰✱✰❣✶✸✫❂❀❘✳✲⑨❇✾✟✺❘✳✲⑨❍✫❃✽✐▼✬✴✹✶✸✫❂❀❤✺❁✩✬✫✿✽❘✺❖✾✔✳✲❀❚✽✢✾❊❀❁✫■✵✟✳✲⑨❍✫❂✴♠P ✫ ❉❇❋❑❏✒⑤◗❛❩❜✔t✉❜ ④▼▲✔④ t✉❜❃❏❷◆❖✮❍✴✹✽ ✳❉✽❘✺❚✽✙✮✟✭✒✾✂◆❄✰✲✮❑✽✻✫❃✶✷✾✟▼✬✺❁✮❍❦✉❀❄✫❃✶✸▼✹◆❖✫❃✶◆❖✮❍✩✬✫❂❀❁✫❂✴✸✺➒✽✻✫❂✺☎✭ ✺❁✮❍✵❍✫❂✺❁✩✬✫❂❀❏♣✪✳✲✺❁✩➌✾❱❲✹✴✸✳☎✺❄✫❱✽❘✫❂✺❏✇❖◆ ✮✟✭✪✳☎✴✸✳✲✺❘✳❉✾✔✰✢◆❖✮❍✴✹✶✼✳✲✺❘✳✲✮❍✴✹✽❱☛✏✺❁✩✬✫■⑨❇✾✔✰✲▼✬✫❃✽✿✾❊✺✗✺❁✩✬✫✿✮❍❀❘✳✲✵✟✳✲✴☞✮✟✭✒✺❁✩✬✫✶✸✫❂❀❘✳✲⑨❇✾❊✺❘✳✲⑨❍✫❃✽✪✺❁✩✹✾✟✺✒✾✟❀❄✫✒▼✬✴✹✶✸✫❂❀✒✺❁✩✬✫✗✽❘✺❚✾✔✳✲❀❚✽ ✎ ❥✸♣✪✳✲✺❁✩✂✺❄✩✬✫⑧✾❍✶✬✶✼✳✲✺❘✳✲✮❍✴✹✾❇✰ ❆✬❀❁✮❍❆s✫❂❀❁✺❘❋➒✺❄✩✹✾✟✺❬✭✯✮❍❀✪✾✔✰✱✰◗P❙❘❚✭✂❥★P✗☛❘➑ ✎ ☛❱❯ ✎ ✠❲❯♥✬▼✬✺❨❳❁❩➏☛⑥➑ ✎ ☛❬❯ ✎✪❭✠❪❯✬P✷★✪✩✬✫❃✽❘✫❅◆❖✮❍✴✹✶✼✳✲✺❘✳✲✮❍✴✹✽❼●✂✾❫❍✼✫✿✳✲✺✿❆s✮❑✽❁✽ ✳✲♥✸✰✲✫✓✺❁✮✷◆❖✮❍●✿❆✬▼✬✺❁✫✚✾✔✰✱✰✢⑨❇✾❇✰☎▼✬✫❃✽❯✾✟✺■✺❁✩✬✫❯✮❍❀❘✳✲✵✟✳✲✴✤✮❊✭⑧✾✔✰✱✰✶✸✫❂❀❘✳✲⑨❇✾❊✺❘✳✲⑨❍✫❃✽❂P✪★✪✩✸✳❉✽✒❋✼✳✲✫❖✰✦✶✬✽✙✺❄✩✬✫✙✭✯✮✟✰✱✰✲✮✟♣✪✳✲✴✬✵✂⑨✼✫❂❀❁❋✂✮❊✰✦✶❯✺❄✩✬✫❂✮❍❀❁✫❂● ✆❵❴s❥❁❛ ✞ P❜☎❝❞✣❢❡❣✜✤✣★❤❥✐❁✧✮❦✢❋❍❡❯❝❍r ▲♠❧ q♦♥✔❜❃r♣❉❇❋✒❏①⑤❸❛✱❜✔t✉❜ ④▼▲✔④ t✉❜❃❏ ☛q✭r✳❁✇★◆ ✎❆s t✚✬❑❜❃❡❘❜✓❜▼t✟q ④ t ④ ❝ ④ q❉r ❧ ❛✱❜✪✉✇✈❘t①✩❂⑤◗❛❩❜②❋❬③✔③④❋✼❡❇❏■❝❍❛⑤❖❋❑⑤✑❜❃❡ ④ ❜✔❡❚q✈❜ ④ ⑤⑥✬✸q♦❉⑦✬➌❝❍❡❘❜ ④ ❋❍❛●✩❑t✉q✚❋❍r ④ ❋❬③✡✭ ❝❍rs❞✵⑤⑥✬❑q✚❉▼✬ ④ ❝❍t✉q ④ ③ ▲ t✚✬❑❜❶q❉rsq❉t✉q✈❝❍❛⑧❉❇❋❍rs❞❍q✈t✉q♦❋❍r ④ ✇★◆✪⑨❶⑩✢✬❑q ④ t①✩❂⑤◗❛❩❜❶q ④❉✰❋✒❏①⑤✿✩❑t✉❝❸❷❂❛✱❜ s q❹⑨✦❜❺⑨➏❜❖❝✒❉▼✬❨❉✰❋❃❜①❻❼❉✔q❉❜✔r✹t❣❋❬③❤❜❖❝✒❉⑦✬✂➑ ❵ q ④ ❉✰❋✒❏①⑤✿✩❑t✉❝❸❷❂❛✱❜❺⑨❽❶✮❍❀❁✫✙❆✬❀❁✫❃◆❄✳❉✽❘✫❖✰✲❋❍❥✹✺❄✩✬✫⑧◆❖✮✸✫✰❾❱◆❄✳✲✫❂✴❑✺❖✽✒✮✟✭✑✾✟✴❱➑ ❵ ✾✟❀❁✫✙✵✟✳✲⑨❍✫❂✴✚♥✸❋✂✾■❀❁✫❃◆❖▼✬❀❚✽⑥✳☎⑨✼✫❤✾✔✰✲✵❍✮❍❀❘✳✲✺❁✩✬●❅P❣❽❶✮❍❀❁✫❂✮✟⑨❍✫❂❀✔❥✟✳✲✺✪✳❉✽✪✫❃✾❍✽ ✳✱✰✲❋❆✬❀❁✮✟⑨❍✫❃✶■✺❄✩✹✾✟✺✪✫❃✾❍◆❁✩❯◆❖✮❑✫✰❾❱◆❄✳✲✫❂✴✸✺✢◆❖✮❍✴✸✺❘✳✲✴❑▼✬✮✼▼✹✽ ✰✲❋❱✶✸✫❂❆s✫❂✴✹✶✬✽✪✮❍✴❯✺❁✩✬✫✒✳✲✴✸✳✲✺❘✳❉✾✔✰ ◆❖✮✼✴✹✶✼✳☎✺✻✳☎✮✼✴✚✇❖◆❼❥❍⑨✼✳☎✫❂♣✪✫❃✶❯✾❍✽❬✫❖✰✲✫❂●✿✫❂✴❑✺✪✮✟✭

✾❏❲✹✴✸✳✲✺❁✫■✶✼✳☎●❼✫❂✴✹✽ ✳✲✮❍✴✹✾✔✰✑⑨❍✫❃◆❖✺❁✮❍❀✢✽✻❆✹✾❍◆❖✫❍P❿ ❾➁➀◗➂ ➆❂➂ ❿➄➃❀➅✟➃ ➂ ❿✲➈❞➆ ➋ ➈◗➁ ➂❫➇ ➀✓➃✹➄➉➈s➈❸➁✟❿ ➂❫➇ ➍

➊①✫❂✴✹◆❖✫❖✭✯✮❍❀❄✺❁✩♠❥✗✺❁✩✬✫✓✭✉✮❍❀❁●❯✾✔✰⑧❆s✮✟♣❣✫❂❀✓✽❘✫❂❀❘✳✲✫❃✽❅➑ ❵ ✾✟❀❁✫☞✾❍✽❁✽❘▼✬●✿✫❃✶ ✺❁✮✡♥✹✫✡✶✸✫❖❲✹✴✬✫❃✶❺♥✸❋❺✾☞❲★✯✬✫❃✶❺◆❖✮❍●✿❆✸✰✲✫❂✺❁✫✡✽❘❋✬✽❘❦✺❁✫❂●➌➋q✭✪✳❄✇❖◆➎➍❚❥❃✾✟✴✹✶❏✺❁✩✬✫❬❀❘✳✲✴✬✵✝➏ ✳❉✽ ✾❍✽❄✽❘▼✬●✿✫❃✶❏✺❁✮✙♥✹✫✪✫❖❧♠✫❃◆❖✺❘✳✲⑨❍✫❍P✑★✪✩✬✫ ❆✬❀❁✮✼♥✸✰☎✫❂● ✳❉✽➏✺❁✮✙✺❁✫❃✽❘✺➏♣✒✩✬✫❂✺❁✩✬✫❂❀❣➐ ❵ ➋⑥➑❞➍⑧➑❲❯✪✭✉✮❍❀✾✔✰✱✰❖➐ ❵ ✳✲✴➒✾①✵✟✳✲⑨❍✫❂✴➒✽❘✫❂✺✘➒❺➐❣➓✰✳❄❂❄❂❃❂❆✳❇➐❞➔➣→ ✮✟✭✬❆❸✶✸❆♠❭❽✽⑩✳✲✴☎➏②↔✒↕■P✢➙➜➛❸➝❉✽➞➝✦✽❞➟❃➓✼▼❸➝☎⑨✟✾❃➠➉➟▼➡❑✺✑✺❅➢✒✺❆➟❃✽❘✺❬➝➉➡★➤✙♣➥➛★➟❂✺❆➛★➟❂❀ ➑✍➝✦✽➏✾✒✽❬➢■➠☎▼✬✺➦➝➄➢❑➡➢❫➧✪✺❆➛★➟✿✽❘❋▲✽✻✺❆➟❂●➨➒❃✭✪✳❇➐ ➓ ✳❃❂❄❂❄❂❅✳❇➐❞➩▼→❑P☎➫⑧➢❍▼❸➠●➝➉➟❂❀❃❭❽✽❏✾❃➠➉➤✒➢❍❀❬➝✲✺❆➛✬●❅❥◗♣✮➛❸➝✦◆❅➛✷♣✒✾❍✽✙✾❃➠●➠✲▼✹✶❸➟❃✶✷✺❆➢✚♥✸➟✰➧❹➢✼❀❆➟❍❥s❲✹❀❚✽❘✺✗❀❆➟❃✶✸▼✹◆✰➟❃✽✐✺❆➛★➟❆✬❀❆➢❍♥❸➠➉➟❂●❈✺❆➢⑧◆✰➢✼●✿❆✬▼✬✺❬➝➉➡★➤❤♣➜➝✲✺❆➛✿✾✟▼✬✺❅➢❍❦✉❀❆➟❃✶✸▼✹◆✰➟❃✶✿◆✰➢✒➛★➟❂❀❅➟▼➡❑✺ ✽❬➟❂✺❖✽❂❥❍✾❍✽➏♣➜➝●➠●➠❸♥✸➟✢✶❸➟❂✺❚✾❃➝●➠➉➟❃✶■♥❁➟✰➠➉➢✟♣❤P❀➭➞➟❂✺❣➯➌♥✸➟ ✾■➡✕✾❊▼✬✺❆➢❍❦❀❆➟❃✶✸▼✹◆✰➟❃✶☞◆✰➢✒➛★➟❂❀❆➟▼➡✸✺❤✽❬➟❂✺❤✾❍✽❁✽➦➢▲◆❅➝❉✾✟✺❆➟❃✶❫♣➜➝✲✺❆➛❊➒❄✭✪✳✰➐ ➓ ✳❃❂❄❂❃❂❆✳❇➐ ➔ →✸❥✤➝✏P❵➟❍P♠✾✚✽❬➟❂✺✗✺❆➛✹✾❊✺❤✽❁✾✟✺❬➝❉✽ ❲❁➟❃✽➁➲ ➯⑧➳➸➵➺➲❵✭r✳❇➐ ➓ ✳❄❂❃❂❄❂❆✳✰➐ ➔ ➳✉❥✾❫➡✹✶❨➻❪➼➽ ❯✔➧①➢❍❀✒✾❃➠●➠✘➻➾❘②➒❄✭✪✳✰➐ ➓ ✳❄❂❄❂❃❂❆✳❇➐ ➔ →❑P❨➜➟❂✺❁▼✬❀❅➡❨➝➉➡❑✺❅➢✿❆✹✽❬➟❂▼✹✶❸➢❍❦✉❀❆➟❃✶✸▼✹◆❖✺➦➝➄➢❑➡✢✶➜➤❫➝✲⑨✒➟▼➡❳✾✿✽➦➟❂✺✍➚➪➢❫➧✑❆❸✶✸❆♠❭❽✽ ❥❸➠➉➟❂✺➹➶r➘✷♥✸➟❤✺❆➛★➟✗❆✬❀❅➢▲✶✸▼✹◆❖✺☞➢❫➧✑✺❆➛★➟☞➝➉➡❸➝☎✺➦➝✦✾❺➠✦✽❏✾❫➡✹✶

✽❬➟❂❆✹✾✟❀❖✾❫➡❑✺❖✽❀➢■➧ ✺❆➛★➟☞➟✰➠➄➟❂●➁➟▼➡❑✺❚✽➴➢❫➧➴➚❺✾■➡✹✶✇❳ ➘ ✺❆➛★➟✗❆✬❀❆➢✬✶✸▼✹◆❖✺➥➢❫➧✑✾❃➠●➠⑩✽➦➟❂❆✹✾✟❀❚✾❫➡✸✺❚✽❣➢❑➡❸➠☎❋❍P✮➷➥➝✲⑨✒➟▼➡❅✾■➡➬➝❉✶❸➟❃✾❃➠◗➮❯♣➥➛❸➝❉◆❅➛r➝✦✽➡★➢❍✺➜➡★➟❃◆✰➟❃✽❁✽❁✾❊❀❬➝●➠☎❋✓✾■✶❑➝❩❧✢➟❂❀❆➟▼➡✸✺❬➝❉✾❃➠✢➝❉✶❸➟❃✾❃➠✑✾❫➡✹✶✚✾■❆❸✶✸❆♠➶☞❥❑➠➉➟❂✺➥➮♠✶❸➶✃➱ ✶❸➟▼➡★➢❍✺❆➟✗✺❅➛★➟❤✽❬➟❂✺➜➢❫➧✍✾❺➠❐➠♠❆◗✶✸❆♠❭❽✽❒➐❮➧①➢❍❀✪♣➥➛❸➝❉◆❅➛✺❆➛★➟❂❀❆➟r➟✰✯❸➝✦✽✻✺❚✽✿✾♠❰Ï❘❮Ð ✽❘▼✹◆❅➛➌✺❆➛✹✾❊✺➎➶②Ñ▼➐Ò❘Ï➮♠P✃➙➴➛❸➝✦✽❼✽❬➟❂✺✔➝✦✽■✾❍◆❖✺❄▼✹✾❃➠●➠☎❋✡✾❫➡Ó➝❉✶❸➟❃✾❃➠⑧✾❫➡✹✶❊➐ ➘➽ ❯❚➝❉✽✔➟❃➓❍▼❸➝✲⑨❇✾❺➠➄➟▼➡✸✺✺❆➢✪➐➾❘Ô➚Õ✶❸➶ ➱➘ ➲✲✐ ❥❁Ö❃➳✏P❣❈♣➝✲✺❆➛✚✺❆➛❸➝❉✽➥➡★➢✼✺❚✾✟✺❬➝➉➢✒➡♠❥❑➝✲✺➥➝❉✽✒◆❅➠➉➟❃✾✟❀✙✺❆➛✹✾✟✺

➲❵➯❀➳✢➵❮➲❵✭✪✳✰➐ ➓ ✳❃❂❄❂❃❂❆✳❇➐ ➔ ➳✢➵❮➲❵➯❀➳✢✶❸➶ ➱➼ ❂➋❱✐❸➍↔❺×

Page 59: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➙➜➛★➟❂❀❆➟✰➧①➢❍❀❆➟✔➝●➧➴➶ ➼ ➋⑥➑❞➍ ❭➑ ❯✬❥s✺❆➛★➟▼➡✷♣➥➛★➟▼➡✷➑✣⑨❇✾❫➡❸➝❉✽❬➛★➟❃✽❏✾✟✺⑧✾❺➠❐➠ ✺❅➛★➟✍➟✰➠➉➟❂●➬➟▼➡✸✺❚✽☞➢❫➧➜➯Ï➝✲✺✗⑨❇✾❫➡❸➝❉✽❬➛★➟❃✽❏✾✟✺✗✾❃➠●➠ ✺❆➛★➟➬➐ ❵ ❭❽✽❂❥✽❬➢❯✺❆➛✹✾✟✺✒✺❅➛★➟➒❆✬❀❅➢❍♥❸➠➉➟❂●❷❀❆➟❃✶✸▼✹◆✰➟❃✽✙✺❆➢✿✺❆➟❃✽✻✺❬➝➉➡★➤✚♣➥➛★➟❂✺❆➛★➟❂❀☞➯➥➋⑥➑❞➍➜➑❙❯✬P ✁ ✺❆➛★➟❂❀❁♣➴➝✦✽➦➟✪➶ ➼ ➋⑥➑❞➍➸➑❙❯❯✾❫➡✹✶ ✺❆➛★➟❤❆✬❀❆➢✼♥❸➠➄➟❂●❀❆➟❃✶✸▼✹◆✰➟❃✽❬✺❆➢❏✺❆➟❃✽❘✺❬➝➉➡★➤❤♣✮➛★➟❂✺❆➛★➟❂❀✒➑➁➝✦✽✪✾❏✽❬➢❫➠✲▼✬✺❬➝➉➢✒➡r➢❫➧♠✺❆➛★➟⑧✽✻❋▲✽❘✺❅➟❂●➺➒❄✭✪✳✰➐❣➓❇✳❃❂❄❂❃❂❆✳❇➐ ➩ ✳❇➶ ➼ →❍P ➔✍❀❆➢✟⑨✒➝❉✶❸➟❃✶■✺❆➛✹✾❊✺ ✺❆➛★➟✙✺❆➟❃✽❘✺➧①➢❍❀❒➯✮➋⑥➑❞➍❒➑ ❯➁➝❉✽☞➟❖❧➞➟❃◆❖✺➦➝☎⑨❑➟❍❥◗✺❆➛❸➝❉✽✗❋❑➝➄➟✰➠❉✶✬✽❏✾❯❀❆➟❃◆❖▼✬❀❚✽➣➝✲⑨✒➟✂✾❺➠➄➤❑➢❍❀❬➝✲✺❆➛✬●❷✺❆➛✹✾✟✺✙✺❆➟❂❀❁●➎➝➄➡✹✾❊✺❆➟❃✽✙♥❁➟❃◆❂✾✟▼✹✽➦➟➬➢❫➧➴➙➴➛★➟▼➢❍❀❆➟❂●✄✂❍P➙✪♣➜➢✿◆❂✾❍✽❬➟❃✽➜➛✹✾✔⑨✒➟✗✺❅➢✿♥❁➟■◆✰➢✒➡✹✽➣➝❉✶❸➟❂❀❆➟❃✶◗❥◗✾❍◆❂◆✰➢❍❀❚✶❑➝➉➡★➤❯✺❆➢■✺❆➛★➟✗⑨❇✾❃➠✲▼★➟✡➢❫➧❀➶ ➼ ➋⑥➑❞➍❆➋❱❯❸➍❚P☎❣❜ ❧ ✩✸❛✱❝❍❡☞❉❚❝ ④ ❜❺⑨ ➙➜➛❸➝❉✽✒◆✰➢❍❀❁❀❆➟❃✽✻❆❁➢✒➡✹✶✬✽❬✺❆➢❏✺❆➛★➟⑧◆❂✾✼✽❬➟✢♣✮➛★➟▼➡ ➶ ➼ ➋❘➑✢➍❅➋❱❯❸➍ ❭➑❲❯✬P❣✴★➢❍❀⑧➟❃✾❍◆❅➛✝✆➺❘❨➯✙❥✞✆➎➋⑥➑❞➍◗➝❉✽✒✾➹➧❹➢✼❀❁●✂✾❃➠❆❁➢✟♣➜➟❂❀ ✽❬➟❂❀❬➝➉➟❃✽❂❥✼♣➥➛❸➝❉◆❆➛✔➝❉✽✠✟▼➟❂❀❅➢☞➝❐➧ ✾❫➡✹✶✔➢✒➡❸➠✲❋ ➝❐➧☛✡✌☞✞✆➎➋⑥➑❞➍❆➋❱❯❸➍❣➑Ï❯✮➧❹➢❍❀✑✾❃➠●➠❸✶❸➟❂❀❬➝✲⑨❇✾❊✺❬➝➉➢✒➡✍✡✌☞✡➋①➝➉➡✹◆❅➠✲▼✹✶❑➝➉➡★➤✿✺❆➛★➟⑧➝❉✶❸➟▼➡❑✺❬➝✲✺❘❋✸➍❚P✫ ❀❖✾✟✺❆➛★➟❂❀✒✺❆➟❃◆❅➛★➡❸➝❉◆❂✾❃➠ ✺❆➛★➟▼➢❍❀❅➟❂● ➲✏✎■➳ ❀❆➟❃✶✸▼✹◆✰➟❃✽✙✺❅➛★➟➒❆✬❀❅➢❍♥❸➠➉➟❂●❷✺❆➢❱◆✰➢❑➡✹✽➣➝❉✶❸➟❂❀❬➝➉➡★➤♠➢✒➡❸➠✲❋✚❲❁➡❸➝✲✺❆➟✰➠✲❋✓●✂✾❫➡✸❋✚●➬➟❂●■♥❁➟❂❀❖✽➥➢❫➧✺❆➛❸➝❉✽✘➝➉➡✸❲❁➡❸➝☎✺❅➟❤✽❬➟❂✺❃P❀➫⑧➟❃◆❂✾✟▼✹✽❬➟☞➢❫➧♠✺❆➛★➟☞➡★➢✒➡✬❦①➡✸▼❸➠❐➠●➝✲✺❘❋✪➢■➧❞➶ ➼ ➋⑥➑❞➍❆➋❱❯❸➍❚❥✟✺❅➛★➟✒⑨❇✾❃➠✲▼★➟❃✽✒✾❊✺ ✺❆➛★➟☞➢❍❀❬➝➉➤❫➝➉➡r➢❫➧ ✾❃➠●➠➇✺❅➛★➟✑✡✞☞✌✆✡➋❘➑✢➍❖❭❽✽✾✟❀❆➟✙❆❁➢■➠☎❋❸➡★➢❍●✡➝❉✾❃➠❉✽➴➝➉➡✚✺❆➛★➟✒✡✔✓✞✆➎➋⑥➑❞➍❆➋❱❯❸➍❞➧❹➢❍❀✖✕ ❭❪✽ ✽❘▼✹◆❅➛✚✺❆➛✹✾✟✺✖✗✙✘✛✚✢✜♠➝✤✣✪▼★➡✦✥❸➟★✧✪✩❆➛★➟✒✣✫✩✭✬❃➝✮✧✭✣⑧➢❫➧◗✭❯❥✞✩❅➛✦✬✯✩⑧➝✰✣➸➧❹➢✱✧✖✬✐❲❁➡❸➝✲✩❅➟➡✸▼✬●➒♥✸➟★✧✝➢❫➧❀➝➉➡❸➝✮✩❬➝✤✬❃➠✒◆✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣❂P✡❽♠➢✔✧❆➟✴✳✵✧❆➟❃◆❅➝✤✣❬➟✰➠✮✶❍❥◗➯✮➋⑥➑❞➍➥➑ ❯➁➝●➧✷✬❫➡✦✥✇➢✒➡❸➠✮✶♠➝●➧✷✬❃➠●➠✸✩❆➛★➟✹✣❬➟✺✡✱✓✌✆✡➋⑥➑❞➍❆➋❱❯❖➍➸➟❃➓✼▼✦✬❃➠➸❯✬P✻ ➝➉➡✹◆✰➟✴✩❆➛★➟✼✟▼➟★✧❆➢❍❦✽✩❆➟✹✣✫✩➜➝➉➡♠➏➺➝✤✣✾✬✱✣✿✣❘▼✬●➬➟✹✥❀✩❅➢✿♥❁➟✔➟❖❧➞➟❃◆✢✩➦➝☎⑨❑➟❍❥✵✩❆➛❸➝✤✣✑✣➦➢❫➠✲⑨✒➟✹✣✖✩❆➛★➟✼✳✵✧❆➢✼♥❸➠➄➟❂● ➝➉➡❁✩❆➛★➟✼✧❅➟▼➤❍▼❸➠✤✬✯✧⑧◆★✬✔✣❬➟❍P❂ ❜❃❏■q➉✈ ④ q✈r ❧ ✩❑❛✱❝❍❡➬❉❖❝ ④ ❜❺⑨Ò➙➜➛❸➝✤✣✿◆✰➢✱✧✿✧❅➟✹✣❃✳❁➢✒➡✦✥✵✣❄✩❆➢❁✩❆➛★➟❅◆★✬✔✣❬➟✂♣✮➛★➟▼➡❼➶ ➼ ➋⑥➑❞➍❆➋❱❯❸➍✔➑ ❯❶♣➥➛❸➝●➠➄➟♠➶ ➼ ➋⑥➑❞➍ ❭➑ ❯ P ✁ ➡✹◆✰➟✬❫➤✞✬❺➝➄➡♠❥❅✩❆➛★➟✘➝➄➡❸➝✮✩❬➝✤✬❃➠✦✳✵✧❅➢❍♥❸➠➉➟❂● ➢✒➡❆✩❆➛★➟❀➐ ❵ ❭✏✣❇✧❅➟✹✥✸▼✹◆✰➟✹✣❇✩❆➢✾✩❆➟✹✣❃✩➦➝➄➡★➤☞➯➥➋❘➑✢➍❣➑Ï❯✬❥❃♥✬▼✵✩❈✩❆➛★➟✖✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✬●❉✥❸➟❂⑨✒➟✰➠➉➢✱✳❁➟✹✥ ➝➉➡✴✩❆➛★➟✧❆➟▼➤❍▼❸➠✤✬✯✧✒◆★✬✱✣➦➟⑧◆★✬❫➡★➡★➢✔✩❣♥✸➟❆✬✯✳✵✳❸➠●➝➉➟✹✥❊✬✱✣✘➝✰✣ P ✫ ➡r➟✰✯✵✳❸➠❐➝❉◆❅➝✮✩✮➧❹➢✱✧❄●➒▼❸➠✤✬ ➧①➢✱✧❣➑ ➝➄➡❊✩❅➟★✧❁●✍✣⑧➢❫➧❇✩❆➛★➟✮➝➄➡❸➝✮✩❬➝✤✬❃➠✑◆✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣✒✇★◆✣❬➛★➢✟♣✑✣❋✩❆➛✦✬✯✩✪➑●✥❸➟★✳❁➟▼➡✦✥✵✣✙◆✰➢✒➡✞✩➦➝➄➡✸▼★➢❍▼✦✣➣➠✮✶r➢✒➡❯✇❖◆❼P ➙➴➛★➟➥➝➉➡❸➝✮✩❬➝✤✬❃➠ ◆✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣✪✇★◆❍✳✵✧❆➢✟⑨✒➝✤✥❸➟✗⑨✙✬❺➠☎▼★➟✹✣➴➢❫➧☛✩❆➛★➟✼✡✞☞✸➑ ❵ ➧①➢✱✧✬❃➠●➠✦■❊✣❘▼✹◆❆➛✴✩❆➛✦✬❏✩☛✡ ☞ ❴ ❵ ➝✤✣➏▼★➡✦✥❸➟★✧✠✩❆➛★➟❑✣❃✩✢✬❃➝✮✧✭✣✢➢■➧❖✭❯P ✻ ➢✙✇★◆ ◆★✬■➡❤♥❁➟✪⑨❑➝➉➟❂♣➸➟✹✥✴✬✱✣▲✬✒⑨✒➟❃◆✢✩❅➢✱✧◆▼⑥➢■➧❖✬✪❲❁➡❸➝✮✩❆➟✷✥❑➝✲●➬➟▼➡✦✣➣➝➉➢✒➡✦✬❃➠✣❃✳✦✬❍◆✰➟❍P◗P❑✬❃➠●➠◗↕✾❘✵✩❆➛★➟✼✧❬➝➉➡★➤✡➢❫➧☛✳❁➢■➠✲✶❸➡★➢❍●✡➝✤✬❃➠✤✣✾❙✤➲✲✱ ➓ ✳❄❂❄❂❃❂❆✳❇✱❯❚❢✳✢✡✞☞ ❴✔❵ ➳s♣➥➛★➟★✧❆➟✼✩❆➛★➟✼■ ❭❱✣❑✬❏✧❆➟✒✣✫❲✹◆❆➛❀✩❆➛✦✬✯✩✷✗✯✘✿❳✢❨✢❩✤➝✤✣✸❲★➡✦✥❸➟★✧✩❆➛★➟✴✣❃✩✭✬❃➝✮✧✭✣➜➢■➧ ✭❬✬❫➡✦✥❭✩❆➛★➟❆✡✞☞ ❴✔❵ ❭❱✣✷✬✯✧❆➟❏⑨✒➝➉➟❂♣➜➟✹✥❁✬✱✣➸➝➄➡✦✥❸➟★✩❅➟★✧✿❪✡➝➉➡✦✬✯✩❆➟✹✣❂P☞➭✤➟★✩➥➡★➢✟♣❉❫ ♥✸➟❴✩❅➛★➟✗⑨✙✬✯✧❬➝➉➟★✩❃✶❁✥❸➟❖❲❁➡★➟✹✥❶♥✞✶✩❆➛★➟✮➝✤✥❸➟✹✬❃➠✢➮➬➢❫➧ ↕✾❘★➤✒➟▼➡★➟★✧✢✬✯✩❆➟✹✥■♥✌✶✺✩❆➛★➟✑✡✌☞✌✆✿❭✏✣✖✣❃❲✦❵❅➛✍✩❅➛✦✬✯✩❑✡✌☞✱✆➪➝✤✣❋❲★➡✦✥❸➟★✧✖✩❆➛★➟✼✣❃✩✭✬❃➝✮✧✭✣✘➢❫➧✢➯✢❥✵✬❫➡✦✥❀❫❛❘✵✩❆➛★➟✙⑨✙✬❏✧❬➝➉➟★✩❜✶✥❸➟❖❲❁➡★➟✹✥❶♥✞✶♠➶ ➼ ➑❶❯❯❝➸➙➜➛★➟❞✧❆➟▼➤✱❲❸➠✤✬✯✧✼❵★✬✱✣❬➟✴✥❸➟✹✬❃➠✮✩✢♣➜➝✮✩❆➛❡✩❆➛★➟✝➝✮❪✺✳❸➠●➝✤❵★✬✯✩❬➝➉➢✒➡❢▼☎❘❁❫ ↔✖❫❛❘❞➑❖❣ ➯✮➋⑥➑❞➍❀➑Õ❯✵❝❋❤q➡●✩❆➛★➟❵✢❲✵✧✿✧❆➟▼➡✌✩✑❵★✬✱✣➦➟❍❥✵✩❆➛★➟☞➧①➢❫➠●➠➄➢✟♣➜➝➉➡★➤❀✩❆➛★➟▼➢✱✧❆➟★❪Ò➲✏✎❃➳❇✧❆➟✹✥✌❲✦❵✰➟✹✣✪✩❆➛★➟✼✳✵✧❆➢❍♥❸➠➉➟★❪✐✩❆➢✍❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❯♣➜➝✮✩❆➛❁✬❃➠➉➤✒➟❂♥✵✧✢✬❃➝✤❵✗⑨✙✬❏✧❬➝➉➟★✩❬➝➉➟✹✣★❝❜☎❝❞✣❢❡❣✜✤✣★❤❦❥❁✧✪❧♠❜❃t✵▼✡❷❁❜✙q❉rsq❉t✉q✈❝❍❛★❉✰❋❍r✹❞✼q❉t✉q✚❋❍r ④❬④ ✩❸❉▼✬✿t✚✬❑❝✼t t✚✬❑❜ ④▼▲✔④ t✉❜❃❏➪➋q✭✪✳❄✇❖◆➎➍ q ④ ❉✰❋✒❏①⑤❸❛✱❜❃t✉❜✙❝❍r✹❞✝➶ ➼ ➋⑥➑❞➍ ❭➑❲❯❁⑨

⑩✢✬❑❜✔r➬➯✮➋⑥➑❞➍❀➑❲❯❞♠✴❣✄▼❒❘ ❫ ↔❑❫ ❘ ⑨➙➜➛❸➝✤✣✖❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡r➝✤✣❋✩❆➟✹✣❃✩❆➟✹✥❼♥✞✶❀❵✰➢✱❪✺✳✵❲✵✩❬➝➉➡★➤✺✬✡➷✾✧❆➢❢➟❂♥★➡★➟★✧✪♥✦✬✱✣➦➟✹✣❣➧①➢✱✧❋✩❆➛★➟✑✧✢✬✱✥❑➝✤❵★✬❃➠✢➢❫➧❇✩❆➛★➟➥➝✤✥❸➟✹✬❃➠✢➮♠✶✒➶ ➱➼ ❲✦✣❱➝➄➡★➤

✬❫➡❁✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪❬✥❸➟✹✣✿❵✢✧❬➝✲♥❁➟✹✥❚➝➉➡✵➲✲✐❃➳✏❥✵✬❫➡✦✥❀✩❆➟✹✣❃✩➦➝➄➡★➤➎➝❐➧❣➟✹✬✱❵❅➛✍✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠ ➢■➧☛✩❆➛★➟✼❵✰➢✒➡✦✣❃✩✿✧✿❲✦❵✢✩❅➟✹✥❯♥✦✬✱✣❬➟✗⑨✙✬■➡❸➝✰✣➦➛★➟✹✣✑✬✯✩✷▼✯❝➙➜➛★➟❞✳✵✧❆➟❂⑨✒➝➉➢✱❲✦✣♦♥❃❲✦✣❃✩❬➝✱❲❖❵★✬✯✩❬➝➉➢✒➡❡✶✒➝➉➟✰➠✤✥✵✣✾✩❆➛★➟❆✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪❬✩❆➛✦✬✯✩✒♣✷✬✱✣⑧➢✱❲✵✩➦➠❐➝➉➡★➟✹✥❶♥❁➟✰➧①➢✱✧❆➟✱❝

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦❃⑨✑⑩▲❶✹❷✱❸⑧❹⑧❺✿❻❇❼✽❽❈❾ ❿✛➀★➁✦➂★➃✢➂★❻❜➄✒❼➆➅✾❾➇❿✿➀★➈❋❸➉❸⑧❹⑧➊✯❹⑧❺✿❻❇❼✽❽☛❾➇❿✛➀➋➂➍➌✞➄✷➎⑤❺✿➏➐❹➉➏➐❶✹➏▲❼➆➑❊❾➇❿✿❾✛➒✒➓♦❺✿➔✱❻➐❺✿→➣❺✿➌✯➏❃➂★➏➣❹⑧❶❅➌✷↔✤❶❅❻✦➏➐↕✱❺☛❻❃➂✹➄✯❹✮➙✿➂➍❸✯❶★↔✞➂❈➛✞➌✔❹➉➏➐❺✿❸⑧➜✖➝✹❺✿➌✯➞

❺✿❻❃➂★➏➣❺✢➄❆➄✯❹❱➟✵❺✿❻➣❺✿➌✯➏➐❹✲➂➍❸✞❹✮➄✯❺✢➂★❸✽❾✹➠✽➌✴➡❈➢❜➤✢➥❜➦❃➦❃➧★➨✰➩✯➫✭➭☛➯✫➲✱➲✙➳✾➵✷➸ ➺➍➻✹❾✯➔✱➔⑤❾✞⑦✢➼ ↕ ➒✵⑦✭➽❅➽✱❾✛➒✺➾✸→➣→➐❶✱➙❃❹✮➂★➏➣❹⑧❶❅➌✾↔✤❶✹❻☛➚❈❶❅➪❆➔✱❷✔➏➣❹⑧➌✱➝✷➑✺➂✹➙➐↕✱❹⑧➌✱❺✛❻➣➜✯➀➶✭➹❅➹✹➘ ❾

⑥➇➴✢⑨✑⑩▲❶✹❷✱❸⑧❹⑧❺✿❻✾❼➆❽✔❻❜➂➍➌❖➷➙❃❶✹❹⑧→❃❿✿❾✌➒ ➬➮❇➱➆✃ ➧❅➦❆➦ ➱ ➨✮❐❋❒✞❮⑧❰★➩ ➱ ❰ ➱ ➨✤➤★➩❁➧❅➦✴Ï ✃ ➦✛❮➉Ï ✃ ➦✫➭❆❰★❮➇➫✹➤★➢✛➨ ➱✤Ð ❐✒➦✫➭❆➦✿➩❁❰➍❮➇➫❖Ñ➦✭Ò✛➢❜➦❞➧★➨ Ó ➬➦✛➢❜➦✛➩ ➱ ➨✤➦✿❮✰❮➉➦✛❾✱➒ÕÔ✠↕✦Ö❺✿→➐❺✹➀× ➌✔❹➉➊❅❺✿❻➣→➐❹⑧➏✱Ø❺✷➄✯❺✷➁✵❹⑧❸⑧❸⑧❺✹➀✯➾✸➔✱❻➐❹⑧❸ ➶✭➹✹➹➍Ù ❾⑥➇Ú✢⑨✑➅❋❺✿➌✱❺❃↔✠❼sÛ✞❾➇❿✸➂➍➌✞➄✴➁✵❹⑧➔✱→➣↕✔❹➉➏➐➃✾❼➆➁❇❾➇❿✛❾✯➒Ü➎⑤❶★Ý☛❺✛❻✠→➣❺✿❻➐❹➉❺✛→❑→➐❶✹❸⑧❷✱➏➐❹➉❶❅➌✱→✠❶★↔☛➂➍❸➉➝❅❺✿Þ✱❻❃➂★❹✮➙✸➄✯❹❱➟✵❺✿❻➣❺✛➌✙➏➐❹✮➂★❸ß❺✭à❅❷✞➂★➏➐❹⑧❶✹➌✱→✢❾✌áâ❰ ➱✤Ð ➦✿❐✼❰ ➱ ➨⑧➭✭➥ Ð ➦➳✖➩✱➩✞❰➍❮➉➦✛➩✱➀✱➊❅❶✹❸✽❾✯➴✹➽✹ã✔➀ ➶✭➹❅ä★Ù ➀❅➔✱➔✦❾✌➴✱⑦✢Ú✢➒❏➴❅Ú ↕ ❾

⑥ ↔ ⑨✷Û✙➂➍➌✱❺✿➏❋❼➆➑❊❾➇❿✛❾★➒✍å✯➜✯→➣➏✭Ö❺✿➪❆❺✛→✸➄✵æ➣Ø❺✭à❅❷✞➂★➏➐❹➉❶❅➌✱→☛➂➍❷✯çè➄❈Ø❺✿❻➣❹⑧➊☛Ø❺✿❺✿→❋➔✞➂★❻➐➏➣❹⑧❺✿❸⑧❸⑧❺✿→✭❾✵é✯➤ ✃ ➢✿➩✞❰➍❮✦➧✹➦❋á✍❰ ➱sÐ ➬➦✛❐✼❰ ➱ ➨✤Ï ✃ ➦✫➭✿➀✯➊✹❶✹❸✽❾ ↕ ➀✹➌✔ê✙Ú✱➀ ➶✭➹❅ë✹ì ❾⑥➇➼✢⑨✑í❋❶✹❸✮➙➐↕✱❹⑧➌✺❼✽î✠❾✞➓✪❾ ❿✛❾★➒●ï❑➨ Ó✸➦✿➢❃➦✿➩ ➱ ➨✤❰➍❮✞➳✖❮➇➫✹➦✢Ò✿➢❃❰★➨✤➥✾ð✠➢❃➤ ✃ ❒✱➭✿❾✯➒❊➾❑➙✛➂✹➄✯❺✿➪❞❹✮➙✸➎ß❻➐❺✿→➣→✢➀òñ♦❺✿Ýôó☛❶✹❻➐õò➀ ➶✢➹✹ö❅÷ ❾⑥➇➽✢⑨✑➎✾Ø❺✿❸✮➂❅➄✱➂★➌✯➞➣ø✖❺✿❻➐➪❴➂✪❼✤➾❋❻➣❹✮➂★➌✔❺✭❿✿❾➍➒✍Ôß❺✿→➣➏➐❹⑧➌✱➝✷❹✮➄✯❺✿➌✯➏➣❹⑧➏➐❹➉❺✛→☛❶➍↔✦→➣❺✿❻➐❹➉❺✛→✸➄✯❺❃➛✞➌✱❺✢➄❆Þ✯➜❆➂➍❸➉➝❅❺✿Þ✱❻❃➂★❹✮➙❈➔✞➂★❻➐➏➣❹✮➂★❸✵➄✯❹❱➟✵❺✿❻➣❺✿➌✯➏➐❹✲➂➍❸✞❺✢à✹❷✌➂★➏➣❹⑧❶❅➌✱→✭❾

➠✽➌ù➳❑➥ ➱ ➦❃➭✍➧✹➦✴➳❋➳ ➮ ➵✠➵✷➸ ú✹ú✹❾❈û✦➦❃➥ ➱✽✃ ➢❜➦❄ü◗➤ ➱ ➦✫➭✺➨✮➩ý➵☛➤➍❐✸❒ ✃❅➱ ➦✛➢❞➲ò➥✿➨s➦✿➩✞➥❃➦✛➀✸➔✔➔✦❾☛Ú × Ú✢➒ ↔✙þ ã✱❾⑤➒ÿå❏➔✱❻➣❹⑧➌✱➝❅❺✿❻✽➞✁�❇❺✿❻➐❸✲➂➍➝✞➀ ➶✭➹❅➹✹➘ ❾➎ß❻➐❶❏➙✫❺✿❺✭➄✯❹⑧➌✱➝❅→✸➾✸➾✖î❇➚✠➚✖æ⑧⑦✹⑦❅➀✱➎❖➂➍❻➣❹⑧→✭➀✵⑦ ×❄× ➼✱❾

⑥➇ã✢⑨✑➓✠❹✮à❅❷✱❹⑧❺✿❻✢❾★➒●û❯➦✫➭✖➭✄✂✢➭ ➱ Ñ➦✛❐✒➦✫➭✑➧✵➸ ➬➦✢Ï ✃ ❰ ➱ ➨✤➤➍➩✯➭✒❰ ✃✆☎ ➧ ➬➦✛➢✿➨✞✝ ➬➦✢➦❃➭✠❒✱❰★➢ ➱ ➨✤➦✛❮✮❮➉➦✫➭✿❾★➒❁ø✷➂★❷✔➏➣↕✱❹⑧❺✿❻ ➞✟�❋❹➉❸⑧❸✮➂★❻➐→✭➀✯➎ß➂★❻➣❹⑧→✢➀ ➶✭➹✔➶✭ì ❾⑥ ↕ ⑨✑➓✠❹⑧➏➐➏✸❼sÛ✹❶✹→➐❺✿➔✱↕✍❽✔❺✿❸⑧→❜❿✛❾❅➒Üï✖➨ Ó✸➦✛➢❜➦✛➩ ➱ ➨s❰★❮✞➳✖❮ ➫➍➦✢Ò✛➢❜❰★❾❅➒❊➾✑❾➇➑❊❾➇å✵❾⑧➀ ➶✭➹❅➘✹ì ➀✱➳✡✠⑧á☛✠⑧➲☞✠❈➵☛➤★❮✰❮➉➤✢Ï ✃ ➨ ✃ ❐✾➀✯➊✹❶✹❸✽❾✍✌✎✌✏✌✸➠➣➠➐➠✿❾

➼ þ

Page 60: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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✚✙✛✢✜✤✣✦✥★✧✢✩✢✪✬✫☛✭✮✜✰✯✱✛✙✭✝✧✲✭✮✪✳➣❋❵✰➢❫➠➉➟❆✳✸➢❫➠✮✶✞✩❆➟✹❵❅➛★➡❸➝❉➓✱❲★➟✴✮➢✢✵✒➟★❪✷✶❁➟★✧➥✐✵✂✝✸▲✂✺✹✝✹❫❴

➲✏✣✫❲✵❪✺❪✍✬✯✧✿✶✱✶✞✶❨➫❋✧✿❲★➡★➢ ✻ ✬❺➠✻✵✌✶❸➳

✼❫➢✱✧➦➝✰✣✽✵✙✬❫➡ ✥❸➟★✧✪➊✮➢❢➟✮✵✒➟▼➡ý✣➦➟★✩✭✣❞❲✵✳ý✬❫➡ ✬❏❪✾✶❸➝✮✩❬➝➉➢✱❲✦✣❄✧❆➟✹✣❬➟✹✬✯✧✭❵❅➛❢✳✵✧❆➢✒➤✱✧✭✬❏❪ ➢■➧✒✬✯❲✵✩❆➢✱❪❀✬✯✩❬➝➉➡★➤❁✩❆➛★➟❁✥❸➟★✧➦➝✻✵✯✬✯✩❬➝➉➢✒➡ ➢❫➧✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵☞➟✰✯ò✳✦✬❫➡✦✣❱➝➄➢❑➡✦✣➜➝➉➡✿✵✯✬✯✧❬➝➉➢✱❲✦✣✾❵✰➢✒➡✌✩❆➟✰✯ò✩✢✣★❝➙➜➛★➟✷✳✵✧❅➢✝✶❸➠➉➟★❪ ➛✦✬✔✣✸✬❃➠✮✧❆➟✹✬✱✥✌✶✱✶❁➟▼➟▼➡❊✣❬➢❫➠❀✵✒➟✹✥✔➝➉➡❊✣❬➟✮✵✒➟★✧✭✬❃➠❇❵★✬✱✣❬➟✹✣★❝❣✴ ➢✱✧❣➟✰✯ò✳✙❁✚➠➉➢✒➤✔➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✍❂ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣➜➢✝✶✵✩✢✬❃➝➉➡★➟✹✥

➧✽✧❆➢✱❪✄✬✂✵✙✬❏✧❬➝✤✬✢✶❸➠➉➟ ✱ ✬❫➡✦✥❢✩❆➛★➟●✣❬➟★✩➬➢❫➧✑✧✢✬✯✩❬➝➉➢✒➡✦✬❃➠❒➡✌❲✵❪✷✶❁➟★✧✭✣✱❃❄✶✌✶ ❵❅➠➉➢✞✣❃❲✵✧❅➟❁❲★➡✦✥❸➟★✧✱❅❁➟✰➠✰✥ ➢✱✳❁➟★✧✢✬✯✩❬➝➉➢✒➡✦✣✺✬❫➡✦✥ ✩❆➛★➟✬✯✳✵✳❸➠●➝✤❵★✬✯✩❬➝➉➢✒➡Õ➢■➧➹➟✰✯✵✳ ✬❫➡✦✥✦➠➉➢✒➤✝❂❆✼■➢✒➛★➡ ✻ ➛✦✬✱❵❆❍❑➟✰➠❐➠✝➤✞✬✒✵✒➟❁✬ô✳✵✧❆➢✵❵✰➟✹✥✌❲✵✧❆➟✇➝➄➡➪➲✲Ö❫➳❈❇✮➛❸➝✰❵❅➛Ï➛★➟♠➟✰✯✵✩❆➟▼➡✦✥❸➟✹✥ ➝➉➡ ➲❱✎❄➳✾✩❆➢➭✸➝➉➢✱❲✙✵❑➝●➠❐➠●➝➆✬■➡✡➧➆❲★➡✦❵✢✩➦➝➄➢❑➡✦✣★❝❈❤q➡✪➲➄❛④➳✍✸▼➛★➟❑✣❬➛★➢✢❇➜➟✹✥☞➛★➢✢❇ù✩❆➢➥➛✦✬■➡✦✥❑➠➄➟✖❵✰➢✱❪✺✳✸➢✞✣➣➝✮✩❬➝➉➢✒➡❴✬■➡✦✥☞➝➉➡✪➲❵❴❫➳❢➫✾❝ ✻ ✬❺➠✻✵✌✶❆✬❫➡✦✥❉✼✵❝ ✻ ➛✦✬✱❵❅❍✒➟✰➠●➠✣❬➛★➢✢❇➜➟✹✥ ➛★➢✢❇❬✩❆➢❢❵✰➢✱❪✺✳✵❲✵✩❆➟●✬❫➡❼➟✰✯✵✳✦✬❫➡✦✣➣➝➉➢✒➡Ï➢❫➧✾❊ ➋❱✱✤➍✴✣❃❲✙✶✵♥❬➟✹❵✢✩✍✩❆➢●❋✔➋❍❊★➍❨➑➨✱ ➧①➢✱✧■❋ ✬❫➡❼➟✰✯✵✳✙❁✚➠➉➢✒➤Ó➧➆❲★➡✦❵✢✩❬➝➉➢✒➡❇❝✫ ✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵✔➟✰✯ò✳✦✬■➡✦✣➣➝➉➢✒➡✦✣✮➧❹➢✔✧✒✥❑➝❑❏✢➟★✧❆➟▼➡✌✩❬➝✤✬❃➠♦✬❺➠➄➤❑➟✮✶✵✧✭✬❃➝✤❵✡➟❃➓✔❲✦✬✯✩❬➝➉➢✒➡✦✣▲❇➜➟★✧❆➟❴✬❺➠✰✣➦➢✍❪✍✬✔✥❸➟✍➟▼❏✢➟✹❵✢✩❬➝❀✵✒➟✷✶✌✶✿✼✵❝ ✻ ➛✦✬✱❵❅❍✒➟✰➠●➠➝➉➡✵➲❖◆❫➳P✸❑➛★➢✢❇➸➟✮✵❑➟★✧❑✩❅➛★➟✒✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪➺➝➉➡❊✩❆➛❸➝✤✣✷❵★✬✱✣❬➟✾✳✦✬❅✶ò✣✘➧①➢✱✧⑧➝✮✩✭✣➜➤✒➟▼➡★➟★✧✭✬❺➠❐➝✮✩❃✶◗✶✞✶✍✬■➡✪➟✰✯✵✳❁➢✒➡★➟▼➡✌✩❬➝✤✬❃➠◆❵✰➢✔❪✺✳❸➠➉➟✰✯❢➝✮✩❃✶❘❇➜➝✮✩❆➛✧❆➟✹✣❃✳✸➟✹❵✢✩✷✩❆➢❞✩❆➛★➟❒➢✔✧✭✥❸➟★✧✝➲❖✹❃➳➣❝ ✫ ➡★➢✱✩❅➛★➟★✧◗✬❏✳✵✳✵✧❆➢✞✬✱❵❅➛✍✩❅➢❴✩❅➛★➟❒➟✰✯✵✳✙❁✚➠➉➢✒➤✔➧➆❲★➡✦❵✢✩❬➝➉➢✒➡❊✳✵✧❅➢✝✶❸➠➉➟★❪❙❇✷✬✱✣✠❲✦✣❬➟✹✥◗✶✌✶✂→✴❝ ➷✑✧✿❲★➡✌✩✿✟✩❆➢✡➝✮❪✺✳❸➠➉➟★❪➬➟▼➡✌✩✾✩❆➛★➟✝➡★➟✮❇❯❚❲❱▼❳❨❱✒❩✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❨➝➉➡✃❽●✬✯✳❸➠➉➟r➲✲✐❃➳➣❝❈Ï➛❸➝●➠➄➟✰✼❯❝ ✻ ➛✦✬✱❵❅❍✒➟✰➠●➠▲✬■➡✦✥❊✣❬➟✮✵✒➟★✧✭✬❃➠✤➢✱✩❆➛★➟★✧✭✣⑧➛✦✬✒✵✒➟▲✶✦✬✱✣❬➟✹✥❀✩❆➛★➟✰➝✮✧❬❇➜➢✱✧❆❍➬➢❑➡✍✩❆➛★➟✾✩❆➛★➟▼➢✱✧✛✶➬➢❫➧ ➊✾✬✯✧✭✥✌✶✷❅❁➟✰➠✤✥✵✣✔➲✏❥❃➳P✸✌✩❆➛★➟

✬✯✳✵✳✵✧❆➢✌✬✱❵❆➛➎➧❹➢❫➠●➠➉➢✢❇➜➟✹✥◗✶✞✶★✼✵❝✲✵✙✬■➡✝✥❸➟★✧➥➊✮➢❢➟✮✵✒➟▼➡r➝✤✣✘➝➉➡✦✣❃✳❸➝✮✧❆➟✹✥❘✶✌✶ ✳➣❋❵★✬❃➠●➠➄➟✝❭❱✣✸✩❅➛★➟▼➢✱✧✿✶➬➢❫➧❇✩✿✧✢✬❫➡✦✣✿✣❬➟★✧❬➝➉➟✹✣☞➲✮✂✰➳➣❝❈❤q➡❸➧①➢✱✧✿❪❀✬❃➠●➠✲✶✝✸✩❆➛★➟★✧❆➟✴✬✯✧❆➟❞✩❍❇➜➢✺❪❀✬❃➝➉➡♠➝➉➡★➤✱✧❅➟✹✥❑➝➄➟▼➡✌✩✭✣✮➝➉➡ù✩❆➛❸➝✤✣❪❇➜➢✱✧❆❍ß❝➥➙➜➛★➟❫❅✦✧✭✣❃✩☞➢✒➡★➟❴❵✰➢✒➡✦✣❱➝✰✣✫✩✭✣✮➝➉➡ ❵✰➢✔❪✺✳✵❲✵✩❬➝➉➡★➤❘❇➜➝✮✩❆➛Ü✬✔✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵✣✿❵★✬❃➠➉➟✹✣❞✣❃❲❸➝✮✩✭✬✢✶❸➠➉➟➬➧①➢✱✧☞➟✰✯ò✳✸➢✒➡★➟▼➡✌✩❬➝✤✬✯✩❬➝➉➢✒➡ ✬❫➡✦✥❚➠➄➢❑➤✞✬✯✧❬➝✮✩❆➛✵❪ ➋❜✣❬➢✝❁➣❵★✬❃➠●➠➉➟✹✥❵❴✸❋✝❛❇❏✷❜✝❝❀❷❞❜✢❡✮❢✮❡✮✸❇✣❬➟▼➟✷✶❁➟✰➠➉➢✢❇✝➍✭❝➬➙➜➛★➟✺✣❬➟✹❵✰➢❑➡✦✥➢✒➡★➟✺❵✰➢✒➡✦✣➣➝✤✣❃✩✢✣➜➝➉➡✂❇➜➢✱✧❆❍❑➝➄➡★➤❊✣➣➝✮❪✴❲❸➠✮✩✭✬❫➡★➟▼➢✱❲✦✣➣➠✮✶✂❇➜➝✮✩❆➛②➟✰✯✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣✮➝➉➡●✩❆➛★➟✹✣❬➟✺✣✿❵★✬❃➠➉➟✹✣✼✬❫➡✦✥●✬➁➛✦✬❫➡✦✥❑➠➉➟✍➢❑➡Ü✩❅➛★➟☎➟✰✯✦✬✱❵✢✩➧✽❲❸➠❐➠➜➝➉➡❸➧①➢✱✧✿❪✍✬✯✩➦➝➄➢❑➡ù✧❆➟✰➠✤✬✯✩❆➟✹✥ô✩❆➢❁✩❅➛★➟★❪❁❝♠➙➜➛❸➝✤✣✔➛✦✬❫➡✦✥❑➠➉➟♠➋➣➡✦✬✯❪➬➟✹✥❣❜✝❝ ❧ ❋✝❛▼❤❥✐✚✬❸❏✾❤✚❉❨❏✡✩❦❝❑✐✦❤❧❡♠❢✒❛✤❤♥❢✮❡✰➍✑❪❀✬❫❍✒➟✹✣☞➝✮✩❞✳❁➢✞✣✿✣❱➝✻✶❸➠➉➟✩❆➢ ❵✰➢✱❪✺✳✵❲✵✩❆➟●❪➬➢✔✧❆➟❁✩❆➟★✧✛❪✍✣r➢❫➧❴✬❫➡Ï➟✰✯✵✳✦✬❫➡✦✣➣➝➉➢✒➡✬❇➥➛★➟▼➡★➟✮✵✒➟★✧❨➡★➟✹❵✰➟✹✣✿✣✛✬✯✧✿✶ ✬■➡✦✥ý✩❅➢✵➝➉➡✲✵✒➢✒❍✒➟ù✬❫➡Ï➢✱✧✭✬✔❵❅➠➄➟✇➧①➢✱✧❀✟▼➟★✧❆➢✝❁➟❃➓✔❲❸➝✻✵✯✬❃➠➉➟▼➡✦❵✰➟➬➢❫➧⑥➧➆❲★➡✦❵✢✩➦➝➄➢❑➡✦✣➜➝➉➡♠➢✔✧✭✥❸➟★✧✷✩❆➢✺✳✵✧❅➟✮✵✒➟▼➡✞✩➴➝➄➡✦✥❸➟▼❅❁➡❸➝✮✩❆➟✺❵★✬❫➡✦❵✰➟✰➠●➠✤✬✯✩❬➝➉➢✒➡❇❝➥❽✇➢✱✧❅➟✼✳✵✧❆➟✹❵❅➝✤✣❬➟❴✥❸➟▼❅❁➡❸➝✮✩❬➝➉➢✒➡✦✣✼✬✯✧❅➟❆✬✱✣➧①➢❫➠●➠➄➢✢❇✑✣➍❝♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q ✂❢✧ ✫ ➡ý✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩❬➝✤❵❀✣✿❵★✬❃➠➉➟r➝✤✣✺✬s❅❁➡❸➝✮✩❆➟♠➢✱✧✢✥❸➟★✧❆➟✹✥ ✣➦➟★✩✪➒✉t ➓ ✳❄❂❄❂❃❂❆✳✈t✱❚❸→❨➢❫➧✑✳✸➢✞✣➣➝✮✩❬➝❀✵✒➟❊❲★➡✲✶❁➢✱❲★➡✦✥❸➟✹✥

➟✰✯✵✳✙❁✚➠➄➢❑➤➬➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✾✣❃❲✦❵❆➛❊✩❅➛✦✬✯✩➜➠➉➢✒➤☎t✝✇❞➑❆①❑➋①➠➉➢✒➤☎t✝✇❀②✸➓❇➍▼✸✒➧①➢✱✧④③ ➑ ✂✒✳❄❂❃❂❄❂❆✳▼⑤★⑥ ✂✱❝♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q✵✐❁✧➜➭✤➟★✩❬t★✶✸➟❆✬❆✳✸➢✞✣➣➝✮✩❬➝❀✵✒➟✼❲★➡✲✶❁➢✱❲★➡✦✥❸➟✹✥❚➟✰✯ò✳✙❁✚➠➉➢✒➤➎➧➆❲★➡✦❵✢✩❬➝➉➢✒➡❇❝ ✫ ❏✡✩✲❝⑦✐✦❤❧❡✮❢✺❛▼❤❥❢✉❡④❇➜➝✮✩❆➛❀✧❆➟✹✣❃✳✸➟✹❵✢✩✷✩❆➢❫t

➝✤✣✑✬✍➧❹➢✱✧✛❪✍✬❃➠ ✣✫❲✵❪➑❨➑⑨⑧

☞✝⑩✺❶ ➑✯☞✗t☞ ✳

✩❆➛★➟✷❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✞✩✭✣❬➑ ☞ ✶❁➟✰➝➉➡★➤✔➟✰✯ò✳✙❁✚➠➉➢✒➤ ➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✠✬■➡✦✥❆✩❅➛★➟✑✣❃❲✵✳✵✳❁➢✔✧✿✩➜❳Ô➵❵❷❊➛✦✬✒✵✒➝➉➡★➤❉❅❁➡❸➝✮✩❆➟✰➠✮✶✡➤✒➟▼➡★➟★✧✭✬❏✩❆➟✹✥✴✣❃❲✵✳✵✳❁➢✱✧✛✩❄✶❳✵➑ ■ ➓ Ð✎❸ ■

✽Ð❹❸❻❺✒❺✺❺✮❸ ■❨❼❃Ð❽❸ù✕❀✳

❇➥➛★➟★✧❆➟✼✩❅➛★➟❴■ ✇ ❭✏✣✖✬✯✧❅➟❆✣❃✩✿✧❬➝✤❵✢✩❬➠✮✶❊✳❁➢✌✣➣➝✮✩❬➝❀✵✒➟❆✧❆➟✹✬❺➠◗➡✞❲✵❪✷✶✸➟★✧✭✣✷✬❫➡✦✥❀✕❊❘❘❷✍❝♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎qù❥❁✧ ✫ ❪❴❲❸➠✮✩❬➝✤✣❬➟★✧➦➝➄➟✹✣➁➟✰✯✵✳✦✬❫➡✦✣➣➝➉➢✒➡❵❇➜➝✮✩❆➛ ✧❆➟✹✣✫✳❁➟✹❵✢✩✺✩❆➢❊➒✮t ➓ ✳❃❂❄❂❃❂❁✳✈t✱❚❑→❦✸⑥➝✤✣✍✬❡❪✴❲❸➠✮✩❬➝✤✣❬➟★✧❬➝➉➟✹✣✱❇➜➝✮✩❆➛ ✧❆➟✮❁

✣❃✳✸➟✹❵✢✩Ü✩❅➢❵t ❚ ✸❉❇➥➛★➟★✧❆➟❊➟✹✬✱❵❅➛ ❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✞✩ù❵★✬❫➡❍✧❆➟✹❵✢❲✵✧✭✣❱➝✻✵❑➟✰➠✲✶❾✶❁➟❊➟✰✯✵✳✵✧❆➟✹✣✿✣❬➟✹✥❍✬✱✣❁✬ ❪✴❲❸➠✮✩❬➝✤✣❬➟★✧❬➝➉➟✹✣✂❇➜➝✮✩❆➛ ✧❆➟✹✣❃✳❁➟✹❵✢✩✩❆➢❨➒✉t ➓ ✳❄❂❄❂❃❂❬✳✈t✱❚✝❿ ➓ →✲✸★➟✹✬✱❵❅➛❊❪❴❲❸➠✮✩❬➝✤✣❬➟★✧➦➝➄➟✹✣▲❇➴➝✲✩❅➛❊✧❆➟✹✣❃✳❁➟✹❵✢✩✾✩❆➢✷t ➓ ➛✦✬✒✵❑➝➉➡★➤✍❵✰➢✒➡✦✣❃✩✭✬■➡✞✩✑❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣★❝

➼✱⑦

Page 61: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q②❴✿✧ ✫ ❴✸❋✝❛✰❏✾❜ ❝ ❷❞❜✢❡✮❤❀❡✝➝✤✣✼✬❫➡●✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩➦➝✰❵✴✣✿❵★✬❺➠➄➟r➒✮t ➓ ✳❃❂❄❂❃❂❆✳✈t✱❚✒→✺✣✿✬✯✩➦➝✰✣❱➧➆✶❑➝➉➡★➤❊✩❆➛★➟✝➧①➢❫➠●➠➉➢ ❇➴➝➄➡★➤●❵✰➢✒➡✙❁✥❑➝✮✩❬➝➉➢✒➡✦✣

➋✭✂❫➍ t ➓ ➑ ➠➄➢❑➤ ❼ ✱ ➋❜❙❨❘②Ð☞➍✤✸ ❇➥➛★➟★✧❆➟☞➠➉➢✒➤ ❼ ✥❸➟▼➡★➢✱✩❆➟✹✣◗✩❆➛★➟☞➠➉➢✒➤✞✬✯✧❬➝✮✩❆➛✵❪ ➝✲✩❅➟★✧✭✬✯✩❆➟✹✥❡❙❀✩❬➝✮❪➬➟✹✣✝➋ ➠➄➢❑➤ ✁ ✱❚➑❲✱✤➍✄✂➋❱✐❸➍ ➠➄➢❑➤☎t ✇ ❘❘❷r➲●➲ t ➓ ✂❄❂❄❂❃❂☎✂✈t ✇ ❿ ➓ ➳➉➳✍✸✒➧①➢✱✧❒✐✝✆❣③✞✆❻⑤❈❝♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q✵Ö❁✧ ✫ ❪✴❲❸➠✲✩➦➝✰✣➦➟★✧❬➝➉➟✹✣✓❇➴➝✲✩❅➛❴✧❅➟✹✣❃✳❁➟✹❵✢✩❋✩❆➢❆✬✝➡★➢✱✧✛❪✍✬❃➠✙✶✦✬✱✣➣➝✤✣➜➒✮t★➓❇✳❃❂❄❂❃❂❆✳✈t ❚ →➜➝✤✣❋✣✿✬❃➝✤✥✴✩❆➢❉✶✸➟✾❜✝❝ ❧ ❋✝❛✤❤♥✐✚✬❢❏✷❤✚❉❇➥➛★➟▼➡✇➝✮✩❴❵✰➢✒➡✲✵✒➟★✧❆➤❑➟✹✣✷✩❆➢❊✬➁➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✟✸☛✬❫➡✦✥❚➧①➢✱✧✼✬❫➡✞✶❁❙Ó❘ Ð✞✟✔➝✮✩✭✣❪❅✦✧✭✣❃✩✼❙●❵✰➢❢➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣❉❇➴➝✲✩❅➛Ü✧❅➟✹✣❃✳❁➟✹❵✢✩✼✩❆➢◗t✱❚❊❵★✬❫➡

✶❁➟✴❵✰➢✱❪✺✳✵❲✵✩❆➟✹✥❊✬■➡✦✥❁✬✯✧❆➟✼✩❅➛★➟★❪✍✣❬➟✰➠❀✵✒➟✹✣✾✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪✡➝✤❵➎➋❜❵✰➢✒➡✦✣❃✩✭✬■➡✞✩✭✣✖✶❁➟✰➝➉➡★➤❁✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪✡➝✤❵❃➍✭❝➙➜➛★➟✺✩❅➛★➟▼➢✱✧❆➟★❪ ✼❯❝✟✵✙✬■➡ ✥❸➟★✧➬➊➥➢❸➟✮✵✒➟▼➡ ✬❃➝✮❪✍✣❞✬✯✩❆✳✵✧❅➢ ✵❑➝➉➡★➤❨➝➉➡●✵✙✬✯✧❬➝➉➢✱❲✦✣❞❵✰➢✒➡✌✩❆➟✰✯ò✩✢✣✝➢❫➧✷✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩❬➝✤❵✡➟✰✯✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣

➝✤✣✖✩❆➛✦✬✯✩✖✩❆➛★➟★✧❅➟❆✬❃➠❀❇◗✬❅✶✵✣⑧➟✰✯❢➝✤✣❃✩✭✣✪✬☎➡★➢✔✧✿❪✍✬❃➠✟✶✦✬✱✣➣➝✤✣✷✬■➡✦✥✇➋➣❲★➡✦✥❸➟★✧✑✣❃❲❸➝✮✩✭✬✢✶❸➠➉➟❞✧❆➟✹✣❃✩✿✧❬➝✤❵✢✩❬➝➉➢✒➡✦✣④➍♦✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪✡➝✤❵✼❪✴❲❸➠✮✩❬➝✤✣❬➟★✧❬➝➉➟✹✣★❝➊✮➟✍➛✦✬✔✣✷✳✵✧❆➢✢✵✒➟✹✥❡✩❆➛❸➝✤✣✾✩❆➛★➟▼➢✔✧❆➟★❪ ➧①➢✱✧☞➟✰✯ò✳✙❁✚➠➉➢✒➤❚➧➆❲★➡✦❵✢✩➦➝➄➢❑➡✦✣✡➲✮✂❄❯❃➳P✸ ❇➥➛★➟★✧❆➟✴✩❆➛★➟ ➝➉➡❦✵✒➟★✧✢✣➣➝➉➢✒➡ù✳✵✧❆➢✝✶❸➠➉➟★❪ ✬❫➡✦✥●✬❃➠➉➤✒➟✮✶✵✧✢✬❃➝✤❵➟❃➓✔❲✦✬✯✩❬➝➉➢✒➡✦✣✮➛✦✬✺✵❑➟④✶✸➟▼➟▼➡ ✬❏✩❀➠➉➟✹✬✱✣✫✩✑✳✦✬✯✧✛✩❬➝✤✬❃➠●➠✲✶❊✩✛✧❆➟✹✬✯✩❆➟✹✥â✩❆➢❸➢✦❝❀➊✮➟★✧❆➟☞➝✤✣✑✬✴✩❅➛★➟▼➢✱✧❆➟★❪➺➧✽✧❆➢✱❪❪➲✮✂❄❯❃➳➣❝❜☎❝❞✣❢❡❣✜✤✣★❤❬✂❢✧ ❂ ❉⑦✬❦❜✝❴✸✩❦❢✒❝✡✠ ❡➥❉❇❋ ❴☞☛✮❢❇❉✒✐①✩❦❛✈❢✰❤✚❏✍✌ ❝❑❤❥❢✉❡④✐✚✬❦❜✝✐ ✐✚✬❦❢✞✎❬❢✺❝✑✏✡❋❬③✰❛✈❢✤❜ ❝☛❜✝❝ ❧ ❢❫❷✮❛✈❜✝❤✚❉❉❢▼t✒✌❁✈❍❝●❋ ❧ ③④✩✲❴❁❉✒✐✦❤♦❋ ❴✙❡❉❤❀❡④❜ ❴❜✒✩✲✐①❋✒❏✷❜✝✐✦❤✚❉ ❢⑦t☎✌ ❜ ❴✙❡✮❤♦❋✝❴✓✎ ❢✒❝✔✏❸⑨✫ ➡✝✬✯❲✵✩❅➢✱❪✍✬✯✩❬➝✤❵✮➟✰✯ò✳✦✬■➡✦✣➣➝➉➢✒➡◗❅❁➟✰➠✤✥➁➝✰✣✪✬❉❅❁➟✰➠✤✥◗❇➥➛★➟★✧❅➟❒➡★➢✱✧✛❪✍✬❃➠ ✶✦✬✔✣❬➟✹✣✷✬❫➡✦✥â❪✴❲❸➠✲✩➦➝✰✣➦➟★✧❬➝➉➟✹✣❬❇➜➝✮✩❆➛❊✧❆➟✹✣❃✳✸➟✹❵✢✩✷✩❆➢❞✩❆➛★➟★❪

❵★✬❫➡◗✶❁➟❆❵✰➢✱❪â✳✵❲✵✩❆➟✹✥➁➧❹➢✔✧❑✬❫➡✌✶➬➟✰➠➉➟★❪➬➟▼➡✌✩✹❝ ✻ ❵❅➛✦✬❫➡✞❲★➟✰➠P❭✏✣✪❵✰➢✒➡✯♥❱➟✹❵✢✩✛❲✵✧❆➟➥➝✤✣✖✧❅➟✰➠✰✬❏✩❆➟✹✥❀✩❆➢❆✩❅➛★➟✑✟▼➟★✧❆➢ ❁①➟❃➓✱❲❸➝❀✵✙✬❺➠➄➟▼➡✦❵✰➟✴✳✵✧❆➢ ✶❸➠➄➟★❪➧①➢✱✧✸❵✰➢✒➡✦✣❃✩✭✬■➡✞✩✭✣➍❝ ✫ ➠➉➤✒➟✮✶✵✧✭✬❺➝✰❵✾✥❑➝❑❏✢➟★✧❆➟▼➡✞✩➦➝✰✬❺➠❁➟❃➓✱❲✦✬✯✩➦➝➄➢❑➡✦✣✸✬❫➡✦✥❞✩❆➛★➟✖✟▼➟★✧❆➢✝❁①➟❃➓✔❲❸➝❀✵✙✬❃➠➉➟▼➡✦❵✰➟✼✳✵✧❆➢ ✶❸➠➄➟★❪➾➝➉➡✍✬☞➤✒➟▼➡★➟★✧✭✬❃➠❖✣➦➟★✩✿✩❬➝➉➡★➤✣❬➛★➢✱❲❸➠✤✥s✶❁➟❆✩✛✧❆➟✹✬✯✩❆➟✹✥➁➝➉➡Ô➲✰✂✱✂✰➳➣❝

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦✫⑨ Øî❇➙✿➂➍❸⑧❸➉❺♦❼✤Û✹❺✢➂★➌✞❿✛❾✿➒✼➯✿➩ ➱ ➢❜➤✢➧ ✃ ➥ ➱ ➨✤➤➍➩✒❰ ✃✍☎✖✕ ➤➍➩✞➥ ➱ ➨✤➤➍➩✯➭♦❰➍➩✞❰★❮ ✂✢➭✭❰✹Ò✛❮➉➦✫➭◆➦ ➱ ❒✌➢❜➦ ✃ ✝➋➦❋➥❜➤➍➩✯➭ ➱ ➢ ✃ ➥ ➱ ➨✞✝➋➦✠➧❅➦❈❮➉❰✖➥❃➤★➩☎✗✢➦❜➥ ➱✽✃ ➢❃➦✠➧✹➦▲ï ✃ ❮⑧❰✹➥✛❾✛➒

✘ ❺✛❻➣➪❴➂➍➌✱➌✦➀✱➎ß➂★❻➐❹⑧→✭➀ ➶✭➹❅➹✹ë ➀✱➳❑➥ ➱➆✃ ❰➍❮✏➨ ➱ ➬➦❃➭✖❐✒❰ ➱✤Ð ➬➦✿❐✼❰ ➱ ➨✤Ï ✃ ➦❃➭✿❾⑥➇➴➋⑨◗ø✖❻➐❷✱➌✯➏➣➃❞❼➆➅❋❶✹➪❞❹➉➌✔❹➉õ✱❿✛❾★➒✚✙✠➩●➵☛➤➍❐✸❒ ✃✹➱ ➨✮➩✯➫✼ûß➨✮❐✾➨ ➱ ➭✾➨✮➩✝❰è➲☞✂★❐✼Ò❃➤★❮❱➨✤➥✪á✍❰★➩✱➨➇❒ ✃ ❮➉❰ ➱ ➨✤➤➍➩❀➲☞✂✢➭ ➱ ➦✛❐✑❾✔➒ý➎ß↕✞➅ ➏➣↕✔❺✿→➣❹⑧→✭➀⑤îßÔ ✘ ➀

✛✢✜❷✱❻➐❹✲➙➐↕✦➀ ➶✭➹❅➹✹➘ ❾⑥➇Ú➋⑨◗➓✠❶❅→➣❺✿➌✔❸➉❹✮➙➐↕✯➏✠❼➆➑â➂✢ç✱Ý☛❺✛❸➉❸✮❿✛❾✢➒ ✘ ➂★❻❜➄❏➜✷➛✞❺✛❸✲➄❏→✭❾✵é✙➤ ✃ ➢✿➩✞❰★❮✵➤ ✕ á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨✤➥❃❰➍❮✙➳✖➩✞❰➍❮ ✂✢➭✿➨⑧➭❑❰➍➩✞➧✖➳✠❒❅❒✞❮✏➨s➥❜❰ ➱ ➨s➤★➩✯➭✿➀❅➊✹❶✹❸✽❾ × Ú✔➀ ➶✭➹❅ä✹÷ ➀

➔✱➔✦❾✌➴ × ã✢➒❏Ú✔⑦✹⑦❅❾⑥ ↔ ⑨◗å✱➂➍❸➉➊✯➜✴❼✽⑩❇❻➐❷✱➌✱❶✙❿✠➂➍➌✞➄❆å❏↕✞➂✹➙➐õ✹❺✛❸➉❸ß❼sÛ✹❶❅↕✱➌✞❿✿❾❏➒✍➾✸→➐➜✯➪❆➔✱➏➐❶✹➏➣❹✮➙♦❺❃ç✱➔✞➂★➌✱→➐❹⑧❶✹➌✱→❈❶★↔⑤↔✤❷✱➌✞➙❃➏➐❹⑧❶✹➌✞➂➍❸✵❹➉➌✯➊❅❺✿❻➣→➐❺✿→✭❾✔➠✽➌✤✣❁➂★➌✔➝✼❼➆➎ß➂★❷✔❸✦å✵❾➇❿

❼✤❺✢➄✯❹⑧➏➣❶✹❻❃❿✿➀♦➲☞✂★❐✒Ò❃➤➍❮✏➨✤➥✴❰★➩✌➧✴➳✖❮➇➫✹➦✭Ò✛➢❜❰➍➨✤➥✴➵☛➤➍❐✸❒ ✃✹➱ ❰ ➱ ➨✤➤➍➩✱❾✦➔✔➔✦❾☛⑦✢Ú þ ➒ò⑦✭Ú❅ã✱❾✌➒❉➾✸➚✠➑ ➎ ❻➣❺✿→➐→✭➀ ➶✢➹✹➹❅ë ❾✦➎ß❻➐❶✱➙❃❺✿❺✭➄✯❹⑧➌✱➝❅→✼❶★↔✸➠➣å❅➞å✯➾✸➚✖æ × ➴✔➀✱⑩❇❺✛❻➣õ✹❺✛❸➉❺✛➜✙➀✔Û✹❷✱❸⑧➜✍⑦ ×❄× ➴✱❾

⑥➇➼➋⑨◗å✯↕✞➂❅➙➐õ✹❺✿❸⑧❸❈❼✤Û❅❶✹↕✱➌✞❿✛❾✔➒ ø✖❻➐❶★Ý✠➏➣↕✺❺✛→➣➏➣❹⑧➪✴➂★➏➣❺✛→✠↔✤❶❅❻✸❺❃ç✱➔✯➞✽❸⑧❶✹➝✾↔✤❷✱➌✌➙❃➏➣❹⑧❶✹➌✔→✭❾❇é✯➤ ✃ ➢✿➩✞❰➍❮ ➤ ✕ ➲ ✂★❐✒Ò❃➤★❮❱➨✤➥✴➵☛➤➍❐✸❒ ✃❅➱ ❰ ➱ ➨✤➤➍➩✱➀✌➊✹❶❅❸➆❾⑤⑦ þ ➀➅❋❺✭➙❃❺✿➪✼Þ✌❺✿❻ ➶✭➹✹➹❅ì ➀❅➔✱➔✦❾✱➽✔⑦✹⑦❃➒✱➽✹Ú❅➴✱❾⑥➇➽➋⑨◗å✯↕✞➂❅➙➐õ✹❺✿❸⑧❸❇❼sÛ✹❶❅↕✱➌✞❿✿❾❅➒Ü➁❯❹⑧➪❆❹⑧➏➣→❇❶➍↔ ➁❯❹➉❶❅❷✱➊✯❹⑧❸➉❸⑧❹✮➂★➌✪↔✤❷✱➌✌➙❃➏➣❹⑧❶✹➌✔→✭❾❅➒❁➎ß❻➣❺✿➔✔❻➣❹⑧➌✯➏✭➀ ➶✭➹❅➹✱➶ ❾

⑥➇ã➋⑨◗å✯↕✞➂❅➙➐õ✹❺✿❸⑧❸❇❼sÛ✹❶❅↕✱➌✞❿✿❾❅➒Üî❖ç❏➏➐❺✿➌✱→➐❹➉❶❅➌✱→✠❶★↔☛➂➍→➣➜✯➪❆➔✱➏➐❶✹➏➐❹✲➙▲➛✌❺✿❸✮➄✯→✸➊✯❹✮➂✷➪❞❺✿❻➣❶❅➪❆❶❅❻➣➔✱↕✱❹✮➙ ↔✤❷✱➌✞➙✫➏➣❹⑧❶✹➌✱→✢❾✯➒❁➎ß❻➣❺✛➔✱❻➣❹⑧➌✯➏✭➀ ➶✭➹✹➹❅ë ❾⑥ ↕ ⑨◗å✯↕✞➂❅➙➐õ✹❺✿❸⑧❸ß❼✤Û❅❶✹↕✱➌✌❿✿❾❅➒❁➓✠❶✹→➐❺✿➌✱❸⑧❹✮➙➐↕✙➏▲➛✞❺✿❸✮➄✯→✢❾✢✥✌➢❜❰★➩❏➭✛❰❅➥ ➱ ➨✤➤➍➩✯➭◗➤ ✕✖➱✤Ð ➦✠➳✖❐✼➦✿➢✿➨s➥❜❰➍➩❞áâ❰ ➱✤Ð ➦✿❐✼❰ ➱ ➨✤➥❃❰★❮✌➲✵➤✭➥✛➨✤➦ ➱ ✂★➀✔➊✹❶✹❸✽❾✯Ú✹Ú❅➼✱➀❅➌ ê ➴✔➀

➶✭➹❅➹✹÷ ➀✯➔✱➔✦❾✱➼✹ã × ➒✱➼ × ➼✔❾⑥ × ⑨◗å✯↕✞➂❅➙➐õ✹❺✿❸⑧❸✠❼sÛ✹❶✹↕✔➌✞❿✖➂★➌✞➄❀å✱➂★❸⑧➊✯➜❀❼➆⑩▲❻➣❷✱➌✔❶✙❿✿❾ò➒ ➳✖➭✄✂★❐✸❒ ➱ ➤ ➱ ➨s➥✍✦❯➤➍➢✿❐✷➭✼❰★➩✞➧❞➳✖❮➇➫✹➦✭Ò✛➢❜❰➍➨✤➥✪ï❑➨ Ó✸➦✿➢❃➦✿➩ ➱ ➨✤❰➍❮ ➮ Ï ✃ ❰ ➱ ➨✤➤➍➩✯➭✿❾✌➒ ➓✠❺❃➞

→➣❺✢➂★❻❜➙➐↕✴❻➣❺✛➔✞❶❅❻➣➏❈➌ ê ➴❅Ú✱⑦ × ➀★➠✽➌✱→➐➏➣❹⑧➏➣❷✱➏❈ñ✸➂★➏➐❹⑧❶✹➌✞➂➍❸✞➄✯❺❑➓♦❺✭➙➐↕✱❺✿❻❃➙➣↕✔❺❑❺✛➌✼➠✽➌✯↔✤❶✹❻➐➪❴➂➍➏➣❹✮à❅❷✱❺☛❺✛➏☛❺✿➌✼➾❋❷✱➏➣❶❅➪❴➂➍➏➣❹✮à❅❷✱❺✹➀★➾❋❷✱➝✹❷✱→➐➏ ➶✭➹❅➹★Ù ❾Ôß❶✒➂➍➔✱➔✌❺✭➂★❻❋❹➉➌❞➏➣↕✱❺✴é✙➤ ✃ ➢✿➩✞❰★❮ß➤ ✕ ➲☞✂★❐✼Ò❃➤★❮✏➨s➥✼➵☛➤➍❐✸❒ ✃✹➱ ❰ ➱ ➨✤➤➍➩✱❾⑥⑧⑦ þ ⑨ �☛➂➍➌✍➄✯❺✿❻ ✘ ❶✯❺✿➊❅❺✿➌❡❼✤Û✹❶❅❻➣❹⑧→❜❿✛❾✔➒ ð✸➦✿➩✞➦✛➢❜❰➍❮❇❰★❮➇➫✹➤★➢✛➨ ➱✤Ð ❐✷➭✷➨✮➩❊❰✢➭✄✂★❐❋❒ ➱ ➤ ➱ ➨✤➥✫➭◗➯✒✧✠ð✸➤★➩✱➩✞➦ ➱ ❰➍➩✞➧❀ð✠➢ ✃ ➩ ➱✩★ ➸ ➭✒❰★❮ ➫➍➤➍➢✿➨ ➱sÐ ❐✫✪ ➯➣➯✒✧

➵☛➤★❐✾❐✼➤★➩ù➤❃❒✱➦✿➢❃❰ ➱ ➨✤➤★➩❏➭✫❾⑤➒❬Ôß❺✭➙➐↕✱➌✱❹✮➙✿➂➍❸✸➓✠❺✿➔✌❶✹❻➐➏✑➌ ê ➁✵➠✁✌✭✬✹➓❋➓✮✬ × ↔ ✬✔⑦ þ ➀ Øî❇➙❃❶✹❸⑧❺✴➔✌❶✹❸⑧➜✯➏➣❺✭➙➐↕✱➌✱❹✮à❅❷✱❺✹➀❈➎ß➂★❸✮➂★❹⑧→➣❺✢➂★❷✦➀❇❽✔❻❜➂➍➌✞➙❃❺✹➀Û✹❷✔❸➉➜ ➶✭➹❅➹★Ù ❾

⑥⑧⑦✹⑦✫⑨ �☛➂➍➌✍➄✯❺✿❻ ✘ ❶✯❺✿➊✹❺✿➌❡❼✤Û❅❶✹❻➐❹➉→❃❿✿❾✌➒ý➳✖➭✄✂★❐❋❒ ➱ ➤ ➱ ➨✤Ï ✃ ➦✪➳ ✃❅➱ ➤➍❐✒❰ ➱ ➨✤Ï ✃ ➦✿❾✔➒ ➎ß↕✌➅Õ➏➣↕✱❺✛→➣❹⑧→✭➀ Øî▲➙❃❶✹❸⑧❺✾➔✞❶❅❸➉➜✯➏➐❺✭➙➐↕✱➌✱❹✮à❅❷✱❺✹➀✦➎ß➂★❸✮➂➍❹➉→➐❺✭➂★❷⑤➀❽✔❻❜➂★➌✌➙❃❺✹➀ ➶✢➹✹➹✰✯ ❾✯Ôß❶✒➂➍➔✱➔✌❺✭➂★❻✢❾

➼✹➴

Page 62: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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❤✈✴✯✮◗❤ ✫✱✰ ➔✠✧❆➢✔♥❱➟★✩✾P ✁ →✗➣ ✻✼✱✬❫➡✌❲✦✬✯✧✿✶❨✐✱❥✙✸▲✂✺✹✝✹✒Ö

➲✏✣❃❲✵❪â❪✍✬✯✧✿✶★✶✌✶❨✴✵✧✭✬❫➡✗✲❵✰➢■➝✰✣☞❽✇➢✱✧✭✬❃➝➉➡★➳✳✵✴✷✶❃➆✘✸✺✹✼✻✾✽✘➂✢➅✟✸✺✿❀✻❞➆

➭✤➟★✩❆❙❚➑❂❁✵❃❉✶❁➟✴✩❆➛★➟❫❅❁➡❸➝✮✩❆➟❫❅❁➟✰➠✤✥✂❇➜➝✮✩❆➛✜❄✡➟✰➠➉➟★❪➬➟▼➡✌✩✭✣✔➋❅❄✺✬❀✳✵✧➦➝✲❪➁➟❴✳✸➢✢❇➸➟★✧❇❆ ➩ ✸☎❈❀✬❫➡✞✶❨➡★➢❑➡★➡★➟▼➤✞✬✯✩❬➝❀✵✒➟ ➝➄➡✌✩❆➟▼➤✒➟★✧⑦➍✭❝✴★➢✔✧✼✩❆➛★➟★✶✦✬✱✣➣➝✤❵✴✳✵✧❅➢✱✳❁➟★✧✿✩➦➝➄➟✹✣✔➢❫➧ ❅❁➡❸➝✮✩❆➟★❅❁➟✰➠✤✥✵✣✮✸✠✬✱✣▲❇➜➟✰➠●➠◗✬✔✣❆✬❫➡✇➝➉➡✞✩✛✧❆➢ò✥✌❲✦❵✢✩➦➝➄➢❑➡ ✩❆➢❨➡★➢✔✧✿❪✍✬❃➠✓✶✦✬✱✣➦➟✹✣✮✸✢➟★✩✭❵✯❝❧✸✟❇➜➟✴❲✵✧❆➤✒➟✩❆➛★➟✼❲★➡❸➧➣✬✯❪✡➝●➠●➝✤✬✯✧✼✧❆➟✹✬✱✥❸➟★✧✷✩❅➢✺✧❆➟✹✬✱✥②➲✏❥✲✸★❴❲✸❖Ö■➳➣❝➭✤➟★✩❀P ✶❁➟✷✬✼❙✲❁✚➠●➝➄➡★➟✹✬❏✧❀➢✱✳✸➟★✧✭✬✯✩❆➢✱✧⑥➢❫➧❖❙ ❚ ✬❫➡✦✥✴❵★✬❃➠●➠❊❉ ✩❆➛★➟✷✬✱✣✿✣❬➢✵❵❅➝✤✬✯✩❆➟✹✥❞❪✍✬✯✩✿✧➦➝❐✯✟✸✯✩❆➛✦✬✯✩❞➝✤✣✠✬❫➡✡➟✰➠➉➟★❪➬➟▼➡✞✩❣➢■➧❊❋ ❚ ➋❜❙✸➍✭❝

➙➜➛★➟❆✬❃➝✮❪➺➢❫➧☛✩❅➛❸➝✰✣◗✩✭✬❃➠➉❍➬➝✤✣✖✩❅➢☎➝➉➡✌✩✿✧❆➢✵✥✌❲✦❵✰➟✼✩❆➛★➟❆✣❬➢✝❁➣❵★✬❺➠❐➠➉➟✹✥ ❂ ✬❦❤ ③✮✐✚✈✚●❉❢✮❡▼❡✮❢✺❴✿❷❞❢✺❛ ❧ ③▼❋✝❛✰❏➺➢❫➧❍❉ ➋ ✻ ➊ ✻ ➧①➢✱✧✿❪➌➧❹➢✔✧◗✣➦➛★➢✱✧✿✩▼➍✬❫➡✦✥ù✥❸➟✹✣✛❵✢✧❬➝❀✶❁➟r➝✮✩✭✣✼✳✵✧❅➢✱✳❁➟★✧✿✩➦➝➄➟✹✣➍❝❊❤q➡ù✳✦✬❏✧✿✩❬➝✤❵✢❲❸➠✤✬✯✧✺✸⑥➝✮✩✰❇➴➝❐➠●➠❈✶❁➟❊✣❬➛★➢✢❇➥➡●✩❆➛✦✬✯✩❞✩❆➛★➟★✧❆➟➬➟✰✯❸➝✤✣❃✩✭✣❞✬r➧➣✬✱✣❃✩❆✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪➨➧①➢✱✧❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❨➶❢❝➊✾✬✺✵❑➝➉➡★➤❆✩❆➛★➟ ✻ ➊ ✻ ➧❹➢✔✧✿❪❥➢❫➧✂❉ ➟▼➡✦✬✢✶❸➠➉➟✹✣❋❲✦✣✠✩❆➢✴✣❬➢❫➠❀✵✒➟✑✣➦➟✮✵✒➟★✧✭✬❃➠ß✳✵✧❆➢✝✶❸➠➉➟★❪✍✣★❝❀✴❞➝✮✧✭✣✫✩✺✸✢❇➜➟✑❵★✬❫➡✱❅❁➡✦✥✍❵✢✶✵❵❅➠●➝✰❵▲✵❑➟✹❵✢✩❆➢✱✧✭✣

➧①➢✱✧❀PÕ✬❫➡✦✥✺✩❅➛★➟★✧❆➟✰➧❹➢✔✧❆➟ ❅❁➡✦✥✍✬ ➡★➢✱✧✿❪✍✬❃➠☛✶✦✬✔✣➣➝✤✣⑥➧①➢✱✧☛❁ ❃❏■ ➢✢✵✒➟★✧☛❁ ❃ ❝⑥❈✵➟✑❵★✬■➡✍✬❃➠✤✣❬➢❉❅❁➡✦✥â✩❆➛★➟✷❪➎➝➄➡❸➝✮❪✍✬❺➠ ✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠✿➢❫➧❉ ❝➥❽♠➢✔✧❆➟▼➢✢✵✒➟★✧✺✸❑➝●➧✓❇➸➟✝➛✦✬✒✵✒➟❞✩❆➛★➟✝➧➣✬✱❵✢✩❆➢✔✧❬➝✤✣✿✬✯✩❬➝➉➢✒➡❨➢❫➧✠✩❆➛★➟✴❵❆➛✦✬✯✧✢✬✱❵✢✩❆➟★✧❬➝✤✣❃✩❬➝✤❵è✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠❀➢❫➧☛❉ ✸ ❇➸➟✴❵★✬❫➡Ü❵✰➢✔❪✺✳✵❲✵✩❆➟✩❆➛★➟❁❵❅➛✦✬✯✧✭✬✱❵✢✩❅➟★✧❬➝✤✣❃✩❬➝✤❵❊✣❃❲✙✶✦✣❃✳✦✬✱❵✰➟✹✣➁➢❫➧➹P✐✬❫➡✦✥ ➤✒➟★✩✴✩❆➛★➟②❦✟❛❱❋❸❷ ❢✒❴☛❤✚✩✝❡➥③▼❋✝❛✰❏ ➋❜✬❯❝❵❍❖❝❱✬✵❝❵❛✈❜✝✐✦❤♦❋ ❴☛❜✝❝➥❉▼❜✝❴✸❋✝❴☛❤✚❉✤❜ ❝✓❴❁❋ ❛❇❏✷❜✝❝③▼❋✝❛❇❏✔➍➜➢❫➧☛❉❦❝ ✁ ➡❸➠✮✶❁✩❅➛★➟❉❅✦✧✭✣❃✩✮➢❫➧◆✩❅➛★➟✹✣❬➟ ✰ ✩❆➛★➟❆❵✰➢✱❪✺✳✵❲✵✩✢✬✯✩❬➝➉➢✒➡♠➢■➧♦❵✢✶✵❵❅➠●➝✰❵✽✵✒➟✹❵✢✩❆➢✱✧✭✣ ✰ ❇➜➝●➠●➠✓✶❁➟❴✥❸➟✹✣✛❵✢✧❬➝❀✶❁➟✹✥✇➝➉➡●✩❆➛❸➝✤✣✣❃❲✵❪✺❪❀✬✯✧✿✶✱❝ →☞➟★✩✭✬❺➝❐➠✤✣✷❵★✬■➡❘✶❁➟✝➧①➢✱❲★➡✦✥ ➝➄➡❊➲✮✂✰➳➣❝❤q➡❊✩❅➛★➟❆✣❬➟✺❑✱❲★➟✰➠P✸❲❇➜➟④❇➜➝●➠●➠✠✧❆➟✹✣❃✩✿✧❬➝✤❵✢✩✖✩❆➢✺✩❅➛★➟✒❵★✬✱✣➦➟❉❇➥➛★➟★✧❆➟✼✩❆➛★➟❆❵❅➛✦✬✯✧✭✬✱❵✢✩❅➟★✧❬➝✤✣❃✩❬➝✤❵✾✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠❣➢❫➧ P❶➝✤✣✷✣▲❑✔❲✦✬✯✧❆➟✰➧✽✧❆➟▼➟✝✸

➛★➟▼➡✦❵✰➟☎➟✺❑✔❲✦✬❃➠☛✩❅➢✺✩❆➛★➟✼❪✡➝➉➡❸➝✮❪✍✬❃➠✠✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠❣➢❫➧ P❞❝▼❊✴✖◆P❖◗➅✛◗❘✿♦➅❚❙❊❯★➅✟✸❱✻☎✹❳❲P❨✤➆✂✽Ï➅✟✻✂❩✜❬✂❨✤➆✂✿❭✻✢➆❪❩✙❨❫✸✺✹✟✿♦➅✟❯❫❲

➭✤➟★✩❒➐✔➋✢❴Ô➍☎✶✸➟❴✬✴❪➬➢❑➡❸➝✰❵è✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠❣➢❫➧✸✥❸➟▼➤✱✧❆➟▼➟✰⑤✂❇➜➝✮✩❆➛❁❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣➜➝➉➡●❙✤✶➐✔➋✢❴Ô➍❣➑❵❴ ❚ ❸ ❚✝❿ ➓

⑧ ✇❀❛ ✁ ❆ ✇ ❴✇ ❂

❤➣✩➴➝✰✣✮➟✹✬✱✣❃✶❀✩❆➢✍✣➦➟▼➟✼✩❆➛✦✬✯✩➥➐✔➋✚❴❊➍❣➝✤✣✖✩❆➛★➟✴❵❆➛✦✬✯✧✢✬✱❵✢✩❆➟★✧❬➝✤✣❃✩❬➝✤❵✾✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠ ➢❫➧✠✩❆➛★➟❆✣❬➢ ❁➣❵★✬❃➠●➠➄➟✹✥❊❉✰❋✒❏✍✌ ❜✝❴❲❤♦❋ ❴♠❏✷❜✝✐✦❛▼❤➉t

◆❇❜②➑❝❞❞❞❞❞❞❡

❯ ❯ ❺✺❺✒❺ ❯ ⑥❢❆ ✁✂ ❯ ❺✺❺✒❺ ❯ ⑥❢❆ ➓❯ ✂ ❺✺❺✒❺ ❯ ⑥❢❆

✽❝ ❝ ❝❯ ❺✺❺✒❺ ✂ ⑥❢❆❯❚✝❿ ➓

❣✐❤❤❤❤❤❤❥❂

➭✤➟★✩❒P✡✶❁➟✴✬✔➠●➝➉➡★➟✹✬✯✧✝➢✱✳❁➟★✧✢✬✯✩❆➢✱✧➜➢✢✵✒➟★✧✷❙❁✬❫➡✦✥➁➠➉➟★✩✝➐ ❩ ➋✚❴❊➍✸✥❸➟▼➡★➢✱✩❆➟☞➝✮✩✭✣◗❪✡➝➉➡❸➝✲❪❀✬❃➠◆✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠➣❝♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q ✂❢✧❋❤①➧✷✗➁➝✤✣✼✬★✵✒➟✹❵✢✩❅➢✱✧➥➝➉➡ù❙ ❚ ✸ß✩❆➛★➟❞❪✡➝➉➡❸➝✮❪✍✬❃➠✸✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠❀➢■➧➴P❍✧❆➟✰➠✤✬✯✩❬➝❀✵✒➟✰➠✮✶●✩❆➢❊✗➁➝✤✣✾✩❆➛★➟✔➠➄➢✢❇➜➟✹✣❃✩

✥❸➟▼➤✱✧❆➟▼➟✔➡★➢✒➡✵✟▼➟★✧❆➢✺✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠✘➐❧❦❫➋✚❴❊➍◆✣✫❲✦❵❆➛❡✩❆➛✦✬✯✩➥➐✂❦❫➋❬P✝➍❜✗➎➑❲❯✵❝➼✹Ú

Page 63: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

♦➬✣✙♣✒✗✦q✤✗❀r✢✗✚❡☎q✵✐❁✧ ✫ ✵✒➟✹❵✢✩❆➢✱✧✑✗➎➝✤✣✷❵★✬❃➠●➠➉➟✹✥❊❉ ▲ ❉✺❝❑❤✚❉☞➝●➧❑✬❫➡✦✥r➢✒➡❸➠✮✶r➝●➧➸➐✂❦❫➋✚❴❊➍⑥➑❲➐❞❩◗➋✢❴Ô➍✢❝✁ ➡★➟☎➛✦✬✔✣✖✩❆➛★➟☞➧①➢❫➠●➠➄➢✢❇➜➝➉➡★➤❁✶❜☎❝❞✣❢❡❣✜✤✣★❤❬✂❢✧✁�➸♥✒❢✺❛ ▲ ❝❑❤❥❴❲❢✤❜ ❛❒❋✄✌✙❢✺❛✈❜✝✐①❋✝❛☞P➌✬❦❜✢❡✷❜✪❉ ▲ ❉✒❝❑❤♦❉✡♥✺❢✰❉✺✐①❋ ❛④⑨❤q➡ô✩❆➛★➟✍❵★✬✱✣❬➟✱❇➥➛★➟★✧❆➟✪➐❞❩❊➝✤✣☎➟✺❑✔❲✦✬❃➠✸✩❆➢❡✩❆➛★➟✍❵❅➛✦✬✯✧✭✬✱❵✢✩❅➟★✧❬➝✤✣❃✩❬➝✤❵✴✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠P✸✸✬■➡✦✥✇➝●➧✪✗❚➝✤✣❆✬❡❵✢✶ò❵❅➠●➝✤❵✱✵✒➟✹❵✢✩❆➢✱✧✺✸▲✩❆➛★➟

❪✍✬✯✩✛✧❬➝●✯ ➢❫➧❀P❶➝➄➡❡✩❆➛★➟❉✶✦✬✱✣➣➝✤✣ ➋❜✗✸✳❇P✾✗❁✳❃❂▼❂❄❂❬✳❇P ❚✝❿ ➓ ✗ ➍❣➝✤✣✷✬✺❵✰➢✔❪✺✳✦✬❫➡❸➝➉➢✒➡❁❪❀✬✯✩✿✧❬➝●✯❇❝➭✤➟★✩❇❉ ✶✸➟✷✩❆➛★➟✷❪❀✬✯✩✿✧❬➝●✯➬➢❫➧➞PÕ✬❫➡✦✥â❵★✬❃➠●➠➞◆Õ✩❆➛★➟✾❵✰➢✱❪✺✳✦✬❫➡❸➝➉➢✒➡❀❪✍✬✯✩✿✧➦➝❐✯✡➢❫➧✤➝✮✩✭✣✸❵❅➛✦✬✯✧✭✬✱❵✢✩❅➟★✧❬➝✤✣❃✩❬➝✤❵✖✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠➣❝➜➙➜➛★➟

✳✵✧❆➢✝✶❸➠➉➟★❪ ❇➸➟✷❇✷✬❫➡✌✩✑✩❅➢✝✣❬➢■➠✻✵❑➟✡➝✤✣✝➛★➢✢❇ ✩❅➢❁❵✰➢✱❪✺✳✵❲✵✩❆➟✺✬❊❵✢✶✵❵❅➠❐➝✤❵✱✵✒➟✹❵✢✩❆➢✱✧✼✬✱✣✮➧➣✬✱✣❃✩❆✬✱✣✪✳❁➢✌✣✿✣➣➝❀✶❸➠➉➟✱❝➬❈✵➟✷❇➜➝●➠●➠❑✳✸➟★✧❬➧❹➢✔✧✿❪✩❆➛❸➝✤✣⑧➢✱✳❁➟★✧✢✬✯✩❬➝➉➢✒➡r➝➉➡❁✣❬➟✮✵✒➟★✧✭✬❺➠ ✣❃✩❆➟★✳✦✣⑦✶☛✩❅➛★➟❈❅✦✧✭✣✫✩➸➢❑➡★➟➥➝✤✣❋✩❆➛★➟✼❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡✪➢❫➧❈✩❆➛★➟ ✻ ➛❸➝●➧✽✩ ❁q➊✮➟✹✣✿✣❬➟▼➡✲✶❁➟★✧❆➤✡➧①➢✱✧✿❪➺➢❫➧✗❉ ✸➡★➢✱✩❆➟✹✥❨➶●✸✦✬■➡✦✥❀✩❆➛★➟❆✣❬➟✹❵✰➢✒➡✦✥ ➝✰✣ ❅❁➡✦✥❑➝➉➡★➤ ◆ ➧➆✧❅➢✱❪ ➶ ❝

✂❧✴☎✄ ➇ ❯✝✆ ➇ ✿✟✞✢✸✡✠☞☛❚❯✭❲✼❲❱❯✸➆✍✌ ❯❫✹❄➈✎✞✚✻☎✹✤❩✏☞✜❖❡✒✑❢❡✔✓❃✗❀r✢✗✚❡☎q ✂❢✧✪❧✟❢✺✐☎❉ ❷ ❢❉❜ ❴ ⑤✖✕ ⑤❊❏✷❜✝✐✦❛▼❤➉t➬❋❬③✝❋ ❚❸➋❜❙✸➍④⑨➎⑩✢✬❦❢✒❛✈❢❉❢▼t ❤❧❡✮✐♥❡ ❜➬❏✷❜✝✐✦❛▼❤ t ➶ ❡♠❤✚❏✷❤❥❝❑❜✝❛▲✐①❋ ❉ ❋❬③

✐✚✬❦❢➜③▼❋✝❛✰❏✘✗ ❝❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❞❡

❯ ❯ ✕ ✕ ✕✂ ❯ ✕ ✕ ✕❯ ❯ ✕ ✕ ✕❯ ✂ ❯ ✕ ✕❯ ❯ ✂ ✕ ✕

⑨ ⑨ ⑨ ❺✺❺✒❺ ❺✺❺✒❺✂ ✕ ✕

❯ ✕✂ ✕

⑨ ⑨ ⑨ ❺✺❺✒❺✕

❣✐❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❥

⑩✢✬❦❢☞❏✷❜✝✐✦❛▼❤➉t➥➶ ❤❀❡➜❉✤❜ ❝❥❝❑❢✄✏❉✐✚✬❦❢ ✻ ➛❸➝●➧➆✩ ❁q➊✮➟✹✣✿✣❬➟▼➡✲✶❁➟★✧❅➤✝➧①➢✱✧✿❪ ❋❬③☛❉ ✙ ❂ ● ❂ ③④❋✝❛ ❡✰✬❢❋✝❛▼✐✛✚❑⑨✢✜❀❋✒❏✍✌✿✩✲✐✦❜✝✐✦❤✚❋✝❴r❋❬③➸➶ ❛❍❢✤✣❄✩✲❤♥❛❍❢✉❡✥ ➋✈⑤ ✺ ➍④❢✒❝⑦❢❃❏✷❢✺❴☛✐✦❜ ❛ ▲ ❋ ✌ ❢✺❛✈❜✝✐✦❤✚❋✝❴ ❡✰❤❥❴❊❙✢⑨✏❒✜★❡◗❡✖♣ ✧①→☞➢❁✬✱✣☞➝➉➡♣➷✒✬✯❲✦✣✛✣✼✧❆➟✹✥✌❲✦❵✢✩❬➝➉➢✒➡✟✸✖✶✵❲✵✩❴✣❃✩✭✬❏✧✿✩❬➝➉➡★➤❨➧✽✧❆➢✱❪ ✩❆➛★➟✍✣❃❲✙✶✙❁➣✥❑➝✤✬❫➤✒➢❑➡✦✬❃➠➣❝❁❤ ➧◗✩❅➛★➟★✧❆➟➬➝✤✣ ➡★➢✃➡★➢❑➡✙❁✽✟▼➟★✧❆➢

➟✰➠➉➟★❪➬➟▼➡✌✩➥➝➉➡❊✩❆➛★➟▲❅✦✧✭✣✫✩✑❵✰➢❫➠✮❲✵❪➬➡✟✸✙✶✸➟✰➠➄➢✢❇❛✩❅➛★➟❆✣❃❲✙✶✙❁➣✥❑➝✤✬❫➤✒➢✒➡✦✬❃➠P✸⑤✩❆➛★➟▼➡❁✥❸➢➬➡★➢✱✩❅➛❸➝➄➡★➤⑤❝ ✁ ✩❆➛★➟★✧ ❇➜➝✤✣❬➟✝✸⑤✬✱✣✿✣❃❲✵❪✡➝➉➡★➤❀✩❆➛✦✬✯✩⑧➝✮✩➝✤✣✝❉ ➓✧✦

✽➋➣✳✸➟★✧✿❪✴❲✵✩❬➝➉➡★➤✔➠❐➝➉➡★➟✹✣➴➝●➧ ➡★➟▼➟✹✥❸➟✹✥✸➍✤✸ ➟✰➠❐➝✮❪✡➝➉➡✦✬✯✩❅➟❴✬❃➠●➠✢➡★➢✒➡✙❁✽✟▼➟★✧❆➢✡➟▼➡✌✩✿✧❬➝➉➟✹✣➜➢❫➧❇✩❆➛❸➝✤✣✷❵✰➢❫➠✮❲✵❪➬➡❇❝ ✫ ✩✖✩❆➛★➟❒➟▼➡✦✥r➢■➧☛✩❆➛★➟

✳✵✧❆➢✵❵✰➟✹✣✿✣✮✸✙❇➜➟✝➟▼➡✦✥❭❲✵✳✿❇➜➝✮✩❆➛❁✬✴❪❀✬✯✩✿✧❬➝●✯❨➢❫➧◆✩❅➛★➟❆✬✢✶❁➢✢✵✒➟☞➧①➢✱✧✿❪❁❝➙➜➛★➟❆❵✰➢✞✣✫✩➥➢❫➧✠✩❆➛❸➝✤✣✷✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ➝✤✣❬✵✒➟★✧✿✶❊❵❅➠➉➢✞✣❬➟❞✩❆➢✺✩❆➛✦✬✯✩➜➢❫➧➜➷✒✬❏❲✦✣✿✣➣➝✤✬❫➡❊✧❆➟✹✥✌❲✦❵✢✩❬➝➉➢✒➡✟✸⑤✩❆➛✦✬✯✩⑧➝✤✣ ✥ ➋❍⑤ ✺ ➍✭❝❤➣✩❞➝✤✣✠❵❅➠➉➟✹✬✯✧✺✸✯✩❆➛✦✬✯✩ ❇➥➛★➟▼➡✷❇➸➟✖❵★✬❫➡❉❅❁➡✦✥✴✬✪✳❸➝❀✵✒➢✱✩❬➝➉➡★➤✝➟✰➠➉➟★❪➬➟▼➡✌✩✢➧①➢✱✧⑥➟✹✬✱❵❆➛✴❵✰➢❫➠✮❲✵❪➬➡✟✸✝❇➜➟⑧➟▼➡✦✥✼❲✵✳✷❇➜➝✮✩❆➛✺✬✷❵✰➢✱❪✺✳✦✬■➡❸➝➄➢❑➡

❪✍✬✯✩✛✧❬➝●✯ ❝❀❽✇➢✱✧❅➟❒➤✒➟▼➡★➟★✧✢✬❃➠●➠✲✶✝✸ß✬❫➡✌✶ ✻ ➊ ✻ ❪❀✬✯✩✿✧❬➝●✯❁❵★✬❫➡❘✶❁➟❫❇✷✧❬➝✮✩✿✩❆➟▼➡❁✬✱✣

➶ ➑❝❞❞❞❡➶✴✜✩★ ✦ ✜✩★ ➶✴✜✩★ ✦ ✜✫✪ ❺✒❺✺❺ ➶✴✜✩★ ✦ ✜✩✬❯ ➶✴✜ ✪ ✦ ✜ ✪ ❺✒❺✺❺ ➶✴✜ ✪ ✦ ✜ ✬❝❝❝ ❝ ❝ ❝ ❝❝❝❯ ❺✒❺✺❺ ❯ ➶✴✜ ✬ ✦ ✜ ✬

❣ ❤❤❤❥➋✭✂❫➍

❇➥➛★➟★✧❆➟☎✉ ➝✤✣✷✬■➡r➝➄➡✌✩❆➟▼➤✒➟★✧✾❵★✬❃➠●➠➄➟✹✥❭✩❆➛★➟ ✌ ❜ ❛❍❜❑❏✾❢✒✐✦❢✺❛✔➢❫➧ ➶ ✬❫➡✦✥◗❇➥➛★➟★✧❆➟✝➟✹✬✱❵❅➛♠➶✴✜ß❩ ✦ ✜✮✭⑧➝✤✣✾✬❴❵✰➢✔❪✺✳✦✬❫➡❸➝➉➢✒➡❁❪❀✬✯✩✿✧❬➝●✯❇❝☛❤➐✩❵★✬❫➡❘✶✸➟❴✣❬➛★➢✢❇➥➡❊✩❆➛✦✬❏✩✷✩❆➛★➟✼❪✡➝➉➡❸➝✮❪✍✬❃➠✠✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✤✣✮➢❫➧◆✩❅➛★➟☎➶✴✜ ❩ ✦ ✜ ✭ ✬✯✧❅➟✼✳✦✬❃➝✮✧ ❇➜➝✤✣❬➟❴❵✰➢✔✳✵✧❬➝✮❪➬➟✱❝

➼ ↔

Page 64: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❿✗✴✁� ✹✼✻✂❩ ✸ ➇ ❯✎✆ ☛ ✆ ✞✢✻❊✹✤❩ ✸❱✻ ✸ ➇ ❯✵➅✟✻❧❩ ❬❧❨✤➆✾✿❭✻✢➆ ✞✢✻❊✹✤❩➙➜➛★➟✝❍✒➟★✶r➢❫➧✠✩❆➛★➟❆✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪ ➝✤✣✖✩❆➛★➟ ➧❹➢■➠❐➠➉➢✢❇➜➝➉➡★➤✪➭✤➟★❪â❪✍✬♠➲✰✂❇➳✂❀✣★❤☞❤☎✄❛✂❢✧✪❧✟❢✺✐◗P ❷❞❢✷❜✝❴ ▲ ❷✮❝●❋❄❉✝✆❄✈❍✐✦❛▼❤♥❜✝❴ ❧ ✩❦❝❑❜✝❛✝❏✷❜✝✐✦❛▼❤➉tr⑤☎❤❥✐✚✬✿✐①⑤❣❋❨❷✮❝●❋❄❉✝✆✺❡ ✗

P❶➑✟✞ P✪✜✩★ ✦ ✜✩★ P✪✜✩★ ✦ ✜✫✪❯ P✪✜ ✪ ✦ ✜ ✪✡✠ ❂

❦✢❋✝❛✓③✘➑ ✂✒✳✰✐ s ❝⑦❢✒✐☞☛ ✇ ➋✚❴❊➍❒❷❞❢❉✐✚✬❦❢☎❏✷❤♥❴☛❤✚❏✾❜ ❝ ✌★❋✝❝ ▲ ❴❁❋✒❏✷❤♥❜✝❝❁❋❬③➥P✪✜ ❩ ✦ ✜ ❩ ⑨✍✌❉❡▼❡▼✩❢❏✷❢✎☛ ➓ ❜ ❴ ✏✏☛ ✽ ❜✝❛✈❢✰❛✈❢✺❝❑❜✝✐✦❤✚♥✺❢✒❝ ▲ ✌ ❛▼❤♦❏✷❢❺⑨❧✟❢✺✐✖✗❅✜ß❩➎❷❞❢❘❜Ô❉ ▲ ❉✒❝❑❤♦❉❨♥✒❢❇❉✒✐①❋✝❛➥③▼❋✝❛➬P✪✜ß❩ ✦ ✜ß❩❱⑨❢❧✟❢✒✐✎✑✽❷ ❢◗❡▼✩❢❉⑦✬ ✐✚✬❦❜✝✐✒✑

✽➋✚❴❊➍✓☛

✽➋✚❴❊➍✕✔ ✂✖❪➁➢ò✥✖☛ ➓ ➋✚❴❊➍④⑨❶⑩✢✬❦❢✺❴❣❜

❉ ▲ ❉✒❝⑦❤✚❉✡♥✺❢✰❉✺✐①❋✝❛⑥③▼❋✝❛➥P ❤❀❡ ❧ ❤♦♥✒❢✺❴✃❷ ▲✗➎➑✟✞✘✗ ✜✩★✗✹✜ ✪ ✠

⑤⑥✬❦❢✒❛❍❢ ✗ ✜ ★ ➑✙✑ ✽ ➋❱P✪✜ ★ ✦ ✜ ★ ➍✛✚①➋✓☛ ✽ ➋❱P ➍ ✗ ✜ ✪ ➍✡✜ ✜ ★ ⑥ù✗❅✜ ★✓✢ ❂⑩✢✬❦❢✡❉✰❋✒❏✍✌✤✣✲✐✦❜✝✐✦❤♦❋ ❴✵❋❬③✑✗②❉▼❜✝❴✵❷ ❢✝✏✒❋✝❴❲❢✷❤❥❴ ✥ ➋✈⑤ ✺ ➍ ✎❬❢✺❝✑✏✪❋ ✌ ❢✺❛✈❜✝✐✦❤✚❋✝❴ ❡⑦⑨✴✮➢ ❇❛✣❃❲✵✳✵✳✸➢✞✣❬➟✷❇➜➟❆✬✯✧❆➟✝➤❫➝❀✵✒➟▼➡♠➶ ➝➉➡❁✩❅➛★➟✝➧①➢✱✧✿❪➺➢❫➧➜➋✭✂❫➍✭❝❈❤①➧➸✉ ➑ ✂✝✸❁➶ ➝✰✣✾✬❃➠✮✧❆➟✹✬✱✥✌✶❁✬â❵✰➢✱❪✺✳✦✬❫➡❸➝➉➢✒➡❡❪✍✬✯✩✿✧❬➝●✯❇❝✠❤①➧

✉ ➑Õ✐✙✸✵✩❆➛★➟❞✳✵✧❆➟✹❵✰➟✹✥❑➝➉➡★➤♠➭✤➟★❪✺❪✍✬❀✬✯✳✵✳❸➠●➝➉➟✹✣★❝➥❈Ï➛★➟▼➡②✉✦✥Ï✐✙✸✵✩❆➛★➟★✧❅➟☎➟✰✯❸➝✰✣✫✩✑✩✈❇➜➢✺✣❃✩✿✧✭✬✯✩❅➟▼➤❫➝➉➟✹✣★❝➸➙➴➛★➟❉❅✦✧✭✣❃✩✮➢✒➡★➟✝➝✤✣✾✩❆➢❵✰➢✱❪✺✳✵❲✵✩❅➟✒✬✴❵✢✶✵❵❅➠❐➝✤❵ ✵✒➟✹❵✢✩❆➢✱✧✘➧❹➢✱✧✖✩❆➛★➟✮➠✤✬✱✣❃✩✖✩✈❇➜➢✰✶❸➠➉➢ò❵❅❍✵✣✮✸✌✧❆➟★✳❸➠✤✬✱❵❅➝➉➡★➤✍✩❆➛★➟✹✣➦➟④✶❸➠➉➢✵❵❆❍✵✣❬✶✌✶✍✬❆❵✰➢✱❪â✳✦✬❫➡❸➝➉➢✒➡❊❪✍✬✯✩✿✧➦➝❐✯✟✸✵✬❫➡✦✥✣❬➢➬➢❑➡✟✸✵❲★➡✞✩➦➝❐➠❈✩❆➛★➟❉❇➥➛★➢❫➠➉➟❆❪❀✬✯✩✿✧❬➝●✯r➝✰✣✾❵✰➢✱❪✺✳✦✬■➡❸➝➄➢❑➡❇❝❀➙➜➛★➟❆✣❬➟✹❵✰➢✒➡✦✥❚➢✒➡★➟☞➝✤✣✷✩❅➢✍✣❃✳❸➠●➝✮✩➹➶ ➝➉➡❁✩❆➛★➟☞➧①➢✱✧✿❪➺➢❫➧

✞ ➶❄✜✩★ ✦ ✜✩★ ➶✴✜✩★ ✦ ✜✫✪❯ ➶✴✜ ✪ ✦ ✜ ✪✧✠➋❱✐❸➍

✣❃❲✦❵❅➛ù✩❆➛✦✬✯✩✼✩❅➛★➟✍✣➣➝✮✟▼➟✹✣✝➢❫➧❒➶✴✜ ★ ✦ ✜ ★ ✬❫➡✦✥✵➶✴✜ ✪ ✦ ✜ ✪ ✬✯✧❅➟➬❍✒➟★✳✵✩✼❲★➡✦✥❸➟★✧❴❵✰➢❑➡✞✩✿✧❅➢❫➠➣❝✪➙➜➛★➟✹✣❬➟❀❵★✬❫➡✂✶❁➟❊❵❆➛★➢✞✣➦➟▼➡ ✣❃❲✦❵❅➛ù✩❆➛✦✬✯✩➟✰➝✮✩❆➛★➟★✧☎➶✴✜✩★ ✦ ✜✩★❀➝✤✣✾✬✍✣➣➝➉➡★➤❫➠➉➟✺❵✰➢✱❪✺✳✦✬■➡❸➝➄➢❑➡✎✶❸➠➉➢✵❵❆❍✇➢❫➧✸✣➣➝✮✟▼➟✩★Ï✐✝⑤✫✪✙❥➁➢✱✧❈✶✸➢✱✩❆➛❁❪❀✬✯✩✿✧❬➝✤❵✰➟✹✣✮➛✦✬✺✵❑➟❴✣➣➝✮✟▼➟ ✆❲✐ ⑤☞✪✯❥✵❝➸➙➴➛❸➝✰✣➠➉➟✹✬✱✥✵✣❞✩❆➢❊✩✈❇➜➢❁✥❸➟★✩❆➟★✧✿❪✡➝➉➡❸➝✤✣❃✩❬➝✤❵❊✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪✍✣★❝❨➙➜➛★➟✷❅✦✧✭✣✫✩☎➢✒➡★➟✡➝✤✣➹➝✲✩❅➟★✧✭✬✯✩❬➝❀✵✒➟❊✬❫➡✦✥②➛✦✬✱✣❞❵✰➢✞✣❃✩ ✥ ➋❍⑤ ✺ ❸❆⑤ ✽ ✉ ✽ ➍ ✂❈✩❆➛★➟✣❬➟✹❵✰➢✒➡✦✥r➢❑➡★➟➥➝✤✣❋✧❆➟✹❵✢❲✵✧✭✣➣➝❀✵✒➟❆✬■➡✦✥➬➛✦✬✱✣✖❵✰➢✞✣✫✩ ✥ ➋✈⑤ ✺ ➍✭❝⑥❈✵➟☞➡★➢✱✩❆➟✾✩❆➛✦✬✯✩⑧➢✒➡✝✬✒✵✒➟★✧✢✬❫➤✒➟✝✸✱✩❅➛★➟✑✳✦✬✯✧✢✬✯❪➬➟★✩❆➟★✧➜✉➺➝✤✣ ✥ ➋①➠➉➢✒➤✓⑤❞➍✭❝✫ ➠❐➠ß✩❆➛★➟✹✣❬➟✑✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪✍✣✘➛✦✬✺✵❑➟❈✶❁➟▼➟▼➡➁➝✮❪✺✳❸➠➉➟★❪➬➟▼➡✞✩❅➟✹✥✡➝➉➡✭✬✯✮✱✰♦❡✘❤ý✬❫➡✦✥✡➤❫➝❀✵✒➟❈✵❑➟★✧✿✶✡➟▼➡✦❵✰➢✱❲✵✧✭✬❫➤❫➝➉➡★➤❞✧✿❲★➡★➡❸➝➉➡★➤❴✩➦➝✲❪➁➟✹✣★❝

✲❊✴✴✳✖✻❊✹✤❩✙❨✘◗ ✌❧❨✘❲❱❯❫❲♦✖✵✙♣✘✰✦q✶✰❀r☞✰✚❡☎qù❥✸✷➜➭✤➟★✩✎✹❄✶✸➟❆✬▲❅❁➡❸➝✮✩❆➟✝➟✰✯✵✩❆➟▼➡✦✣➣➝➉➢✒➡❨➢❫➧☛✥❸➟▼➤✱✧❅➟▼➟✰⑤❨➢❫➧☛❙ß❝✻✺☞➡✪➟✰➠➉➟★❪➬➟▼➡✌✩✑■❊❘✼✹ ➝✤✣❉❴✸❋✝❛❇❏✷❜✝❝✸➝●➧✸✬❫➡✦✥

➢✒➡❸➠✮✶r➝●➧ ✹Ò➑✾✽❣➟✹❵✢✩✤❼❃➋❜■⑧✳✭■ ❃ ✳✢■ ❃ ✪ ✳❄❂❃❂❄❂❆✳✢■ ❃ ■❀✿ ★ ➍❇❂❤①➧✸■Ó➝✤✣➥➡★➢✔✧✿❪✍✬❃➠P✸✌✩❆➛★➟▼➡✵➋❃■❀✳✢■ ❃ ✳✢■ ❃ ✪ ✳❄❂❃❂❄❂❬✳✭■ ❃ ■✡✿ ★ ➍❣➝✤✣✾❵★✬❃➠●➠➄➟✹✥❡✬❘❴❁❋ ❛❇❏✷❜✝❝❣❷ ❜✗❡♠❤❧❡➋❝❁✾✣➣➝➉➡★➤ ✬✇➡★➢✱✧✿❪❀✬❃➠④✶✦✬✱✣➣➝✤✣✔➝✤✣â✳✦✬✯✧✿✩❬➝✤❵✢❲❸➠✤✬✯✧❬➠✮✶ ❲✦✣❬➟✰➧✽❲❸➠❉❇➥➛★➟▼➡ý❵✰➢✱❪✺✳✵❲✵✩❬➝➉➡★➤❢✳❁➢✢❇➜➟★✧✭✣✡➢❫➧✝➟✰➠➉➟★❪➬➟▼➡✌✩✭✣✮✸✖✣➣➝➉➡✦❵✰➟Ü✩❅➛❸➝✰✣✍➝✰✣✧❆➟✹✬✱✥❑➝●➠✮✶❁✥❸➢✒➡★➟❫✵✒➝✤✬✺✬✺❵✢✶✵❵❅➠●➝✤❵❴✣➦➛❸➝❐➧✽✩❄✶

➋✓❂ ✁ ✳❃❂ ➓ ✳❃❂❄❂❄❂❅✳❃❂✔❚✝❿ ➓ ➍ ❃ ➑Õ➋✓❂✔❚✝❿ ➓ ✳❃❂ ✁ ✳❄❂❃❂❄❂❬✳❃❂✔❚✝❿ ✽ ➍❇❂❽✇➢✱✧❆➟▼➢✢✵✒➟★✧✺✸⑦➝✮✩❣➝✤✣⑧➟✹✬✱✣❃✶❞✩❆➢❆❵✰➢✒➡✦✣❃✩✿✧✛❲✦❵✢✩❑✬✾❪✴❲❸➠✮✩❬➝✮✳❸➠❐➝✤❵★✬✯✩➦➝➄➢❑➡❊✩✭✬✢✶❸➠➉➟➜➧①➢✱✧✸❙✷✶✌✶❴✳✵✧❅➟✹❵✰➢✱❪✺✳✵❲✵✩❬➝➉➡★➤❆✩❅➛★➟✯❑✱❲✦✬■➡✞✩❬➝✮✩❬➝➉➟✹✣❋■✘✕❆■ ❃ ❩➧①➢✱✧✑✬❃➠●➠ ③✛❝◗❈Ó➟❆❵★✬❫➡Ü✣❬➟▼➟✼✩❅➛❸➝✰✣✾✬✱✣⑧➧①➢❫➠●➠➉➢✢❇✑✣★❝❣❈ù✧➦➝✲✩❅➟

▼✮➑❅❄ ❚ ❿ ➓⑧ ✇❀❛ ✁ ❂ ✇ ■ ❃❩❇❆ ❄ ❚ ❿ ➓⑧ ✇❀❛ ✁✱❈ ✇ ■ ❃

❩❇❆ ➑❉❄ ❚✝❿ ➓⑧ ✇ ❛ ✁ ▼ ✇ ■❃ ❩❊❆ ❂

➙➜➛★➟▼➡●▼ ✁ ➑❆❋ ✁ ➋✓❂✸✳ ❈ ➍⑥➝✤✣✷✬✷✶❸➝●➠●➝➉➡★➟✹✬✯✧❴✣❃✶✌❪✺❪➬➟★✩✛✧❬➝✤❵✮➧❹➢✱✧✛❪❁❝✻❁✑✣➣➝➉➡★➤❊▼ ❃ ■❀✿★ ➑✙❂ ❃ ■❀✿ ★ ❈ ❃ ■❀✿

★ ❇➜➟❆✥❸➟✹✥✌❲✦❵✰➟❆✩❆➛✦✬✯✩➋✓❂ ➓ ■❘❸❋❂

✽■ ❃ ❸❻❺✺❺✺❺❅➍❆➋ ❈ ➓ ■ ❸ ❈ ✽ ■ ❃ ❸❻❺✺❺✺❺❅➍❣➑ ▼ ➓ ■ ❸❻❺✒❺✺❺

➼✹➼

Page 65: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➢✱✧✼▼ ➓ ➑✕❋ ✁ ➋✓❂✁�❢✳ ❈ �❫➍❬❇➥➛★➟★✧❆➟✄✂❢✥❸➟▼➡★➢✱✩❆➟✹✣✪✩❆➛★➟❴✣❬➛❸➝●➧✽✩✝➢✱✳❁➟★✧✢✬✯✩❬➝➉➢✒➡❇❝➥❈Ó➟❄✣➦➟▼➟❆✩❆➛✦✬✯✩✼❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❁✬❺➠❐➠✸▼ ✇ ❭✏✣➜➡★➟▼➟✹✥✵✣☞➢✒➡❸➠✮✶➢✒➡★➟✼❪✍✬❏✩✿✧❬➝●✯ ➢✔✳❁➟★✧✭✬✯✩➦➝➄➢❑➡✟✸❸➧❹➢■➠❐➠➉➢✢❇➜➟✹✥❘✶✌✶✝❵✰➢❑➡✯♥❜❲★➤✞✬❏✩❬➝➉➢✒➡❇❝❤➣✩➴➝✰✣✮➟✹✬✱✣❃✶❀✩❆➢✺✣❬➟▼➟❞✩❆➛✦✬✯✩❄✶✏✆☎❖❡✒✑❢❡✔✓ ✰❀r☞✰✚❡☎q✵✐✸✷✪❧✟❢✺✐✞✝❊✶★✱✠✟ ➽ ✱ ❃ ✏ ❢✺❴❁❋ ✐✦❢ ✐☛✡❦❢➎❦✘❛❬❋❢❷❞❢✺❴❲❤❇✣ ❡✰❜✘✣✲✐①❋✒❏✡❋✝❛ ✌☞✡❦❤❧❡④❏➬⑨ ⑩✌✡❦❢✺❴❡■ ❤❧❡✰❴❁❋ ❛❇❏✷❜✝❝☎❤ ③✾❜✝❴ ✏

❋✝❴❲❝ ▲ ❤ ③✑■✬❤❧❡✰❜❨❉ ▲ ❉✺❝❑❤✚❉☎♥✒❢❇❉✒✐①❋✝❛⑥③④❋ ❛✍✝❀⑨❁✾✣➣➝➉➡★➤ ✩❆➛★➟●✧❆➟✹✣✫❲❸➠✲✩✢✣➬➢❫➧❆✩❅➛★➟❁✳✵✧❆➟✹❵✰➟✹✥❑➝➉➡★➤ý✣❬➟✹❵✢✩❬➝➉➢✒➡✦✣✉✸✑✬❫➡✦✥ ➡★➢✱✩❬➝➉➡★➤ ✩❅➛✦✬✯✩✍✩❅➛★➟❁❪✡➝➉➡❸➝✮❪✍✬❃➠❆✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠➹➢❫➧✎✝❲➝✰✣❴ ❚ ⑥ ✂✝✸✵✩❆➛✦✬✯✩⑧➝✤✣✾✣▲❑✱❲✦✬❏✧❆➟✰➧➆✧❅➟▼➟☞➧❹➢✱✧ ➋❍⑤⑥✳✚❆✤➍⑥➑ ✂✝✸✙❇➜➟✝➤✒➟★✩❜☎❝✫✵❢❡✞☎✶✵★❤❥✐✸✷✑✏❘❢❨❉▼❜✝❴ ✎❬❴ ✏ ❜✎❴✸❋✝❛✰❏✾❜ ❝✓❢✺❝❑❢❃❏✾❢✒❴☛✐❈❤♥❴ ✏✝❢✒✐✦❢✺❛✰❏✾❤♥❴☛❤❧❡✮✐✦❤♦❉◗✐✦❤♦❏✷❢ ✥ ➋❍⑤ ✺ ❸❻⑤ ✽ ➠➉➢✒➤✝❄❑➍ s ⑤✒✡❦❢✒❛❍❢❘✐☛✡✲❢❝❑❜✢❡✮✐✓✐✦❢✺❛✰❏❙❜✒❉✰❉✰❋✘✣❦❴❲✐♥❡❣③④❋ ❛✰✐☛✡❦❢✡❉✰❋✒❏✍✌✤✣❦✐✦❜ ✐✦❤♦❋✝❴Ó❋❬③✾❜r❏✷❜✝✐✦❛✤❤ t ❛✈❢ ✌ ❛❍❢✉❡♠❢✒❴☛✐✦❤♥❴ ❧ ✝❀⑨➙➜➛❸➝✤✣✪✧❆➟✹✣❃❲❸➠✮✩☞➝✮❪✺✳✵✧❆➢✢✵✒➟✹✣✪❲✵✳❁➢✒➡✇➟✹✬✯✧❬➠●➝➉➟★✧✼✧❆➟✹✣❃❲❸➠✮✩✭✣▲✶✌✶❘✵✒➢✒➡❊✟★❲✵✧✔➷✒✬✯✩❆➛★➟▼➡●✬❫➡✦✥②➷✮➝➉➟✹✣✈✶✵✧❆➟✹❵❅➛✞✩❉❇➥➛★➢➁➤✞✬✒✵✒➟❆✬✺✳✵✧❅➢✝✶✦✬✢❁

✶❸➝●➠●➝✰✣✫✩❬➝✤❵❊✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ➝➉➡ ✥✔✓ ➋❍⑤ ✽ ➠➉➢✒➤ ❄❑➍✝➋➣❲✦✣❱➝➄➡★➤r➧➣✬✱✣❃✩✼✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠❑❪✴❲❸➠✮✩❬➝✮✳❸➠●➝✰❵★✬❏✩❬➝➉➢✒➡✤➍✝➢✱✧ ✥ ➋❍⑤ ✺ ➠➄➢❑➤ ❄❑➍❈❇➜➝✮✩❆➛★➢✱❲✵✩☞➧➣✬✱✣❃✩❪✴❲❸➠✮✩❬➝✮✳❸➠❐➝✤❵★✬✯✩➦➝➄➢❑➡✟✸❇✬❫➡✦✥❁✬✺✥❸➟★✩❅➟★✧✿❪✡➝➉➡❸➝✤✣❃✩❬➝✤❵✴✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪❬✧✛❲★➡★➡❸➝➄➡★➤➁➝➉➡❁✩❬➝✮❪➬➟ ✥ ➋❍⑤ ✾ ❸❵⑤ ✽ ➠➉➢✒➤✝❄❑➍✭❝❤➣✩➴➝✰✣✪✳❁➢✌✣✿✣➣➝❀✶❸➠➉➟❴✩❅➢❴✩✛✧❆➟✹✬✯✩✑✬❃➠➉➢✒➡★➤â✩❆➛★➟❆✣✿✬✯❪➬➟☞➠●➝➉➡★➟✹✣✾✩❆➛★➟❆❵★✬✱✣➦➟❉❇➥➛★➟★✧❆➟✾⑤✇➑ ❆ ❼ ❝♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④

⑥⑧⑦❃⑨✷➾✸❷✔➝✹❶✹➏♦❼➆➅✖➂★➌✱❹⑧❺✿❸✮❿❇➂➍➌✞➄❆➚✠➂➍➪❆❹⑧❶✹➌è❼➆➎ß➂★❷✱❸✮❿✛❾★➒ ✙✠➩ ➱✤Ð ➦✷➥❃➤★❐❋❒ ✃❅➱ ❰ ➱ ➨s➤★➩✺➤ ✕ ❐✾➨✮➩✱➨✮❐✼❰★❮✯❒✱➤★❮ ✂★➩✞➤★❐✾➨✤❰★❮✖✕ ➥ ✂✹➥✿❮❱➨✤➥ ✝★➦❃➥ ➱ ➤★➢❃➭❑❰➍➩✞➧ ➱sÐ ➦✦❇➢❜➤❅Ò❜➦✛➩✱➨ ✃ ➭ ✕ ➤➍➢✿❐✑❾➍➒❁➓✠❺✿→➐❺✭➂★❻❃➙➣↕❀➓✠❺✿➔✌❶✹❻➐➏✸➌ ê ➴ þ✹þ ➽✱➀❅➠➣ñ✸➓♦➠✽➾✑➀✯➾✸❷✔➝✹❷✱→➐➏ ➶✭➹✹➹❅÷ ❾

⑥➇➴✢⑨✑ø✖❹⑧❺✿→➐Þ✱❻➣❺✭➙➐↕✯➏✺❼✽➑✺➂★❻➐õ ✣ù❹⑧❸⑧❸⑧❹✮➂★➪❆❿✿❾✔➒✄ü✷➦❜❰➍➢✿❮ ✂❀➤❃❒ ➱ ➨✮❐✼❰★❮✖❰★❮➇➫✹➤★➢✛➨ ➱✤Ð ❐✷➭ ✕ ➤★➢✺➥❃❰★➩✞➤➍➩✱➨✤➥❃❰★❮✖❐✼❰ ➱ ➢✿➨ ☎ ✕ ➤➍➢✿❐✪➭✫❾❯➒ ➎ß↕✞➅ ➏➣↕✱❺✛→➣❹⑧→✭➀× ➌✔❹➉➊❅❺✿❻➣→➐❹⑧➏✽➜✼❶★↔❇Ôß❶✹❻➣❶❅➌✯➏➣❶✞➀ ➶✭➹❅➹✹÷ ❾⑥➇Ú✢⑨✑➁✵❹✮➄✯❸✪❼➆➓♦❷✞➄✯❶✹❸❱↔✿❿✼➂★➌✞➄ùñ♦❹⑧❺✭➄✯❺✿❻➐❻➣❺✿❹⑧➏➣❺✛❻❊❼ ✘ ➂★❻❜➂➍❸✮➄✱❿✿❾ ➒ ✦❇➨✮➩✱➨ ➱ ➦✝✦❇➨✤➦✛❮➉➧➋➭✿❾ß➒ ➾✖➄✱➄✯❹⑧→➣❶❅➌✯➞ ✣❊❺✛→➣❸⑧❺✿➜✯➀ ➶✢➹✹ä❅÷ ➀ ➮ ➩✌➥✄✂✹➥✛❮➉➤✫❒❏➦❃➧★➨s❰Ü➤ ✕á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨s➥❃➭✑❰★➩✌➧✼➨ ➱ ➭✸➳✠❒✹❒✌❮✏➨✤➥❃❰ ➱ ➨✤➤➍➩✯➭✿➀✯➊✹❶❅❸➆❾✯➴ þ ❾

⑥ ✗★⑨✑➑✺➙✿î ❸➉❹⑧❺✭➙✫❺✷❼➆➓♦❶✹Þ✌❺✿❻➣➏❃❿✿❾❅➒ ✦❇➨✮➩✱➨ ➱ ➦✙✘☛➦✛❮➉➧✢➭ ✕ ➤★➢✖➥❃➤★❐❋❒ ✃❅➱ ➦✛➢❋➭✭➥✿➨✤➦✛➩ ➱ ➨⑧➭ ➱ ➭❑❰➍➩✞➧❆➦✛➩✯➫★➨✮➩✞➦❃➦✛➢❃➭✿❾★➒✍í❋❸⑧❷✙Ý❈❺✿❻❈➾❑➙✿➂❅➄✯❺✿➪❞❹✲➙✠➎ ❷✱Þ✱❸⑧❹⑧→➣↕✱❺✿❻➐→✭➀➶✭➹❅ä✹ä ➀✛✚✷❮ ✃✢✜ ➦✛➢✖➨✮➩ ➱ ➦✿➢✛➩✞❰ ➱ ➨✤➤★➩✌❰★❮✵➭✭➦✛➢✿➨✤➦✫➭❑➨✮➩❀➦✿➩✯➫★➨✮➩✞➦❃➦✛➢✿➨✮➩✯➫❆❰★➩✌➧❴➥❃➤➍❐✸❒ ✃✹➱ ➦✛➢✸➭✭➥✛➨✤➦✛➩✞➥❃➦✿❾

⑥➇➼✢⑨✑➑✴❺✿➌✔❺✿➃✿❺✿→✾❼✤➾❋❸❱↔✤❻➣❺✭➄❞Û✌❾ ❿✛❾❅➒❭➳♦❒✹❒✌❮✏➨✤➥❃❰ ➱ ➨✤➤➍➩✯➭✑➤ ✕ ✦❇➨✮➩✱➨ ➱ ➦ ✦❇➨✤➦✛❮➉➧➋➭✿❾✯➒❁í✸❸⑧❷✯Ý❈❺✿❻✠➾❑➙✿➂❅➄✯❺✿➪❞❹✲➙❋➎ß❷✱Þ✱❸⑧❹⑧→➣↕✔❺✿❻➣→✢➀ ➶✭➹❅➹✹÷ ❾⑥➇➽✢⑨✑➈❋➃✿❺✿❸⑧❸⑧❶✼❼➆➎ß➂➍➏➣❻➣❹✮➙➐õ✱❿✿❾✢➒ù➵☛❰➍❮➉➥ ✃ ❮✌➦ ☎ ❰✹➥ ➱ ➧✹➦✫➭ ✕ ➤★➢✿❐✼➦❃➭✸➧✹➦✪é✙➤➍➢❜➧❅❰★➩❴➦ ➱ ➧✹➦ ✦❇➢❃➤✹Ò❃➦✿➩✔➨ ✃ ➭❑➧✵➸ ✃ ➩✞➦✖❐✼❰ ➱ ➢✿➨✤➥❃➦✛❾✢➒❴Ô✠↕✦Ö❺✿→➣❺✹➀ × ➌✱❹⑧➊✹❺✿❻➐→➣❹⑧➏✱Ø❺

å✱➙❃❹⑧❺✿➌✯➏➐❹✏➛✵à✹❷✔❺❑Ôß❺✭➙➐↕✱➌✔❶✹❸⑧❶✹➝❅❹✲à❅❷✱❺❋❺✿➏✸➑❢Ø❺✭➄❏❹✲➙✛➂★❸⑧❺✷➄✯❺✑ø✖❻➐❺✿➌✱❶✹Þ✔❸➉❺❅➀ ➶✭➹✹ä❅ö ❾⑥➇ã✢⑨✷➊✹❶❅➌✷➃✿❷✱❻❇ø✷➂➍➏➣↕✱❺✛➌✼❼✤Û✌❾ ❿ß➂➍➌✞➄✷ø✖❹⑧❺✿→➐Þ✱❻➣❺✭➙➐↕✯➏✠❼✽➑❊❾➇❿✿❾✛➒✒➚❈❶✹➌✔→➣➏➣❻➐❷✞➙❃➏➐❹➉➌✔➝❑➌✔❶✹❻➣➪✴➂★❸❅Þ✞➂★→➐❺✿→ß❹➉➌◗➛✞➌✱❹⑧➏➣❺▲➛✞❺✿❸✮➄✯→✢❾✞é✯➤ ✃ ➢✿➩✞❰➍❮❏➤ ✕ ➲☞✂★❐✼Ò❜➤➍❮✏➨✤➥

➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨✤➤★➩✔➀✯➊✹❶✹❸✽❾✵⑦ þ ➀ ➶✭➹❅➹✹ì ➀✹➔✱➔⑤❾✞➼✣✗✯ã✢➒✱➼✹ã þ ❾

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Page 66: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✏☎✠ ✌✲✄✝✆✂✁✝☞✚✠✁�✄✂✰✆✂✄ ✑☛✠✓✆✟✞✕☞✍✠☎✄P✏❚✓ ✕ ✞✘✁ ✏❉☞✢✠✓☞ ✄ ✞ ✏❉☞✚✞✵✄✚✡ ✏✥✱✩✢✪ ✣P✭❱✦✆☎❪✩ ✪ ✩✢✜✤✣✍✛❁✮➡❸➝❀✵✒➟★✧✭✣➣➝✮✩❃✶❨➢❫➧❀➙✢➢✔✧❆➢✒➡✌✩❆➢✼✱✬❫➡✌❲✦✬✯✧✿✶❨✐✱❥✙✸▲✂✺✹✝✹✒Ö

➲✏✣❃❲✵❪✺❪✍✬❏✧✿✶★✶✌✶ ✮➜➟★✶❸➡✦✬❃➠✤✥②➭✤➟★✧✭❵❅➝➉➟★✧❆➳➭✤➟★✩ ❄❚➑ ❆✞✝❾❇➥➛★➟★✧❆➟P❆✇➝✰✣❞✬❀✳✵✧❬➝✮❪➬➟✍✬❫➡✦✥Ó✉ ❘♣Ð✠✟✉✸✸➠➄➟★✩ ☛●✶❁➟✍✬❀❪➁➢✒➡❸➝✤❵✴❲★➡❸➝❀✵✙✬✯✧❬➝✤✬✯✩❅➟✍✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠➸➢❫➧✷✥❸➟▼➤✱✧❆➟▼➟

⑤Ó➝➉➡ ❁✵❃❫➲ ❴②➳ ✂ß✩❆➛❸➝✤✣✼✩✢✬❃➠➉❍ ✣✫❲✵✧ ✵✒➟★✶✵✣✝❍❸➡★➢ ❇✮➡ ✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪✍✣è✩❆➢◗❅❁➡✦✥●✩❆➛★➟✍❵✰➢✔❪✺✳❸➠➉➟★✩❆➟➬➧➣✬✱❵✢✩❆➢✔✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡❋☛ ➑ ☛☛✡ ★➓ ❺✒❺✺❺ ☛ ✡✌☞➩❇➥➛★➟★✧❆➟✪✩❆➛★➟✯☛ ✇ ❭✏✣✸✬❏✧❆➟✷❪➬➢✒➡❸➝✤❵✷✥❑➝✤✣❃✩➦➝➄➡✦❵✢✩➴➝✲✧✛✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➄➟❞✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✤✣✷✬❫➡✦✥✽❇➥➛★➟★✧❆➟✎✍ ✇ ❘ Ð✠✟ ➧❹➢✱✧❬③❣❘②➒✞✂❑✳❄❂❄❂❃❂❬✳ ❈❑→✱❝ ➙➴➛❸➝✰✣✳✵✧❆➢✝✶❸➠➉➟★❪ ✳❸➠✤✬✹✶✵✣❀✬❫➡ ➝✮❪✺✳✸➢✱✧✿✩✭✬❫➡✌✩✺✧❆➢■➠➄➟❚➝➉➡❆✵✯✬✯✧❬➝➉➢✱❲✦✣✽❅❁➟✰➠✤✥✵✣➁➠❐➝➉❍✒➟ù❵✰➢✱❪â✳✵❲✵✩❆➟★✧✝✬❺➠➄➤❑➟✮✶✵✧✭✬✙✸✷❵✢✧✿✶✌✳✵✩❆➢✒➤✱✧✢✬✯✳★➛✞✶✝✸⑧➡✌❲✵❪✾✶✸➟★✧✩❆➛★➟▼➢✱✧✛✶✝✸✦❵✰➢ò✥❑➝➉➡★➤❀✩❆➛★➟▼➢✱✧✿✶✝✸✤❂❃❂❄❂✴❞➝✮✧✭✣❃✩✺✸ ❇➜➟❀✳✵✧❆➟✹✣❬➟▼➡✌✩✺✩❆➛★➟❀❪✍✬❃➝➉➡❊➝✤✥❸➟✹✬✱✣✷✶❁➟▼➛❸➝➉➡✦✥♣➫❀➟★✧➦➠➄➟▼❍✯✬✯❪✺✳✟❭✏✣â✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ➋ ✻ ➟✹❵✢✩❬➝➉➢✒➡❛✂❫➍✭❝②➙➜➛★➟▼➡✟✸ ❇➸➟r➤❫➝❀✵✒➟❊✬

➤✒➟▼➡★➟★✧✭✬❺➠✢➧ ✬✔❵✢✩❆➢✱✧❬➝➉➡★➤✺✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪✐❵✰➢✱❪✺✳❁➢✌✣❬➟✹✥❨➢❫➧❈✩❆➛✵✧❆➟▼➟❆✣❃✩✭✬■➤✒➟✹✣✮➋❜✣▲❑✔❲✦✬✯✧❆➟✰➧✽✧❆➟▼➟✝✸✦✥❑➝✤✣❃✩❬➝➉➡✦❵✢✩ ❁➣✥❸➟▼➤✱✧❅➟▼➟❴✬❫➡✦✥❚➟✺❑✱❲✦✬❃➠❀❁➣✥❸➟▼➤✱✧❅➟▼➟➧➣✬✱❵✢✩❆➢✱✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡✤➍✰❇➥➛❸➝✤❵❆➛ ✳✵✧❅➢ ✵❑➝✤✥❸➟✹✣✍✬✃➧➆✧✭✬❏❪➬➟✮❇➜➢✱✧❆❍✇➧❹➢✔✧✍✣❬➟✮✵✒➟★✧✭✬❺➠➴➢✔✩❆➛★➟★✧✺✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪✍✣ ➋ ✻ ➟✹❵✢✩❬➝➉➢✒➡❲✐❖➍✭❝ ✴❞➝➄➡✦✬❺➠❐➠✮✶✝✸❬❇➜➟➢✱❲✵✩❬➠●➝➉➡★➟✷✶❁➟✹✣❃✩✮❍❢➡★➢✢❇➥➡❁✬✱✣✫✶✞❪✺✳✵✩❅➢✱✩❬➝✤❵✼❵✰➢✱❪✺✳❸➠➉➟✰✯❸➝✲✩❃✶✝✸ß❵✢❲✵✧✿✧❆➟▼➡✌✩❈✶❁➢✔✩✿✩❬➠➉➟▼➡★➟✹❵❆❍✵✣✾✬❫➡✦✥❀✧❆➟✹❵✰➟▼➡✌✩✷✧❆➟✹✣❃❲❸➠✮✩✭✣ ➋ ✻ ➟✹❵✢✩❬➝➉➢✒➡●❥❸➍✭❝➙❞➢❆❵✰➢✱❪✺✳✦✬✯✧❆➟✖✩❆➛★➟✹✣➦➟◗✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪✍✣✮✸✔✩❆➛★➟✖❲★➡❸➝✮✩❑❵✰➢✞✣❃✩☎❇➴➝❐➠●➠ ✶❁➟✷❪✴❲❸➠✮✩❬➝✮✳❸➠●➝✰❵★✬❏✩❬➝➉➢✒➡r➝➉➡ ❁ ❃ ❝❣❽✇➢✱✧❆➟▼➢✢✵✒➟★✧✺✸❅✩❆➛★➟✷✬✯✧❬➝✮✩❆➛✵❪➁➟★✩❬➝✤❵

❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❆➟✹✥❚➝✤✣⑧➧➣✬✱✣❃✩➜➧①➢✱✧✖✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠✸✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪✍✣✷✬❫➡✦✥❡❵❅➠✰✬✔✣✿✣➣➝✤❵★✬❃➠✢➧①➢✱✧➜➠●➝➉➡★➟✹✬✯✧✼✬❃➠➉➤✒➟✮✶✵✧✭✬✵❝✏☎❡✟r ✄✙r☞✰♦❡✖q ✷⑧➙➜➛✵✧❆➢✱❲★➤❑➛★➢✱❲✵✩✷✩❆➛★➟❆✣❃❲✵❪â❪✍✬✯✧✿✶✝✸✲❇➜➟☞➠➉➟★✩ ✥✒✑ ➋P⑤❞➍❀➑ ✥ ➋❍⑤✮➠➉➢✒➤ ❼ ➋❍⑤❞➍❆➍✓❇✮➛★➟★✧❆➟❆❙r➝✤✣✷✬✺❵✰➢❑➡✦✣❃✩✭✬❫➡✌✩✹❝

✳✘✴✔✓P❯✭✹✟◗❭❯✖✕ ❨☎❩✜❬ ❨✘◗ ➈✘✻☎✹❳✿❭✸ ➇ ❩➫⑧➟★✧❬➠➉➟▼❍✙✬✯❪â✳✟❭✏✣⑧➝✤✥❸➟✹✬✱✣✝➲✮✂✰➳✸➠➉➟✹✬✱✥❀✩❆➢✺✬❫➡r➟✰❾✝❵❅➝➉➟▼➡✞✩✾✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ✩❆➢✔➧➣✬✱❵✢✩❆➢✱✧❬➝✮✟▼➟✼✬❞✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠ ☛ ❇➜➝✮✩❆➛r➡★➢✴✧❆➟★✳❁➟✹✬✯✩❅➟✹✥

➧➣✬✱❵✢✩❆➢✱✧✭✣➍❝ ➭➞➟★✩➎↕ ✶❁➟❀✩❆➛★➟✍✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠✷✧❬➝➉➡★➤ ❁✵❃❫➲ ❴②➳ ✪✒➋✓☛❞➍✷✬❫➡✦✥❊↕ ✇ ✶✸➟✍✩❅➛★➟✺✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✑✧➦➝➄➡★➤✌✣ ❁✘❃❫➲ ❴✃➳ ✪✒➋✓☛ ✇ ➍❒➧①➢✱✧③❣❘②➒✌✂✒✳❄❂❃❂❄❂❬✳ ❈❑→✝✸✵✩❆➛★➟▼➡

↕✘✗❲↕ ➓ ✕❹❺✒❺✺❺ ✕✃↕☞➩✶✌✶✍✩❆➛★➟✴P⑧➛❸➝➄➡★➟✹✣➦➟ ✮➴➟★❪✍✬❃➝➉➡✦✥❸➟★✧➹➙➴➛★➟▼➢✱✧❆➟★❪❁❝❣❈Ó➟❆❵✰➢✒➡✦❵✰➟▼➡✞✩✛✧✭✬✯✩❆➟✝➡★➢✢❇Õ➢✒➡❊✩❅➛★➟☎✴✵✧❆➢✝✶✸➟▼➡❸➝✮❲✦✣✾❪✍✬✯✳✚✙❼➢✒➡♠↕➪➤■➝✻✵❑➟▼➡✿✶✌✶

✙❲✶✒↕⑨⑥ ➽ ↕✡✳✑ ✟ ⑥ ➽ ✑ ❃ ❂➙➜➛★➟❆✣❬➟★✩✮➢❫➧❨❅★✯★➟✹✥❊✳✸➢❫➝➉➡✞✩✢✣➥➢❫➧✁✙ ➝✤✣

✆➾➑Õ➒ ✑❨❘♠↕✡✳ ✑ ❃ ➑✙✑✤→✬❫➡✦✥❊✬❫➤✌✬❃➝➉➡✿✶✌✶✍✩❆➛★➟✴P⑧➛❸➝➄➡★➟✹✣➦➟ ✮➜➟★❪✍✬❺➝➄➡✦✥❸➟★✧☎➙➴➛★➟▼➢✱✧❆➟★❪✿✸✙❇➜➟✝➛✦✬✒✵✒➟

✆✛✗ ❁ ➩❃ ❂➙➜➛❸➝✤✣✾❪➬➟✹✬❫➡✦✣✪✩❆➛✦✬✯✩✾✆➌➝✤✣✼✬✷❁✘❃❫✵✒➟✹❵✢✩❆➢✔✧✑✣❃✳✦✬✱❵✰➟✔➢❫➧❑✥❑➝✮❪➬➟▼➡✦✣➣➝➉➢✒➡ ❈✲✸✵✩❆➛★➟✡➡✌❲✵❪✷✶❁➟★✧☞➢❫➧❣➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟✍✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠✰✣ ☛ ✇ ❝➫⑧➟★✧❬➠➉➟▼❍✙✬✯❪â✳Ü✳✵✧❅➢ ✵❑➟✹✥✺✩❆➛★➟ ➧❹➢■➠❐➠➉➢✢❇➜➝➉➡★➤❀✩❆➛★➟▼➢✱✧❆➟★❪❁❝❜☎❝✫✵❢❡✞☎✶✵★❤❬✂ ✷✪❧✟❢✺✐☞✑✇❘❁✆ s ✐☛✡❦❢✺❴ ☛✇➑✢✜

☞ ⑩✤✣✦✥ ➤✌❵★✥✸➋✓☛★✧ ✑★⑥ù■✘➍✪✩

➼✹ã

Page 67: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❤q➡ ➧ ✬✔❵✢✩✺✸❬❇➜➟♠➢✝✶✵✩✭✬❺➝➄➡Õ✬②➡★➢✒➡Õ✩✿✧❬➝❀✵❑➝✤✬❃➠❒➧➣✬✱❵✢✩❆➢✔✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡ ➢❫➧✕☛♣➧①➢✱✧✍✥❸➟▼➤✎✑ ★ ✂✵➋①➝●➧❴✥❸➟▼➤☎✑ ➑➨❯✙✸❬❇➜➟♠➢ ✶✵✩✭✬❃➝➉➡✙☛❪✴❲❸➠✮✩❬➝✮✳❸➠❐➝➉➟✹✥✂✶✌✶●✂❫➍✭❝✁�☞➟▼❅❁➡❸➝✮✩❬➝➉➢✒➡ ✂✝➢✱❲✵✩❬➠●➝➉➡★➟✹✣✑✬■➡r➝✲❪â✳❁➢✱✧✿✩✢✬❫➡✞✩✪✳✵✧❆➢✱✳❁➟★✧✛✩❜✶r➢❫➧✸✆✺❝♦✖✵✙♣✘✰✦q✶✰❀r☞✰✚❡☎q ✂ ✷✍✺ ✣❬➟★✩r❳ ➑➨➒ ✑ ➓ ✧ ✩ ✩ ✩ ✧ ✑✄✂❅→r➝✰✣❀❵★✬❃➠●➠➉➟✹✥ý✬●✣❬➟★✳✦✬✯✧✢✬✯✩❬➝➉➡★➤ù✣❬➟★✩✡➧①➢✱✧✖☛❊➝●➧❒➧①➢✱✧✺✬❫➡✌✶ ✩✈❇➜➢Ü✥❑➝✤✣❃✩➦➝➄➡✦❵✢✩

➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟➬➧➣✬✱❵✢✩❆➢✔✧✭✣✎☛ ✇ ✬❫➡✦✥✼☛✆☎✝✸⑤✩❆➛★➟★✧❆➟✔➟✆✝❢➝✤✣❃✩✢✣ ✑☛❼✔❘❊❳ ✬❫➡✦✥●■ ❼☎❘✜❁✵❃❆✣❃❲✦❵❅➛❁✩❆➛✦✬❏✩✯✑❲❼❈⑥ ■ ❼☞➝✤✣✼✥❑➝❀✵❑➝✰✣❱➝✻✶❸➠➉➟◗✶✞✶✼☛ ✇ ✸✶✵❲✵✩➥➡★➢✱✩✒☛ ☎ ❝➙➜➛★➟▼➢✱✧❅➟★❪ ✐✺❵✰➢✒➡★➡★➟✹❵✢✩✭✣✮➙➜➛★➟▼➢✱✧❆➟★❪ ✂ ❇➜➝✮✩❆➛✞�☞➟▼❅❁➡❸➝✮✩❬➝➉➢✒➡❢✂✱❝

❜☎❝✫✵❢❡✞☎✶✵★❤❥✐✸✷✪❧✟❢✺✐⑥➒✞✂ ✧✭✗✠✟✤✧ ✩ ✩ ✩ ✧✭✗❃➩▼→❨❷ ❢✷❜✓✌❖❋✝❝ ▲ ❴❁❋✒❏✷❤♥❜✝❝◗❷❞❜✢❡✮❤❀❡✝❋❬③✒✆ s ✐☛✡❦❢✺❴✇➒✙✗✠✟ ✧ ✩ ✩ ✩ ✧✢✗❄➩✰→❘❤❀❡✰❜✱❡✮❢ ✌ ❜ ❛❍❜ ✐✦❤❥❴ ❧ ❡✮❢✺✐③▼❋✝❛ ☛❣⑨➙➜➛★➟✹✣❬➟✼✧❅➟✹✣❃❲❸➠✮✩✭✣❬❅❁➡✦✬❺➠❐➠✮✶❚➠➄➟✹✬✔✥❊✩❆➢✴✩❆➛★➟☞➧①➢❫➠●➠➉➢ ❇➴➝➄➡★➤❊✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪❙❇➥➛★➢✞✣❬➟✴❵✰➢✱❪✺✳❸➠➉➟✆✝❸➝✲✩❃✶r➝✤✣ ✥ ✑✡➋❍⑤☛✡ ❸ ❄ ⑤ ✟ ➍✭❝➋✭✂❫➍✌☞★➢✱✧✿❪ ✩❆➛★➟✼❪❀✬✯✩✿✧❬➝✍✝❨➢❫➧◆✩❅➛★➟✼❪✍✬✯✳✵✳❸➝➉➡★➤ ✙●⑥●❤❜✥❘❇➴➝✲✩❅➛❁✧❆➟✹✣❃✳✸➟✹❵✢✩✷✩❆➢✺✩❅➛★➟❉✶✦✬✱✣➣➝✤✣✝➒✌✂ ✧▲❴✚✧ ✩ ✩ ✩ ✧ ❴ ❚✝❿ ➓ →✝➢❫➧❀↕✝✂➋❱✐❸➍ ✁ ✶✵✩✭✬❃➝➉➡Ü✬❫✶✦✬✱✣➣➝✤✣ ➒✞✂ ✧✢✗✎✟✤✧ ✩ ✩ ✩ ✧✭✗❃➩▼→☎➢❫➧✠✆➌➑❼❍✒➟★✧▼➋ ✙❹⑥ô❤❜✥✸➍✸❲✦✣➣➝➉➡★➤✇➷✒✬✯❲✦✣✛✣➣➝✤✬❫➡❨➟✰➠●➝✲❪➎➝➄➡✦✬❏✩❬➝➉➢✒➡✢✂➋❜❥❸➍✌☞✦✬✱❵✢✩❆➢✔✧ ☛●❵✰➢✱❪â✳✵❲✵✩❬➝➉➡★➤ ☛❚➑✢✜

☞ ⑩✤✣ ✥ ➤✞❵★✥✸➋✓☛ ✧✭✗✠✟✓⑥ù■✘➍

✬❫➡✦✥●✧❆➟▼❅❁➡★➟✺✩❅➛★➟✺✳✦✬✯✧✿✩❬➝✤✬❃➠❣➧➣✬✱❵✢✩❆➢✔✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡ ✣❃❲✦❵★❵✰➟✹✣✛✣➣➝❀✵✒➟✰➠✮✶ ❲✦✣➣➝➉➡★➤●✗ ✡ ✧ ✩ ✩ ✩ ✧✢✗❃➩✼❲★➡✞✩❬➝●➠✖✩❆➛★➟✍❵✰➢✱❪✺✳❸➠➉➟★✩❆➟➁➧➣✬✱❵✢✩❆➢✱✧ ❁➝✲✟✹✬❏✩❬➝➉➢✒➡♠➢❫➧✻☛✇➝✤✣➜➢✝✶✵✩✭✬❃➝➉➡★➟✹✥ß❝▼❊✴✑✏Ò➈✘❯✸➆☎❯✭✹✼❨✘◗ ✞✚❨❁➅✟✸❱✻☎✹✟✿①➆✤➈ ❨✘◗➉➈✵✻❊✹✟✿❭✸ ➇ ❩

❈✵➟☞➧①➢ò❵✢❲✦✣➴➡★➢ ❇❮➢✒➡❁✬✺✥❑➝❑❏✢➟★✧❆➟▼➡✞✩✾✬✯✳✵✳✵✧❆➢✞✬✱❵❅➛r➧①➢✱✧➜➧➣✬✱❵✢✩❆➢✱✧❬➝➉➡★➤✴✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠✤✣☞➢✢✵✒➟★✧❬❅❁➡❸➝✮✩❆➟ ❅❁➟✰➠✤✥✵✣★❝✸❤➐✩➜➝✤✣✑✬✔➤✒➟▼➡★➟★✧✢✬❃➠❪➬➟★✩❆➛★➢✵✥❀✩❆➛✦✬✯✩❪✶✵✧❆➟✹✬❫❍✵✣✖✩❆➛★➟✼✳✵✧❆➢✝✶❸➠➉➟★❪ ➝➉➡✞✩❆➢â✩❆➛✵✧❆➟▼➟❴✣✫❲✙✶✵✳✵✧❆➢✝✶❸➠➉➟★❪✍✣★❝

❂ ✣ ✣✲❜✝❛✈❢▼✈ ③♠❛✈❢▼❢✡③✮❜✒❉✺✐①❋✝❛▼❤✓✒♠❜✝✐✦❤✚❋✝❴✩✗✔☞❞➝➄➡✦✥ ❪➬➢✒➡❸➝✤❵❢✣▲❑✔❲✦✬✯✧❆➟✮❁✚➧✽✧❆➟▼➟ù✳✦✬❃➝✮✧ ❇➜➝✤✣❬➟❢✧❆➟✰➠✤✬✯✩❬➝❀✵✒➟✰➠✮✶❛✳✵✧➦➝✲❪➁➟ù✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✤✣t ➓ ✧ ✩ ✩ ✩ ✧✈t✱❚✴✣❃❲✦❵❆➛❡✩❆➛✦✬✯✩ ☛✇➑ t ➓ t ✟✟ ❺✒❺✺❺ t ❚❚ ✩✕ ❤❧❡♠✐✦❤♥❴❁❉✒✐ ✏✝❢ ❧ ❛✈❢✤❢✤③✮❜✒❉✒✐①❋✝❛✤❤✓✒✮❜✝✐✦❤♦❋ ❴✍✗ ✻ ✳❸➠●➝✲✩✖✬✑✣ ❑✱❲✦✬✯✧❅➟✮❁✚➧➆✧❆➟▼➟❋✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠★➝➉➡✌✩❆➢✼✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✤✣✠✩❅➛★➟❣➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟➧ ✬✱❵✢✩❅➢✱✧✭✣⑧➢❫➧❨❇➥➛❸➝✤❵❅➛♠➛✦✬✒✵✒➟✼✩❆➛★➟✴✣✿✬✯❪➬➟✼✥❸➟▼➤✱✧❆➟▼➟✱❝� ✣ ✣✲❜✝❝✢✏ ❢ ❧ ❛❍❢▼❢❣③✮❜✒❉✒✐①❋✝❛✤❤✓✒✮❜✝✐✦❤♦❋ ❴✍✗✪P❀➢✱❪â✳❸➠➄➟★✩❅➟✰➠✲✶r➧➣✬✱❵✢✩❆➢✔✧✑✬✴✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠✠✩❆➛★➟☞➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟✺✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠◗➧➣✬✱❵▼❁✩❆➢✱✧✭✣⑧➢❫➧☎❇➥➛❸➝✤❵❆➛✇➛✦✬✒✵✒➟✑✩❅➛★➟❴✣✿✬✯❪➁➟❆✥❸➟▼➤✱✧❆➟▼➟✱❝

▼❊✴ ✳✵✴✖✆✗✖ ➂❊❨✘✹✼❯ ✠✧✞✐✹✼❯ ❯ ✞✚❨❁➅ ✸❱✻❊✹✟✿✙✘✤❨❫✸✺✿❀✻❞➆❍✴ ➙➜➛❸➝✤✣✼✣❃❲✙✶✵✳✵✧❅➢✝✶❸➠➉➟★❪ ➝✰✣✼✣➦➢❫➠❀✵✒➟✹✥✇➟✹✬✱✣➣➝●➠✮✶✿✶✌✶❊❪➬➢✱✧❆➟✔➢✱✧➥➠➉➟✹✣✿✣✾❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤✩❆➛★➟✝➤✞❵★✥❚➢❫➧ ☛✂❇➴➝✲✩❅➛r➝✲✩✢✣✑✥❸➟★✧❬➝❀✵✯✬✯✩❬➝❀✵✒➟✕☛⑤❘✽❝❀❽✇➢✱✧❆➟✾✧❬➝➉➤✒➢✱❲✵✧❅➢✱❲✦✣➣➠✮✶✝✸❖✬❄✳❁➢✞✣✿✣❱➝✻✶❸➠➉➟✺✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪➺➝✤✣✖✩❆➛★➟✝➧①➢❫➠●➠➉➢✢❇➜➝➉➡★➤✃➲✏❥❃➳➣❝

③✁✚●➑❛✂ ✂❁↕✛✚●➑ ✂ ✂✸❂✑✚●➑ ☛ ✂ ❈ ✚➄➑ ☛ ❘ ✂✦▼✜✚●➑❼➤✌❵★✥✸➋✓❂★✧ ❈ ➍ ✂✣✢✤✚●➑✙❂ ✪✙▼ ✂❇➥➛❸➝●➠➄➟✴▼ ❭➑❛✂❆✥❸➢

❊✑✚●➑❼➤✌❵★✥✸➋✥✢ ✧✢▼❃➍ ✂✣✦✧✚●➑★✢ ✪✢❊ ✂★↕✩✚●➑Ï↕✫✪✬✦ ✇ ✂☛③✬✚●➑❆③ ❸ý✂ ✂✄✢✭✚●➑✬❊ ✂✵▼✮✚●➑ý▼ ✪ ❊↕✯✚➄➑❲↕✫✪✰✢ ✇ ✂✧❆➟★✩✿❲✵✧❆➡✤➋❱↕✔➍

➙➜➛❸➝✤✣✪❪➬➟★✩❆➛★➢✵✥r➛✦✬✱✣✷❵✰➢✞✣❃✩ ✥ ✑ ➋❍⑤❞➍✭❝➼✲✱

Page 68: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

▼❊✴❘▼☎✴✁�✖✿ ❲✔✸✺✿①➆✢➅✟✸✖✽✂❯❸➈❊✹✼❯ ❯ ✞✢❨❁➅✟✸❱✻❊✹✟✿✓✘✛❨❫✸✺✿❀✻❞➆❍✴ ➙➴➛❸➝✰✣✾✣❃❲✙✶✵✳✵✧❆➢ ✶❸➠➄➟★❪ ➝✤✣✷✣➦➢❫➠❀✵✒➟✹✥❘✶✌✶ ➙➴➛★➟▼➢✱✧❆➟★❪ ❥❨➲ ❴❺➳➐❝❜☎❝✫✵❢❡✞☎✶✵★❤❦❥✸✷✮❦✢❋✝❛✷❢❄♥✒❢✺❛ ▲ ③✝❘ÏÐ s ✐☛✡❦❢ ✌ ❛❬❋ ✏ ✣❢❉✒✐✝❋❬③ ❜✝❝♥❝❀❏✡❋✝❴❲❤♦❉◗❤❥❛▼❛✈❢ ✏ ✣❢❉✒❤❹❷✉❝⑦❢ ✌★❋✝❝ ▲ ❴❁❋✒❏✷❤♥❜✝❝ ❡➎❋❑♥✺❢✺❛P❁✘❃✇⑤✒✡❢❋✢❡✮❢

✏✝❢ ❧ ❛✈❢▼❢✮❡ ✏✝❤♦♥✒❤ ✏ ❢ ③▲❤❧❡✰❢ ✣ ✣❦❜ ❝✟✐①❋ ❴ ❃ ❩ ⑥✜❴❼⑨➙➜➛❸➝✤✣✼✩❅➛★➟▼➢✱✧❆➟★❪❪➠➉➟✹✬✱✥✵✣è✩❆➢❁✩❅➛★➟☎➧①➢❫➠●➠➉➢✢❇➜➝➉➡★➤ ✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪ ❇✮➛❸➝✰❵❅➛❢✧❆➟★✩✿❲✵✧❆➡✦✣✼✬ ⑤☛❁✽✩✛❲✵✳❸➠➄➟✇➋✦t ➓ ✧ ✩ ✩ ✩ ✧✈t✱❚✒➍▲❇➥➛★➟★✧❆➟➬➟✹✬✱❵❅➛

✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠ t ✇ ❵✰➢❑➡✞✩✭✬❺➝➄➡✦✣✪✬❃➠●➠☛✩❆➛★➟☞➧➣✬✱❵✢✩❆➢✱✧✭✣⑧➢❫➧✸✥❸➟▼➤✱✧❆➟▼➟✷③⑥➢❫➧ ☛☛❝➋✭✂❫➍ ✻ ➟★✩ ✑ ✁ ➑ ❴✄✬❫➡✦✥ ☛ ✁ ➑✙☛ ✂➋❱✐❸➍✌☞★➢✱✧❈③⑥➑ ✂ ✧ ✩ ✩ ✩ ✧✤⑤ ✸✵✥❸➢

✂ P❀➢✱❪✺✳✵❲✵✩❆➟✏✑ ✇✢➑✙✑ ❃✇ ❿ ➓ ❪➬➢✵✥✕☛ ✂✂ P❀➢✱❪✺✳✵❲✵✩❆➟▲t ✇ ➑❼➤✞❵★✥✸➋✓✑ ✇ ⑥✙❴✚✧❃☛ ✇ ❿ ➓ ➍✖✬❫➡✦✥ ☛ ✇ ➑ ☛ ✇ ❿ ➓ ✪✮t ✇ ✂

➋❜❥❸➍ ✮➜➟★✩✿❲✵✧❆➡②➋✦t ➓ ✧ ✩ ✩ ✩ ✧✈t✱❚❸➍✭❝➙➜➛★➟❞❪✍✬❃➝➉➡Ü❵✰➢✞✣✫✩➥➢❫➧✠✩❆➛❸➝✤✣✷✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ➝✤✣✷✩❅➛★➟❆❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡♠➢❫➧❢❴ ❃ ❩ ➧①➢✱✧④③⑥➑❉✂ ✧ ✩ ✩ ✩✌✧✤⑤❈❝❀➫❋✶❊✧❆➟★✳✸➟✹✬✯✩❆➟✹✥❡✣▲❑✱❲✦✬❏✧❬➝➉➡★➤☛✸✩❆➛❸➝✤✣✼❵✰➢✞✣❃✩✮➝✤✣ ✥ ✑ ➋ ⑤ ✟ ➠➉➢✒➤ ❄❑➍✭❝ ✺ ✶✸➟★✩✿✩❆➟★✧▲❇◗✬❅✶❨➢❫➧❑❵✰➢✔❪✺✳✵❲✵✩❬➝➉➡★➤❊✩❆➛❸➝✤✣✎❑✱❲✦✬■➡✞✩❬➝✮✩❃✶❁❵✰➢✒➡✦✣➣➝✤✣❃✩✢✣✮➝➄➡●❲✦✣➣➝➉➡★➤●✬❫➡Ü✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪✩❆➢✇➝✮✩❆➟★✧✭✬✯✩❅➟❊✩❆➛★➟ ☞✵✧❆➢ ✶❁➟▼➡❸➝✮❲✦✣✺❪❀✬✯✳❇❝ ✺✷✩✷❅✦✧✭✣❃✩✷❇➜➟❁❵✰➢✱❪✺✳✵❲✵✩❅➟✖❴ ❃ ❪➁➢ò✥✖☛Õ✬❫➡✦✥❢✩❅➛★➟▼➡❼➤✒➢ù✥❸➢✱❲✙✶❸➠●➝➉➡★➤ ➟✮✵✙✬❃➠✮❲✦✬✯✩➦➝➄➡★➤❴ ❃ ❩ ❪➬➢✵✥✖☛❚➝➉➡ ❴ ❃ ✩❆➢✡➢✝✶✵✩✭✬❃➝➉➡✖❴ ❃ ❩☎✄ ★ ❝ ✻ ➢ ❴ ❃ ✪ ❪➬➢✵✥✖☛✇➑ ❴ ❃ ➋✚❴ ❃ ➍❇❪➬➢✵✥✖☛ ✸ ❴ ❃✝✆ ❪➬➢✵✥ ☛✇➑ ❴ ❃ ✪ ➋✚❴ ❃ ➍❇❪➬➢✵✥✖☛ ✸✬❫➡✦✥❊✣❬➢➁➢✒➡❇❝❀➙➜➛★➟❆❵✰➢✞✣✫✩➥➢❫➧✠✩❆➛❸➝✤✣✷❪➬➟★✩❅➛★➢ò✥➁➝✤✣ ✥ ✑ ➋❍⑤ ✟ ❸ ⑤✮➠➄➢❑➤ ❄❑➍▼❊✴✟✂❧✴✁✞ ✖ ➂❊❨✘◗ ✽✂❯❸➈❊✹✼❯ ❯✘✞✚❨❁➅ ✸❱✻❊✹✟✿✙✘✤❨❫✸✺✿❀✻❞➆❍✴ ➙➜➛★➟✪✳✵✧❆➢✝✶✦✬✢✶❸➝●➠●➝✤✣❃✩❬➝✤❵✑✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪⑨❇➜➟✑✬✯✧❆➟➜➤✒➢■➝➄➡★➤✼✩❅➢❆✥❸➟✹✣✿❵✢✧❬➝❀✶❁➟✾✩❆➢❪❅❁➡✦✥

✩❆➛★➟ ❈ ➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟✔➧ ✬✱❵✢✩❅➢✱✧✭✣☎☛ ➓ ✧ ✩ ✩ ✩ ✧❃☛❃➩➜➢❫➧♦✥❸➟▼➤✔✧❆➟▼➟✠✟➬➢■➧◆✬✴✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠✻☛♠➢■➧♦✥❸➟▼➤✱✧❅➟▼➟✰⑤✇➑✡✟ ❈➹➝➉➡ ❁✘❃▲❇➴➝✲✩❅➛ ❄☎➢✵✥✵✥➝✤✣✑✥✌❲★➟❞✩❆➢❀P❑✬❫➡✌✩❆➢✱✧ ❁☞☛ß✬✱✣✿✣❬➟▼➡★➛✦✬✯❲✦✣☞➲✲✐■➳➣❝❤①➧ß✩❆➛★➟★✧❆➟➥➟✆✝❸➝✤✣❃✩✭✣✠✬✾✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠ ▼✝❘ ❁✵❃❫➲ ❴②➳✞✣❃❲✦❵❅➛✺✩❆➛✦✬✯✩✸▼❋❪➬➢✵✥✖☛ ✇ ➑Ï❯✼✬❫➡✦✥✺▼❋❪➬➢✵✥✖☛✆☎ ❭➑❲❯✮➧❹➢✔✧✷✂ ✆❻③✍✌✏✎ ✆ ❈✲✸

✩❆➛★➟▼➡❊➤✞❵★✥✸➋❜▼ ✧ ☛✢➍✼✣❃✳❸➠●➝✮✩✭✣ ☛☛❝②➙❞➢Ü✩✢✬❫❍✒➟✍✬✱✥✲✵✯✬❫➡✌✩✭✬❫➤✒➟➬➢■➧✑✩❆➛❸➝✤✣ ➝✰✥❸➟✹✬ ✸☎❇➜➟✝❵❅➛★➢❢➢✌✣❬➟✝✬❏✩❆✧✭✬❫➡✦✥❸➢✔❪ ✬❡✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✯❂✇➢❫➧❁ ❃ ➲ ❴✃➳ ✪✒➋✓☛❞➍✭❝✵➙➜➛★➟▼➡ ✩❆➛★➟❊✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠✤✣ ❂✝✇✔➑❅❂è❪➬➢ò✥ ☛✺✇✮➧①➢✱✧❊✂ ✆❙③ ✆ ❈●✬✯✧❆➟r➝➉➡✦✥❸➟★✳❁➟▼➡✦✥❸➟▼➡✌✩❁✬❫➡✦✥❢❲★➡❸➝●➧①➢✱✧✿❪✡➠✮✶✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❆➟✹✥✇➟✰➠➉➟★❪➬➟▼➡✌✩✭✣➴➝➄➡✙❁✘❃❫➲ ❴②➳ ✪❑➋✓☛ ✇ ➍✢❝ ✻ ➢

❂ ✥✒✑ ✿ ★✪✇ ✔✔✓❆✂✷❪➬➢✵✥✖☛ ✇❇➜➝✮✩❆➛❡✳✵✧❆➢✝✶✦✬✢✶❸➝●➠●➝✮✩❜✶ù✂ ✪❺✐✔➟✹✬✱❵❆➛❇❝◗P❀➢✒➡✦✣❬➟✺❑✔❲★➟▼➡✞✩➦➠✲✶✝✸✶❂ ✥✒✑ ✿ ★✪ ⑥ ✂❆✥❸➢❸➟✹✣➜➡★➢✱✩➜➧➣✬✱❵✢✩❆➢✔✧ ☛ ❇➜➝✮✩❆➛❊✳✵✧❆➢✝✶✦✬✢✶❸➝●➠●➝✮✩❃✶✃✐❸➋✭✂ ✪❺✐❸➍ ➩ ❝➙➜➛❸➝✤✣➴➝✰✥❸➟✹✬➎➠➉➟✹✬✱✥✵✣✪✩❆➢✴✩❆➛★➟☞➧❹➢■➠❐➠➉➢✢❇➜➝➉➡★➤❊✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ❇➥➛❸➝✤❵❆➛❡✧❆➟★✩✿❲✵✧❆➡✦✣➴➢✒➡★➟☞➧ ✬✔❵✢✩❆➢✱✧➜➢❫➧ ☛♠➢✔✧ ☞ ✺✑❤❬➭✠❝

➋✭✂❫➍âP❀➛★➢❢➢✌✣❬➟✏❂➬❘ ❁✵❃❫➲ ❴②➳ ✪✒➋✓☛❞➍✠✬✯✩✷✧✭✬❫➡✦✥❸➢✔❪ ✂➋❱✐❸➍âP❀➢✱❪✺✳✵❲✵✩❆➟❪t✪➑♣➤✞❵★✥✤➋✓❂ ✧❃☛❞➍✭❝▲❤①➧☎t ❭➑ ✂✝✸✌✩❆➛★➟▼➡❁✧❅➟★✩✿❲✵✧❆➡◗t✢✂➋❜❥❸➍âP❀➢✱❪✺✳✵❲✵✩❆➟ ❈ ➑✙❂

✥ ✑ ✿ ★✪ ⑥ý✂✖❪➁➢ò✥✖☛ ✂➋q❴★➍âP❀➢✱❪✺✳✵❲✵✩❆➟❪t✪➑♣➤✞❵★✥✤➋ ❈ ✧ ☛❞➍✭❝❇❤ ➧❨t ❭➑ ✂✝✸✵✩❆➛★➟▼➡❊✧❅➟★✩✿❲✵✧❆➡◗t❨➟✰➠✰✣➦➟❆✧❆➟★✩✿❲✵✧❅➡ ☞ ✺✑❤❬➭✠❝

❤➣✩✢✣✷❵✰➢✞✣❃✩➜➝✤✣ ✥ ✑ ➋❍⑤ ✟ ➠➄➢❑➤ ❄❑➍✿❝✂❧✴✖✕ ❯❖➅✟❯✸➆✘✸ ✹✼❯❫❲❫➂✂◗❀✸✺❲

✴✮➟✮❇❛✧❆➟✹✣❃❲❸➠✮✩✭✣➴➝✮❪✺✳✵✧❆➢✢✵✒➟✼✩❆➛★➟❆✣✿❵❅➛★➟★❪➬➟✴✥❸➟✹✣✿❵✢✧❬➝❀✶❁➟✹✥❚➝➉➡ ✻ ➟✹❵✢✩❬➝➉➢✒➡②✐✵❝✂ ✼✵❝✲✵✒➢✒➡❀✟★❲✵✧✝➷✒✬✯✩❅➛★➟▼➡✝✬❫➡✦✥✴✽✴❝ ✻ ➛★➢✱❲✵✳✵➲●❛❄➳ ✚ �✮➝✤✣❃✩➦➝➄➡✦❵✢✩✾✥❸➟▼➤✱✧❆➟▼➟☞➧➣✬✱❵✢✩❆➢✱✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡ ✚ ✥ ✑✡➋❍⑤ ✟ ❸ ⑤✮➠➉➢✒➤ ❄❑➍ ✂❸➟✺❑✔❲✦✬❃➠✥❸➟▼➤✱✧❆➟▼➟☞➧➣✬✱❵✢✩❆➢✱✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡ ✚ ✥ ✑ ➋❍⑤ ➓☞✗ ✘ ❸❵⑤✮➠➄➢❑➤ ❄❑➍✭❝

✂✚✙ ❝✜✛✼✬❃➠✮✩❆➢❫➧①➟▼➡ ✬❫➡✦✥ ✽✴❝ ✻ ➛★➢✱❲✵✳ ✬■➡★➡★➢✱❲★➡✦❵✰➟✹✥②➝➉➡Ï➲✏✎❫➳ ✚ �✮➝✰✣✫✩❬➝➉➡✦❵✢✩❄✥❸➟▼➤✔✧❆➟▼➟✡➧➣✬✱❵✢✩❆➢✱✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡ ✚ ✥ ➋❍⑤ ➓✢✗ ✣✰➓✥✤ ➠➄➢❑➤ ❄❑➍✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩❬➝✤❵★✬❃➠●➠✮✶●✶✵❲✵✩ ✥ ➋❍⑤ ✟ ✗ ✤ ❸❆⑤✮➠➉➢✒➤❇❄✒➍☞➝➉➡ ✳✵✧✭✬✱❵✢✩➦➝✰❵✰➟ ✂➜➟✺❑✔❲✦✬❃➠✑✥❸➟▼➤✱✧❆➟▼➟r➧➣✬✱❵✢✩❆➢✔✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡ ✚ ✥ ➋❍⑤ ✟ ➠➉➢✒➤❬⑤✂❸⑤✮➠➄➢❑➤ ❄❑➍⑥➝➄➡❡✳✵✧✭✬✱❵✢✩❬➝✤❵✰➟✱❝

✴✮➟✮✵✒➟★✧✿✩❆➛★➟✰➠➉➟✹✣✿✣✮✸▲✩❆➛★➟❆❪❀✬❃➝➉➡ ❵✰➢✞✣❃✩✾✧❆➟★❪✍✬❃➝➉➡✦✣✾✩❆➛★➟✺❵✰➢✱❪â✳✵❲✵✩✭✬✯✩❬➝➉➢✒➡✇➢❫➧ ❴ ❃ ❩ ➧❹➢✔✧ ③➴➑ ✂ ✧ ✩ ✩ ✩✌✧▼⑤☛❝✮☞❯❲✵✧✿✩❆➛★➟★✧✿❪➬➢✔✧❆➟✝✸❁➢✔✩❆➛★➟★✧✧❆➟✹❵✰➟▼➡✌✩✷✧❆➟✹✣❃❲❸➠✮✩✭✣✪❪✴❲✦✣❃✩❬✶❁➟✴❵❅➝✲✩❅➟✹✥ß❝

✂✚✙ ✵✵✥❸➢✒❍✒➝✮❪➬➢✢✵✇➋✭✂✺✹✝✹✔❥❸➍ ✚☞✺❉✥❸➟★✩❆➟★✧✿❪➎➝➄➡❸➝✤✣❃✩➦➝✰❵✴✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪✿✸✘❑✔❲✦✬✱✣➣➝❇✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠✠✩❬➝✮❪➬➟✭✚ ⑤✧✦ ★✢✩ ❚ ➠➄➢❑➤ ❄ ✢✫✪✧✬ ➓✥✭ ❝✂ ✴➜➝➉➟✹✥❸➟★✧✿✧❆➟✰➝✮✩❆➟★✧✡➲✲Ö❫➳ ✚✛✺➪➡★➟✮❇❉✥❸➟★✩❆➟★✧✿❪✡➝➉➡❸➝✤✣❃✩❬➝✤❵✴✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪❡❝

➼ ×

Page 69: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✂ ✛✼✬❃➠✮✩❆➢❫➧①➟▼➡✙❁q➭✤➢✝✶❁➢Ï➋✢✂✺✹✝✹❫❴★➍✆✚ ✮✪✬❫➡✦✥❸➢✱❪✡➝✮✟▼➟✹✥Õ➫⑧➟★✧❬➠➉➟▼❍✙✬❏❪✺✳✬❇➜➝✮✩❆➛Ï❈❼➝➉➟✹✥❸➟★❪✍✬■➡★➡✟❭✏✣✡➠●➝➉➡★➟✹✬✯✧●✣❬➢❫➠❀✵✒➟★✧✺✸⑧➝➉➡Õ✩❬➝✮❪➬➟✥ ✑✔➋❍⑤ ✟ ❸ ⑤✮➠➄➢❑➤ ❄❑➍✭❝

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦❃⑨✑⑩▲❺✿❻➣❸⑧❺✿õ✹➂➍➪❆➔❞❼➆î✠❾✹➓✪❾➇❿✿❾✢➒✺❽✞➂❅➙❃➏➣❶❅❻➣❹⑧➌✱➝✖➔✞❶❅❸⑧➜✙➌✔❶✹➪❆❹✮➂➍❸➉→✵❶★➊❅❺✿❻❇❸✮➂★❻➐➝✹❺▲➛✞➌✱❹⑧➏➣❺❈➛✌❺✿❸✮➄✯→✭❾✔á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨✤➥✫➭❑➤ ✕ ➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨✤➤★➩✱➀✯➊❅❶✹❸✽❾★➴✣✗✌➀

➌✱ê✱⑦❅⑦✹⑦✹➀ ➶✢➹✹ö❅ì ➀❅➔✱➔✦❾✞ã✔⑦✭Ú➋➒❏ã✹Ú❅➼✱❾⑥➇➴✢⑨✑➚✠➂★➌✯➏➐❶✹❻❞❼➆➅✾❾❖øè❾ ❿✾➂★➌✌➄ ✛ ➂★→➐→➣❺✿➌✔↕✞➂★❷✱→✴❼ ✘ ❾➇❿✿❾⑤➒❬➾❍➌✱❺✿Ý❉➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✔➪❦↔s❶✹❻✪↔➆➂✹➙❃➏➐❶✹❻➐❹➉➌✔➝✺➔✞❶❅❸⑧➜✙➌✔❶✹➪❆❹✮➂➍❸➉→❋❶★➊✹❺✿❻✾➛✌➌✱❹⑧➏➣❺✼➛✌❺✿❸✮➄✯→✭❾

á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨s➥❃➭✑➤ ✕ ➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨s➤★➩✱➀✯➊❅❶✹❸✽❾✱Ú✹➽✔➀ ➶✭➹✹ä✔➶ ➀❅➔✱➔✦❾✱➼ ✱✹ã✢➒✱➼ × ➴✱❾⑥➇Ú✢⑨✑ø✖❺✭➄✔➄✯❺✿→✷❼✽í❋❺✿❹⑧➏➣↕✍➈✾❾➇❿✿➀✵➚❈➃✭➂➍➔✞❶❅❻✷❼➆å❏➏➣❺✿➔✱↕✔❺✿➌✝➓✪❾➇❿✿➀✱➂★➌✌➄✺➁✦➂➍Þ✞➂★↕✱➌❀❼✽ø✖❺✿❶✹❻➐➝✹❺✭❿✛❾✔➒ ➳✖❮➇➫✹➤★➢✛➨ ➱✤Ð ❐✷➭ ✕ ➤➍➢✼➵☛➤★❐❋❒ ✃❅➱ ➦✿➢❋➳✖❮➇➫✹➦✭Ò✛➢❜❰➍❾❅➒

í❋❸⑧❷✙Ý❈❺✿❻✠➾✖➙✿➂✹➄✯❺✛➪❆❹✮➙✸➎ß❷✔Þ✱❸⑧❹➉→➐↕✱❺✿❻➐→✭➀ ➶✢➹✹➹❅ë ❾⑥ ✗★⑨✑➁✵❹✮➄✯❸✪❼➆➓♦❷✞➄✯❶✹❸❱↔✿❿✼➂★➌✞➄ùñ♦❹⑧❺✭➄✯❺✿❻➐❻➣❺✿❹⑧➏➣❺✛❻❊❼ ✘ ➂★❻❜➂➍❸✮➄✱❿✿❾ ➒ ✦❇➨✮➩✱➨ ➱ ➦✝✦❇➨✤➦✛❮➉➧➋➭✿❾ß➒ ➾✖➄✱➄✯❹⑧→➣❶❅➌✯➞ ✣❊❺✛→➣❸⑧❺✿➜✯➀ ➶✢➹✹ä❅÷ ➀ ➮ ➩✌➥✄✂✹➥✛❮➉➤✫❒❏➦❃➧★➨s❰Ü➤ ✕

á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨s➥❃➭✑❰★➩✌➧✼➨ ➱ ➭✸➳✠❒✹❒✌❮✏➨✤➥❃❰ ➱ ➨✤➤➍➩✯➭✿➀✯➊✹❶❅❸➆❾✯➴ þ ❾⑥➇➼✢⑨✑ñ✠❹⑧❺✭➄❏❺✿❻➣❻➐❺✿❹⑧➏➣❺✿❻❋❼ ✘ ❾ ❿✛❾✢➒❴❽✌➂✹➙❃➏➐❶✹❻➣❹⑧➌✱➝✖➔✌❶✹❸⑧➜✯➌✱❶✹➪❞❹✮➂★❸⑧→✵❶★➊✹❺✿❻ ➛✞➌✱❹⑧➏➣❺▲➛✞❺✿❸✮➄✯→❇❷✔→➣❹⑧➌✱➝✑➄✯❹❱➟✵❺✿❻➣❺✛➌✙➏➐❹✮➂★❸✱❺✭à❅❷✞➂➍➏➣❹⑧❶✹➌✔→☛➂★➌✞➄✪➌✱❶❅❻➣➪❴➂➍❸✹Þ✞➂➍→➣❺✿→✢❾

á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨s➥❃➭✑➤ ✕ ➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨s➤★➩✱➀✯➊❅❶✹❸✽❾✱➽✹➴✔➀ ➶✭➹✹➹➍Ù ➀❅➔✱➔✦❾ ✱✔⑦ × ➒ ✱✹Ú þ ❾⑥➇➽✢⑨✑å✯↕✱❶❅❷✱➔✺❼ �✑❾➇❿✿❾❏➒✝➾ ➌✔❺✿Ý ➔✌❶✹❸⑧➜✯➌✱❶❅➪❆❹✮➂★❸✯↔✽➂✹➙❃➏➐❶✹❻➣❹⑧➃✭➂➍➏➣❹⑧❶✹➌✴➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✔➪ ➂➍➌✞➄❞❹⑧➏➣→✠❹⑧➪❆➔✱❸⑧❺✿➪✼❺✛➌✙➏❃➂★➏➐❹➉❶❅➌✦❾✛➒ ➶✭➹❅➹★Ù ❾✯➎ß❻➐❺✿➔✱❻➣❹⑧➌✯➏✭❾⑥➇ã✢⑨✷➊✹❶❅➌✼➃✿❷✱❻✸ø✷➂➍➏➣↕✱❺✛➌✺❼✤Û✌❾➇❿☛➂➍➌✞➄✼å✯↕✱❶❅❷✱➔✺❼ �✑❾➇❿✿❾❅➒✍➚❈❶✹➪❞➔✱❷✱➏➐❹➉➌✔➝◗❽✔❻➣❶❅Þ✞❺✛➌✱❹⑧❷✱→☛➪✴➂★➔✼➂★➌✞➄✒↔➆➂✹➙✫➏➣❶✹❻➐❹⑧➌✱➝✷➔✌❶✹❸⑧➜✯➌✱❶✹➪❞❹✲➂➍❸⑧→✭❾✌➵☛➤★❐❋❒ ✃❅➱ ❰✁�

➱ ➨✤➤★➩✞❰➍❮ß➵☛➤★❐❋❒✞❮⑧➦ ☎ ➨ ➱ ✂★➀✯➊✹❶✹❸✽❾✱➴✔➀ ➶✭➹✹➹❅ë ➀❅➔✱➔✦❾⑤⑦ ✱✹ã➋➒❏➴❅➴✣✗✞❾

➽ þ

Page 70: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

☞ ✆✟✞✕✔ ✁☎✄✝✠❲✄✗☞✍✆✂✠❾✆✁�✰✄✄✂☛✞✆☎❳✠ ✄✛✞★�✂✁ ✠❊✄✑✆❘✠ ✏✢☞P✏✿✆✝�✾✠☎✠⑨�✙✄ �✂✞✟✞☛✁✝✠ ☞P✌ ✏☎✁☛✠✓✌✲✄✝☞✍✆✂✠ ✏❉☞✢✞✘✄✢✡ ✠☎✠☛✡�✂✔ ✔☛✄P☞✍✌✙✠❲✄✗☞✍✆✂✠✡✄✗✆ ✄✄✂☛✞ ✂✰✠☎✁✝✠ ✞❪✞✙✄✛✁✝☞✡✠✙✠❲✄✗☞✍✆✂✠✕✆✁�✷�✙✄ �✂✞✟✞☛✁✝✠ ☞P✌ ☞ ✁☛✁✟✕✗✞❲✏

☛❣✩✢✜✌☞❵✧✢✩✢✪❵✯★✛✙✭✮✣✎✍❁✮➡❸➝❀✵✒➟★✧✭✣➣➝✮✩❃✶❨➢❫➧✓✴➜➝➇♥❃❪➬➟▼➤✒➟▼➡✼✯❲★➡★➟➁❛❦✸ß✂✺✹✝✹✒Ö

➲❱✣❃❲✵❪✺❪✍✬✯✧✛✶ ✶✌✶ ➭▲✬✯❲✵✧❆➟▼➡✌✩❒➫⑧➟★✧✿✩✿✧✭✬❫➡✦✥❸➳

✏✼r✒✑✔✓✢✇★①✖✕✗✓➾❢➌✱❺✿Ý❢➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✱➪❉⑥⑧⑦➐⑨✵↔✤❶❅❻☛➙❃❶✹➪❞➔✱❷✱➏➐❹➉➌✔➝✑➂★➌❞❹➉➌✯➏➐❺✿➝✹❻❃➂★❸✌Þ✞➂★→➐❹➉→❈❶★↔❇➂★➌❆➂➍❸➉➝❅❺✿Þ✱❻❃➂★❹✮➙❈↔✤❷✔➌✞➙❃➏➣❹⑧❶❅➌✼➛✞❺✿❸✮➄è❹➉→❈➔✱❻➐❺❃➞

→➣❺✿➌✯➏➣❺✢➄✵❾❈Ô✠↕✱❹⑧→✸➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✱➪Õ❹⑧→✠➏➣↕✔❺✿➌✍➂★➔✔➔✱❸⑧❹➉❺✢➄❆➏➐❶✼➏➣↕✱❺✷➙❃❶❅➪❆➔✱❷✔➏❜➂★➏➐❹⑧❶✹➌❆❶➍↔❖➔✞➂➍❻❜➂➍➪❆❺✿➏➐❻➣❹⑧➃✭➂★➏➐❹⑧❶✹➌✱→❈❶★↔☛➂★❸⑧➝❅❺✿Þ✱❻❜➂➍❹✮➙➙❃❷✱❻➣➊❅❺✿→✸❶➍↔❖➝❅❺✿➌✯❷✱→✠➃✿❺✿❻➐❶✍⑥➇➴✛⑨➣❾

✳✵✴✖◆ ✻❧❩ ❬✘➂☎✸❱❨❫✸✺✿❀✻❞➆ ✻✫✞✝✸ ➇ ❯✜✿①➆✵✸❱❯❢➈☎✹✺❨✘◗ ✌❧❨✘❲✺✿❘❲➭✤➟★✩✙✘ ✶❁➟✴✬❫➡❁✬❃➠➉➤✒➟✮✶✵✧✭✬❃➝✤❵★✬❃➠●➠✮✶Ü❵❅➠➉➢✞✣➦➟✹✥❘❅❁➟✰➠✤✥❚➢❫➧♦❵❅➛✦✬✯✧✭✬✔❵✢✩❆➟★✧❬➝✤✣❃✩❬➝✤❵✾✟▼➟★✧❆➢✍✬■➡✦✥✛✚❘✶✸➟❆✩✿✧✢✬❫➡✦✣✿❵✰➟▼➡✦✥❸➟▼➡✌✩✭✬❃➠◗➢✢✵✒➟★✧✜✘✷❝⑧➭✤➟★✩

❊ ✶❁➟❊✬❃➠➉➤✒➟✮✶✵✧✭✬❃➝✤❵✡➢✢✵✒➟★✧✢✘➜➋✣✚➞➍❈❇➜➝✮✩❆➛ù❪✡➝➉➡❸➝✮❪✍✬❃➠✷✳✸➢❫➠✮✶❢➡★➢✱❪➎➝✰✬❺➠ ☛ ➢■➧◗✥❸➟▼➤✱✧❆➟▼➟◗⑤❵❇➜➝✮✩❆➛ù✧❅➟✹✣❃✳❁➟✹❵✢✩✴✩❆➢✿❊⑤❝✥✤✵➟❀✣❃❲✵✳✵✳❁➢✞✣➦➟✩❆➛✦✬✯✩❉❊r➝✤✣✮➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠❣➢✢✵✒➟★✧✦✘➥➲✧✚ ➳P✸❖✣➦➢✩☛ ➝✤✣✼❪➬➢✒➡❸➝✤❵✔➢✢✵✒➟★✧✦✘➥➲✧✚ ➳➣❝✝➭✤➟★✩☎◆ ✶❁➟✺✩❆➛★➟✴✬❃➠➉➤✒➟✮✶✵✧✭✬❃➝✤❵✺❵✢❲✵✧❞✵✒➟✺✥❸➟▼❅❁➡★➟✹✥✂✶✞✶❡✩❆➛★➟➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡ ☛✢➋✢❴ ✧✩★➬➍❣➑❲❯✬❫➡✦✥➁➠➉➟★✩✦✘➜➋❱◆➎➍ ✶✸➟❆✩❆➛★➟☞➧✽❲★➡✦❵✢✩❬➝➉➢✒➡s❅❁➟✰➠✰✥

✘➴➋❱◆✡➍❣➑✪✘➜➋✣✚ ✧✤❊ ➍◗➑✫✘➴➋✚❴❊➍❇➲✎★✝➳ ✪❑➋✓☛❞➋✚❴ ✧✩★☎➍❅➍✪✩✺ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡r➢❫➧✝✘➴➋❱◆✡➍✸➝✤✣✸❵★✬❃➠●➠➉➟✹✥ ❤❥❴❲✐✦❢ ❧ ❛❍❜ ❝❸➝●➧✿➝✮✩✖✣✿✬✯✩❬➝✤✣✍❅❁➟✹✣❋✬✾❪➬➢✒➡❸➝✤❵⑧➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟✼✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠ ❇➜➝✮✩❆➛✍❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✞✩✭✣➝➉➡✬✘✮➲✧✚★➳➣❝⑥➙➜➛★➟✝➝➉➡✌✩❆➟▼➤✱✧✭✬❺➠▲❵❅➠➉➢✞✣✫❲✵✧❆➟✢✭Õ➢❫➧✮✘➥➲✧✚ ➳❁➝➉➡✛✘➴➋❱◆✡➍⑥➝✤✣✖✩❆➛★➟❆✣❬➟★✩✮➢❫➧◆✬❃➠●➠✢➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠✤➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣★❝✠❤➐✩➜➝✤✣✑✬❺➠✰✣➦➢❴✩❅➛★➟❆✣❬➟★✩➢❫➧◆✬❺➠❐➠❞➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣❪❇➜➝✮✩❆➛❨➡★➢❫❅❁➡❸➝✮✩❆➟❆✳✸➢❫➠➉➟✝✸❖✬■➡✦✥✡➝✮✩➜➝✤✣✾✬✝➧✽✧❆➟▼➟✼❪➬➢✵✥✌❲❸➠➉➟☎➢❫➧❈✧✭✬❫➡✰✯❘⑤♠➢✢✵✒➟★✧✜✘✮➲✧✚★➳➣❝✫✺❒➡❹❤♥❴☛✐✦❢ ❧ ❛✈❜✝❝✢❷❞❜✢❡✮❤❀❡✮➝✰✣✩❆➛★➟▼➡●✬❴✣➦➟★✩✝➒ ❈ ✁ ✧ ✩ ✩ ✩ ✧ ❈ ❚✝❿ ➓ →☎➢❫➧◗➟✰➠➉➟★❪➬➟▼➡✌✩✭✣✮➢❫➧✱✘➴➋❱◆✡➍✸✣❃❲✦❵❅➛❁✩❅➛✦✬✯✩✭Õ➑✫✘✮➲✧✚★➳ ❈ ✁ ❸✬❺✺❺✒❺✮❸✲✘✮➲✧✚★➳ ❈ ❚✝❿ ➓ ✩➙➜➛★➟✴✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪❬✳✵✧❅➟✹✣❬➟▼➡✞✩❅➟✹✥♠➛★➟★✧❅➟❴❵✰➢✱❪✺✳✵❲✵✩❅➟✹✣✑✬❫➡r➝➉➡✌✩❆➟▼➤✱✧✭✬❺➠❨✶✦✬✱✣➣➝✤✣❪❇➜➝✮✩❆➛Ü✬❃➠●➠⑥➝✮✩✭✣➥➟✰➠➉➟★❪➬➟▼➡✌✩✭✣➴➝➉➡ ✹Ó➋✣✚ ✧✤❊ ➍☎❇➥➛★➟★✧❆➟✹ ➝✤✣✑✬✡➤■➝✻✵❑➟▼➡❁✣❃❲✙✶✲❅❁➟✰➠✤✥♠➢■➧✱✘ ❵✰➢✒➡✞✩✢✬❃➝➉➡❸➝➄➡★➤❊✬❃➠●➠☛✩❆➛★➟❆❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣➥➢■➧ ☛❈❝✳✘✴ ✳✵✴✑✏✖◗➉➈✵✻❊✹✟✿❭✸ ➇ ❩ ✴ ➙➜➛★➟✺✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪ ❵★✬❫➡✂✶❁➟✍✥❸➟✹✣✿❵✢✧➦➝✻✶✸➟✹✥ ✬✔✣➜➧①➢❫➠●➠➉➢ ❇✾✣★❝✳✤Ó➟☎➠➉➢❸➢✄✯❨➧①➢✱✧❆✬❫➡✇➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠☎✶✦✬✱✣➣➝✤✣☞➢❫➧

✩❆➛★➟❚➧❹➢✱✧✛❪ ➒ ❈ ✁ ✧ ✩ ✩ ✩✌✧ ❈ ❚✝❿ ➓ →ù✣❃❲✦❵❅➛ý✩❆➛✦✬✯✩ ❈ ✇ ➝✤✣❀✬●✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✝➢❫➧❴✥❸➟▼➤✱✧❆➟▼➟✂③☞➝➉➡✕❊❹❇➴➝✲✩❅➛ ❵✰➢❸➟✰❾✝❵❅➝➉➟▼➡✞✩✭✣➁➝➉➡ ✹✵➋✴✚✤➍✭❝❽✇➢✱✧❆➟▼➢✢✵✒➟★✧ ❈ ✁ ❵★✬❫➡❘✶✸➟❴❵❅➛★➢✞✣❬➟▼➡✇➟✺❑✱❲✦✬❃➠❈✩❆➢❊✂✱❝❀➙➜➛★➟☞➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠ ✶✦✬✱✣➣➝✤✣⑧➝✤✣✑❵✰➢✔❪✺✳✵❲✵✩❆➟✹✥❁✣✫✩❆➟★✳❘✶✞✶❊✣❃✩❆➟★✳❇❝ ✻ ❲✵✳✵✳❁➢✞✣❬➟❞✩❆➛✦✬✯✩➒ ❈ ✁ ✧ ✩ ✩ ✩ ✧ ❈✶✵ ❿ ➓ →➛✦✬✒✵✒➟❉✶❁➟▼➟▼➡●❵✰➢✱❪✺✳✵❲✵✩❆➟✹✥ ✸❯✩❆➛★➟▼➡✿❇➜➟❆❵✰➢✱❪✺✳✵❲✵✩❅➟ ❈✶✵ ✣❃❲✦❵❅➛❁✩❅➛✦✬✯✩✘➥➲✧✚ ➳ ❈ ✁ ❸❻❺✺❺✒❺✺❸✷✘✮➲✧✚★➳ ❈✶✵ ➑Õ➒ ❂➁❘✸✭✯✚✱✥❸➟▼➤✸➋✓❂ ➍✮✆ ✟★→✬❫➡✦✥❊✥❸➟▼➤✸➋ ❈✶✵ ➍❣➑✡✟✍✬✔✣⑧➧❹➢■➠❐➠➉➢✢❇✑✣ ✚➋✭✂❫➍ ➠➄➟★✩ ❈✶✵ ✶✸➟✾❊ ❈✶✵ ❿ ➓ ✂

➽✱⑦

Page 71: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➋❱✐❸➍ ➠➄➟★✩✁� ➑Õ➒ ❂✪❘ ✭✯✚✱✥❸➟▼➤❁➋✧❂★➍✮✆ ✟ →➜↔ ✘➥➲ ✚★➳ ❈ ✁ ❸❆❺✒❺✺❺✉❸✷✘➥➲✧✚ ➳ ❈✶✵ ✂❇➥➛❸➝●➠➄➟✂� ❭➑☎✄✺✥❸➢➋❜✬❸➍✴❵❆➛★➢❸➢✞✣❬➟✖❂✇❘✆�❬✣❃❲✦❵❅➛Ü✩❅➛✦✬✯✩✯❂✇➑ ➋✧❂ ✁ ❈ ✁ ❸✬❺✺❺✒❺✺❸✾❂✵ ❈ ✵ ➍❀✪✙❙s❇➜➝✮✩❆➛ ❂ ✁ ✧ ✩ ✩ ✩ ✧ ❂ ✵ ✬■➡✦✥Ü❙ ➝➉➡❋✹❊➲✧✚★➳✠✬❫➡✦✥❂

✵➑ ✂ ✂

➋P✶✤➍✺✣❃❲✙✶✦✣❃✩❬➝✮✩✿❲✵✩❆➟ ❈✶✵ ✶✌✶✼❂✦❝❤q➡✇➢✱✧✭✥❸➟★✧✾✩❆➢✍❵✰➢✱❪â✳✵❲✵✩❆➟❴✬❫➡✇➟✰➠➉➟★❪➬➟▼➡✞✩✏❂❊✣✛✬✯✩❬➝✤✣➣➧✽✶✒➝➉➡★➤❀✩❆➛★➟❴❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣☞➢■➧➥➋❜✬❸➍✤✸✵✩❅➛★➟❴✬✯❲✵✩❆➛★➢✔✧✑✬✯✳✵✳❸➠●➝➉➟✹✣✾✩❆➛★➟✴✧❆➟✹✣❃❲❸➠✮✩✣✿✬❅✶❑➝➄➡★➤ô✩❆➛✦✬✯✩ ✚✂⑥Õ■❉✬✯✳✵✳❁➟✹✬❏✧✭✣✔➝➉➡Õ✩❆➛★➟❁✥❸➟▼➡★➢✱❪✡➝➉➡✦✬✯✩❆➢✔✧✝❙Ó➝●➧❴✬❫➡✦✥ ➢✒➡❸➠✮✶❊➝❐➧✍◆ ➛✦✬✱✣❀✬ù✣➣➝➉➡★➤✱❲❸➠✤✬✯✧❬➝✮✩❃✶ ➢✒➡ý✩❅➛★➟r➠❐➝➉➡★➟✚✇➑❛■✸❝☎✺✮➧➆✩❅➟★✧✷✩❆➛✦✬✯✩✺✸❖➧❹➢✱✧✼❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❀✩❆➛★➟ ❂ ✇ ❭✏✣✮✸✞✝♦❲❸➝✤✣❬➟★❲ ✝✃➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣✼✬✯✧❅➟✼❲✦✣❬➟✹✥●✬❫➡✦✥❁✬❃➠✤✣❬➢◗✶❁➢✔❲★➡✦✥✵✣➜➧①➢✱✧✾✩❆➛★➟✹✣❬➟➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣✾✬❫➡✦✥➁➧❹➢✔✧✷✩❆➛★➟❆✥❸➟▼➤✱✧❆➟▼➟✔➢❫➧✠✩❆➛★➟❆✥❸➟▼➡★➢✱❪✡➝➉➡✦✬✯✩❆➢✔✧✹❝❀➙➜➛★➟☞➝✤✣✿✣❃❲★➟ ➝✤✣✷✩❆➛★➟✼✧❅➟✹✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡♠➢■➧♦✬✔➠●➝➉➡★➟✹✬✯✧✼✣❃✶✵✣❃✩❆➟★❪❁❝

▼❊✴✑✏✖❬ ❬ ◗ ✿✚➅✟❨❫✸✺✿❭✻✢➆ ✸❱✻ ✸ ➇ ❯✜❬✂❨✘✹✼❨☎❩✙❯ ✸✺✹✟✿✓✘✛❨❫✸✺✿❀✻❞➆ ✻✫✞✑❨✘◗ ➈✘❯✮✌✗✹✼❨✘✿✚➅✃➅❖➂✾✹✼❙☎❯✭❲➊✮➟★✧❆➟✯☛ ➝✤✣❑✣✫❲✵✳✵✳❁➢✞✣❬➟✹✥❀✩❅➢✰✶❁➟✮➝✮✧✿✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➉➟✡➢❫➧☛✥❸➟▼➤✱✧❆➟▼➟❉⑤❘❇➜➝✮✩❆➛❀✧❆➟✹✣❃✳✸➟✹❵✢✩❑✩❅➢✽❊⑤❝❣➙➜➛★➟✼❵✢❲✵✧ ✵✒➟✝◆Ï➝✤✣❋✩❆➛★➟✾✳✵✧❆➢✱♥❬➟✹❵✢✩❬➝❀✵✒➟

✬❃➠➉➤✒➟✮✶✵✧✭✬❺➝✰❵✴❵✢❲✵✧ ✵❑➟❄✥❸➟▼❅❁➡★➟✹✥ ✶✌✶✼☛❈❝➹➭➞➟★✩ ❋ ✶❁➟✴✩❆➛★➟✔➛★➢✱❪➬➢✒➤❑➟▼➡❸➝✲✟✹✬❏✩❬➝➉➢✒➡②➢❫➧ ☛❈❝✷❤➣✩✼❪➁➟✹✬❫➡✦✣✷✩❅➛✦✬✯✩ ❋✔➋✢❴ ✧✩★ ✧✠✟❒➍⑥➝✤✣✾✩❆➛★➟✳❁➢■➠✲✶❸➡★➢✱❪✡➝✤✬❃➠➥➢❫➧✷✣❃❪✍✬❃➠●➠➉➟✹✣❃✩✺✥❸➟▼➤✱✧❆➟▼➟❀✣❃❲✦❵❆➛ô✩❆➛✦✬✯✩✏☛♣➑ ❋✔➋✚❴✚✧✔★ ✧✹✂❫➍✭❝ ✺ ✳✦✬✯✧✭✬✯❪➁➟★✩❆➟★✧✝❆②➝✤✣❆✬ ➧➆❲★➡✦❵✢✩➦➝➄➢❑➡Ô➤✒➟▼➡★➟★✧✢✬✯✩❬➝➉➡★➤✘➜➋❬◆✡➍✤✸❑➝➣❝❵➟✱❝❀✸❸➟✮✵✒➟★✧✿✶➁➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❨➝➉➡✬✘➴➋❱◆✡➍✠❵★✬❫➡✿✶✸➟❉❇✷✧❬➝✮✩✿✩❆➟▼➡❁✬✔✣✷✬❞✧✭✬✯✩❬➝➉➢✒➡✦✬❃➠✤➧✽❲★➡✞✩➦➝➄➢❑➡❨➝➉➡✷❆❇❝✠❤➐✩➜➝✤✣⑧➝➉➡❨➧➣✬✱❵✢✩✑✬ ➧➆❲★➡✦❵✢✩➦➝➄➢❑➡❇➜➝✮✩❆➛ ➢✒➡❸➠✮✶ ➢✒➡★➟❊✳✸➢❫➠➉➟✿❇➥➛❸➝✤❵❅➛ ➝✤✣➁➢❫➧❒➢✱✧✭✥❸➟★✧❡✂❨➢✒➡❼◆✺❝ ✺✐✳✦✬✯✧✭✬✯❪➁➟★✩✿✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡ ➢❫➧✝◆ ➝✤✣✺✬●✳✦✬❃➝✮✧✇➋ ❴Ô➋☛✡❆➍✪✧✩★✡➋☞✡❆➍❆➍✝➢❫➧✧✭✬✯✩➦➝➄➢❑➡✦✬❃➠✤➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✾✣❃❲✦❵❅➛❁✩❆➛✦✬❏✩ ☛✔➋✢❴Ô➋☛✡❆➍✪✧✩★☎➋☞✡❅➍❆➍❣➑❲❯✺✬■➡✦✥✛✘❚➋ ❴❊➋☞✡❅➍✪✧✔★✡➋☛✡❆➍❆➍❣➑✫✘➴➋☞✡❆➍✢❝P✸❲✵✧ ✵❑➟✹✣✷✬❃➠●➠➉➢ ❇➴➝➄➡★➤❀✳✦✬✯✧✭✬❏❪➬➟★✩✿✧❬➝✮✟✹✬✯✩❬➝➉➢✒➡✦✣✪✬✯✧❆➟❆❵★✬❃➠●➠➉➟✹✥❡✧✭✬✯✩❬➝➉➢✒➡✦✬❃➠✠❵✢❲✵✧ ✵✒➟✹✣★❝❀➙➴➛★➟★✶❁✬✯✧❆➟☞➝➉➡❨➧➣✬✱❵✢✩✑❵✢❲✵✧ ✵❑➟✹✣➜➢❫➧❣➤✒➟▼➡✞❲✦✣☞❯✵❝

➙➜➛★➟❊✬❃➝✮❪ ➢❫➧✷✩❆➛❸➝✤✣❴✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪Ò➝✤✣❆✩❅➢Ü❵✰➢✱❪✺✳✵❲✵✩❅➟★❇➥➛★➟▼➡Ó➝✲✩✔➝✤✣❞✳❁➢✞✣✛✣➣➝❀✶❸➠➄➟●✬❊✳✦✬✯✧✢✬✯❪➬➟★✩✿✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡Ô➢❫➧✑✬❚➤❫➝❀✵✒➟▼➡ ❵✢❲✵✧❞✵✒➟✝✸❲✦✣➣➝➉➡★➤❀✩❆➛★➟❆✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ➧❹➢✱✧✾❵✰➢✱❪✺✳✵❲✵✩❬➝➉➡★➤❊✬❫➡r➝➉➡✞✩❆➟▼➤✔✧✭✬❃➠✟✶✦✬✱✣➣➝✤✣✪✳✵✧❆➟✹✣❬➟▼➡✌✩❆➟✹✥❘✶✸➟✰➧❹➢✱✧❅➟✱❝▼❊✴ ✳✵✴✑✏✖◗➉➈✵✻❊✹✟✿❭✸ ➇ ❩ ✴ ➙➜➛★➟❆✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪➺➧①➢✱✧✑❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❊✬✴✳✦✬✯✧✢✬✯❪➬➟★✩✿✧❬➝✮✟✹✬✯✩➦➝➄➢❑➡r➝✰✣◗✩❆➛★➟✝➧①➢❫➠●➠➉➢ ❇➴➝➄➡★➤☛✚➋✭✂❫➍âP❀➢✱❪✺✳✵❲✵✩❆➟✼✬✴✳✦✬✯✧✢✬✯❪➬➟★✩❆➟★✧☛❆ ✂➋❱✐❸➍ ✙ ✝✵✳✵✧❆➟✹✣✿✣✜✚❡✬❫➡✦✥❘❊✍✬✔✣✖✧✭✬✯✩❬➝➉➢✒➡✦✬❺➠✿➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣➴➝➉➡ ❆❇❝

☞★➢✔✧✷✩❆➛★➟❆❵✰➢✱❪✺✳✵❲✵✩✢✬✯✩❬➝➉➢✒➡♠➢■➧♦✬✴✳✦✬❏✧✭✬✯❪➬➟★✩❆➟★✧✒✸✦✥❑➝❀✵✒➝✤✥❸➟✴✩❆➛★➟❆✳✵✧❅➢✱♥❬➟✹❵✢✩❬➝❀✵✒➟✼✳❸➠✤✬❫➡★➟✔➝➄➡❡✩✈❇➸➢✺✥❑➝✤✣s♥❬➢❫➝➉➡✞✩✾✳✦✬✯✧✿✩✢✣➥P❉✬❫➡✦✥❁✆â❝P❀➢✱❪â✳✵❲✵✩❆➟❆✬✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡②➐⑨❇➜➝✮✩❆➛✇➢✒➡❸➠✮✶❨➢✒➡★➟❆✳✸➢❫➠➉➟✍➢■➧◆❪✴❲❸➠✮✩❬➝✮✳❸➠●➝✰❵❅➝✮✩❃✶ ✂☞➝➉➡✵P✍✌❨◆✺❝➜➙➜➛★➟▼➡Ü❵✰➢✱❪â✳✵❲✵✩❆➟❆✬✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡②➻❇➜➝✮✩❆➛②➡★➢❀✳❁➢❫➠➉➟✔➝➉➡ P✎✌❨◆ ✬❫➡✦✥❁✣❃❲✦❵❅➛●✩❆➛✦✬✯✩✝➐✬❸ ➻❥➛✦✬✔✣➥➡★➢❀✳❁➢❫➠➉➟✡➝➉➡ù✆✏✌ ◆â❝✝➋✥☞ ➢✱✧✷✩❆➛✦✬✯✩✒✸✦✩❆➛★➟✴❵✰➢✱❪✺✳✵❲✵✩✭✬❏✩❬➝➉➢✒➡♠➢❫➧✬❫➡r➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠ ✶✦✬✱✣➣➝✤✣⑧➝✤✣✷❲✦✣➦➟✹✥✸➍✭❝❀➙➜➛★➟▼➡●✬✴✳✦✬✯✧✭✬✯❪➁➟★✩❆➟★✧⑧➝✰✣☞➐❣❸✦➻â❝➙➜➛★➟☞➠✤✬✱✣❃✩✪✩❆➛❸➝➉➡★➤✍✩❆➢❀✥❸➢✡➝✤✣✖✩❆➢➬➟✆✝✵✳✵✧❆➟✹✣✿✣✜✚❡✬❫➡✦✥✿❊❀✬✱✣✖✧✢✬✯✩❬➝➉➢✒➡✦✬❃➠✤➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣➜➝➉➡✪❆❘✶✞✶❊❵✰➢✱❪✺✳✵❲✵✩➦➝➄➡★➤❊✬✯✳✵✳✵✧❆➢✔✳✵✧❬➝✤✬✯✩❆➟✹✥

✧❆➟✹✣❃❲❸➠✮✩✭✬■➡✞✩✭✣➍❝➙➜➛★➟●❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡❼➢❫➧✝➝➉➡✌✩❆➟▼➤✱✧✭✬❃➠▲✶✦✬✱✣➣➝✤✣❊❵★✬❫➡ ✬❺➠✰✣➦➢ ✶✸➟❁❲✦✣❬➟✹✥ ✩❆➢ ❵✰➢✔❪✺✳✵❲✵✩❆➟●✩❆➛★➟♠➤❑➟▼➡✞❲✦✣➁➢❫➧❆✬ ❵✢❲✵✧ ✵❑➟♠➢✱✧❀✩❆➛★➟

✤✵➟✰➝➉➟★✧✭✣❃✩✛✧✭✬✱✣✿✣➜➡★➢✔✧✿❪✍✬❃➠✤➧①➢✱✧✿❪ ➢❫➧✠✬✺❵✢❲✵✧ ✵✒➟✔➢❫➧◗➤✒➟▼➡✌❲✦✣❆✂ ✸ò✣➦➟▼➟✪➲✮✂✢✸✦❥❃➳➣❝♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④

⑥⑧⑦❃⑨✷➊✹➂★➌ ✘ ❶✯❺✿❹ ✑✖❼➆➑â➂★❻➣õ✱❿✛❾★➒✍➾❋➌❴➂➍❸➉➝❅❶✹❻➐❹➉➏➐↕✱➪ ↔s❶✹❻✠➙❃❶✹➪❞➔✱❷✱➏➣❹⑧➌✱➝✷➂➍➌❆❹⑧➌✯➏➣❺✿➝❅❻❜➂★❸✌Þ✞➂➍→➣❹⑧→☛❹⑧➌✴➂★➌❆➂★❸⑧➝❅❺✿Þ✱❻❜➂➍❹✮➙❈↔✤❷✱➌✌➙❃➏➣❹⑧❶✹➌è➛✞❺✿❸✮➄✵❾✵é✯➤ ✃ ➢✿➩✞❰➍❮➤ ✕ ➲☞✂★❐✼Ò❃➤★❮❱➨✤➥✼➵☛➤➍❐✸❒ ✃❅➱ ❰ ➱ ➨✤➤➍➩✱➀✱➊❅❶✹❸✽❾✵⑦ ✱✔➀ ➶✢➹✹➹➍Ù ➀✯➔✱➔✦❾✱Ú❅➼✹Ú➋➒❏Ú✹➽❅Ú✱❾

⑥➇➴✢⑨✷➊✹➂★➌ ✘ ❶✯❺✿❹ ✑◗❼➆➑✺➂➍❻➣õ✱❿✿❾➍➒✍➚❈❶✹➪❆➔✔❷✱➏➣❹⑧➌✱➝❋➔✞➂★❻❃➂★➪❆❺✛➏➣❻➣❹⑧➃✭➂➍➏➣❹⑧❶✹➌✔→❇❶★↔✦❻❃➂★➏➣❹⑧❶❅➌✞➂★❸✞➂➍❸⑧➝✹❺✿Þ✱❻❃➂★❹✮➙✠➙❃❷✱❻➐➊✹❺✿→✢❾✯➠✽➌✺➲☞✂★❐✼Ò❃➤★❮❱➨✤➥✷❰★➩✌➧✖➳✖❮➇➫✹➦✭Ò✛➢❜❰➍➨✤➥➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨✤➤★➩✔❾✯➾✸➚✠➑❊➀✱➔✱➔⑤❾✵⑦ ✱✹ã➋➒ò⑦ ×✹þ ❾➍➒❁ñ✠❺✿Ýôó☛❶✹❻➐õ✵➀ ➶✭➹✹➹➍Ù ❾✱➎ß❻➐❶✱➙❃❺✿❺✭➄✯❹⑧➌✱➝❅→✸➠➣å✱å❏➾✸➚✖æ × ✗✞➀✱➈♦ç✯↔✤❶✹❻❃➄✵➀✱îß➌✱➝❅❸✮➂★➌✞➄✵❾

⑥➇Ú✢⑨✷➊✹➂★➌ ✘ ❶✯❺✿❹ ✑✠❼✽➑✺➂★❻➐õ✱❿✿❾➍➒❆➾✸➌✼➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✱➪❢↔s❶✹❻❇➙❃❶✹➪❞➔✱❷✱➏➐❹➉➌✔➝✸➏➣↕✔❺✞✣ù❺✿❹⑧❺✿❻➣→➐➏➣❻❃➂★→➣→❈➌✱❶❅❻➣➪❴➂➍❸★↔✤❶❅❻➣➪❀❾✿➠✽➌✴➲☞✂★❐✼Ò❃➤★❮✏➨s➥❑❰➍➩✞➧❋➳✖❮➇➫✹➦✭Ò✛➢❜❰➍➨✤➥➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨✤➤★➩✔❾✯➾✸➚✠➑❊❾✯➒❊➾✸➚✠➑ ➎ß❻➣❺✿→➐→✭➀ ➶✭➹❅➹✹➘ ❾✙➎ß❻➐❶✱➙❃❺✿❺✭➄✯❹⑧➌✱➝❅→✖➠➣å✱å✯➾✸➚✖æ × ➼✔➀✙➑✴❶❅➌✯➏➣❻➣❺✢➂★❸✽➀✱➚✠➂★➌✞➂❅➄✱➂✱❾

➽✹➴

Page 72: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�❨✑✓✞ ✞❈✆✂✄✍☞P✌ ☞ ✆✟✞✕✔ ✁☎✄✝✠❲✄✗☞✍✆✂✠✕✆✁�✂✁❹✑✓✔ ✞✘✁✛✞✵✄✚✄P☞✍✔☎✄✝☞✦✌ ☎✟✠✟✄✛✞ �✂✁✝✠☎✄P✏✠❊✠ ✡⑨�✙✁✝☞✦✄✄✂✓✞ ✞✙✄✝☞P✌ ☞✚✠❾✄✄✂☛✞☎✄ ✠ ✌✙✆✒✞ ☞P✠☎✠

✆ ✩✭✩✲✜✒✭✮✪✗✬✞✝❫✭✮✜✟✬P✜✒✩✢✪ ✫❁✮➡❸➝✻✵❑➟★✧✭✣➣➝✮✩ ✳➟✴✥❸➟☎➭✸➝✮❪➬➢✒➤✒➟✹✣✼✯❲★➡★➟➁❛❦✸ß✂✺✹✝✹✒Ö

➲❱✣❃❲✵❪✺❪✍✬✯✧✛✶★✶✞✶②➷✼✬ ✳➟★✩✢✬❫➡✪➊✾✬✱❵❆➛ ✳➟▼➳

✳✵✴✷✶❃➆✘✸✺✹✼✻✾✽✘➂✢➅✟✸✺✿❀✻❞➆➙➜➛★➟r➝➉➡✌✩❆➟★✧❆➟✹✣❃✩➬➢■➧✑✩❆➛❸➝✤✣✴✩✭✬❃➠ ✯Ó➝✤✣✴✩❆➛★➟r➝➉➡✞✩❅➟▼➤✱✧✭✬✯✩❬➝➉➢✒➡ ➢■➧❒➛✞✶✌✳❁➟★✧❅➟✰➠❐➠●➝✮✳✵✩❬➝✤❵✇➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣★❝ ➙➜➛★➟❊✩❆➟✹❵❅➛★➡❸➝ ❑✱❲★➟❡❲✦✣❬➟✹✥❊➧①➢✱✧

✣❃❲✦❵❅➛✵➝➉➡✌✩❆➟▼➤✱✧✭✬❏✩❬➝➉➢✒➡✵➧①➢❫➠●➠➉➢✢❇✑✣❞✩❆➛★➟✍❲✦✣✫❲✦✬❃➠✷✳✦✬✯✩✿✩❆➟★✧❆➡ ➧❹➢✱✧✴✩❆➛★➟➁➝➉➡✞✩❅➟▼➤✱✧✭✬✯✩❬➝➉➢✒➡Ó➢❫➧✒✬❃➠➉➤✒➟✮✶✵✧✭✬❺➝✰❵➁➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ✥❸➟✮✵✒➟✰➠➉➢✱✳❁➟✹✥ ✶✞✶✮✼❝❀➊❞❝❇✮⑧➝✤✣✿❵❆➛✟✸➥➫✾❝❀❽❢❝❀➙▲✧✭✬❫➤❑➟★✧✺✸ ✼❯❝❀➊❆❝ �✼✬✺✵❑➟▼➡✵✳❁➢✱✧✿✩❀✬❫➡✦✥ ✬●✧❆➟★✳✵✧❆➟✹✣➦➟▼➡✞✩✭✬❏✩❬➝➉➢✒➡❼➢❫➧❆✥❑➝❀✵✒➝✤✣❬➢✔✧✭✣➬➢✢✵✒➟★✧➁➛✞✶✌✳❁➟★✧❆➟✰➠●➠●➝✮✳✵✩❬➝✤❵❵✢❲✵✧ ✵✒➟✹✣✪✥✌❲★➟❆✩❆➢ �✴❝✸➷✴❝ßP❑✬❫➡✌✩❆➢✱✧✹❝ ☞★➢✱✧✮➟✆✝❯✬✯❪â✳❸➠➄➟✝✸ ❇➸➟❉❇✷✬❫➡✌✩✖✩❆➢✍❵✰➢✱❪â✳✵❲✵✩❆➟✼✩❆➛★➟✝➝➉➡✌✩❆➟▼➤✱✧✭✬❺➠

✟ ✡✟

❥✄✚ ✤ ⑥ ✚✷❸ ✐➋✣✚ ✟ ⑥ ✚ ✤ ⑥✷✚✷❸ý✂■➍✡✠ ✚ ✤ ❸✲✚★⑥ ✂ ✟ ✚ ✩➋✭✂❫➍

❤①➧✸✩❅➛★➟☎➟✆✝✦✬✱❵✢✩④✵✯✬❃➠✮❲★➟➬➢❫➧✠✩❆➛❸➝✤✣✮➝➉➡✞✩❆➟▼➤✔✧✭✬❃➠✢➝✤✣☞➡★➟▼➟✹✥❸➟✹✥ ✸ß✩❆➛★➟▼➡✇➢✒➡★➟☎➡★➢✱✧✛❪✍✬❃➠●➠✮✶Ü❵✰➢✱❪✺✳✵❲✵✩❅➟✹✣✑✬â✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟✱❝✾❤q➡❡✩❆➛❸➝✤✣✼❵★✬✱✣❬➟➝✮✩➜➝✤✣➥➟✺❑✔❲✦✬❃➠☛✩❅➢

➠➉➢✒➤ ❄ ✚✽❸ ✠ ✚ ✤ ❸✲✚✱⑥ ✂✚✱⑥☛✠ ✚ ✤ ❸✲✚✱⑥ ✂

❆ ✩❤①➧☎❇➜➟❆✣❬➟★✩

❊ ✟ ➑✫✚ ✤ ❸✷✚✱⑥ý✂ ✧➋❱✐❸➍✩❆➛★➟▼➡✇➢✒➡★➟❆❵★✬❫➡❁❵✰➢✒➡✦✣➣➝✤✥❸➟★✧✾✩❆➛★➟✝➝➉➡✌✩❆➟▼➤✱✧✭✬❺➠

✟ ❥✄✚ ✤ ⑥ ✚✷❸ ✐➋✣✚ ✟ ⑥ ✚ ✤ ⑥ ✚✷❸Õ✂❫➍❍❊ ✟ ✚

➢✢✵✒➟★✧✖✩❆➛★➟❴✬❺➠➄➤❑➟✮✶✵✧✭✬❃➝✤❵☞➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❘❅❁➟✰➠✤✥❚➢❫➧◆✩❅➛★➟❆✬❃❾✪➡★➟❆❵✢❲✵✧ ✵✒➟☞ ➑Õ➒✒➋✓❂ ✧ ❈ ➍⑥❘✍✌ ✟ ➋✡✎❣➍✜✚ ❈ ✟ ⑥ ❂ ✤ ⑥ ❂❫❸ý✂☞➑Ï❯❸→ ✩

▼❊✴✪✶❃➆✘✸❱❯❢➈☎✹✼❨❫✸✺✿❀✻❞➆ ✻❫❙☎❯❫✹ ✞❆➂⑥➆✢➅✟✸✺✿❀✻❞➆ ➃❢❯✭◗❘✽❵✻✫✞❒➅❸➂✂✹✼❙☎❯✭❲➙➜➛★➟✡➤✒➟▼➡★➟★✧✭✬❺➠♦✣❬➟★✩✛❲✵✳♠➝✤✣✾✩❆➛★➟✔➧①➢❫➠●➠➉➢ ❇➴➝➄➡★➤⑤❝➹➭➞➟★✩✏✹ ✶✸➟❄✬✽❅❁➟✰➠✤✥②➢❫➧❑❵❅➛✦✬✯✧✭✬✱❵✢✩❅➟★✧❬➝✤✣❃✩❬➝✤❵✡❯✙✸ ✹✄✬❫➡ù✬❃➠➉➤✒➟✮✶✵✧✭✬❺➝✰❵✴❵❅➠➉➢✞✣❃❲✵✧❅➟

➢❫➧ ✹ ✬❫➡✦✥✂❋ ❘ ✹Ô➲ ✚ ✧✤❊❑➳☛✬❫➡ù✬✢✶✦✣➦➢❫➠✮❲✵✩❆➟✰➠✮✶♠➝✮✧✿✧❅➟✹✥✌❲✦❵❅➝✻✶❸➠➉➟❀✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠☞➋➣✩❆➛✦✬✯✩✮➝✤✣❉❋ ➝✤✣➹➝✲✧✛✧❆➟✹✥✌❲✦❵❅➝❀✶❸➠➄➟r➢✢✵✒➟★✧ ✹✵➍✢❝✦✤✵➟❵✰➢✒➡✦✣➣➝✤✥❸➟★✧✾✩❆➛★➟☞➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❘❅❁➟✰➠✤✥ ✹Ó➋ ☞ ➍◗➑ ✹✵➋✴✚✤➍❇➲❖❊❑➳ ✪✑✏✍❋✓✒❇➥➛★➟★✧❆➟ ☞ ➝✤✣✪✩❆➛★➟❆❵✢❲✵✧ ✵✒➟✴✥❸➟▼❅❁➡★➟✹✥❘✶✌✶■❋✔➋✣✚ ✧✤❊ ➍❣➑❲❯✵❝♦✖✵✙♣✘✰✦q✶✰❀r☞✰✚❡☎q ✂ ✷✍✺ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✵➶Ò➝✤✣✼✣✿✬❃➝✤✥❡✩❆➢◗✶❁➟✍✬■➡ ❢✺❝❑❢✕✔✾❢✒❴☛✐✦❜✝❛✗✖✓✌ ❛✤❤✘✔✷❤❥✐✦❤✚♥✺❢r➢❫➧ ✑Ó❘ ✹Ó➋ ☞ ➍❀➝●➧➴➶ ❘ ➑ ✑ù✬❫➡✦✥

➝●➧➹➶ ❵★✬■➡ ✶✸➟ ❇✷✧➦➝✲✩✛✩❆➟▼➡✵➧✽✧❆➢✱❪Ò➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✔➢❫➧✯✹Ó➋ ☞ ➍✷❲✦✣➣➝➉➡★➤ ❵✰➢✱❪✷✶❸➝➉➡✦✬✯✩❬➝➉➢✒➡✦✣➎➢❫➧➜➠➄➢❑➤✞✬✯✧❬➝✮✩❆➛✵❪✍✣✉✸◗➟✆✝✵✳❁➢❑➡★➟▼➡✞✩❬➝✤✬❃➠✤✣❀✬❫➡✦✥✬❃➠➉➤✒➟✮✶✵✧✭✬❺➝✰❵ ➟✆✝ò✳✵✧❅➟✹✣✿✣➣➝➉➢✒➡✦✣★❝

➽✹Ú

Page 73: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❤q➡❡✩❆➛★➟✼✳✵✧❆➟✮✵❑➝➉➢✱❲✦✣➥➟✆✝✦✬✯❪✺✳❸➠➉➟ ✑❚➑ ❥✄✚ ✤ ⑥ ✚✽❸✦✐➋✣✚ ✟ ⑥ ✚ ✤ ⑥ ✚✽❸ ✂❫➍❍❊ ✧

✩❆➛★➟❆❵✢❲✵✧ ✵❑➟☎➛✦✬✱✣⑧➧①➢✱✧➜➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡❊ ✟ ⑥ ✚ ✤ ⑥ ✚✷❸Õ✂☞➑❲❯

✬❫➡✦✥ ✑✇➛✦✬✱✣⑧➧①➢✱✧➜➟✰➠➉➟★❪➬➟▼➡✌✩✭✬✯✧✿✶❊✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟➠➉➢✒➤ ✞ ✚✷❸❵❊

✚★⑥●❊ ✠ ✩✤✵➟❉❇✷✬❫➡✌✩✖✩❆➢✍✬❫➡✦✣✈❇➜➟★✧✷✩❅➛★➟☞➧❹➢❫➠●➠➉➢✢❇➜➝➉➡★➤ ❑✔❲★➟✹✣❃✩❬➝➉➢✒➡✦✣ ✚

➋✭✂❫➍✌�☞➢❢➟✹✣✷✬ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ✑✇❘✼✹Ó➋ ☞ ➍❣➛✦✬✒✵✒➟❆✬❫➡❨➟✰➠➉➟★❪➬➟▼➡✌✩✭✬✯✧✿✶❀✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟➬➶❪➑✁� ✑ ✟ ✚❨➢✢✵✒➟★✧ ✛✄✂➋❱✐❸➍❞❤①➧✸✣❬➢☛✸✲❇➥➛✦✬✯✩➜➝✤✣✪✩❆➛❸➝✤✣✖✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟☎✂✮⑧➝✤✣✿❵❅➛♠➛✦✬✒✵✒➟❆✣❬➛★➢✢❇➥➡❊✩❅➛✦✬✯✩⑧➝❐➧➸➶ ➝✤✣✷✬❫➡❨➟✰➠➉➟★❪➬➟▼➡✌✩✭✬✯✧✛✶❊✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟☎➢✢✵✒➟★✧ ✹ ✩❆➛★➟▼➡

➶❪➑Õ✗ ✁ ❸❼⑧ ✇❀❛✸➓ ▼ ✇ ➠➉➢✒➤✸➋❜✗ ✇ ➍➋❜❥❸➍

❇➥➛★➟★✧❆➟●✗ ✁ ❘ ✹Ó➋ ☞ ➍✤✸✸▼▼✇✡❘ ✹ ✬■➡✦✥ ✗✺✇➬❘ ✹Ó➋ ☞ ➍✭❝ ➙➜➛★➟Ü✬❃➠➉➤✒➟✮✶✵✧✢✬❃➝✤❵❊✳✦✬✯✧✿✩❀✗ ✁ ➝✰✣❀❵✰➢✱❪✺✳✵❲✵✩❅➟✹✥ ❲✦✣➣➝➉➡★➤ ➊➥➟★✧✿❪➎➝✲✩❅➟✝❭✏✣✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪ ✬❫➡✦✥❊✩❅➛★➟☞➠➄➢❑➤✞✬✯✧❬➝✮✩❆➛✵❪✡➝✤❵è✳✦✬✯✧✿✩➜➝✤✣✷✥❸➢✒➡★➟❞❲✦✣➣➝➉➡★➤ ✮➸➝✰✣✛❵❆➛✟❭✏✣✾✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪❁❝☞★➢■➠❐➠➉➢✢❇➜➝➉➡★➤➁➝✰✣✪✬✺✣❬➛★➢✱✧✿✩✮➛❸➝✰✣✫✩❆➢✱✧✿✶r➢❫➧⑥➝➄➡✌✩❆➟▼➤✱✧✢✬✯✩❬➝➉➢✒➡❨➢❫➧✸✬❃➠➉➤✒➟✮✶✵✧✭✬❃➝✤❵➹➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣➍❝✂✺◆✱❥✱❥ ✚⑧➭✸➝➉➢✱❲✙✵✒➝●➠●➠➉➟✝❭✏✣✾✳✵✧❬➝➉➡✦❵❅➝✮✳❸➠➉➟ ✂✢➤❫➝❀✵✒➟✹✣✖✩❅➛★➟✝➧①➢✱✧✿❪➺➢❫➧✠✩❆➛★➟✝➟✰➠➉➟★❪➬➟▼➡✞✩✢✬✯✧✿✶❊✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟ ✂✂✺◆❸❛❺✐ ✚⑧➊➥➟★✧✿❪➎➝✲✩❅➟✝❭✏✣✷✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪ ✂✦✬❃➠●➠➉➢✢❇✑✣✖✩❆➛★➟❆❵✰➢✱❪â✳✵❲✵✩✭✬✯✩❬➝➉➢✒➡❨➢❫➧✠✩❆➛★➟❆✬❃➠➉➤✒➟✮✶✵✧✢✬❃➝✤❵✼✳✦✬✯✧✿✩✰✂✂✺✹❸❛❺❯ ✚ ✮⑧➝✤✣✿❵❆➛✟❭❱✣✼✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪ ✂❈✬❃➠●➠➉➢ ❇✾✣✼✩❆➛★➟✺❵✰➢✱❪✺✳✵❲✵✩✢✬✯✩❬➝➉➢✒➡②➢❫➧❑✩❅➛★➟✡➠➉➢✒➤✞✬✯✧❬➝✮✩❆➛✵❪➎➝✰❵❄✳✦✬✯✧✿✩✹❝✰✴✮➟▼➟✹✥✵✣❆✬❏✧❬➝✮✩❆➛✵❪➬➟★✩❬➝✤❵✡➢✢✵✒➟★✧

✥❑➝✻✵❑➝✤✣❬➢✱✧✭✣✮➢❫➧✢➧✽❲★➡✦❵✢✩❬➝➉➢✒➡s❅❁➟✰➠✰✥✵✣✼✬■➡✦✥❀✳✵✧❬➝➉➡✦❵❅➝✲✳✦✬❺➠❐➝✮✩❃✶●✩❆➟✹✣❃✩ ✂✂✺✹✝◆✵✂ ✰ ✂✺✹ ◆❫❴✄✚ �✼✬✒✵✒➟▼➡✵✳✸➢✱✧✿✩✑✬■➡✦✥❨➙❇✧✭✬■➤✒➟★✧✷✬❃➠➉➤✒➢✱✧❬➝✮✩❆➛✵❪✍✣ ✂✲❅✦✧✭✣❃✩➜➝✮❪✺✳❸➠➉➟★❪➬➟▼➡✌✩✭✬✢✶❸➠➉➟✺✬❃➠➉➤✒➢✱✧➦➝✲✩❅➛✵❪✍✣★❝

✂❧✴ ✆✂❬ ❯❖➅✛✿❭❨✘◗➥➅✟❨✘❲✔❯✝✆ ➇ ❖✗❬ ❯❫✹✺❯❫◗❘◗ ✿❘❬✂✸✺✿✚➅✵➅❸➂✂✹✼❙☎❯✭❲❤q➡❊➛❸➝✤✣✴✩❆➛★➟✹✣➣➝✤✣✮✸⑧➫✑❝⑥➙❇✧✢✬❫➤✒➟★✧✡➤❫➝❀✵✒➟✹✣✴✬❫➡ ✬❃➠➉➤✒➢✔✧❬➝✮✩❆➛✵❪ ❇➥➛❸➝✤❵❆➛ý✣❬➢■➠✻✵❑➟✹✣❆✩❅➛★➟✍✳✵✧❆➟✮✵❑➝➉➢✱❲✦✣ ❑✱❲★➟✹✣✫✩❬➝➉➢✒➡✦✣✔➝➉➡ ✩❆➛★➟➬➤✒➟▼➡★➟★✧✢✬❃➠

❵★✬✱✣❬➟✹✣➍❝❀➙➜➛★➟❉❇➜➢✱✧✔✯➬➢■➧ ➭✠❝❁➫⑧➟★✧✿✩✿✧✢✬❫➡✦✥❊✣❃✩✿❲✦✥❑➝➉➟✹✣✖✩❆➛★➟❆❵★✬✔✣❬➟❉❇➥➛★➟★✧❆➟ ☞ ➛✦✬✱✣⑧➤✒➟▼➡✌❲✦✣ t✩★♣✐r➋q➛✌✶✞✳✸➟★✧❆➟✰➠●➠❐➝✮✳✵✩❬➝✤❵❃➍✑✬❫➡✦✥ ✹Ó➋ ☞ ➍➝✤✣✷✬ ❑✔❲✦✬✱✥✌✧✭✬❏✩❬➝✤❵➥➟✆✝✵✩❆➟▼➡✦✣➣➝➉➢✒➡❨➢❫➧✻✹✵➋✴✚✤➍❨❇➴➝✲✩❅➛ ✚✇❘✼✹Ó➋ ☞ ➍☛✩✿✧✢✬❫➡✦✣✿❵✰➟▼➡✦✥❸➟▼➡✌✩✭✬❃➠✿➢✢✵✒➟★✧☎✹❢❝❀➭✤➟★✩✜✘●✶❁➟✼✩❆➛★➟✮➧✽❲★➡✦❵✢✩❬➝➉➢✒➡◗❅❁➟✰➠✤✥➢❫➧❣➤✒➟▼➡✌❲✦✣ t✪➢❫➧✠✩❆➛★➟❴❵✢❲✵✧❞✵✒➟ ☞ ✥❸➟▼❅❁➡★➟✹✥❘✶✌✶✍✩❆➛★➟✔➟✺❑✱❲✦✬❏✩❬➝➉➢✒➡

❊ ✟ ➑✙☛❞➋✣✚✤➍➋q❴★➍❇➥➛★➟★✧❆➟✏☛❞➋✣✚➞➍⑥➝✰✣✪✣▲❑✱❲✦✬❏✧❆➟☞➧➆✧❅➟▼➟✝➢❫➧◆✥❸➟▼➤✱✧❆➟▼➟☎✉●❝♦❤q➡❊✩❆➛❸➝✤✣✷❵★✬✱✣➦➟✝✸✞✩❅➛★➟❆❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡❨➢❫➧☛✩❆➛★➟☞➠➉➢✒➤✞✬❏✧❬➝✮✩❆➛✵❪✡➝✤❵✾✳✦✬✯✧✿✩➥➢■➧☛✩❆➛★➟✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟✔➝✤✣✖✧❆➟✹✥✌❲✦❵✰➟✹✥❡✩❆➢✴✩❆➛★➟❆❵✰➢✱❪â✳✵❲✵✩✭✬✯✩❬➝➉➢✒➡✇➢❫➧☛✩❆➛★➟❞✳✵✧❬➝✮❪✡➝✮✩❬➝❀✵✒➟☎➢❫➧✠✩❆➛★➟☞➧①➢❫➠●➠➉➢ ❇➴➝➄➡★➤❀✩❃✶✞✳✸➟

✟✁✞ ❇➥➛★➟★✧❆➟ ✞ ➑ ➐✔➋✣✚✤➍➻✡➋✴✚✤➍❍❊ ✟✖✚

❇➜➝✮✩❆➛❙➐ ✧✰➻ ❘ ✹❊➲✧✚ ➳❆✣❃❲✦❵❆➛ ✩❆➛✦✬✯✩r➤✞❵★✥✤➋❱➻ ❘ ✧✰➻✡➍②➑ ➤✞❵★✥✸➋❱➐ ✧✰➻✡➍②➑ ➤✞❵★✥✸➋✧☛★✧✰➻✡➍②➑ ✂✱❝ ➙❞➢ý✩❆➛★➟ù✥❑➝❑❏✢➟★✧❆➟▼➡✞✩➦➝✰✬❺➠ ✞➝✤✣✺✬✱✣✿✣➦➢ò❵❅➝✤✬✯✩❆➟✹✥❢✣❬➢✱❪➁➟✍✟▼➟★✧❆➢ù✥❸➟▼➤✱✧❅➟▼➟❁✥❑➝✻✵❑➝✤✣❬➢✱✧✭✣✠✟ ➓ ✧✡✟✧✟✪✧ ✩ ✩ ✩ ✧✡✟★❼➁➢✢✵✒➟★✧❆✩❅➛★➟✪➡★➢✱✧✛❪✍✬❃➠●➝✮✟▼➟✹✥ ➢❫➧✑✩❅➛★➟✝✬❃❾r➡★➟✝❵✢❲✵✧ ✵❑➟ ☞✥❸➟▼❅❁➡★➟✹✥✂✶✌✶②➋q❴★➍✭❝ ✺ ➡★➟✹❵✰➟✹✣✿✣✿✬✯✧✛✶Ü❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡②➧①➢✱✧✷✩❅➛★➟❴✳✵✧➦➝✲❪➎➝✲✩➦➝✻✵❑➟✺✩❆➢◗✶❁➟✡➟✰➠➉➟★❪➬➟▼➡✞✩✢✬✯✧✿✶r➝✤✣✾✩❆➛✦✬✯✩✼✬❃➠●➠◆✩❅➛★➟✹✣❬➟✺✥❑➝✻✵❑➝✤✣❬➢✱✧✭✣✬✯✧❆➟❞✩❆➢✱✧✭✣❱➝➄➢❑➡Ü✥❑➝❀✵✒➝✤✣❬➢✔✧✭✣✮✸⑤✩❆➛✦✬✯✩✮➝✰✣✪✩❆➛★➟★✧❆➟✡➟✆✝❸➝✤✣❃✩➹✉ ✇ ✸❞➋❍③❣➑❦✂ ✧ ✩ ✩ ✩✌✧✭❙✸➍✤✸✦✣✫❲✦❵❆➛●✩❆➛✦✬✯✩☞✉ ✇ ✟ ✇ ✬✯✧❆➟❞✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠➣❝☎➙➜➛★➟▼➡●✩❆➛★➟➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣✑✗ ✇ ❘✼✹Ó➋ ☞ ➍♦✣✫❲✦❵❆➛❡✩❆➛✦✬✯✩☞➋❜✗ ✇ ➍❣➑✬⑤ ✇ ✟ ✇ ✬✯✧❆➟❆❵★✬❫➡✦✥❑➝✤✥✵✬✯✩❅➟✹✣✷✩❆➢✷✵✒➟★✧➦➝❐➧✽✶②➋❜❥❸➍✢❝

➽✣✗

Page 74: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❿ ✴✖✕ ❯✭❬ ✹✼❯✭❲✔❯❁➆✘✸❱❨❫✸✺✿❭✻✢➆ ✻ ✞✯✽✗✿❭❙✗✿❘❲❱✻☎✹❳❲☞★➢✔✧✯❑✱❲✦✬✔✥✌✧✭✬✯✩❬➝✤❵✝➟✆✝✵✩❆➟▼➡✦✣➣➝➉➢✒➡✦✣✉✸✿➭✠❝✤➫⑧➟★✧✿✩✿✧✭✬■➡✦✥❨➛✦✬✱✣✷✥❸➟✮✵❑➟✰➠➄➢✔✳❁➟✹✥ù✬❫➡❁✬❺➠➄➤❑➢✱✧❬➝✮✩❆➛✵❪ ❇➥➛❸➝✤❵❆➛✇➝✤✣✷❪✴❲✦❵❅➛❁❪➬➢✔✧❆➟✝➟✰❾✝❵❅➝➉➟▼➡✞✩

✩❆➛✦✬❫➡❼➙▲✧✭✬❫➤❑➟★✧✺❭✏✣✔➢✒➡★➟✱❝❼➙➜➛❸➝✤✣➎➝✤✣★✶✸➟✹❵★✬✯❲✦✣❬➟❁✩❅➛★➟❁✩❆➟✹✣❃✩➁➢❫➧✑✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠●➝✮✩❜✶♣➝✤✣➁➤✱✧❆➟✹✬✯✩❬➠✮✶Ó➝✮❪✺✳✵✧❆➢✢✵✒➟✹✥●✶✌✶ ✩❆➛★➟❡❲✦✣❬➟❨➢❫➧❆✬✣➣➝✮❪✺✳❸➠➉➟★✧✾✧❆➟★✳✵✧❆➟✹✣❬➟▼➡✌✩✭✬✯✩❬➝➉➢✒➡❨➢■➧♦✥❑➝❀✵❑➝✰✣➦➢✱✧✭✣➜➢✢✵✒➟★✧✑✣✫❲✦❵❆➛ ❑✔❲✦✬✱✥✌✧✭✬✯✩➦➝✰❵☞➟✆✝✵✩❆➟▼➡✦✣➣➝➉➢✒➡✦✣➍❝✰☞★➢❫➠●➠➉➢✢❇➜➝➉➡★➤➬➝✤✣✾✬❫➡r➢ ✵❑➟★✧ ✵✒➝➉➟✮❇Õ➢■➧♦✣❃❲✦❵❅➛✧❆➟★✳✵✧❆➟✹✣➦➟▼➡✞✩✭✬❏✩❬➝➉➢✒➡✦✣★❝❀➙❬❇➜➢✺❵★✬✱✣❬➟✹✣✪✬✯✧❆➟❆❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❆➟✹✥ ✚

✂ ✉ ➑Ï✐✒t✰❸ ✂❞✬❫➡✦✥ ☞ ➛✦✬✱✣✷✬✴❲★➡❸➝ ❑✔❲★➟❆✳❁➢■➝➄➡✌✩✼✬✯✩➜➝➉➡✲❅❁➡❸➝✮✩❜✶ ✂

✂ ✉ ➑Ï✐✒t✰❸✦✐â✬❫➡✦✥ ☞ ➛✦✬✱✣➜➟✆✝✦✬✱❵✢✩❬➠✮✶✍✩✈❇➜➢✴✳❁➢❫➝➉➡✌✩✭✣✾✬✯✩⑧➝➄➡✲❅❁➡❸➝✮✩❃✶✱❝✜✓❜✢❡✮❢✝✉ ➑❲✐✒t✰❸Õ✂❢⑨ ✺☞➡✌✶✝✥❑➝❀✵❑➝✰✣➦➢✱✧ ✟ ➢❫➧✸✥❸➟▼➤✱✧❆➟▼➟☎❯✴❪❀✬✹✶◗✶❁➟❫❇✷✧❬➝✮✩✿✩❆➟▼➡

✟➺➑❼⑧ ✇❀❛✸➓ ⑤ ✇ ➐ ✇ ⑥

❼⑧ ✇ ❛✸➓ ⑤ ✇ ➐ ➱ ✩➋❱Ö❸➍

❤➣✩➴➝✰✣✪✧❆➟★✳✵✧❆➟✹✣➦➟▼➡✞✩❆➟✹✥s✶✞✶❀✩✈❇➜➢❴✳✸➢❫➠✮✶❢➡★➢✔❪✡➝✤✬❃➠✤✣➲ ❂★➋✴✚✤➍✪✧ ❈ ➋✣✚✤➍q➳❇➥➛★➟★✧❆➟

✂ ❂★➋✣✚➞➍❣➑ ✁ ❼✇ ❛✸➓ ➋✣✚✷⑥ ✚✙✇➣➍ ❚ ❩ ✂

✂ ➧❹➢✱✧✷✬❃➠●➠ ③❞✸❁❰✼❜❣➋❍❊❉⑥ ❈ ➋✣✚✤➍❅➍ ★❻⑤ ✇ ✂

✂ ✥❸➟▼➤ ❈ ✌ý✥❸➟▼➤ ❂⑤❝✜✓❜✢❡✮❢✝✉ ➑❲✐✒t✰❸ ✐❁⑨ ✺☞➡✌✶✝✥❑➝❀✵❑➝✰✣➦➢✱✧ ✟ ➢❫➧✸✥❸➟▼➤✱✧❆➟▼➟☎❯✴❪❀✬✹✶◗✶❁➟❫❇✷✧❬➝✮✩✿✩❆➟▼➡

✟ ➑❼⑧ ✇❀❛✸➓ ⑤ ✇ ➐ ✇ ❸ ⑤ ➱ ✄ ➐ ➱ ✄ ❸ ⑤ ➱ ✿❁➐ ➱ ✿

❇➜➝✮✩❆➛✄✂ ❼✇❀❛✸➓ ⑤ ✇ ❸ ⑤ ➱ ✄ ❸❵⑤ ➱ ✿✪➑❲❯â✬❫➡✦✥❊✩❆➛★➟✼✧❅➟★✳✵✧❆➟✹✣❬➟▼➡✌✩✭✬✯✩❬➝➉➢✒➡❨➢❫➧ ✟ ➝✰✣✮➤❫➝❀✵✒➟▼➡❘✶✌✶➲ ❂ ➋✣✚➞➍✪✧ ❈ ➋✣✚➞➍✪✧✆☎❃➳❇➥➛★➟★✧❆➟✒❂❴✬■➡✦✥ ❈ ✬✯✧❆➟✾✥❸➟▼❅❁➡★➟✹✥➁➝➄➡â✩❆➛★➟✒✣✛✬✯❪➬➟✖❪✍✬❫➡★➡★➟★✧✷✬✱✣❞➝➉➡❀✩❆➛★➟✒❵★✬✔✣❬➟❒✉ ➑❲✐✒t❈❸●✂✷✬❫➡✦✥✷❇➥➛★➟★✧❆➟✝☎ ➑❆⑤ ➱ ✄ ⑥ ⑤ ➱ ✿ ❝✲❊✴ ✏✖✹❳✿❭✸ ➇ ❩ ❯ ✸✺✿♦➅ ✿①➆ ✸ ➇ ❯♠➀☎❨❁➅✟✻✩✌✗✿❭❨✤➆

➙❞➢✑✩❆➟✹✣✫✩✢➝●➧ ✬✾✥❑➝❀✵✒➝✤✣❬➢✔✧ ✟❮➝✰✣✠✬✪✩❆➢✱✧✢✣➣➝➉➢✒➡✺✥❑➝✻✵❑➝✤✣❬➢✱✧✺✸❫➢❑➡★➟◗❵✰➢✔❪✺✳✵❲✵✩❆➟✹✣▲✩❆➛★➟➜➢✱✧✭✥❸➟★✧⑥➢❫➧✝✟❮➝➉➡❴✩❅➛★➟ ✼✔✬✱❵✰➢✝✶❸➝✤✬❫➡✡➢✢✵✒➟★✧◆✣➦➟✮✵✒➟★✧✭✬❃➠❇➜➟✰➠●➠❖❵❆➛★➢✞✣➦➟▼➡✷❅❁➡❸➝✮✩❆➟✷✳✵✧❬➝✮❪➬➟❬❅❁➟✰➠✤✥✵✣✮➋q➡★➢✱✩❅➟✸✩❆➛✦✬✯✩❣➢✢✵✒➟★✧ ❅❁➡❸➝✮✩❆➟❪❅❁➟✰➠✰✥✵✣✉✸✞✬❫➡✌✶❆✟▼➟★✧❆➢❆✥❸➟▼➤✔✧❆➟▼➟✑✥❑➝❀✵✒➝✤✣❬➢✔✧❣➝✤✣✸✬✾✩❆➢✔✧✭✣➣➝➉➢✒➡✺✥❑➝❀✵✒➝✤✣❬➢✱✧✣➣➝➉➡✦❵✰➟✴✩❆➛★➟★✼✱✬✱❵✰➢✝✶❸➝✤✬❫➡②➢❫➧✠✩❆➛★➟✴❵✢❲✵✧ ✵✒➟✔➝✤✣❬❅❁➡❸➝✮✩❆➟❫➍✭❝ ❁✾✣➣➝➉➡★➤❊✩❆➛★➟☎➢✔❲✵✩✭❵✰➢✱❪➬➟✔➢❫➧◆✩❅➛★➟✹✣❬➟✡➢✱✧✭✥❸➟★✧✼❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡✟✸❁➢✒➡★➟✴❵★✬❫➡✥❸➟✹❵❅➝✤✥❸➟✔➝❐➧✸✩❅➛★➟❆✥❑➝✻✵❑➝✤✣❬➢✱✧ ✟➺➝✤✣✾✬✴✩❆➢✱✧✢✣➣➝➉➢✒➡✝✥❑➝❀✵❑➝✤✣❬➢✱✧✝➢✱✧➜➡★➢✱✩✹❝➙➜➛★➟❊❵✰➢✱❪✺✳✵❲✵✩✭✬❏✩❬➝➉➢✒➡Ô➢■➧◗✩❅➛★➟✪➢✱✧✢✥❸➟★✧☎➢❫➧✒✬❡✥❑➝❀✵✒➝✤✣❬➢✱✧➎➝✰✣✴✥❸➢✒➡★➟◗✶✌✶ù✳❁➟★✧❬➧①➢✱✧✿❪➎➝➄➡★➤ù✬❡✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠●➝✮✩❜✶ ✩❅➟✹✣❃✩☎➢❫➧✟✞ ✟Ò➧①➢✱✧✞✘➑ ✂ ✧✰✐✞✧ ✩ ✩ ✩✸❲★➡✌✩❬➝●➠ ❇➜➟❫❅❁➡✦✥✄✞✸✣❃❲✦❵❅➛●✩❆➛✦✬✯✩✝✞ ✟ ➝✤✣✾✳✵✧❬➝➉➡✦❵❅➝✲✳✦✬❺➠ ❝✡➙❞➢❁✥❸➢✝✣❬➢➁➝➉➡ ✬❫➡✇➟✰❾✝❵❅➝➉➟▼➡✞✩❫❇◗✬❅✶✝✸ ➧ ✬✔✣❃✩✑✬✯✧❬➝✮✩❆➛✵❪➁➟★✩❬➝✤❵

❵✰➢✱❪✺✳✵❲✵✩✢✬✯✩❬➝➉➢✒➡❊➢ ✵❑➟★✧❴✩❅➛★➟■✼✱✬✔❵✰➢✝✶❸➝✤✬❫➡ ➝✤✣✡➡★➟▼➟✹✥❸➟✹✥ß❝ ☞★➢■➠❐➠➉➢✢❇➜➝➉➡★➤②➝✤✣✺✬❫➡❊➢✢✵✒➟★✧ ✵❑➝➉➟✮❇ ➢■➧❒➛★➢✢❇❥➝✮✩✡➝✤✣✺✥❸➢❑➡★➟❊❲✦✣➣➝➉➡★➤ù✩❆➛★➟✧❆➟★✳✵✧❆➟✹✣➦➟▼➡✞✩✭✬❏✩❬➝➉➢✒➡♠➢❫➧❑✥❑➝❀✵❑➝✤✣❬➢✱✧✭✣▲✶✌✶❊✩✈❇➸➢â✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✤✣✔➋①➧①➢✱✧✷❪➬➢✱✧❅➟❴✥❸➟★✩✭✬❃➝●➠✤✣✼✣❬➟▼➟❨➲✮✂✰➳①➍✭❝➥➭➞➟★✩ ✟ ✶✸➟❄✬❀✥❑➝❀✵✒➝✤✣❬➢✔✧✼✧❆➟★✳✵✧❆➟✮❁✣❬➟▼➡✌✩❆➟✹✥ ✶✞✶❊➲ ❂ ✧ ❈ ➳➣❝✝➙➜➛★➟▼➡❵⑥ ✟Ò➑ ➲ ❂★✧✒⑥ ❈ ➳☛⑥ ➋✓❂ ➍✭❝☎➭➞➟★✩ ✟ ➓ ✬❫➡✦✥ ✟✑✟▲✶✸➟✺✩✈❇➜➢✍✥❑➝❀✵✒➝✤✣❬➢✱✧✢✣✼✧❆➟★✳✵✧❆➟✹✣➦➟▼➡✞✩❆➟✹✥ ✶✞✶❊➲ ❂ ➓ ✧ ❈ ➓ ➳✬❫➡✦✥②➲ ❂ ✟ ✧ ❈ ✟➣➳❇✧❆➟✹✣❃✳✸➟✹❵✢✩❬➝❀✵✒➟✰➠✮✶✱❝➥➙➜➛★➟▼➡

✟ ➓ ❸ ✟✑✟⑧➑✡✠ ❂ ➓ ❂ ✟✟ ✟ ✧ ✑ ➓ ❂ ➓ ❈ ✟ ❸ ✑✄✟ ❂✣✟ ❈ ➓ ❸❋✑ ✡ ➋ ❈ ➓ ❈ ✟ ❸❋☛❞➍✟ ❪➬➢✵✥✼❂☞☛ ❸ ➋☞✟★➍➋❜✎❸➍❇➥➛★➟★✧❆➟

✟✡➑❼➤✌❵★✥✸➋✓❂ ➓ ✧❃❂ ✟ ✧ ❈ ➓ ❸ ❈ ✟④➍❀➑✙✑ ➓ ❂ ➓ ❸ ✑☛✟❀❂ ✟☎❸ ✑ ✡ ➋ ❈ ➓ ❸ ❈ ✟✰➍✪✩➽✹➼

Page 75: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✺❼➡★➢✔✩❬➝➉➢✒➡✡➢❫➧✦✧❆➟✹✥✌❲✦❵✰➟✹✥✺✥❑➝❀✵❑➝✰✣➦➢✱✧⑥➝✤✣✸❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❆➟✹✥â✬❫➡✦✥❞✩❆➛★➟✸✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠●➝✮✩❃✶✍✩❆➟✹✣✫✩☛✧❆➟✰➠●➝➉➟✹✣❣➢❑➡❄✬✪✩❆➛★➟▼➢✱✧❅➟★❪ ✣❃✩✢✬✯✩❬➝➉➡★➤✼✩❆➛✦✬✯✩✬â✧❆➟✹✥✌❲✦❵✰➟✹✥●✥❑➝✻✵❑➝✤✣❬➢✱✧ ✟ ➝✤✣✾✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠❀➝●➧❑✬❫➡✦✥✇➢✒➡❸➠✮✶❚➝❐➧ ✟ ➑❥➲✮✂ ✧❇❯■➳➣❝ ❁✾✣➣➝➉➡★➤❊✩❆➛★➟✴✬✯✧❬➝✮✩❆➛✵❪➬➟★✩❬➝✤❵✔➢✢✵✒➟★✧✷✩❆➛★➟✷✼✱✬✱❵✰➢✝✶❸➝✤✬❫➡✟✸➢✒➡★➟✷❵★✬❫➡✍❵✰➢✔❪✺✳✵❲✵✩❆➟⑧➧❹➢✔✧✸✬❫➡✞✶✴✥❑➝❀✵✒➝✤✣❬➢✱✧ ✟❦✬❫➡➁➟✺❑✱❲❸➝❀✵✙✬❺➠➄➟▼➡✌✩✖✧❆➟✹✥✌❲✦❵✰➟✹✥✺✥❑➝❀✵❑➝✰✣➦➢✱✧ ✟ ✁ ✸✯✩❆➛✦✬✯✩⑥➝✤✣✠✣❃❲✦❵❅➛✺✩❆➛✦✬❏✩ ✟➺➑ ✟ ✁ ❸✪➋✓✑➞➍➧①➢✱✧✒✣➦➢✱❪➬➟✝➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ✑②❘ ✹Ó➋ ☞ ➍✭❝✖❤q➡❡✩❆➛★➟✺❵★✬✱✣❬➟❫❇➥➛★➟★✧❆➟➬✉❪➑❙✐ t✰❸❼✐✙✸✦✬❀✣➣➝✮❪✡➝●➠✰✬❏✧☎➡★➢✱✩❬➝➉➢✒➡✇➢❫➧✸✧❆➟✹✥✌❲✦❵✰➟✹✥●✥❑➝❀✵✒➝✤✣❬➢✔✧☞➝✰✣❲✦✣❬➟✹✥ ✸✦✬■➡✦✥❁✬✴✧❆➟✹✥✌❲✦❵✰➟✹✥❡✥❑➝❀✵✒➝✤✣❬➢✱✧ ✟ ➝✰✣✪✳✵✧❬➝➉➡✦❵❅➝✮✳✦✬❃➠⑥➝❐➧❑✬■➡✦✥r➢✒➡❸➠✮✶r➝❐➧ ✟ ➑❙➲✮✂ ✧✰❯✞✧❇❯■➳➣❝

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦❃⑨✑➚✠➂★➌✯➏➐❶✹❻✷❼✽➅✾❾òøè❾ ❿✛❾✔➒ ➚❈❶✹➪❆➔✔❷✱➏➣❹⑧➌✱➝✼❹⑧➌✺➏➐↕✱❺✼Û✙➂❅➙❃❶✹Þ✱❹✮➂➍➌✺❶★↔✸➂★➌✺↕✯➜✯➔✌❺✿❻➣❺✿❸⑧❸⑧❹⑧➔✱➏➣❹✮➙✾➙❃❷✱❻➐➊✹❺✹❾ßá✍❰ ➱✤Ð ➦✿❐✼❰ ➱ ➨✤➥✫➭è➤ ✕ ➵☛➤★❐❋❒ ✃❅➱ ❰ ➱ ➨s➤★➩✱➀

➊✹❶❅❸✽❾ ✗✠✱✱➀✯➌✱ê✌⑦✭ã✹ã✔➀ ➶✢➹✹ä❅ö ❾

➽✹➽

Page 76: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✂✰✠☎✁✢✄✁��✂✏✒✑✓✞✕✔✖✄✗✆✘✄✗☞✍✌✿�✙✠✓✠☎✄ ✑✓✏ ☞✍✏

Page 77: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 78: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✏✺✑✓✞✡✔☎✄✝✆ ✄✝☞P✌✙✏★✆✝�✁�❙✠✁✂☛✄✢✞✘✁ ✍ ✞❲✌✙✁☛✁✛✁✤✞✘✠✓✌❫✞❲✏✄✂✆❘☞✚✠✓✠☎✁✢✑✘✂✰✠☎✁✢✄✝☞✦✄✝☞P✆❧✠✓✏✆☎ ✞☛☞ � ✂✟✄✛✞✘✡ ✞ ✑ ✄✄✂☛✞ �●✁✓✞ ✞ ✞✘✁❘✆✁� � ✁✓✞✡✞✕✠☎✠☛✡✓✏☎✞✝ ✣❘✦❥✣✠✟✡✟✓✭ ✥✪✩✄☛●✩✗✥

❤✈✴✯✮◗❤ ✺✷✸❊✮➜➢✵❵❱❑✔❲★➟▼➡✦❵✰➢✱❲✵✧✿✩�☞➟✹❵✰➟★❪✷✶❁➟★✧✝Ö✙✸❇✂✒✹✝✹❫❴

➲❱✣❃❲✵❪✺❪✍✬✯✧✛✶ ✶✌✶ ➊✾✣➣➝➉➟▼➡✙❁✥✛✾❲★➟✰➝➸➊❪❇◗✬■➡★➤✒➳

✏✼r✒✑✔✓✢✇★①✖✕✗✓Ô✠↕✔❺✑➂★→➐➜✙➪❞➔✱➏➣❶❅➏➣❹✮➙✠Þ✌❺✿↕✞➂✢➊✯❹⑧❶✹❷✔❻✠❶★↔❖➏➐↕✱❺✷➌✯❷✱➪✼Þ✌❺✿❻✠❶★↔❇Þ✱❹⑧➌✞➂➍❻➣➜✼➔✞➂➍❻➣➏➐❹➉➏➐❹⑧❶✹➌✱→✖❼s→➣❷✱➪❞➪❴➂★➌✌➄✯→❇Þ✌❺✿❹⑧➌✱➝❆➔✌❶★Ý☛❺✛❻➣→

❶★↔❇➏✽Ý☛❶✯❿❈Ý☛❺✛❹➉➝❅↕✯➏➣❺✭➄✴Þ✯➜✴➏➣↕✔❺✑➌✯❷✱➪✼Þ✌❺✿❻✠❶★↔❇→➐❷✱➪❆➪✴➂★➌✞➄✯→❈❹⑧→✠❹⑧➌✙➊❅❺✿→➣➏➐❹⑧➝✙➂★➏➐❺✭➄✵❾✠Ô✠↕✔❺✑➪❞❺✿➏➣↕✱❶✱➄✯→✠❶➍↔❇➔✱❻➣❶✯❶★↔❈❻➣❺✿❸⑧❹⑧❺✿→❶✹➌❆➏➐↕✱❺✑➑✴❺✛❸➉❸⑧❹⑧➌✯➞➣➎⑤❺✿❻➣❻➐❶✹➌✼↔s❶✹❻➣➪✼❷✔❸✲➂✔❾

✳✵✴✷✶❃➆✘✸✺✹✼✻✾✽✘➂✢➅✟✸✺✿❀✻❞➆P❀➢✒➡✦✣❱➝✰✥❸➟★✧✾✩❆➛★➟✝➤✒➟▼➡★➟★✧✢✬✯✩❬➝➉➡★➤✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡

☛❞➋✥✦❸➍⑧➑ ⑧❚✌☞ ✁❂✔❚✣✦ ❚ ➑ ✜❼✍☞ ✁

✂✂❬⑥✏✎ ✦ ✟✒✑ ✧ ➋✓✎✁✥❼❯❖➍✪✧➋✭✂❫➍

❇➥➛❸➝✤❵❅➛Ü✣✿✬✯✩➦➝✰✣❍❅❁➟✹✣✖✩❆➛★➟✝➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✬❃➠⑥➟✺❑✱❲✦✬✯✩➦➝➄➢❑➡♠➢❫➧❀❽●✬❫➛❸➠➉➟★✧✷✩❃✶✞✳✸➟ ✚☛❞➋✥✦❸➍❅➋✭✂❬⑥✏✎ ✦❸➍❣➑✙☛❞➋✥✦ ✟ ➍✤✩➋❱✐❸➍➙➜➛★➟✝➤✒➟▼➡★➟★✧✢✬❃➠☛✳✵✧❆➢✝✶❸➠➉➟★❪ ➢❫➧⑥➝➄➡✌✩❆➟★✧❆➟✹✣✫✩➥➛★➟★✧❆➟✝➝✤✣✪✩❆➛★➟❆✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵▲✶❁➟▼➛✦✬✒✵✒➝➉➢✱❲✵✧☞➢❫➧✠✩❆➛★➟❆✣❬➟✺❑✔❲★➟▼➡✦❵✰➟✕❂✔❚☛✸✦✬✱✣❬⑤ ➽ ❸✕✔ý❝�✮➝❑❏✢➟★✧❆➟▼➡✞✩❪✵✙✬❃➠✮❲★➟✹✣☞➢❫➧✖✎❨➤❫➝❀✵✒➟✼✧❬➝✤✣❬➟✴✩❆➢✍✥❑➝❑❏✢➟★✧❆➟▼➡✌✩❈✶❁➟▼➛✦✬✒✵❑➝➉➢✱❲✵✧✭✣☞➢❫➧ ❂✱❚⑤❝➸➙➜➛★➟✴✣➣➝✮❪✺✳❸➠➉➟✹✣❃✩❆❵★✬✱✣❬➟☞➝✤✣❪❇➥➛★➟▼➡✗✎✁✥❍✂✱❝ ✁ ➡★➟➟✹✬✱✣➣➝●➠✮✶❁✥❸➟✹✥✌❲✦❵✰➟✹✣✮➧✽✧❆➢✱❪ ➋❱✐❸➍ ❂✱❚✡➑ ☛✴✚✘✎ ❿ ✟ ✢ ✎ ❚ ❸ ✥✚✙ ✎ ❚✜✛ ✟✣✢ ✧ ➋✈⑤ ➽ ❸✕✔ ➍✪✩

✤Ï➛★➟▼➡✏✎✵➑❬✂✝✸✱❂✱❚❊✧❅➟★✳✵✧❆➟✹✣❬➟▼➡✌✩✭✣✼✩❆➛★➟➁➡✞❲✵❪✷✶❁➟★✧✔➢❫➧✷✳✦✬✯✧✿✩❬➝✮✩❬➝➉➢✒➡✦✣ ➢❫➧ ⑤Ó➝➉➡✌✩❆➢Ü✣✫❲✵❪✺❪✍✬❫➡✦✥✵✣ ❇➥➛❸➝✤❵❆➛ ✬✯✧❆➟✴✳❁➢✢❇➜➟★✧✭✣☞➢❫➧✩✈❇➜➢✦❝ ✺✼✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵★✣✝➢■➧✯❂✱❚ ❇➜➟★✧❆➟✪➢✔✧❬➝➉➤❫➝➉➡✦✬❃➠●➠✲✶ ✣❃✩✿❲✦✥❑➝➉➟✹✥●✶✌✶ P✑❝⑥➭✠❝ ✻ ➝➄➟▼➤❑➟✰➠✒✬❫➡✦✥❽✶✞✶ ✛✴❝⑥❽●✬❫➛❸➠➉➟★✧✺✸✸✬❫➡✦✥ ➠✤✬✯✩❆➟★✧✷✶✞✶✴❞❝➥➷✴❝✸✥❸➟✃➫❋✧✿❲❸➝➇♥❬➡ ➲ ✐❫➳➣❝Õ➙➜➛★➟❡✳✵✧❬➝➉➡✦❵❅➝✲✳✦✬❺➠❆❪➬➟★✩❆➛★➢✵✥✵✣✺❲✦✣❬➟✹✥❣✶✌✶★�☞➟✃➫❋✧✿❲❸➝➇♥❬➡ ✬❏✧❆➟✃❽✇➟✰➠●➠●➝➄➡ ✩✿✧✭✬❫➡✦✣➣➧①➢✱✧✿❪ ➋P❇➴➝✲✩❅➛★➢✱❲✵✩➟✆✝✵✳❸➠❐➝✤❵❅➝✮✩✼❪➬➟▼➡✌✩❬➝➉➢✒➡✤➍✷✬❫➡✦✥❀✩❆➛★➟❆✣✿✬✱✥✵✥❑➠➉➟✮❁✽✳✸➢❫➝➉➡✞✩✼❪➬➟★✩❅➛★➢ò✥ß❝❀➊➴➝✤✣✷✧❅➟✹✣❃❲❸➠✮✩➥➝✤✣➠➉➢✒➤✎❂ ✟➐❚ ➑ ➠➉➢✒➤✎❂ ✟➐❚ ②✸➓❣➑ ✂

✐ ➠➄➢❑➤➸✐ ✞ ➠➉➢✒➤ ⑤➠➉➢✒➤ ⑤ ✠ ✟

❸ ✞ ✂✐ ❸ ✂➠➄➢❑➤➴✐ ❸

➠➄➢❑➤❣➠➉➢✒➤➸✐➠➉➢✒➤➸✐ ✠ ➠➉➢✒➤ ⑤❘⑥

⑥ ✞ ✂ ❸ ➠➄➢❑➤❣➠➉➢✒➤➥✐➠➉➢✒➤➥✐ ✠ ➠➉➢✒➤✘➠➄➢❑➤ ⑤◗❸✥✤ ✞ ➠➉➢✒➤ ⑤s⑥✇➠➄➢❑➤❣➠➉➢✒➤❈⑤➠➉➢✒➤➸✐ ✠ ❸ ✥ ✞ ➋①➠➉➢✒➤❣➠➉➢✒➤❬⑤✢➍ ✟➠➄➢❑➤ ⑤ ✠ ✧

✬✱✣▲⑤ ➽ ❸✕✔❻✸ ❇➥➛★➟★✧❆➟✦✤❨➋ ✗ ➍❣➝✤✣✼✬â✳❁➟★✧❬➝➉➢✵✥❑➝✰❵➎➧✽❲★➡✦❵✢✩❬➝➉➢✒➡②➢❫➧✸✳❁➟★✧❬➝➉➢✵✥ ✂❫❇➥➛★➢✞✣❬➟✌☞★➢✱❲✵✧❬➝➉➟★✧✝➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡✇➝✤✣☞➟✆✝ò✳❸➠●➝✤❵❅➝✮✩❆➟✹✥ß❝✺☞➡★➢✱✩❆➛★➟★✧✼✬✯✳✵✳✵✧❆➢✞✬✱❵❅➛②➋P❇➜➝✮✩❆➛ ❇➜➟✹✬ ✯✒➟★✧➥➟★✧✿✧❅➢✱✧✷✩❆➟★✧✿❪❚➍✸✩❆➢✍✣➣➝✮❪✡➝●➠✤✬✯✧✼✳✵✧❆➢ ✶❸➠➄➟★❪❀✣❈✶✌✶ ✝⑥➟▼➡★➡❸➝➉➡★➤✱✩❅➢✒➡ ➲●❛▼➳❇✳✵✧❆➢✵❵✰➟▼➟✹✥✵✣✼✬❃➠➉➢✒➡★➤❤q➡★➤❑➛✦✬✯❪✿❭✏✣➥➙❈✬✯❲✙✶✸➟★✧❬➝✤✬❫➡❁✩❆➛★➟▼➢✔✧❆➟★❪❁❝➙➜➛★➟✺✳✵✧❅➢✝✶❸➠➉➟★❪ ✶❁➟✹❵✰➢✔❪➬➟✹✣❫✵✒➟★✧✿✶Ü❵✰➢✔❪✺✳❸➠➉➟✆✝ ❇➥➛★➟▼➡✏✎Ó➑ ✍ ✇●➔ ✸◗❯ ✌★✧ ✡✩✧ ✆ ✝☎✸ ✡✾✧❆➟✹✬❃➠➣❝ ✺ ✣✫✩✿❲✦✥✌✶②➢❫➧✷✩❆➛★➟✷✵✙✬✯✧❬➝➉➢✱❲✦✣

✶❁➟▼➛✦✬✒✵❑➝➉➢✱❲✵✧✭✣✮➢❫➧ ❂✔❚✴❲✦✣➣➝➉➡★➤✪➟✰➠➉➟★❪➬➟▼➡✌✩✭✬✯✧✛✶❊❪➬➟★✩❆➛★➢✵✥✵✣⑧➝✤✣✑❵✰➢✒➡✌✩✭✬❃➝➉➡★➟✹✥ ➝➄➡ ✵✙✬❫➡❁✥❸➟★✧✝➊✮➢❢➟✮✵✒➟▼➡✟❭❱✣ � ✙ ✺❍❪➬➟★❪➬➢❫➝✮✧✹❝➽ ×

Page 79: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➙➜➛❸➝✤✣✾✩✭✬❃➠ ✯❚➝✰✣❞❵✰➢✒➡✦❵✰➟★✧❆➡★➟✹✥✂❇➴➝✲✩❅➛Ü✩❅➛★➟✍❵★✬✱✣❬➟✷❇➥➛★➟▼➡✵❯ ✌ ✎ ✌❦✂✱❝ ✺✼✣✮➝➉➡✦✥❑➝❀✵✒➝✤✥✌❲✦✬❃➠✷✩❆➟★✧✿❪ ✬❏✧❆➟☎➛❸➝➉➤✒➛❸➠✮✶②➝✮✧✿✧❆➟▼➤✔❲❸➠✰✬❏✧✺✸➢✒➡★➟❆❵✰➢✒➡✦✣❱➝✰✥❸➟★✧✢✣✷✩❆➛★➟✴✣❃❲✵❪✺❪✍✬❏✩❆➢✱✧✿✶✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✇➢❫➧ ❂✔❚✵❝❜☎❝✫✵❢❡✞☎✶✵★❤❬✂ ✷✪❧✟❢✺✐✸❂✔❚ ❷❞❢ ✏✝❢ ✎ ❴☛❢✄✏✰❤♥❴✝✙✱✂ ✚ ⑤☎❤♥✐☛✡✍❯ ✌ ✎ ✌❛✂✷❜✝❴ ✏❫❡✮❢✺✐ ❋❇❚✡➑ ✂ ✁ ✁ ❼ ✁ ❚ ❂✲❼✒⑨✡⑩✌✡✲❢✺❴★❋▲❚ ❡✮❜✝✐✦❤❧❡ ✎❬❢✮❡

❋ ❚ ➑❲➐✔➋①➠➉➢✒➤ ✟ ⑤✢➍✈⑤ ☞ ❸ ✥✚✙ ⑤ ☞ ②✄✂ ❿ ➓ ✛ ✟✒✢ ✧ ➋✆☎✏✥❼❯❖➍✪✧➋❜❥❸➍❜✢❡④⑤ ➽ ❸✕✔ s ⑤✒✡❦❢✺❛✈❢❆■Ó➑ ⑥r➠➉➢✒➤✸➋✭✂❈⑥ ✎❁➍✡✪✒➋①➠➉➢✒➤❣✐❸➍ ✥Ï❯✿❜ ❴ ✏✡➐✔➋ ✗ ➍✰❤❧❡✰❜ ✌ ❢✒❛✤❤✞✝ ✏✝❤✞✟⑧③ ✣✲❴✠✟✒✐✦❤✡✝ ❴☛✝➦③ ✗ ⑤✒✡☞✝✗❡♠❢✂✔✷❢✤❜ ❴♥✺❜ ❝ ✣✲❢✷❤❀❡✰❜ ✌ ✌ ❛✌✝❫t ❤✘✔✷❜✝✐✦❢✺❝ ✖ ❧ ❤✚♥✺❢✒❴ ❷ ✖

✍ ❿✎✍ ✛ ✦ ★☞✩ ✟✏⑥➋❜■s❸ ✂■➍ ➋✫✂❪⑥✗✎❁➍✒✑ ✛ ✬ ✦ ★✢✩ ✟ ✭ ❿ ➓ ✛ ✟ ✧ ⑤✒✡❦❢✺❛✈❢ ✓✪➑ ⑧❼ ☞ ➓➠➉➢✒➤✷❙❙ ✎ ❼ ✩

▼☎✴✕✔ ✹✼✻☎✻✫✞➙❞➢✍✥❸➟★✧❬➝❀✵✒➟➬➋❃❥❸➍✤✸❸➢✒➡★➟❆✣❃✩✭✬❏✧✿✩✭✣✘➧➆✧❅➢✱❪ ✩❆➛★➟✍❽✇➟✰➠●➠●➝➄➡✙❁☞✝⑥➟★✧✛✧❆➢✒➡❨➧①➢✱✧✿❪✴❲❸➠✤✬ ✚

⑧➓ ✁ ☎ ✁ ❚ ❂ ☎ ➑ ✂✐✝③ ✝

✟✗✖ ②✲✇ ➱✖ ❿ ✇ ➱

⑤ ✂ ②✸➓✘✚✙ ➋ ✘ ➍❜✥ ✘ ✧➋q❴★➍❇➥➛★➟★✧❆➟❆▼✮➝✤✣✪✩✭✬ ✯✒➟▼➡❊✩❅➢✾✶✸➟✝➠✤✬✯✧❆➤❑➟★✧✷✩❆➛✦✬❫➡❊✩❆➛★➟✴✬✢✶✦✣✿❵❅➝✤✣✿✣✿✬➎➢❫➧♦✬✗✶✦✣❬➢❫➠✮❲✵✩❆➟❆❵✰➢✒➡✲✵✒➟★✧❆➤✒➟▼➡✦❵✰➟✔➢❫➧☛✩❆➛★➟✌�✮➝✮✧❬➝✤❵❆➛❸➠➉➟★✩✼✣❬➟★✧❬➝➉➟✹✣

✙ ➋ ✘ ➍✰✚➄➑ ⑧☎ ☞ ➓ ❂✲☎ ✎ ❿ ✂ ✩

➙❞➢❄✬❏✳✵✳❸➠✲✶✇➋q❴★➍▼✸✒➢✒➡★➟✼✧❆➟✺❑✔❲❸➝✮✧❆➟✹✣✖✩❆➛★➟❆✬■➡✦✬❃➠✮✶✞✩❬➝✤❵✼❵✰➢✒➡✌✩❬➝➉➡✌❲✦✬✯✩❬➝➉➢✒➡❨➢❫➧ ✙ ✩❆➢✺✬ ➠✤✬✯✧❆➤✒➟★✧➜➛✦✬❃➠●➧✦❁✽✳❸➠✰✬■➡★➟➬➋➣✩❆➛✦✬■➡➬➝✮✩✭✣➜➢✔✧❬➝➉➤❫➝➉➡✦✬❃➠✥❸➢✱❪✍✬❺➝➄➡✇➢❫➧◆✬❫➡✦✬❺➠✲✶✌✩❬➝✤❵❅➝✮✩❃✶❁➍✷✬❫➡✦✥❀✩❆➛★➟❞❪✍✬❫➤✒➡❸➝✮✩✿❲✦✥❸➟✝➢❫➧❣➤✱✧❆➢✢❇✷✩❅➛✪➢❫➧✠✩❆➛★➟❆❵✰➢✒➡✌✩❬➝➉➡✌❲★➟✹✥r➧✽❲★➡✦❵✢✩❬➝➉➢✒➡Ü✬✯✩✆✂ ✓ ③✒✔ý❝➙➜➛★➟✺✬✢✶✦✣✿❵❅➝✤✣✿✣✛✬r➢❫➧❑❵✰➢✒➡✲✵✒➟★✧❆➤✒➟▼➡✦❵✰➟✡➢❫➧ ✙ ➝✤✣✼✥❸➟★✩❆➟★✧✿❪✡➝➉➡★➟✹✥✂✶✌✶❁✩❅➛★➟✍➤✔✧❆➢✢❇✷✩❆➛❨➢✱✧✭✥❸➟★✧✝➢■➧ ❋❇❚☛✸❇❵❅➧✿❝⑥➲❖◆✙✸✜✛♠✹✵❝✮✂⑦❴✒➳➣❝ ☞❯✧❆➢✱❪

✩❆➛★➟❆✥❸➟▼❅❁➡❸➝➉➡★➤❨➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡✵➋✢✂❫➍✤✸✒➢❑➡★➟❆✧❆➟✹✬✱✥❑➝●➠✮✶❨➢✝✶✵✩✭✬❺➝➄➡✦✣✪✩❆➛★➟✼✧❆➟✹❵✢❲✵✧✛✧❆➟▼➡✦❵✰➟✢ ❂ ✁ ➑ ✂ ✂❂✔❚ ➑ ✎ ❂✱❚ ❿ ➓ ❸❋❂✔❚✜✛ ✟ ✧➋❱Ö❸➍

❇➜➝✮✩❆➛❀✩❆➛★➟✑❵✰➢✒➡✲✵✒➟▼➡✌✩❬➝➉➢✒➡✺✩❆➛✦✬❏✩ ❂✤✣☎➑❲❯ ❇➥➛★➟▼➡ ✚ ❭❘✦✥✼❝ ☞✵✧❆➢✔❪❦✩❆➛❸➝✤✣✮✸❸➢✒➡★➟✑✥❸➟✹✥✌❲✦❵✰➟✹✣◗✩❆➛★➟➜➧①➢❫➠●➠➄➢✢❇➜➝➉➡★➤✴✧❆➟✰➠✤✬✯✩❬➝➉➢✒➡✦✣✘➧①➢✱✧ ❋▲❚✙✸✢ ❋ ✁ ➑ ✂ ✂❋▲❚ ➑ ✎✙❋▲❚✝❿ ➓ ❸ ❋▲❚✜✛ ✟ ❸ ❋ ✬ ❚ ❿ ➓✥✭ ✛ ✟ ✧

✬❫➤✞✬❺➝➄➡✂❇➜➝✮✩❆➛❡✩❆➛★➟✺❵✰➢✒➡✲✵✒➟▼➡✞✩➦➝➄➢❑➡Ü✩❅➛✦✬✯✩ ❋✜✣➬➑❙❯✱❇➥➛★➟▼➡ ✚ ❭❘✧✥è❝ ☞❯✧❆➢✱❪✐✩❆➛❸➝✤✣✮➠✰✬✔✣❃✩✑✧❅➟✹❵✢❲✵✧✿✧❆➟▼➡✦❵✰➟✝✸✢➢❑➡★➟❴❵★✬❫➡✂✵✒➟★✧❬➝●➧✽✶✝✸ ✶✞✶➝➉➡✦✥✌❲✦❵✢✩❬➝➉➢✒➡✟✸ß✩❆➛✦✬✯✩

❋✔➋✈⑤✢➍❣➑ ✥ ➋❍⑤ ☞ ➍★✩➙➜➛✌❲✦✣✮✸❲✶✞✶✵➲❖◆✲✸✜✛✤✹✵❝✮✂❄Ö■➳P✸✵✩❆➛★➟✴✬✢✶✦✣✿❵❅➝✤✣✿✣✿✬➁➢❫➧❑✬✢✶✦✣❬➢■➠✲❲✵✩❅➟❴❵✰➢✒➡✲✵✒➟★✧❆➤✒➟▼➡✦❵✰➟✔➢❫➧✸✩❆➛★➟✌�✮➝✲✧➦➝✰❵❅➛❸➠➉➟★✩❴✣❬➟★✧➦➝➄➟✹✣ ✙ ➋ ✘ ➍❀➝✤✣✮➡★➢✱✩❒➤✔✧❆➟✹✬✯✩❆➟★✧✩❆➛✦✬❫➡ ■❋❝ ✺❬✳✵✧❆➢ ✶✦✬✢✶❸➝●➠❐➝✤✣❃✩➦➝✰❵●✬✯✧❅➤✱❲✵❪➬➟▼➡✌✩❄❵✰➢❑➡✦❵✰➟★✧❆➡❸➝➉➡★➤ù✩❆➛★➟❁✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡♣➢❫➧✑✩❆➛★➟r➡✌❲✵❪✾✶✸➟★✧➬➢❫➧✒✣✫❲✵❪✺❪✍✬❫➡✦✥✵✣ ➝➉➡ý✬✶❸➝➉➡✦✬✯✧✿✶●✳✦✬✯✧✿✩➦➝✲✩➦➝➄➢❑➡ù✳❁➟★✧✿❪➎➝✲✩✢✣❆✩❅➢❁✣❬➛★➢✢❇❉✩❆➛✦✬✯✩✼✩❆➛★➟✍✬✗✶✦✣✿❵❅➝✤✣✿✣✿✬❨➢■➧✪✬✗✶✦✣❬➢❫➠✮❲✵✩❆➟✍❵✰➢✒➡✲✵✒➟★✧❆➤❑➟▼➡✦❵✰➟➬➢❫➧ ✙ ➋ ✘ ➍➜➝✤✣☞➝➉➡Ó➧ ✬✱❵✢✩☞➠➉➟✹✣✿✣✩❆➛✦✬❫➡❁■❋❝➙➜➛★➟❆✬❫➡✦✬❺➠✲✶✌✩❬➝✤❵✼❵✰➢✒➡✌✩❬➝➉➡✞❲✦✬❏✩❬➝➉➢✒➡♠➢❫➧ ✙ ❵★✬❫➡❘✶❁➟❆❵✰➢✱❪â✳✵❲✵✩❆➟✹✥◗✶✞✶✇➋❱Ö❸➍✸✬❫➡✦✥❀✩❅➛★➟✼✩❆➟✹❵❆➛★➡❸➝ ❑✔❲★➟❆❲✦✣❬➟✹✥➁➝➉➡❊➲✮✂✰➳➣❝ ✁ ➡★➟✼✩❆➛✌❲✦✣

➢✝✶✵✩✭✬❺➝➄➡✦✣➋✭✂❈⑥✗✎✷⑥✵✐ ❿ ✂ ➍ ✙ ➋ ✘ ➍⑥➑ ✎❫❸✥✎ t✿➋ ✘ ➍✪✧❇➥➛★➟★✧❆➟

t✿➋ ✘ ➍❣➑ ⑧☎ ☞ ➓ ❂ ☎ ✚ ✎ ❿ ✂ ⑥❊➋ ✎❉❸Õ✂❫➍ ❿ ✂ ✢ ➑ ⑧❼✍☞ ➓ ❄ ✘ ❸ ❙✷⑥ ✂

❙❆ ➋✤⑥✼✂❫➍ ❼ ②✸➓ ✙ ➋❜❙ ❸ ✘ ➍✪✩

➙➜➛★➟❆✣❬➟✹❵✰➢❑➡✦✥❨➟✆✝✵✳✵✧❆➟✹✣✿✣➣➝➉➢✒➡❡✳✵✧❆➢✢✵✒➝✤✥❸➟✹✣✪✩❆➛★➟✼✧❆➟✺❑✔❲❸➝✲✧❅➟✹✥❁✬❫➡✦✬❃➠✮✶✌✩❬➝✤❵❆❵✰➢✒➡✌✩❬➝➉➡✌❲✦✬✯✩❬➝➉➢✒➡♠➢■➧ ✙ ✩❆➢✴✩❆➛★➟❫❇➥➛★➢❫➠➉➟ ✘ ❁✽✳❸➠✤✬❫➡★➟✱❝ã þ

Page 80: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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� ✰✂✁☎✄✌☎✶✵✝✆ ✷ ➙➜➛★➟✾✧❆➟✹✥✌❲✦❵✰➟✹✥❀✣❬➟✺❑✔❲★➟▼➡✦❵✰➟✏☛ ❚ ✪ ⑤ ☞ ✬✔✣✿✣❬➢✵❵❅➝✰✬❏✩❆➟✹✥✺✩❅➢ ✎➬➑❍✂ ✪❺✐❆❵✰➢❑➡✞✩✿✧✢✬✱✣❃✩❆➟✹✥✷❇➴➝✲✩❅➛✺✩❆➛★➟❪➬➟✹✬❫➡✿✵✯✬❃➠✮❲★➟☎➢❫➧✠✩❆➛★➟✼✳✸➟★✧❬➝➉➢ò✥❑➝✤❵ ➧➆❲★➡✦❵✢✩➦➝➄➢❑➡ ➐✔➋❃✗★➍✭❝

➙➜➛★➟✷✧❅➟★❪✍✬❃➝➉➡❸➝➉➡★➤❄✬■➡✦✬❃➠✮✶ò✣➣➝✤✣ ➧❹➢❫➠●➠➉➢✢❇✑✣✸❵❅➠➉➢✞✣➦➟✰➠✲✶â✩❆➛★➟➜➠●➝➉➡★➟✹✣❣➧①➢✱✧✠✩❆➛★➟✮➡✞❲✵❪✷✶❁➟★✧⑧➢❫➧✿➢✵✥✵✥✡➡✌❲✵❪✷✶❁➟★✧✭✣ ➝➄➡ ✝✠✬✱✣✿❵★✬❺➠ò✩✿✧➦➝✰✬■➡★➤❫➠➉➟➝➉➡Õ➲❵❴❫➳➣❝②➙➜➛★➟✪➟✆✝✵✳✵✧❆➟✹✣✿✣❱➝➄➢❑➡❊➧❹➢✱✧✴✩❆➛★➟❊✬✯✳✵✳✵✧❆➢ ✝❸➝✮❪✍✬✯✩❆➟✺❪➁➟✹✬❫➡✙❁✦✵✙✬❃➠✮❲★➟✇➢❫➧❒➐✔➋ ✗ ➍☞➝✤✣✡➢✝✶✵✩✭✬❺➝➄➡★➟✹✥❽✶✌✶Ô❽✇➟✰➠❐➠●➝➉➡ý✩✛✧✭✬❫➡✦✣➣➧①➢✱✧✿❪✣❃✩✭✬❏✧✿✩❬➝➉➡★➤✡➧✽✧❆➢✱❪

➠➄➢❑➤ ☛❞➋ ✍ ❿ ➔ ➍⑧➑ ⑧☎✍☞ ✁

➠➉➢✒➤ ✂✂❈⑥ ✎✖✍ ❿ ✟ ✭ ➔✟✞ ⑥✷■ ➠➉➢✒➤ ✡ ❸ ❆✤➋①➠➉➢✒➤ ✟ ✡❆➍ ❸ ❄❑➋☞✡❆➍✤✧

✬✱✣ ✡ ➽ ❯ ② ✸✙❇➥➛★➟★✧❆➟❇❆➁➝✤✣✷✬❀✂✮❁✽✳❁➟★✧❬➝➉➢✵✥❑➝✤❵✝➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❁✬❫➡✦✥✖❄➹➝✤✣✷✬❫➡r➟▼➡✞✩❬➝✮✧❆➟☞➧✽❲★➡✦❵✢✩❬➝➉➢✒➡❇❝➜➙➜➛★➟ ✯✒➟★✶✍✳✸➢❫➝➉➡✞✩⑧➝✤✣✖✩❆➛★➟❆✣✫✩✿✧❆➢✒➡★➤❵✰➢✱✧✿✧❅➟✹✣❃✳❁➢✒➡✦✥❸➟▼➡✦❵✰➟✇➋❜✣❬➟▼➟✇➲✲Ö❃➳①➍❈✶❁➟★✩✈❇➜➟▼➟▼➡ù✩❆➛★➟✍✬✔✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵❫✶❁➟▼➛✦✬✒✵❑➝➄➢✔❲✵✧☎➢❫➧✑✬➁➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✵➝➉➡ù✩❅➛★➟★✵✒➝✤❵❅➝➉➡❸➝✮✩❃✶✵➢❫➧➴❯❡✬❫➡✦✥✩❆➛★➟✴✣➣➝➉➡★➤✱❲❸➠✤✬✯✧❬➝✮✩❬➝➉➟✹✣☞➢❫➧❣➝✮✩✭✣☞❽♠➟✰➠●➠●➝➉➡●✩✿✧✭✬❫➡✦✣➣➧①➢✱✧✿❪❡❝❀➙➜➛❸➝✤✣✾✳✵✧❆➢✢✵✒➝✤✥❸➟✹✣✾✬✴✳✵✧❆➟✹❵❅➝✤✣❬➟✡➟✹✣❃✩❬➝✮❪✍✬❏✩❬➝➉➢✒➡❨➧①➢✱✧✷✩❆➛★➟❞✧❆➟✹✣➣➝✤✥✌❲★➟✹✣☞➢❫➧✠✩❆➛★➟❽✇➟✰➠●➠❐➝➉➡ù✩✛✧✭✬❫➡✦✣➣➧①➢✱✧✿❪➺➢❫➧ ☛❞➋ ✍ ❿ ➔ ➍✤✸☛❇✮➛❸➝✰❵❅➛✇➝✤✣ ✏⑥➋ ✘ ➍ ✙ ➋ ✘ ➍✭❝➜➙➜➛★➟✴✩❆➛★➟▼➢✱✧❆➟★❪ ➢■➧✸✧❆➟✹✣➣➝✤✥✌❲★➟✹✣✮➝✤✣✷✩❆➛★➟▼➡●✬✯✳✵✳❸➠●➝➉➟✹✥ ✸✢➛★➟▼➡✦❵✰➟✴✩❆➛★➟✩❆➛★➟▼➢✱✧❅➟★❪ ✣❃✩✭✬✯✩❅➟✹✥ß❝ ✻ ➟▼➟✌☞❞➝➉➤✱❲✵✧❆➟✺✂☞➧①➢✱✧✑✬❫➡r➝●➠●➠✮❲✦✣❃✩✿✧✭✬❏✩❬➝➉➢✒➡❇❝

✂✂✴✪◆ ✻❞➆➞➅✤◗①➂✂✽✗✿ ➆✤➈ ✹✺❯✵❩✙❨✘✹ ✕❧❲➙➜➛★➟✔➡✞❲✵❪✷✶❁➟★✧☞➢❫➧✠❲★➡✵✧❆➟✹✣❃✩✿✧➦➝✰❵✢✩❅➟✹✥❁✳✦✬❏✧✿✩❬➝✮✩❬➝➉➢✒➡✦✣ ➋P❇➥➛★➢✞✣❬➟❆✣✫❲✵❪✺❪✍✬❫➡✦✥✵✣✾✬✯✧❆➟✼✳✸➢✞✣➣➝✮✩❬➝❀✵✒➟✔➝➉➡✞✩❆➟▼➤❑➟★✧✭✣✰➍✓❇➜➟✰➝➉➤✒➛✌✩❆➟✹✥❘✶✌✶❊✩❆➛★➟

➡✌❲✵❪✾✶✸➟★✧❒➢■➧◆✣❃❲✵❪✺❪✍✬■➡✦✥✵✣➥➛✦✬✱✣➴➤✒➟▼➡★➟★✧✭✬✯✩❬➝➉➡★➤✡➧✽❲★➡✦❵✢✩❬➝➉➢✒➡⑧❚ ☞ ✁

❆➞➋❍⑤❞➍✥✦ ❚ ➑ ✜❼✍☞ ➓✂

✂❪⑥✏✎ ✦ ❼ ✩➙➜➛★➟❊❵✰➢✱✧✿✧❆➟✹✣✫✳❁➢✒➡✦✥❑➝➉➡★➤ ✬✱✣✫✶✞❪✺✳✵✩❅➢✱✩❬➝✤❵★✣✔➛✦✬✺✵❑➟★✶❁➟▼➟▼➡ ✩❆➛★➢✔✧❆➢✱❲★➤✒➛❸➠✮✶ ✣❃✩✛❲✦✥❑➝➄➟✹✥Ó➝➉➡ ✩❆➛★➟➁➠●➝✮✩❆➟★✧✭✬✯✩✿❲✵✧❅➟✱❝✵➙➜➛★➟✝❵★✬✔✣❬➟ ✎❊➑ ✂➠➉➟✹✬✱✥✵✣❞✩❆➢❁✩❅➛★➟✡➧ ✬❏❪➬➢✱❲✦✣✝➊✾✬✯✧✭✥✌✶✲❁✚✮✷✬✯❪✍✬❫➡✌❲✯♥✿✬❫➡✙❁✚✮✷✬✱✥❸➟★❪✍✬✔❵❆➛★➟★✧✔➧①➢✱✧✿❪✴❲❸➠✤✬✙✸☛✬❫➡✦✥Ó➢✱✩❆➛★➟★✧✴❵★✬✱✣❬➟✹✣ ❇➸➟★✧❅➟✍❵✰➢✱❪✺✳❸➠➉➟★✩❆➟✹✥❽✶✞✶✤ù✧❬➝➉➤✒➛✌✩☎➲❖✹❃➳➣❝➙➜➛★➟❀❪➬➟★✩❆➛★➢✵✥✵✣❞✳✵✧❆➟✹✣❬➟▼➡✌✩❆➟✹✥Ó➝➉➡ ✩❆➛❸➝✤✣✴✩✭✬❃➠ ✯ ✸◆✬✔✥✵✬✯✳✵✩❆➟✹✥ ➧➆✧❆➢✔❪ ➲ ❴❺➳✍✸❨✶✸➟✹❵✰➢✱❪➬➟❊❪➬➢✔✧❆➟✪➢✔✧☎➠➉➟✹✣✿✣✴✣❃✩✢✬❫➡✦✥✵✬✯✧✭✥❢✬❫➡✦✥❢✬✯✧❆➟

✳❁➢✢❇➜➟★✧❬➧✽❲❸➠❖➟▼➡★➢✔❲★➤✒➛✴✩❆➢④✶✸➟✷✬✯✳✵✳❸➠●➝✰❵★✬✗✶❸➠➄➟✾✩❆➢☞➢✱✩❆➛★➟★✧❈✳✵✧❆➢✝✶❸➠➉➟★❪✍✣✮✸■➠●➝ ✯❑➟✯❄✒❁✽❪❴❲❸➠✮✩❬➝✮✳❸➠●➝✤❵★✬✯✩❬➝❀✵✒➟✮➧➆❲★➡✦❵✢✩➦➝➄➢❑➡✦✣➜➲✏✎❃➳P✸✯✩❆➛★➟➥➷☞➢❫➠✤✥✲✶❁➟★✧❆➤✳✵✧❆➢✝✶❸➠➉➟★❪ ➢❫➧✸✥❸➟★✩❆➟★✧✿❪✡➝➉➡❸➝➉➡★➤✍✩❅➛★➟❴✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵❈✶✸➟▼➛✦✬✺✵❑➝➉➢✱❲✵✧☞➢❫➧◆✩❅➛★➟❆❵✰➢❢➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣

➲ ✦ ❚ ➳❄➟✆✝✵✳❝❡ ⑧☎✍☞ ✁

✦ ✟✭ ❣❥ ✧

✥❑➝❀✵✒➝✤✥❸➟✮❁➣✬❫➡✦✥●❵✰➢✒➡✘❑✔❲★➟★✧✾✧❆➟✹❵✢❲✵✧✿✧❆➟▼➡✦❵✰➟✹✣✮✸✸➟★✩✭❵✯❝ã✱⑦

Page 81: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦❃⑨✷➾✸❸⑧❸⑧❶✹❷✌➙➣↕✔❺✖❼✤Û✹❺✢➂★➌✯➞➣➎ß➂★❷✱❸✮❿✠➂★➌✌➄❆➚❈❶✹↕✔❺✿➌✺❼ ✘ ❺✿➌✱❻➐❹✮❿✿❾❅➒✝➅❋❹⑧❻➣❹✮➙➐↕✱❸⑧❺✿➏❈→➣❺✿❻➐❹➉❺✛→✸➂★➌✞➄❞➙❃❷✱❻➣❹⑧❶❅❷✱→✠❹⑧➌✯➛✞➌✱❹⑧➏➣❺❋➔✱❻➣❶✱➄✯❷✌➙❃➏➣→✢❾✁� ✃ ❮✰❮➉➦ ➱ ➨✮➩✺➤ ✕✸➱sÐ ➦

û✦➤★➩✞➧❅➤★➩âáâ❰ ➱✤Ð ➦✿❐✼❰ ➱ ➨✤➥❃❰★❮❯➲ò➤✢➥✿➨✤➦ ➱ ✂★➀✯➊✹❶✹❸✽❾✵⑦✢ã✱➀ ➶✭➹✹ä❅➘ ➀✯➔✱➔⑤❾✱➼✹Ú✱⑦✫➒❏➼❅Ú✲✱✱❾⑥➇➴✢⑨✑➄✯❺✖⑩❇❻➐❷✱❹ ✑❃➌✺❼✽ñ✷❾✱ø✼❾➇❿✿❾➍➒✝➈❋➌❴➑â➂★↕✱❸⑧❺✿❻✢æ →❈➔✞➂➍❻➣➏➣❹⑧➏➐❹➉❶❅➌❆➔✱❻➐❶✹Þ✱❸⑧❺✿➪❀❾✹➯✿➩✌➧✹❰✢➫✹❰ ➱ ➨✤➤➍➩✞➦❃➭✖á✍❰ ➱sÐ ➦✛❐✼❰ ➱ ➨✤➥❃❰✹➦✛➀✱➊✹❶❅❸✽❾✱⑦ þ ➀ ➶✢➹★Ù✙ä ➀✹➔✔➔✦❾✱➴✱⑦ þ ➒➴✹➴ þ ❾➍➒✝❻➐❺✿➔✱❻➐❹➉➌✯➏➐❺✭➄❞↔✤❻➐❶✹➪ ✚✑➤★➩✔➨✮➩✄✂★❮✏➨ ✗☎✂✹➦◗ü◗➦❃➧✹➦✛➢✿❮➉❰➍➩✞➧✢➭✭➦❋➳❑➥❃❰❅➧✹➦✛❐✑➨✤➦✡✝★❰★➩✝✆❴➦ ➱ ➦✛➩✯➭✭➥ Ð ❰❃❒❅❒❏➦✛➩✢✕❈➡☛➢❜➤✢➥❃➦❜➦❃➧➍➨✮➩✯➫✢➭✫❾

⑥➇Ú✢⑨✑➅❋❷✱➪❴➂➍→✾❼➆➎ß↕✦❾➇❿✛❾✵➒❦➾❋→➣➜✯➪❆➔✱➏➐❶✹➏➐❹✲➙✫→✷❶★↔✷➑✺➂★↕✱❸⑧❺✿❻➐❹✮➂★➌❊❻➣❺✢➙❃❷✱❻➣❻➐❺✿➌✞➙❃❺✛→✟✞✺Þ✔❹➉➌✌➂★❻➣➜❀➔✞➂➍❻➣➏➣❹⑧➏➐❹➉❶❅➌✱→✷Ý❈❺✿❹⑧➝✹↕✯➏➣❺✢➄❊Þ✯➜✍➏➐↕✱❺✴➌✯❷✱➪✼Þ✞❺✛❻✷❶★↔→➣❷✔➪❆➪❴➂➍➌✞➄✯→✢➀ ➶✭➹❅➹ ✯ ❾❅Ôß❶✒➂➍➔✱➔✌❺✭➂★❻✢❾

⑥ ✗★⑨✑❽⑤❸✮➂ ✑❃❶✹❸⑧❺✿➏✖❼✽➎ß❾➇❿✿➀✞ø◗❻❜➂★Þ✔➌✱❺✿❻✷❼✽➎ß❾➇❿✿➀✞í❋❹⑧❻➣→❃➙➐↕✱❺✿➌✱↕✱❶➍↔✤❺✿❻✼❼✽➎ß❾➇❿✿➀✞➎ ❻➣❶✱➄✯❹⑧➌✱➝✹❺✛❻✷❼ ✘ ❾➇❿✿➀✵➂★➌✞➄❄Ô✠❹✲➙➐↕✯➜✺❼✽➓✷❾✌❽☛❾➇❿✛❾✱➒ ➑✴❺✛❸➉❸⑧❹⑧➌✴➏➣❻❃➂★➌✱→ ↔✤❶✹❻➐➪❆→➂★➌✌➄❆➂★→➐➜✯➪❆➔✱➏➐❶✹➏➣❹✮➙❃→✠✞❖➄❏❹➉➝❅❹⑧➏❜➂★❸✵→➐❷✱➪❆→✢❾✖✥ Ð ➦❃➤★➢❜➦ ➱ ➨✤➥❃❰★❮ß➵☛➤★❐❋❒ ✃❅➱ ➦✿➢◗➲ò➥✿➨s➦✿➩✞➥❃➦✛➀✱➊❅❶✹❸✽❾✞⑦✢➴✹Ú✔➀✯➌ ê ➴✔➀ ➶✭➹✹➹➍Ù ➀❅➔✱➔✦❾✌➴ × ⑦✫➒❏Ú✔⑦ ✗✞❾

⑥➇➼✢⑨✑❽⑤❸✮➂ ✑❃❶✹❸⑧❺✿➏♦❼➆➎ß↕✦❾➇❿✛➀✱ø✖❶✹❷✱❻❃➄✯❶✹➌✴❼ ✌✑❾➇❿✿➀✱➂➍➌✞➄✼➅❋❷✱➪❴➂➍→✠❼➆➎ ↕✦❾➇❿✿❾➍➒✝➑✴❺✿❸⑧❸⑧❹⑧➌✼➏➣❻❜➂➍➌✱→✽↔s❶✹❻➣➪❞→☛➂★➌✌➄❆➂★→➐➜✯➪❆➔✱➏➐❶✹➏➣❹✮➙❃→✡✞ ✘ ➂★❻➐➪❆❶❅➌✱❹✮➙❇→➐❷✱➪❆→✢❾✥ Ð ➦❃➤➍➢❜➦ ➱ ➨✤➥❃❰➍❮✦➵☛➤➍❐✸❒ ✃✹➱ ➦✛➢✖➲ò➥✛➨✤➦✿➩✌➥❜➦✛➀✱➊❅❶✹❸✽❾✌⑦ ✗ ✗✌➀✯➌✱ê✞⑦✫➒❏➴✔➀✹Û❅❷✱➌✱❺ ➶✢➹✹➹✹➘ ➀✯➔✱➔✦❾✱Ú➋➒❏➼✲✱✔❾

⑥➇➽✢⑨✑ø✖❻❃➂★Þ✱➌✱❺✛❻✠❼➆➎ß❾➇❿✿❾✛➒✺➚❈❶✹➪❆➔✔❸➉❺✛➏➣❺✿❸⑧➜☞☛✛➞➆➪✼❷✔❸➉➏➐❹⑧➔✱❸⑧❹➉➙✿➂➍➏➣❹⑧➊✹❺⑤↔✤❷✱➌✌➙❃➏➣❹⑧❶✹➌✔→✟✞⑤➏➣↕✱❺✸➑✴❺✛❸➉❸⑧❹⑧➌✾➏➣❻❜➂➍➌✱→✽↔s❶✹❻➣➪Õ➂★➔✱➔✔❻➣❶✙➂❅➙➐↕✦❾✹➳✖➥ ➱ ❰✸➳✖➢✛➨ ➱✤Ð ❐✒➦ ➱ ➨✤➥❃❰★➀➊✹❶❅❸✽❾✙➽❅➼✱➀ ➶✭➹❅➹✹÷ ➀✹➔✱➔⑤❾✣✱✹➼➋➒ × ➽✱❾

⑥➇ã✢⑨✑➎⑤❺✿➌✱➌✱❹⑧➌✱➝❅➏➣❶❅➌✼❼ ✣ý❾✢⑩✸❾➇❿✛❾✿➒❆➈❋➌✑➑✺➂➍↕✱❸⑧❺✿❻✭æ →ß➔✞➂★❻➐➏➣❹⑧➏➣❹⑧❶❅➌❑➔✔❻➣❶✹Þ✔❸➉❺✛➪✍❾✭➳✖➩✔➩✞❰★❮ ➭◆➤ ✕ á✍❰ ➱sÐ ➦✛❐✼❰ ➱ ➨✤➥❃➭✿➀★➊❅❶✹❸✽❾✭➼❅ã✱➀ ➶✭➹❅➘✹÷ ➀✿➔✱➔✦❾★➼❅Ú✱⑦❃➒✱➼✣✗✯➽✱❾⑥ ✱✢⑨✷Ô✠❹⑧➏❜➙➐↕✱➪✴➂★❻➣→➐↕✴❼➆î✠❾✱➚✖❾➇❿✛❾★➒ ✥ Ð ➦ ➱sÐ ➦❃➤★➢✄✂✼➤ ✕ ✕✿✃ ➩✞➥ ➱ ➨✤➤★➩✯➭✿❾❏➒â➈♦ç✯↔✤❶❅❻❜➄ × ➌✱❹⑧➊❅❺✿❻➣→➐❹➉➏✽➜❆➎ ❻➣❺✿→➐→✭➀✞➈♦ç✯↔✤❶❅❻❜➄✵➀ ➶✢➹✹÷✹➹ ➀✹→➐❺✭➙❃❶❅➌✞➄❞❺✭➄✯❹⑧➏➣❹⑧❶✹➌⑤❾⑥ × ⑨ ✣❊❻➣❹⑧➝❅↕✙➏✪❼➆î✠❾⑤➑❊❾➇❿✿❾✔➒ ➾❋→➣➜✯➪❆➔✱➏➐❶✹➏➐❹✲➙✪➔✞➂➍❻➣➏➣❹⑧➏➐❹➉❶❅➌✴↔✤❶❅❻➣➪✼❷✱❸✮➂★❺✌✞✖❼✤➠➐➠➣❿✸Ý❈❺✿❹⑧➝✹↕✯➏➐❺✭➄✺➔✌➂★❻➣➏➐❹⑧➏➣❹⑧❶✹➌✱→✢❾ß➡☛➢❃➤✭➥❃➦❃➦❃➧★➨✮➩✯➫✢➭❆➤ ✕✾➱sÐ ➦✾û✦➤★➩✌➧✹➤★➩

á✍❰ ➱sÐ ➦✛❐✒❰ ➱ ➨s➥❜❰➍❮✌➲ò➤✢➥✿➨✤➦ ➱ ✂★➀✱➊✹❶❅❸✽❾✱Ú✹➽✱➀ ➶✭➹❅÷✹÷ ➀✯➔✱➔✦❾✵⑦✹⑦✢ã✢➒✵⑦ ✗✞⑦❅❾

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Page 82: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✓✿✏✢✌✙☞✚✄✢✄P✠❲✄✝☞✚✠✆� ✍✂☞ ✕✗✞✘✁✝✏� ✜✺✩✢✪✂✁✔☞ ☛●✣✄✁ ✝ ✭❱✦❁✮➡❸➝❀✵✒➟★✧✭✣➣➝✮✩ ✳➟❆✥❸➟✾✴➴➝✰❵✰➟☞★➟✮✶✵✧✿❲✦✬❏✧✿✶✝✎ ✸❇✂✺✹✝✹✒Ö

➲✏✣✫❲✵❪✺❪✍✬✯✧✿✶✱✶✞✶❘✼✱✬✱❵❱❑✔❲★➟✹✣✼P✖✬✯✧❆➟★✩✿✩❆➟▼➳✏✼r✒✑✔✓✢✇★①✖✕✗✓

➾❋➌❆❶❅→❜➙❃❹⑧❸⑧❸✮➂★➏➣❹⑧➌✱➝✖❻➐❹➉➊❅❺✿❻❇❹⑧→✠➂★➌✼❶✹→❃➙❃❹⑧❸⑧❸✲➂➍➏➣❹⑧➌✱➝✷➂★→➐➜✯➪❆➔✱➏➐❶✹➏➣❹✮➙❈→➐❶✹❸⑧❷✱➏➣❹⑧❶❅➌✑❶➍↔❖➂★➌❆❶❅❻❜➄✯❹⑧➌✞➂➍❻➣➜✼➄✯❹❱➟ò❺✛❻➣❺✿➌✯➏➣❹✮➂➍❸✞❺✭à❅❷✞➂➋➞➏➣❹⑧❶✹➌✴Ý✠↕✱❺✿❻➐❺✑➏➐↕✱❺✿❻➐❺✑❹⑧→✭➀✵➂➍➏✠❹➉➌❏➛✞➌✱❹⑧➏✽➜✙➀✌➂★➌✴❺❃ç✱➔✌❶✹➌✱❺✿➌✯➏➐❹✲➂➍❸❇➙❃❶✹➌✞➙✫❺✿➌✯➏➣❻❜➂➍➏➣❹⑧❶✹➌â❶★↔☛→➐❶✹❸⑧❷✱➏➣❹⑧❶❅➌✱→✠❶★↔❇➏➣↕✔❺✒➄✯❹❱➟✵❺✿❻➣❺✛➌✙➏➐❹✮➂★❸❺✭à❅❷✞➂★➏➐❹➉❶❅➌✦❾⑤Ô✠↕✱❺✷➂★❹⑧➪❛❶★↔ß➏➣↕✱❹⑧→✠➏❃➂★❸⑧õ✼❹⑧→☛➏➐❶✼➔✱❻➣❺✿→➐❺✿➌✯➏❑➂◗↔✤❺✿Ý ➙✿➂★→➐❺✿→✸Ý✠↕✔❺✿❻➣❺✷→➐❷✞➙➐↕✺➙✿➂★➌✴Þ✌❺❑➔✔❻➣❶★➊✹❺✢➄❆➏➐❶✼❶✱➙✿➙❃❷✱❻✢❾

✳✵✴✷✶❃➆✘✸✺✹✼✻✾✽✘➂✢➅✟✸✺✿❀✻❞➆☞✖❝✞✬■➡✦✥✪❽❢❝✣�✮➝➉➟▼➡★➟★✧➥➛✦✬✒✵✒➟✾✧❆➟✹❵✰➟▼➡✌✩❬➠✮✶✍✣❃✩✿❲✦✥❑➝➉➟✹✥❊✣❬➢✔❪➬➟✒❵★✬✔✣❬➟✹✣⑧➢❫➧☛✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣➜➢❫➧✢➢✱✧✢✥❑➝➄➡✦✬❏✧✿✶✍✥❑➝❑❏✢➟★✧❆➟▼➡✞✩➦➝✰✬❺➠◗➟✺❑✱❲✦✬❏✩❬➝➉➢✒➡✦✣

❇➥➛❸➝✤❵❅➛ý✬✯✧❆➟➬➟✆✝✵✳❁➢✒➡★➟▼➡✌✩❬➝✤✬❃➠●➠✮✶ý❵❅➠➉➢✞✣❬➟❀✩❆➢②➟✹✬✱❵❆➛Ó➢✱✩❆➛★➟★✧✺✬✯✩✝➝➉➡✲❅❁➡❸➝✮✩❃✶Õ➲✮✂✢✸◗✐✙✸✠❥❃➳➣❝♠➙➴➛❸➝✰✣➎➡★➟✮❇ ✩❃✶✌✳❁➟r➢❫➧✑✬✯✩✿✩✿✧✢✬✱❵✢✩❆➢✱✧❉❇✷✬✱✣✶✦✬✯✳✵✩❬➝✤✣❬➟✹✥✆☎✞✝❁➟★❲✙✵✒➟✠✟ ✸✒➢✱✧✡☎✢✧❬➝❀✵✒➟★✧☛✟❞✬✝➡✦✬✯❪➬➟✾✣❃❲★➤✒➤✒➟✹✣❃✩❅➟✹✥✷✶✞✶✴✩❆➛★➟✼❵✰➢✱✧✿✧❅➟✹✣❃✳❁➢✒➡✦✥❑➝➉➡★➤✴✳★➛✦✬✱✣❬➟✾✳❁➢✔✧✿✩✿✧✭✬❃➝✮✩✭✣⑧➋❃✣❬➟▼➟ ☞❞➝➉➤✱❲✵✧❆➟✴✂❫➍✭❝❤①➧❣➢✒➡★➟✴❵✰➢✒➡✦✣➣➝✤✥❸➟★✧✭✣✾✬✺✣✿❵★✬❃➠✤✬✯✧➥➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡

✟✟★✟✤❴ ➑

❚⑧☎ ❛ ✁

➐☛☎❫➋✚❴❊➍ ★ ☎

❇➥➛★➟★✧❆➟✾✩❆➛★➟✝➐✄☎■➋✚❴❊➍☛✬✯✧❆➟❪❅❁➡❸➝✲✩❅➟❆✣❃❲✵❪✍✣❣➢■➧☛✧✭✬✯✩❬➝➉➢✒➡✦✬❺➠❖✳❁➢✢❇➜➟★✧✭✣✘➢❫➧✗❴❄❇➜➝✮✩❆➛❊❵✰➢✱❪✺✳❸➠➉➟✆✝❁❵✰➢❢➟✰❾✝❵❅➝➉➟▼➡✌✩✭✣✮✸✌✩❆➛★➟▼➡❊✩❆➛★➟★✧❅➟❒➟✆✝❸➝✤✣❃✩➟▼❏✢➟✹❵✢✩❬➝❀✵✒➟✾❪➬➟★✩❆➛★➢✵✥✵✣✸✩❅➢❴✬✱✣✿❵✰➟★✧✛✩✭✬❃➝➉➡✺✩❆➛★➟✾✳✵✧❆➟✹✣❬➟▼➡✦❵✰➟☞➢❫➧☛✧❬➝❀✵✒➟★✧✢✣★❝❣➙➜➛★➟✒✬✔✣✿✣❬➢✵❵❅➝✰✬❏✩❆➟✹✥✍✣➦➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✖✬✯✧❆➟➥➟✰➝✮✩❆➛★➟★✧✷✬✯✩✿✩✛✧✭✬✱❵✢✩❬➝❀✵✒➟✝✸➝➉➡❻❇➥➛❸➝✤❵❅➛ ❵★✬✱✣➦➟❁✩❆➛★➟★✧❆➟r➝✤✣❀✬❫➡❊➝➉➡✲❅❁➡❸➝✮✩❜✶♣➢❫➧✒✣❬➢■➠✲❲✵✩➦➝➄➢❑➡✦✣★❇➥➛❸➝✤❵❅➛❛✣❬➛✦✬✯✧❆➟❊✩❆➛★➟❁✣✛✬✯❪➬➟❁✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵◗✶❁➟▼➛✦✬✒✵✒➝➉➢✱❲✵✧✒✸➜➟✰➠✰✣➦➟✩❆➛★➟★✶●✬✯✧❆➟❆✧❅➟★✳✵❲❸➠✰✣❱➝✻✵❑➟✝✸✤➝➉➡❹❇➥➛❸➝✤❵❅➛ ❵★✬✱✣❬➟❞✩❆➛★➟★✧❆➟✔➝✤✣✼✬❀❲★➡❸➝❭❑✔❲★➟✍✬✱✣✫✶✞❪✺✳✵✩❅➢✱✩❬➝✤❵★✬❃➠●➠✮✶❁❲★➡✦✣❃✩✭✬✗✶❸➠➄➟❀✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡❇❝☎➙➜➛★➟✹✣➦➟❴✧➦➝✻✵❑➟★✧✭✣➤✒➟▼➡★➟★✧✭✬❺➠❐➠✮✶●✳❁➢✌✣✿✣❬➟✹✣✿✣✼✥❑➝❀✵✒➟★✧❆➤❑➟▼➡✞✩✼✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩➦➝✰❵✔➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣✮➝➉➡②➧✽✧✭✬✱❵✢✩❬➝➉➢✒➡✦✬❺➠◆✳✸➢ ❇➜➟★✧✭✣✮➢❫➧☛❴❵✸❲✶✵❲✵✩✼✩❆➛★➟★✶❁✬✯✧❆➟✺✬❃➠❀❇✷✬❅✶ò✣➷❒➟✮✵✌✧❆➟★✶✱❝

▼☎✴☎✄ ➇ ❯☛✔✑❯❫✹✟✿❀✻✂✽ ✿♦➅✌☞ ✻✂✽✂❯❫◗➙➜➛★➟✼✧❆➟✹✣✫❲❸➠✲✩✢✣➜➟✹✣❃✩✭✬✢✶❸➠●➝✤✣❬➛★➟✹✥❚➧①➢✱✧✖✩❆➛★➟☎➐✄☎❃➋✚❴❊➍⑥➝➉➡❊✩❆➛★➟❆❵❅➠✤✬✱✣✿✣✷✥❸➟▼❅❁➡★➟✹✥●✬✢✶✸➢✢✵✒➟✝✸✵✬✯✧❆➟✼✣❃✩❬➝●➠●➠❨✵✙✬❃➠●➝✤✥❚➝●➧◆✩❆➛★➟✹✣➦➟☞➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣

✳❁➢✌✣✿✣❬➟✹✣✿✣❞✬❀✳❁➢❫➠➉➟✍✬✯✩✼✳❸➠✮❲✦✣➹➝➄➡✲❅❁➡❸➝✮✩❃✶✝✸☎✶✵❲✵✩✝➡★➢✱✩☞➝●➧➥➢✒➡★➟➬➢■➧❑✩❆➛★➟★❪❪➛✦✬✱✣✼✬■➡✵➟✹✣✿✣❬➟▼➡✌✩❬➝✤✬❃➠❑✣➣➝➉➡★➤✱❲❸➠✤✬✯✧❬➝✮✩❃✶✱❝✖✺✼✣✾✩❆➛★➟✷❅❁➤✔❲✵✧❆➟✹✣✣❬➛★➢✢❇✰✸▲✩❆➛❸➝✤✣☞➝✤✣✔➡★➢✱✩❴✬❫➡Ó➢✝✶✦✣❃✩✭✬✱❵❅➠➉➟✡➧①➢✱✧❆✣❃❲✦❵❅➛❢✧❬➝❀✵✒➟★✧✭✣✼✩❅➢❨➢ò❵★❵✢❲✵✧✹❝❨➊✮➢✢❇➸➟✮✵❑➟★✧✺✸ ☞✖❝✢❽❚➝✤❵❆➛★➟✰➠❈✶✸➟✰➠❐➝➉➟✮✵✒➟✹✣❄✩❆➛✦✬✯✩☞➝✮✩✝➝✤✣❞✩❆➛★➟✳❁➟★✧➦➝➄➢✵✥❑➝✤❵❊✣❃✩✿✧✿❲✦❵✢✩✛❲✵✧❆➟✡➢❫➧❑✩❆➛★➟✔➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣❆❵✰➢❑➡✦✣➣➝✤✥❸➟★✧❆➟✹✥❹❇✮➛❸➝✰❵❅➛ù❪✍✬ ✯✒➟✹✣✾✩❆➛★➟✺✳★➛★➟▼➡★➢✱❪➁➟▼➡★➢✒➡ù✳❁➢✌✣✿✣➣➝❀✶❸➠➉➟✱❝✪➙➜➛❸➝✤✣☞➠➉➟✹✬✱✥✵✣✩❆➢✺✩❅➛★➟❆✣❃✩✿❲✦✥✌✶r➢❫➧◆✩❅➛★➟☞➧❹➢❫➠●➠➉➢✢❇➜➝➉➡★➤✍❪➁➢ò✥❸➟✰➠ ✚

✟✟★✟✛❴ ➑ ⑧ ✇ ⑩✎✍ ❂ ✇ ➋✚❴❊➍✚❴ ✝ ❩ ★ ❚ ❩➋✭✂❫➍

❇➥➛★➟★✧❆➟✡✉ ✇ ❘✂❃ ✧▼⑤ ✇ ❘✵Ð✎✧✑✏✡➝✤✣✾✬✷❅❁➡❸➝✮✩❆➟✴✣❬➟★✩✺✸✶❂ ✇ ➋✚❴❊➍❀❘ ☞ ✸ ❇➥➛★➟★✧❆➟ ☞ ➝✰✣✪✩❆➛★➟✴✬❃➠➉➤✒➟✮✶✵✧✭✬➁➢❫➧ ☞ ➱❍✳❁➟★✧❬➝➉➢✵✥❑➝✰❵✍➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣➢❫➧ ❅ ✝❖➟✹✥❭✳❁➟★✧❬➝➉➢✵✥✓✒ß❝➙➜➛★➟✷✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵✓✶✸➟▼➛✦✬✒✵✒➝➉➢✱❲✵✧⑧➢❫➧❖✩❆➛★➟✹✣➦➟✷✧❬➝❀✵✒➟★✧✭✣✠✥❸➢❸➟✹✣❣➡★➢✱✩⑥➧①➢❫➠●➠➉➢✢❇❊➧➆✧❆➢✔❪ ✩❆➛★➢✌✣❬➟➜➢❫➧❖✩❆➛★➟✪✳✵✧❆➟✮✵✒➝➉➢✱❲✦✣❋❵★✬✱✣❬➟☞➋➣✩❆➛✦✬❏✩❨❇➜➟

✣❬➛✦✬❃➠●➠☛✧❅➟✰➧❹➟★✧✷✩❅➢❄✬✔✣✸✩❅➛★➟✼✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠✸❵★✬✱✣❬➟❫➍✭❝❈❤q➡❚➧ ✬✔❵✢✩✺✸✌✩❆➛★➟★✧❆➟❉❇➜➝●➠●➠❨✶❁➟❞✩❆➛✵✧❆➟▼➟❆❵★✬✱✣➦➟✹✣✮✸✵✥❸➟★✳❁➟▼➡✦✥❑➝➉➡★➤❨➢✒➡❁✬✴✳✦✬✯✧✢✬✯❪➬➟★✩❆➟★✧▼✷❇➥➛❸➝✤❵❅➛ ✥❸➟★✳✸➟▼➡✦✥✵✣✡➢✒➡ù✩❅➛★➟✪✉ ✇ ✬❫➡✦✥●✩❆➛★➟❘⑤ ✇ ❝❨➙➜➛★➟✺❪➁➟★✩❆➛★➢ò✥ ❲✦✣❬➟✹✥ù✩❅➢❁✳✵✧❆➢✢✵✒➟✴✩❆➛★➟❀✩❆➛★➟▼➢✱✧❆➟★❪❀✣▲❇➜➝●➠❐➠❈✶✸➟✍✩❆➢✇➤❫➝❀✵✒➟

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Page 83: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❑✔❲✦✬❃➠●➝✲✩✢✬✯✩❬➝❀✵✒➟❆✧❅➟✹✣❃❲❸➠✮✩✭✣✑✬✗✶❁➢✱❲✵✩✑✣➦➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✷✩❅➛✦✬✯✩❬✶❁➢✱❲★➡✦✥ ➋❜✬✢✶❁➢✢✵✒➟❆✬■➡✦✥◗✶❁➟✰➠➉➢✢❇✝➍❑✩❅➛★➟✼✩✿✧✭✬✯♥❬➟✹❵✢✩❆➢✱✧➦➝➄➟✹✣⑧➢❫➧⑥➝➉➡✞✩❅➟★✧❆➟✹✣❃✩✹❝❀➙➴➛❸➝✰✣➝✤✣❋✩❆➢✰✶✸➟✒❵✰➢✒➡✌✩✿✧✭✬✔✣❃✩❆➟✹✥✴✩❆➢❞✩❆➛★➟✾❪➬➟★✩❆➛★➢✵✥✵✣✸❲✦✣➦➟✹✥✡➧①➢✱✧✸✩❅➛★➟✷✳❁➢❫➠✮✶❸➡★➢✱❪✡➝✤✬❃➠◆❵★✬✔✣❬➟✝✸✝❇➥➛❸➝✤❵❅➛❘❇➜➟★✧❆➟✑✣➣➝➉➡★➤✱❲❸➠✤✬✯✧✷✳✸➟★✧✿✩✿❲✵✧ ✶✦✬❏✩❬➝➉➢✒➡✦✣✬❫➡✦✥r➡★➢✒➡✙❁➣✣✫✩✭✬❫➡✦✥✵✬✯✧✭✥❭✩❆➟✹❵❅➛★➡❸➝❭❑✔❲★➟✹✣★❝

� ✰ ✁☎✄✌☎✶✵ ✆ ✷✑✮⑧➝❀✵✒➟★✧✭✣ ✚✮★❞❘✤➑ ★ ✟ ⑥✙❴✄✬❫➡✦✥ ★❆❘✤➑ ★ ✟ ⑥❊➋✢✂❬❸ ✣➣➝➉➡✯❴ ✪❺✐❸➍✚❴ ❝

✂✂✴✴✳✖✻✵✸❱❨❫✸✺✿❀✻❞➆✙ ✵❑➟▼➡✺✩❆➛★➢✱❲★➤✒➛â✩❆➛★➟✑✧❅➟✹✣❃❲❸➠✮✩✭✣✸✬✯✧❅➟✒✣❃✩✛✧✭✬❃➝➉➤✒➛✌✩❬➧❹➢✔✧ ❇✷✬✯✧✭✥✼✩❅➢❆✣❃✩✭✬✯✩❆➟➴➝➄➡◗✵✙✬■➤✱❲★➟✑✩❅➟★✧✿❪✍✣✮✸✯✩❆➛★➟☞➟✆✝✦✬✱❵✢✩❣➧①➢✱✧✿❪✴❲❸➠✤✬✯✩❬➝➉➢✒➡➬➡★➟▼➟✹✥✵✣✬✡➡✌❲✵❪✷✶❁➟★✧➥➢❫➧✠✳✵✧❆➟✰➠●➝✮❪✡➝➉➡✦✬✯✧✿✶●❵✰➢✒➡✦❵✰➟★✳✵✩✭✣✪✩❆➢✷✶❁➟❴✥❸➟▼❅❁➡★➟✹✥ß❝♦✖✵✙♣✘✰✦q✶✰❀r☞✰✚❡☎q ✂ ✷❋❤①➧❆❙✸➋✚❴❊➍✪❘ ☞ ➝✤✣✺✬ ➡★➢✒➡✙❁✽✟▼➟★✧❆➢Ó➧➆❲★➡✦❵✢✩❬➝➉➢✒➡Õ✬❫➡✦✥ ★➬➋✢❴Ô➍☞➝✤✣❀✬❁✧❅➟✹✬❃➠➥➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ✥❸➟▼❅❁➡★➟✹✥ ➢✒➡ý✬

➡★➟✰➝➉➤✒➛✲✶❁➢✱❲✵✧❆➛★➢❸➢✵✥❼➢■➧✰❸✕✔ ✬❫➡✦✥ ❈ ❘ ❃✐✩❆➛★➟▼➡❵❇➜➟❁✣✿✬❅✶ù✩❆➛✦✬❏✩✥★➬➋✚❴❊➍☞➝✤✣✺✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵❀✩❆➢ù❙✸➋✚❴❊➍✚❴ ➩ ➋✍❇➥➛❸➝✤❵❆➛❵❇➜➟✥❸➟▼➡★➢✱✩❆➟✦★r➋✚❴❊➍ ✞ ❙✸➋✚❴❊➍✚❴ ➩ ➍✘➝❐➧

★➁➋✚❴❊➍◗➑Õ❙✸➋✚❴❊➍✚❴ ➩ ❸ ①❑➋✚❴ ➩ ➍✤✧ ❴ ➽ ✔ ✩✴✮➢✱✩❆➟✷✩❆➛✦✬❏✩❀➝●➧◆✬ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡r➝✤✣✖✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩❬➝✤❵✪✩❆➢❴❙✸➋✢❴Ô➍✢❴ ➩ ✩❅➛★➟▼➡❊✩❆➛★➟✑✩❅➟★✧✿❪ ❙✸➋✚❴❊➍❞➝✰✣⑧➡★➟✹❵✰➟✹✣✿✣✛✬✯✧❬➝●➠✮✶❊❲★➡❸➝❭❑✔❲★➟❉❇➥➛❸➝✤❵❅➛

❪✍✬ ✯❑➟✹✣ ☞ ✬❫➡❁✬❏✳✵✳✵✧❆➢✱✳✵✧❬➝✤✬✯✩❆➟✴✣❃✳✦✬✱❵✰➟☞➧①➢✱✧✑✣❃✩✛❲✦✥✌✶✒➝➉➡★➤❀✩❆➛★➟❆✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩➦➝✰❵▲✶✸➟▼➛✦✬✒✵✒➝➉➢✱❲✵✧☞➢❫➧◆✣❬➢■➠✲❲✵✩➦➝➄➢❑➡✦✣➥➢❫➧❣➢✱❲✵✧✷❪➁➢ò✥❸➟✰➠➣❝✺✼✣❣➝✤✣❋❲✦✣❃❲✦✬❃➠✤➝➉➡❁✥❸➟✹✬❃➠●➝➉➡★➤★❇➜➝✮✩❆➛❊✥❑➝❑❏➞➟★✧❅➟▼➡✞✩❬➝✤✬❃➠⑥➟✺❑✱❲✦✬✯✩➦➝➄➢❑➡✦✣✮✸✵❵✢✧✿❲✦❵❅➝✤✬❃➠✤➝➄➡❸➧①➢✱✧✿❪❀✬✯✩❬➝➉➢✒➡➁➝✰✣✪❵✰➢✒➡✞✩✢✬❃➝➉➡★➟✹✥✡➝➉➡❊✩❆➛★➟❉✴➥➟✮❇✪✩❆➢✒➡✳❁➢■➠✲✶❸➤✒➢✒➡✁� ✸▲✩❆➛★➟❊❵✰➢✒➡❦✵❑➟✆✝ ➛✌❲❸➠●➠➥➢❫➧✷✩❆➛★➟✍✣❬➟★✩✔➢❫➧➥➛★➢✱✧❬➝✮✟▼➢✒➡✌✩✭✬❃➠➸➛✦✬❺➠❐➧✦❁✚➠●➝➉➡★➟✹✣➬➤✒➢■➝➄➡★➤❚➠➉➟✰➧➆✩✔➧✽✧❆➢✱❪ ✩❅➛★➟✺✳❁➢❫➝➉➡✌✩✭✣➁➋❱✉ ✇ ✧▼⑤ ✇ ➍✭❝✺ ✧✭✬✯✩❬➝➉➢✒➡✦✬❺➠➸➡✌❲✵❪✾✶✸➟★✧ ❈◗❇➜➝●➠●➠❈✶❁➟❊❵★✬❃➠●➠➉➟✹✥ ✬❡❵✰➢✝❁➣✣➣➠➉➢✱✳❁➟r➢❫➧✂� ➝❐➧✯❈➁➝✤✣❞✩❆➛★➟✍✣➣➠➉➢✱✳✸➟✪➢■➧➴➢❑➡★➟➬➢❫➧✷✩❆➛★➟➬➡★➢✱✧✛❪✍✬❃➠✤✣✼✩❆➢❡✩❆➛★➟✣❬➟▼➤✱❪➁➟▼➡✞✩✭✣➴➢❫➧✄�✍❝✴✮➢✱✩❆➟➸➻➎➋❆❳ ✧ ❴ ✧✩★☎➍⑧➑ ✂ ✇ ⑩ ✍ ❂ ✇ ➋❆❳❀➍✚❴✚✝ ❩ ★ ❚✱❩ ❇➥➛★➟★✧❆➟✎❂ ✇ ➋✢❴Ô➍✆☎ ☞ ✬■➡✦✥❴✬❏✧❆➟❀➡★➢✱✩⑥➝✤✥❸➟▼➡✌✩❬➝✤❵★✬❃➠●➠✮✶✺✟▼➟★✧❆➢✦❝❣➙➜➛★➟➜➡✌❲✵❪✾✶✸➟★✧

✝❂ ✇ ➝✤✣✸✩❅➛★➟❆✬✺✵❑➟★✧✭✬❫➤✒➟➥➢■➧✫❂ ✇ ➢✢✵✒➟★✧⑧➢✒➡★➟✑✳✸➟★✧❬➝➉➢ò✥ ✸ß✬❫➡✦✥ ✓❂ ✇ ➋✚❴❊➍⑥➑✙❂ ✇ ➋✚❴❊➍✙⑥ ✝❂ ✇ ❝ ✤✵➟✼✬❃➠✤✣❬➢✡➤✒➟▼➡★➟★✧✭✬❺➠❐➝✤✣❬➟✼✩❅➛❸➝✰✣➴➡★➢✱✩✭✬✯✩❬➝➉➢✒➡❀✩❆➢✬❫➡✌✶➬➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✇➢❫➧✗❴❵✸✲✶✞✶❘❇➥➛❸➝✤❵❅➛❘❇➜➟✼❪➬➟✹✬❫➡❁✩❅➛✦✬✯✩✷✬✷✶✦✬✯✧➜➝➉➡✦✥❑➝✤❵★✬✯✩❆➟✹✣✾✬❫➡❁✬✒✵✒➟★✧✭✬❫➤❑➟✒✬❫➡✦✥❡✬❞✩❬➝●➠✰✥❸➟✴✩❆➛★➟✼✟▼➟★✧❅➢✝❁➣✬✒✵✒➟★✧✭✬❫➤✒➟✩✿✧✭✬■➡✦✣➣➠✤✬✯✩❬➝➉➢✒➡❇❝➭✤➟★✩✎❈✞☎❹❃◗✸✞✩❅➛★➟▼➡✿❇➜➟❆✥❸➟▼❅❁➡★➟✞✟ ✁ ➑ ❪✍✬✎✝✿➋❱✉ ✇ ❸ ❈✢⑤ ✇ ➍❑✬❫➡✦✥❁▼ ➑❉✂❈⑥ ❈▲⑥✠✟ ✁ ❝ ☞★➢✱✧✪✩❆➛★➟❴✣➣➠➉➢✱✳✸➟✷❈❦✸ß▼✾❪➬➟✹✬✱✣✫❲✵✧❆➟✹✣✩❆➛★➟✺✬✯✩✿✩✛✧✭✬✱❵✢✩❬➝➉➢✒➡②➋q➢✔✧✑✧❆➟★✳✵❲❸➠✤✣➣➝➉➢✒➡✤➍☞➢❫➧✸✩❆➛★➟✺✬✱✣✿✣➦➢ò❵❅➝✤✬✯✩❆➟✹✥●✣❬➢■➠✲❲✵✩➦➝➄➢❑➡✟✸✸➝❐➧⑧➝✮✩✝➟✆✝❢➝✤✣❃✩✭✣➍❝➹➭➞➟★✩ ❄★✶✸➟❴✩❅➛★➟❄✣✫❪✍✬❃➠●➠➉➟✹✣❃✩✼✳❁➢✞✣❱➝✲✩➦➝✻✵❑➟

➝➉➡✞✩❅➟▼➤✒➟★✧❆✣❃❲✦❵❅➛Ü✩❅➛✦✬✯✩ ❈ ⑥ ⑤✫✪❳❄➎➧❹➢✱✧❉⑤✁☎❊Ð❛✩✭✬ ✯✒➟✹✣✮➢✒➡●✬❃➠●➠✓✵✙✬❃➠✮❲★➟✹✣✝➢■➧➸✉ ✇ ❸ ❈✢⑤ ✇ ➧①➢✱✧ ③✡☎ ✏❁✬❫➡✦✥❡✩❆➛★➟✰✵✯✬❃➠✮❲★➟ ❈❉⑥Õ✂✱❝☞✵✧❅➢✱❪ ✩❆➛★➟✹✣❬➟✰✵✯✬❃➠✮❲★➟✹✣❈❇➜➟❆❵★✬❫➡❁✥❸➟▼❅❁➡★➟✎❆r➑ ▼❱❄✴✬❫➡✦✥☛✟ß❚➁➑☞✟ ✁ ⑥●⑤☞✪✟❄✞❝✁☞❯❲✵✧✿✩❆➛★➟★✧✿❪➬➢✔✧❆➟✝✸✙❇➜➟✒✣➦➟★✩

➻ ❚➩ ➋❆❳ ✧ ❴ ✧✩★✡➍❣➑ ⑧✝ ❩ ② ➩➣❚✱❩ ❛✍✌ ■ ❂ ✇ ➋❅❳❀➍✣✚ ✝ ❩ ★ ❚✱❩ ✧ ✝➻ ❚➩ ➋✚❴✚✧✔★✡➍❣➑ ⑧

✝ ❩ ② ➩➣❚✱❩ ❛✍✌ ■ ✝❂ ✇ ✚ ✝ ❩ ★ ❚✔❩ ✩ã✣✗

Page 84: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✤✵➟✂❇➜➝●➠●➠☎➢✒➡❸➠✮✶❛✥❑➝✰✣✛❵✢❲✦✣✿✣❀✩❆➛★➟✂✵✙✬✯✧➦➝➄➢✔❲✦✣♠➻ ✁➩ ➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣r➛★➟★✧❆➟✝✸▲✶✵❲✵✩❊✩❆➛★➟②➢✱✩❅➛★➟★✧➬➧✽❲★➡✦❵✢✩❬➝➉➢✒➡✦✣❁❵★✬■➡❆✶✸➟●❲✦✣❬➟✹✥Õ✩❆➢✥❸➟★✩❆➟★✧✿❪➎➝➄➡★➟✼✩❅➛★➟✑✣❃❲✦❵★❵✰➟✹✣✿✣➣➝❀✵✒➟✼✩❅➟★✧✿❪✍✣⑥➝➉➡❀✩❆➛★➟✼✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩❬➝✤❵➜➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡❇❝✱✤✵➟✒✥❸➟▼➡★➢✔✩❆➟④✶✌✶✺✬✼❘✵✩❆➛★➟✼✥❸➟★✧❬➝❀✵✙✬❏✩❬➝❀✵✒➟✝➢❫➧❇✩❆➛★➟✬✢✶✸➢ ✵❑➟☞➧➆❲★➡✦❵✢✩❬➝➉➢✒➡✦✣❪❇➜➝✮✩❆➛❊✧❆➟✹✣✫✳❁➟✹❵✢✩✾✩❆➢✥★✍❝⑧➙➜➛★➟❆✥❑➝❑❏➞➟★✧❅➟▼➡✞✩❬➝✤✬❃➠❣➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡

✟ ★✟✤❴ ➑Ï➻ ✁➩ ➋✚❴✚✧✹✂ ✧✔★✔➍➋❱✐❸➍

❇➜➝●➠●➠ ✶✸➟✝➝✮❪✺✳✸➢✱✧✿✩✭✬❫➡✌✩✹❝✁☞❞➝➉➡✦✬❃➠●➠✮✶✝✸✤➡★➢✱✩❆➟❉✶✌✶♠➋ ✪❑➍♦✬■➡❨➟✆✝ò✳✦✬❫➡✦✣❱➝➄➢❑➡♠➢❫➧✠✩❆➛★➟☞➧①➢✱✧✿❪⑧ ✇ ☞ ✁

■ ✇ ➋✚❴❊➍✚❴ ➩ ❿ ✇ ✛✐❃➧①➢✱✧✑■ ✇①➋✚❴❊➍ ☎ ☞ ❝❣➙➜➛❸➝✤✣➜➝✤✣✪✩❆➛★➟✼❪➬➢✵✥❸➟✰➠☛❲✦✣❬➟✹✥r➧①➢✱✧✷✬❫➡❁✬✱✣✫✶✞❪✺✳✵✩❅➢✱✩❬➝✤❵☞➟✆✝ò✳✦✬■➡✦✣➣➝➉➢✒➡❇❝

❿✗✴ ✕✷❯❫❲❫➂✂◗❀✸✺❲✙ ✬✔❵❆➛✔➢❫➧✦✩❆➛★➟⑧➧❹➢■➠❐➠➉➢✢❇➜➝➉➡★➤✼✩❆➛✵✧❆➟▼➟❋✩❆➛★➟▼➢✱✧❆➟★❪❀✣✢➛✦✬✱✣❈✩✈❇➜➢✑✣❃❲✙✶✙❁➣❵★✬✔✣❬➟✹✣✮✸✱✣❃❲✙✶✙❁➣❵★✬✱✣➦➟❒➋❃✬❸➍ ❵✰➢✔✧✿✧❆➟✹✣❃✳✸➢✒➡✦✥✵✣❈✩❆➢✷✩❆➛★➟✷✬✯✩✛✩✿✧✭✬✱❵✢✩❬➝❀✵✒➟❵★✬✱✣❬➟✝✸⑤✬❫➡✦✥❊✣❃❲✙✶✙❁➣❵★✬✱✣❬➟➁➋P✶✤➍✸✩❆➢✴✩❆➛★➟❞✧❆➟★✳✵❲❸➠✤✣➣➝❀✵✒➟❴❵★✬✔✣❬➟✱❝❜☎❝✫✵❢❡✞☎✶✵★❤❬✂ ✷✪❧✟❢✺✐✂❈ ☎✿❃ s ❙✸➋✢❴Ô➍✆☎ ☞ s ❙ ❭➑ ✁ ❷❞❢❉❡ ✣☞✟ ✡✿✐☛✡❦❜✝✐➋✭✂❫➍ ❈❘❤❀❡❉❜ ✟ ✝❫✈P❡✮❝ ✝✄✌ ❢ ✝❬③ �✄✂➋❱✐❸➍✴▼ ✥ ✂☎✂➋❜❥❸➍✝✆✘❴ s ➻ ✁➩ ➋✚❴✚✧✹✂ ✧✢❙✸➋✚❴✵➍❅➍✿➑ ✁ ✂➋q❴★➍ ✙P❜✤✚✞✆✘❴ s ➋❱➻ ✁➩ ➍➣❘➉➋✚❴✚✧✹✂ ✧✭❙✸➋✚❴❊➍❆➍✜✌ ✁ s ✝ ❛✘✙❱❷✧✚✟✆✘❴ s ➋❱➻ ✁➩ ➍➣❘ ➋✚❴✚✧✹✂ ✧✢❙✸➋✚❴❊➍❱➍✱✥ ✁ ⑨

⑩✌✡❦❢✒❴ ✐☛✡✲❢✺❛✈❢❘❢▼t✢❤❀❡✮✐♥❡ ❜ ❡♠❢✒❛✤❤♥❢✮❡ ✝❬③❘✐☛✡❦❢❘✐ ✖✒✌ ❢r➋ ✪✒➍✍⑤✒✡❦❤✞✟✣✡●❤❀❡★❜✡③ ✝✝❛✗✔✾❜ ❝☎❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ✝❬③ ✙✔✂✤✚✃⑤☎❤♥✐☛✡❁■ ✁ ➋✚❴❊➍❒➑ ❙✸➋✚❴❊➍④⑨❦☞✣❦❛▼✐☛✡❦❢✒❛ ✔ ✝✝❛✈❢ s ✐☛✡❦❢✺❛✈❢❘❢▼t✢❤❀❡✮✐♥❡★❜✝❴●❤❥❴ ✎ ❴☛❤♥✐✦❢★❴ ✣✑✔➬❷❞❢✺❛ ✝❬③★❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ❡✽❜✗❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟❘✐✒✝❊❙✸➋✚❴❊➍✚❴ ➩ ❤❥❴●✐☛✡❦❢❘❜✝✐✦✐✦❛✈❜ ✟✒✐✦❤♦♥✒❢✟▼❜✢❡♠❢ s ❜✝❴ ✏❘❜✭✣❦❴❲❤ ✣ ✣❦❢ ✝✝❴☛❢◗❤♥❴❹✐☛✡❦❢◗❛❍❢ ✌✤✣✲❝❖❡✮❤✚♥✺❢ ✟✤❜✢❡✮❢❺⑨ ⑩✌✡❦❢✽❡♠❢✒❛✤❤♥❢✮❡✔➋ ✪✒➍✰❤❧❡✾✐☛✡❦❢❘❜✢❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟ ❢⑦t☎✌ ❜ ❴✙❡✮❤✡✝✝❴ ✝❬③★✐☛✡☞✝✢❡✮❢❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴✙❡❄⑨P❀➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣➁➋❜❥❖➍✑✬❫➡✦✥❊➋q❴★➍☞➟✆✝ò✳✵✧❅➟✹✣✿✣✼✩❆➛✦✬❏✩❴❙✸➋✚❴❊➍✚❴ ➩ ➝✰✣❞✩❆➛★➟✽❅✦✧✭✣❃✩❆✩❅➟★✧✿❪ ➝➉➡ ✩❆➛★➟❊✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵☎➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡❊➧①➢✱✧

✬â✩✿✧✭✬✯♥❬➟✹❵✢✩❆➢✱✧✛✶★❇➜➝✮✩❆➛Ü❵✰➢❑➡✦✣❃✩✭✬❫➡✌✩ ✁ ✥❸➟★✧❬➝❀✵✙✬✯✩❬➝❀✵✒➟❀✬❃➠➉➢✒➡★➤✍✩❅➛✦✬✯✩✷✩✿✧✭✬❏♥❱➟✹❵✢✩❅➢✱✧✿✶✱❝➜➙➜➛★➟❉❅✦✧✭✣✫✩✒❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡ ➝✰✣✪✩❆➢➁➝➉➡✦✣❃❲✵✧❆➟✴✩❆➛✦✬✯✩✩❆➛★➟✔➧✽❲★➡✦❵✢✩❬➝➉➢✒➡Ô➻ ✁➩ ➝✤✣✝➡★➢✱✩✾✧❆➟✹✥✌❲✦❵✰➟✹✥ô✩❆➢✪➢❑➡★➟❴✩❅➟★✧✿❪ ➋P❇➥➛★➟★✧❆➟✡➢✒➡❸➠✮✶●✩❆➛★➟✔➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ❙✸➋✚❴❊➍☎✔ ✁ ❇➜➢✱❲❸➠✤✥ù✣✿✬❏✩❬➝✤✣➣➧➆✶❡✩❆➛★➟✩❆➛❸➝✮✧✭✥❢❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✤➍✭❝♠➙➴➛★➟✍❵★✬✱✣❬➟✹✣➹➝➄➡ P❀➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡♣➋q❴★➍✮➝➉➡✦✥❑➝✰❵★✬❏✩❆➟ ❇✮➛★➟★✩❆➛★➟★✧✴✩❆➛★➟★✶✵✧✭✬❫➡✦❵❅➛✵➢❫➧✷✩❆➛★➟❀✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡●❇➸➟❀✬✯✧❆➟❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❬➝➉➡★➤❚➝✰✣✾✬✯✩✿✩✛✧✭✬✱❵✢✩❬➝❀✵✒➟✝➢✱✧✾✧❆➟★✳✵❲❸➠✤✣➣➝❀✵✒➟✱❝✝➙➜➛★➟✔➧➣✬✱❵✢✩✷✩❆➛✦✬✯✩✼▼ ✥❉✂ ➝➉➡✦✥❑➝✰❵★✬❏✩❆➟✹✣✾✩❆➛✦✬✯✩☞➤✒➟▼➢✱❪➬➟★✩✛✧❬➝✤❵★✬❃➠●➠✲✶❡✩❆➛★➟☎➡★➟✹✬❏✧ ✶✞✶✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✮➢✞✣✿❵❅➝●➠●➠✤✬✯✩❆➟✴✬❃➠➉➢✒➡★➤ ❇➴➝✲✩❅➛❊✩❆➛★➟✼✩✿✧✭✬❏♥❱➟✹❵✢✩❆➢✔✧✿✶✍❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❆➟✹✥ß❝❜☎❝✫✵❢❡✞☎✶✵★❤❥✐✸✷✪❧✟❢✺✐✂❈ ☎✿❃ s ❙ ☎ ❷ s ❙ ❭➑ ✁ ❷ ❢❫❡ ✣☞✟ ✡■✐☛✡❦❜ ✐➋✭✂❫➍ ❈❘❤❀❡❉❜ ✟ ✝❫✈P❡✮❝ ✝✄✌ ❢ ✝❬③ �✄✂➋❱✐❸➍ ✁ ✌ý▼ ✌❛✂☎✂➋❜❥❸➍ ✝➻ ✁➩ ➋✭✂ ✧✭❙✸➍⑥➑ ✁ ✂➋q❴★➍ ✙P❜✤✚✡➋ ✝➻ ✁➩ ➍ ❘ ➋✭✂ ✧✢❙✸➍ ✌ ✁ s ✝✝❛✘✙❱❷✧✚➬➋ ✝➻ ✁➩ ➍ ❘ ➋✭✂ ✧✭❙✸➍✻✥ ✁ ⑨

⑩✌✡❦❢✒❴ ✐☛✡✲❢✺❛✈❢❘❢▼t✢❤❀❡✮✐♥❡ ❜ ❡♠❢✒❛✤❤♥❢✮❡ ✝❬③❘✐☛✡❦❢❘✐ ✖✒✌ ❢r➋ ✪✒➍✍⑤✒✡❦❤✞✟✣✡●❤❀❡★❜✡③ ✝✝❛✗✔✾❜ ❝☎❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ✝❬③ ✙✔✂✤✚✃⑤☎❤♥✐☛✡❁■ ✁ ➋✚❴❊➍❒➑ ❙✸➋✚❴❊➍④⑨❦☞✣❦❛▼✐☛✡❦❢✒❛ ✔ ✝✝❛✈❢ s ✐☛✡✲❢✺❛✈❢✷❢▼t ❤❧❡✮✐♥❡ ❜✝❴✂❤♥❴☞✎❬❴☛❤♥✐✦❢✰❴✸✣ ✔➬❷ ❢✒❛ ✝➦③❉❡ ✝✝❝ ✣✲✐✦❤✡✝ ❴✙❡✰❜✢❡ ✖ ✔ ✌ ✐✒✝✝✐✦❤✡✟✷✐✒✝✴❙ ❴ ➩ ❤♥❴✿✐☛✡❦❢✱❜✝✐✦✐✦❛✈❜ ✟✺✐✦❤✚♥✺❢ ✟▼❜✢❡♠❢ s❜✝❴ ✏❉❜✏✣✲❴☛❤ ✣ ✣✲❢ ✝✝❴❲❢❈❤♥❴★✐☛✡❦❢▲❛❍❢ ✌✤✣✲❝❖❡✮❤✚♥✺❢ ✟✤❜✗❡♠❢❫⑨✔⑩✌✡❦❢❬❡✮❢✺❛▼❤♥❢✮❡❀➋ ✪✒➍ ❤❧❡ ✐☛✡✲❢④❜✢❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟④❢⑦t☎✌ ❜ ❴✙❡✮❤✡✝✝❴ ✝❬③ ✐☛✡☞✝✗❡♠❢❪❡ ✝ ❝ ✣✲✐✦❤✞✝✝❴✙❡❄⑨✻ ➝➉➡✦❵✰➟ ✁ ✌❦▼ ✌❬✂ ✸❇✩❆➛★➟❀✧❬➝❀✵✒➟★✧✭✣❞✥❸➢♠➡★➢✱✩✔➢✞✣✿❵❅➝●➠●➠✰✬❏✩❆➟❁✣❃✩✭✬✯✧✛✩❬➝➉➡★➤Ü✬✯✩✼✩❆➛★➟✱❅✦✧✭✣❃✩✴✬✯✳✵✳✵✧❆➢ ✝❸➝✲❪❀✬✯✩❬➝➉➢✒➡✟✸☛✬■➡✦✥ù✩❆➛✌❲✦✣☞➝✮✩ ➝✰✣

➡★➟✹❵✰➟✹✣✿✣✿✬❏✧✿✶ù✩❆➢❚➠➄➢❸➢✄✯ ✬❏✩❆✩❆➛★➟❊✬✒✵✒➟★✧✭✬❫➤✒➟✹✥✃➧➆❲★➡✦❵✢✩❬➝➉➢✒➡ ✝➻ ✁➩ ➝➉➡✦✣❃✩❆➟✹✬✔✥ ✸☎✶✵❲✵✩✴✩❆➛★➟✍❪➁➟✹✬❫➡❸➝➉➡★➤✃➢■➧◗✩❅➛★➟✍✩❆➛❸➝✮✧✭✥ ✬■➡✦✥✇➧❹➢✔❲✵✧✿✩❆➛❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣✾✬✯✧❆➟✝➟✹✣✿✣➦➟▼➡✞✩❬➝✤✬❃➠●➠✮✶❁✩❅➛★➟❆✣✿✬✯❪➬➟❆✬✱✣➸➝➄➡❡✩❆➛★➟✼✳✵✧❆➟✮✵❑➝➉➢✱❲✦✣✷✩❅➛★➟▼➢✱✧❆➟★❪❁❝❜☎❝✫✵❢❡✞☎✶✵★❤❦❥✸✷✪❧✟❢✺✐✂❈ ☎✿❃ s ❙✸➋✢❴Ô➍✆☎ ☞ s ❙✸➋✚❴❊➍ ❭➑ ✁ ❷❞❢❫❡ ✣✄✟✣✡❘✐☛✡❦❜✝✐➋✭✂❫➍ ❈❘❤❀❡❉❜ ✟ ✝❫✈P❡✮❝ ✝✄✌ ❢ ✝❬③ �✄✂➋❱✐❸➍✴▼➥➑❍✂☎✂

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Page 85: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➋❜❥❸➍✴❙✸➋✚❴❊➍ ❤❧❡✰❜ ✌ ❢✒❛✤❤✞✝ ✏ ❤✡✟❫❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ✝❬③☎✙❄✐ ✚ ✂➋q❴★➍ ✙P❜✤✚ ➋❱➻ ✁➩ ➍ ❘ ➋✚❴✚✧✹✂ ✧✢❙✸➋✚❴✵➍❆➍✜✌ ✁ s ✝✝❛☎✙❬❷ ✚ ➋❱➻ ✁➩ ➍ ❘ ➋✚❴ ✧❅✂ ✧✭❙✸➋✢❴✵➍❆➍☞✥ ✁ ⑨

⑩✌✡❦❢✒❴ ✐☛✡✲❢✺❛✈❢❘❢▼t✢❤❀❡✮✐♥❡ ❜ ❡♠❢✒❛✤❤♥❢✮❡ ✝❬③❘✐☛✡❦❢❘✐ ✖✒✌ ❢r➋ ✪✒➍✍⑤✒✡❦❤✞✟✣✡●❤❀❡★❜✡③ ✝✝❛✗✔✾❜ ❝☎❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ✝❬③ ✙✔✂✤✚✃⑤☎❤♥✐☛✡❁■ ✁ ➋✚❴❊➍❒➑ ❙✸➋✚❴❊➍④⑨❦☞✣❦❛▼✐☛✡❦❢✒❛ ✔ ✝✝❛✈❢ s ✐☛✡❦❢✺❛✈❢❘❢▼t✢❤❀❡✮✐♥❡★❜✝❴●❤❥❴ ✎ ❴☛❤♥✐✦❢★❴ ✣✑✔➬❷❞❢✺❛ ✝❬③★❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴ ❡✽❜✗❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟❘✐✒✝❊❙✸➋✚❴❊➍✚❴ ➩ ❤❥❴●✐☛✡❦❢❘❜✝✐✦✐✦❛✈❜ ✟✒✐✦❤♦♥✒❢✟▼❜✢❡♠❢ s ❜✝❴ ✏❘❜✭✣❦❴❲❤ ✣ ✣❦❢ ✝✝❴☛❢◗❤♥❴❹✐☛✡❦❢◗❛❍❢ ✌✤✣✲❝❖❡✮❤✚♥✺❢ ✟✤❜✢❡✮❢❺⑨ ⑩✌✡❦❢✽❡♠❢✒❛✤❤♥❢✮❡✔➋ ✪✒➍✰❤❧❡✾✐☛✡❦❢❘❜✢❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟ ❢⑦t☎✌ ❜ ❴✙❡✮❤✡✝✝❴ ✝❬③★✐☛✡☞✝✢❡✮❢❡ ✝✝❝ ✣❦✐✦❤✞✝✝❴✙❡❄⑨➙➜➛★➟✼❵★✬✱✣❬➟✼▼✮➑ ✂✮➝✰✣✖✬❫➡➁➝➉➡✞✩❅➟★✧✿❪➬➟✹✥❑➝✤✬✯✩❆➟✼✣➣➝✮✩✿❲✦✬✯✩❬➝➉➢✒➡ ✚♦✩❆➛★➟★✧❆➟✼✬✯✧❆➟☞➢✞✣✿❵❅➝●➠●➠✰✬❏✩❬➝➉➢✒➡✦✣➜➢❫➧❇✩❆➛★➟✾✩❃✶✞✳✸➟✒❙✸➋✚❴❊➍✚❴ ➩ ✸✝✶✵❲✵✩✷❙✸➋✚❴❊➍

✥❸➢❸➟✹✣❀➡★➢✔✩◗❵✰➢✔✧✿✧❆➟✹✣❃✳✸➢✒➡✦✥➬➟✆✝✦✬✱❵✢✩❬➠✮✶❀✩❆➢❆✩❅➛★➟❒➢✞✣✛❵❅➝❐➠●➠✤✬✯✩❬➝➉➢✒➡✦✣✮➢❫➧❇✩❆➛★➟✾✩✿✧✭✬❏♥❱➟✹❵✢✩❆➢✔✧✿✶✱❝✒✤Ï➛★➟▼➡r➝✮✩➜➟✆✝❢➝✤✣❃✩✭✣✉✸❦❇➜➟☞➢✝✶✦✣❬➟★✧ ✵❑➟✷✩❆➛✦✬✯✩⑧➝✮✩➝✤✣➥➤❑➟▼➡★➟★✧✭✬❃➠●➠✮✶❨➢✱❲✵✩➥➢❫➧✠✳★➛✦✬✱✣❬➟❆✬❫➡✦✥r➢■➧♦✣❃❪❀✬❃➠●➠➄➟★✧✼✬✯❪✺✳❸➠●➝✮✩✿❲✦✥❸➟✱❝

✤✵➟❉❇➜➝●➠●➠✠✩❆➛★➟▼➡❁❵★✬❃➠●➠ ✝✗❡ ✟✒❤❥❝♥❝❑❜✝✐✦❤❥❴ ❧ ❛▼❤♦♥✒❢✺❛❞✩❆➛★➟❆✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✾✥❸➟✹✣✿❵✢✧❬➝❀✶✸➟✹✥✿✶✌✶❨➟✹✬✱❵❅➛❨➢❫➧✠✩❆➛★➟✼✳✵✧❆➟✹❵✰➟✹✥❑➝➉➡★➤❊✩❆➛★➟▼➢✱✧❆➟★❪❀✣★❝✲❊✴ ✞ ✁ ❨☎❩✜❬ ◗❀❯➭✤➟★✩✼❲✦✣❞❵✰➢✒➡✦✣➣➝✤✥❸➟★✧❆✩❆➛★➟✡➟✺❑✔❲✦✬✯✩❬➝➉➢✒➡ ★ ❘ ➑❥➋✡★ ✟ ⑥♣➋❱✐ ❸ ✣❱➝➄➡❞➋✚❴❊➍❆➍❆➍✚❴ ☞ ❝✡➙➜➛★➟✷❅✦✧✭✣✫✩❆❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡②➝➉➡ ✬❃➠●➠✸✩❆➛★➟▼➢✱✧❅➟★❪✍✣

➝✮❪✺✳❸➠●➝➉➟✹✣✴✩❆➛✦✬✯✩✝➡★➟✹❵✰➟✹✣✿✣✛✬✯✧❬➝●➠✮✶ ❈❚➑ ✁ ❝ ☞✵✧❆➢✱❪ ✩❅➛❸➝✰✣✉✸❨❇➜➟✺❵★✬❫➡ ❵★✬❃➠✤❵✢❲❸➠✤✬✯✩❆➟❊▼➬➑✐✂❈❸ ■❋❝✪➙➴➛✞❲✦✣✮✸➞➝●➧✒■ ✥ ✁ ✸❇✩❆➛★➟✷❅✦✧✢✣❃✩✩❆➛★➟▼➢✱✧❅➟★❪❪➤❫➝❀✵✒➟✹✣✾✩❆➛✦✬✯✩▲❇➜➟☎➛✦✬✒✵✒➟✺✬✺✧➦➝✻✵❑➟★✧❴✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵✼✩❆➢ ✓✝➋❱✐ ❸ ✣❱➝➄➡❞➋✚❴❊➍❆➍ ➓ ✛ ✟ ✸✸➝●➧✒✂ ✌❛■ ✌ ✁ ✸✦✩❆➛★➟✺✣❬➟✹❵✰➢❑➡✦✥②➢✒➡★➟➤❫➝❀✵✒➟✹✣â✧❬➝❀✵✒➟★✧✭✣❀✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩➦➝✰❵❀✩❅➢ ✓ ✠ ✐❢✬❫➡✦✥Ó➝●➧❄■➺➑ ✁ ✸❋✩❆➛★➟❚➠✰✬✔✣❃✩✍✩❅➛★➟▼➢✱✧❆➟★❪ ➠➉➟✹✬✱✥✵✣â❲✦✣✺✩❅➢ ✣❬➟✹✬✯✧✭❵❅➛ ➧①➢✱✧✺✳✸➟★✧❬➝➉➢ò✥❑➝✤❵✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✮➢❫➧✸✬✴✳❁➟★✧➦➝➄➢✵✥❑➝✤❵✔➟✺❑✱❲✦✬✯✩➦➝➄➢❑➡✟✸✙❇➥➛★➟★✧❆➟✔➢✒➡★➟❆❵★✬❫➡❁❵✰➢✒➡✦✣❃❲❸➠✮✩✾✩❆➛★➟☞➠✤✬✯✧❆➤✒➟ ➠●➝✲✩❅➟★✧✭✬✯✩✿❲✵✧❆➟✝➢❑➡❊✩❆➛❸➝✤✣✑✣❃❲✙✶❯♥❱➟✹❵✢✩✹❝

✂✂✴ ✔ ✹✼✻☎✻✫✞✯✶❱✽❧❯ ❨✘❲➙❞➢Ü✳✵✧❅➢ ✵❑➟✍✩❆➛✦✬❏✩❆✩❆➛★➟★✧❆➟❨➟✆✝❸➝✤✣❃✩✭✣✺✣➦➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣✺✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵✺✩❆➢ù❙✸➋✚❴❊➍✚❴ ➩ ✸✠✩❆➛★➟r➡★➢✱✩❬➝➉➢✒➡ ➢❫➧✾✐ ✣✲❴☛❴❲❢✺❝ ❡➬➝✤✣✴❲✦✣➦➟✹✥ß❝ù❤①➧

✩❆➛★➟★✧❆➟✝➟✆✝❸➝✤✣❃✩✭✣ ❴ ✁ ✧✰❰ ❿ ✧❇❰✢② ☎❘❷✕❇➜➝✮✩❆➛②❰ ❿ ✌❼❰✢②ù✣❃❲✦❵❅➛❁✩❅➛★➟✼✧❬➝➉➤✒➛✞✩✮➛✦✬❫➡✦✥❁✣➣➝✤✥❸➟✔➢❫➧➸➋✢✂❫➍❣➝✤✣✖✳❁➢✌✣➣➝✮✩❬➝❀✵✒➟✔➧❹➢✱✧✷✬❃➠●➠❢❴ ★ ❴ ✁➧①➢✱✧✦★➨➑➺❰✝❿ ✬❫➡✦✥②➡★➟▼➤✞✬❏✩❬➝❀✵✒➟✡➧①➢✱✧✦★➨➑➺❰ ② ✸❇✩❆➛★➟▼➡ù✩❅➛★➟✍✣❬➟★✩➬➒❑➋✚❴ ✧✩★✡➍✁✧☎❴ ★ ❴ ✁ ✧❇❰ ❿ ✌ ★ ✌❥❰ ② →✡➝✤✣❴❵★✬❺➠❐➠➉➟✹✥❢✬✩✿❲★➡★➡★➟✰➠➣❝❋❤q➡❁✩❅➛★➟❆✬✯✳✵✳✵✧❆➢✱✳✵✧❬➝✤✬✯✩❅➟❆❵✰➢❢➢✱✧✢✥❑➝➄➡✦✬❏✩❆➟✹✣✮✸✵✩❆➛★➟✝➛✌✶✌✳❁➢✱✩❆➛★➟✹✣➦➟✹✣➜➝✮❪✺✳❸➠✮✶❨➟✹✬✱✣➣➝●➠✮✶❊✩❆➛✦✬✯✩✷✣❃❲✦❵❅➛❁✩✛❲★➡★➡★➟✰➠✰✣✮➟✆✝❸➝✰✣✫✩✺✸✙❇➥➛❸➝✤❵❅➛✩❆➛★➟▼➡②➧①➢✱✧✭❵✰➟â✩❆➛★➟➬➟✆✝❸➝✰✣✫✩❆➟▼➡✦❵✰➟✪➢■➧◗✩❅➛★➟✍✬✱✣❃✶✌❪✺✳✵✩❆➢✱✩➦➝✰❵â✣❬➢❫➠✮❲✵✩❬➝➉➢✒➡✦✣★❝❨➙❞➟✹❵❆➛★➡❸➝✤❵★✬❃➠✷❵✰➢✱❪✺✳✵❲✵✩✭✬✯✩➦➝➄➢❑➡✦✣❆✣❬➛★➢✢❇❦✩❅➛★➟➬➟✆✝❢➝✤✣❃✩❅➟▼➡✦❵✰➟➢❫➧❴✬ ➧❹➢✔✧✿❪✍✬❃➠✑✣❬➟★✧❬➝➉➟✹✣❊✣❬➢■➠✲❲✵✩➦➝➄➢❑➡❇❝ ✺☞➡✦✥ ❅❁➡✦✬❃➠●➠✮✶✝✸✒✬✃➧❹➟✮❇ ❪➬➢✔✧❆➟❁✬✯✧❆➤✱❲✵❪➁➟▼➡✞✩✭✣✱❇➜➝✮✩❆➛ ✩✿❲★➡★➡★➟✰➠✤✣❁✬❫➡✦✥✦➠➄➟✹✬✔✥❑➝➄➡★➤ ✩❅➟★✧✿❪❵✰➢✱❪✺✳✦✬❏✧❬➝✤✣❬➢✒➡✦✣❆✬❺➠❐➠➉➢✢❇ ❲✦✣✼✩❆➢●❵✰➢✒➡✦❵❅➠✮❲✦✥❸➟❊✩❆➛✦✬✯✩❞✩❆➛❸➝✤✣❆✣❬➟★✧❬➝➉➟✹✣ ➝✤✣✴✬✱❵✢✩✿❲✦✬❃➠●➠✮✶ ✬❫➡ ✬✔✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵✺✣❬➟★✧➦➝➄➟✹✣✔➟✆✝✵✳✦✬❫➡✦✣➣➝➉➢✒➡✦✣✔➧①➢✱✧✩❆➛★➟❆✣❬➢■➠✲❲✵✩➦➝➄➢❑➡✦✣✑✣❬➛★➢✢❇➥➡❊✳✵✧❅➟✮✵✒➝➉➢✱❲✦✣➣➠✮✶❡✩❆➢✡➟✆✝❢➝✤✣❃✩✹❝

♣✪qsr❖tsqs✉✞✈✌✇★①✱②✦③⑤④⑥⑧⑦❃⑨✑➅❋❹⑧❺✿➌✱❺✿❻â❼➆❽❈❾➇❿✿❾▲➒ å❏❹➉➌✔➝✹❷✱❸✮➂★❻➐❹⑧➏✱Ø❺✿→✴➄✯❺✿→ Ø❺✭à❅❷✞➂★➏➐❹⑧❶✹➌✱→✺➄✯❹❱➟❑Ø❺✿❻➣❺✿➌✯➏➐❹➉❺✛❸➉❸⑧❺✿→✢➀❑➅❋❹ ✑❃❶❅➌ ⑦ × ✱❅➼✱❾☛➳◗➭ ➱ ➬➦✛➢✿➨⑧➭✭Ï ✃ ➦✛➀✠➊❅❶✹❸✽❾✸⑦✢➼ þ ➞✿⑦✭➼✔⑦✹➀ ➶✭➹❅ä✹ö ➀

➔✱➔✦❾✱➼ × ➒✱➽✹➽✱❾⑥➇➴✢⑨✑➅❋❹⑧❺✿➌✱❺✿❻ß❼✽❽☛❾➇❿✛❾❃➒✑➎ß❻➣❶❅➔✱❻➣❹✢Ø❺✿➏✱Ø❺✿→❇➂★→➐➜✙➪❞➔✱➏➣❶❅➏➣❹✮à❅❷✱❺✿→✦➄✯❺✛→☎✄✞❺✿❷✔➊✹❺✿→✢❾✞➵☛➤➍❐✸❒ ➱ ➦✫➭ �✝✆◆➦✛➩✞➧ ✃ ➭✸➧✹➦❈❮➣➸ ➳❑➥❃❰✹➧ ➬➦✿❐✾➨✤➦❈➧✹➦✫➭❇➲ò➥✛➨✤➦✛➩✞➥❃➦❃➭✿➀✢➊✹❶❅❸➆❾✿Ú þ ➴✔➀

➹✹ä✰✯ ➀❅➔✱➔✦❾✌➼✹➼✢➒✱➼✲✱✔❾⑥➇Ú✢⑨✑➅❋❹⑧❺✿➌✱❺✿❻✼❼✽❽❈❾ ❿✪➂★➌✞➄❊➅❋❹⑧❺✿➌✱❺✿❻❞❼➆➑❭❾ ❿✛❾✌➒❦❽✦❸⑧❺✿❷✔➊✹❺✿→✴⑦❃➞➣➴✢➞➣Ú ✞✑➪❞❶✱➄✯❺✒➄❯æ ❺✛➪❆➔✱❸⑧❶✹❹✽❾✔➠✽➌❁➅✸❹⑧❺✿➌✔❺✿❻❆❼✽➑❊❾➇❿✷➂★➌✌➄ ✣❁➂★❸⑧❸⑧❺✿➏✷❼✽ø✼❾➇❿✾❼✤❺✭➄❏❹✏➞➏➣❶❅❻➣→❃❿✿➀✵á✍❰ ➱✤Ð ➬➦✿❐✼❰ ➱ ➨✤Ï ✃ ➦✫➭ ✘❇➩✔➨ ➱ ❰➍➨✮➢❜➦✫➭◗➦ ➱ ❰★➩✞❰➍❮ ✂✢➭✭➦✾➩✞➤★➩â➭ ➱ ❰➍➩✞➧✹❰➍➢❜➧➍❾✯➔✱➔✦❾✞➴ þ❄× ➒❏➴✱⑦✢➽✱❾➍➒Ü➎ß❷✱Þ✱❸⑧❹✮➙✿➂➍➏➣❹⑧❶✹➌✱→✠➑✺➂➍➏➣↕✠Ø❺✿➪✴➂★➏➐❹✲à❅❷✱❺✛→◆➄✯❺❸✽æ × ➌✱❹⑧➊✹❺✛❻➣→➣❹⑧➏✱Ø❺❑➄✯❺✑➎ß➂➍❻➣❹⑧→ �❋➠➣➠✿➀ ➶✭➹✹ä❅➹ ❾

⑥ ✗★⑨✑➑✴❹✮➙➐↕✱❺✿❸✵❼✽❽✱❻❃➂★➌✞➙➐õ✱❿✿❾➋➒❄❽⑤❸⑧❺✿❷✱➊✹❺✛→❇❶✹→❃➙❃❹⑧❸➉❸✮➂➍➌✙➏➐→✭❾✄� ✃ ❮✮❮➉➦ ➱ ➨✮➩❆➤ ✕♦➱✤Ð ➦ �✸➦✛❮➇➫★➨✤❰★➩èáâ❰ ➱✤Ð ➦✿❐✼❰ ➱ ➨✤➥❃❰★❮✔➲ò➤✢➥✿➨s➦ ➱ ✂★➀✹➊❅❶✹❸✽❾★➴✱➀ ➶✢➹✹➹❅➘ ➀★➔✱➔⑤❾✱⑦✭➴❅ã✢➒⑦ ✗✌⑦✹❾

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Page 86: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✙✠✓✠☎✄✦✑☎✄✝☞P✌✙✠☎✄▲�✂✔✓✔☛✁ ✆✟✠ ✌✄✂⑨✄✝✆ �☎✆✟✞❪✞ ✂ ✁✝✆✒✞☛✄✢✞☛✞✕✏ ☎❳✠❧✕❨✆✂✄ ✕✓☞✚✠✁� ✓ ✁✛✡☛✞✵✁☎�❨✄✝✠❲✄✗☞✍✏✒✄✗☞✍✌✙✏�❽✛ ✍ ✁✤✣✍✭ ✁ ✝✂✁☎✄ ✟ ✩✢✪✁☞ ✛✝✆❈✥✩☞☛✣

✝♦❲✵✧✭✥✌❲★➟✕❁✮➡❸➝❀✵✒➟★✧✭✣➣➝✮✩❃✶✼✯❲★➡★➟❊✂✹✎ ✸❖✂✒✹✝✹✒Ö

➲✏✣❃❲✵❪✺❪❀✬✯✧✿✶★✶✌✶ �✼✬■➡❸➝✟✞➟✰➠➉➟➬➷✒✬❏✧✭✥✌✶❢➳

✏✼r✒✑✔✓✢✇★①✖✕✗✓➈❋❻❃➄✯❺✿❻✼→➣➏❃➂★➏➐❹➉→➐➏➣❹✮➙❃→✢➀❇→➣❷✌➙➣↕●➂★→✾➏➣↕✱❺✺➄✯❹⑧→➐➏➣❻➣❹⑧Þ✱❷✔➏➣❹⑧❶✹➌❊❶➍↔✸➏➣↕✱❺✴➪❴➂➋ç✱❹➉➪✾❷✱➪❍❶★↔✡✠❁❻❃➂★➌✞➄❏❶✹➪ ➊✹➂★❻➐❹✲➂➍Þ✱❸⑧❺✿→✭➀❇➂➍❻➣❺

❷✱→➣❷✞➂➍❸⑧❸➉➜✪→➣➏➣❷✌➄✯❹⑧❺✭➄✪↔✤❻➣❶❅➪ ➂✖➔✔❻➣❶✹Þ✌➂★Þ✱❹⑧❸⑧❹⑧→➣➏➣❹✮➙ß➔✌❶✹❹⑧➌✯➏❇❶➍↔ò➊✯❹⑧❺✿Ý✷❾⑤Ô✠↕✱❹⑧→❇➏❜➂➍❸➉õ✪➔✱❻➣❺✿→➐❺✿➌✯➏➣→✸➂➍➌✒➂➍➌✞➂★❸⑧➜✯➏➣❹✮➙✿➂➍❸❏➂➍➔✱➔✱❻➐❶✙➂✹➙➐↕➏➣↕✞➂➍➏◆➙✿➂➍➌✴Þ✞❺✷➂★➔✔➔✱❸⑧❹➉❺✢➄✼➏➣❶✼➂✾→➣❺✢à✹❷✔❺✿➌✞➙❃❺✷❶➍↔❖❹⑧➌✞➄✯❺✛➔✞❺✿➌✌➄✯❺✿➌✯➏✸❻❃➂★➌✞➄✯❶❅➪❛➊✹➂★❻➐❹✮➂★Þ✱❸⑧❺✿→✢➀✙➂➍➌✞➄❞➏➣❶✼➄✯❺✿➔✌❺✿➌✞➄✯❺✿➌✯➏❋➊✹➂★❻➣❹❱➞➂★Þ✱❸⑧❺✿→✢❾☛➾❋➔✱➔✱❸⑧❹✮➙✿➂★➏➐❹⑧❶✹➌✱→✠❹⑧➌✞➙❃❸⑧❷✞➄❏❺✷→➣➏❃➂★➏➣❹⑧→➐➏➣❹✮➙❃→✖❶✹➌✺➄✯❹⑧➝✹❹⑧➏❃➂★❸✵→➣➏➐❻➣❷✞➙✫➏➣❷✱❻➐❺✿→✭➀⑤➏➣↕✱❺✾➂★➌✞➂➍❸➉➜✯→➐❹➉→✠❶➍↔☛➂✼❸⑧❺✭➂✹➄❏❺✿❻✸❺✿❸⑧❺✭➙✫➏➣❹⑧❶✹➌➂★❸⑧➝✹❶❅❻➣❹⑧➏➣↕✱➪❀➀★➂★➌✞➄✴➂★➌✴❺❃ç✱➏➐❺✿➌✱→➣❹⑧❶❅➌❴❶➍↔❖➔✱❻➐❶✹Þ✞➂➍Þ✱❹⑧❸⑧❹➉→➐➏➣❹✮➙✸➙✫❶✹❷✱➌✯➏➣❹⑧➌✱➝✌❾

✳✘✴☞☛ ✹✟✽❧❯✭✹✪❲❱✸❱❨❫✸✺✿❘❲❱✸✺✿✚➅✛❲➭✤➟★✩❢❴ ➓ ✧▲❴ ✟✤✧ ✩ ✩ ✩ ✧ ❴✺❚❈✶✸➟◗✬✼✣➦➟✺❑✱❲★➟▼➡✦❵✰➟➜➢❫➧❖✥❑➝✤✣✿❵✢✧❆➟★✩❅➟✷✧✭✬❫➡✦✥❸➢✱❪❾✵✙✬❏✧❬➝✤✬✢✶❸➠➉➟✹✣☞✂✌✩❆➛★➟❀➢✱✧✢✥❸➟★✧✸✣❃✩✭✬✯✩❬➝✤✣❃✩➦➝✰❵★✣➞➝✤✣❈✩❆➛★➟✷✣❬➟✺❑✔❲★➟▼➡✦❵✰➟

✬✯✧✿✧✢✬❫➡★➤✒➟✹✥➁➝➉➡♠➡★➢✒➡✦✥❸➟✹❵✢✧❅➟✹✬✱✣➣➝➉➡★➤✪➢✔✧✭✥❸➟★✧✲✚❢❴ ✬ ➓ ✭ ✆ ❴ ✬ ✟ ✭ ✆✡❺✺❺✺❺ ✆ ❴ ✬ ❚ ✭❃❝❀➙➜➛★➟❆❵❅➠✤✬✱✣✛✣➣➝✤❵★✬❃➠◆✩❅➛★➟▼➢✱✧✿✶r➢❫➧ ➢✔✧✭✥❸➟★✧✑✣❃✩✭✬❏✩❬➝✤✣❃✩❬➝✤❵★✣✩✭✬ ✯❑➟✹✣✸✳❸➠✤✬✱❵✰➟✔➝➉➡Ü✬❞✳✵✧❆➢ ✶✦✬✢✶❸➝●➠❐➝✤✣❃✩➦➝✰❵✍➧➆✧✭✬❏❪➬➟ ✂✵✣❬➟▼➟✝➧①➢✱✧➜➟✆✝❯✬❏❪✺✳❸➠➉➟✪➲✲✐❫➳✤➢✱✧✔➲✮✂❄✐❃➳➣❝✺✼✣✿✣❃❲✵❪➬➟✾✩❆➛✦✬✯✩✖✩❆➛★➟❉✵✯✬✯✧❬➝✤✬✢✶❸➠➉➟✹✣❇❴ ✇ ✬❏✧❆➟✾❢⑦t ✟ ✡❦❜✝❴ ❧ ❢✤❜❸❷✮❝❑❢ ✗❈✩❅➛★➟ ⑤✍✌✵✳✸➟★✧✿❪✴❲✵✩✭✬✯✩❬➝➉➢✒➡✦✣ ❴ ✇ ★ ✧ ✩ ✩ ✩✌✧ ❴ ✇ ■ ➛✦✬✒✵✒➟✾✩❆➛★➟✒✣✛✬✯❪➬➟♥❬➢❫➝➉➡✞✩✼✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡ ➲✏❥✙✸❯✳❇❝✿✐✒✐ ◆❫➳➣❝ ➓ �☞➟▼❅❁➡★➟✷❉ ❚ ➑ ❪✍✬✎✝✿➒✺❴❚➓✪✧ ✩ ✩ ✩✌✧▲❴ ❚ →❴✬✔✣✷✩❆➛★➟❞❪✍✬ ✝❸➝✮❪❴❲✵❪ ➢❫➧✠✩❆➛★➟✾⑤ ✵✙✬✯✧❬➝✤✬✢✶❸➠➉➟✹✣★❝➫❋✶✍✩❅➛★➟✝➝➉➡✦❵❅➠✮❲✦✣➣➝➉➢✒➡✙❁①➟✆✝❯❵❅➠✮❲ß✣➣➝➉➢✒➡ù✳✵✧❬➝➉➡✦❵❅➝✮✳❸➠➉➟✝✸✟❇➜➟✝➛✦✬✒✵✒➟✼✩❆➛✦✬✯✩

✝✠✧▼➒✟❉ù❚✖✥ý❙✸→✝➑❚⑧➩ ❛✸➓ ➋✤⑥✼✂❫➍ ➩ ②✸➓ ❄ ⑤ ❈ ❆ ✝♦✧▼➒✺❴ ➓ ✥ý❙ ✧ ✩ ✩ ✩ ✧ ❴✺❚✕✥❵❈✒→ ✩➋✭✂❫➍

�☞➟▼❅❁➡★➟✎❋✢➩❃➋✥✦❸➍❣➑ ⑧❼ ☞ ✁

✝✠✧▼➒✼❴ ➓ ✥ý❙ ✧ ✩ ✩ ✩ ✧▲❴➬➩☎✥ý❙✸→✎✦ ❼ ✂ ✏❉ô❚★➋✥✦❖➍❣➑ ⑧❼ ☞ ✁✝✠✧⑦➒❳❉ù❚✖✥ ❙✸→✎✦ ❼ ✩

➙➜➛★➟▼➡ ✙ ❑✔❲✦✬✯✩❬➝➉➢✒➡②➋✭✂❫➍✠✩✿✧✢✬❫➡✦✣➣➠✤✬✯✩❆➟✹✣➜➢❑➡❊✩❆➛★➟✝➤✒➟▼➡★➟★✧✭✬✯✩➦➝➄➡★➤❊✣❬➟★✧❬➝➉➟✹✣✾✬✱✣

✏❉ù❚★➋ ✦❸➍❣➑❚⑧➩ ❛✸➓ ➋✤⑥✼✂❫➍ ➩ ②✸➓ ❄ ⑤ ❈ ❆ ✎❋✢➩❃➋✥✦❸➍✤✩

➊✮➟▼➡✦❵✰➟✺✩❆➛★➟✡➤✒➟▼➡★➟★✧✭✬✯✩➦➝➄➡★➤❚➧➆❲★➡✦❵✢✩➦➝➄➢❑➡✵➢❫➧ ❉ô❚②➋q➢✱✧☞➢❫➧❑✩❆➛★➟✷❈❅✩❆➛✙❁✽✧✭✬■➡✰✯✒➟✹✥ ✵✙✬✯✧❬➝✤✬✢✶❸➠➉➟r➢❫➧✸✩❆➛★➟✍✣➦➟✺❑✱❲★➟▼➡✦❵✰➟❫➍✮➝✰✣☞➟✆✝✵✳✵✧❆➟✹✣✿✣➦➟✹✥✶✌✶ ✬■➡ ✬❃➠✮✩❆➟★✧❆➡✦✬✯✩➦➝➄➡★➤●✣❃❲✵❪✿✸ ❇➥➛❸➝✤❵❆➛ ✣❃❲★➤✒➤✒➟✹✣✫✩✭✣✾✩❆➛✦✬✯✩❆✬✇❽♠➟✰➠●➠●➝➉➡✙❁✚✮⑧➝✤❵✰➟Ü✬✯✳✵✳✵✧❅➢✞✬✱❵❅➛ù✩❆➢❊✩❆➛★➟✍✬✔✣❃✶✞❪â✳✵✩❆➢✱✩❬➝✤❵★✣✼❪➎➝➄➤❑➛✞✩❉✶✸➟✣❃❲✦❵★❵✰➟✹✣✿✣❱➧➆❲❸➠➜➋❜✣❬➟▼➟☞➧①➢✱✧➜➟✆✝❯✬❏❪✺✳❸➠➉➟✪➲✏✎❫➳✸➧①➢✱✧✑✬✡➤❑➟▼➡★➟★✧✭✬❃➠✢➝➉➡✌✩✿✧❆➢✵✥✌❲✦❵✢✩❬➝➉➢✒➡❁✩❆➢✴✩❆➛❸➝✤✣✾✣❃❲✙✶✵♥❬➟✹❵✢✩▼➍✭❝➓ ➾❋➌✱❶✹➏➐↕✱❺✿❻✸➄✯❺❃➛✌➌✱❹⑧➏➣❹⑧❶✹➌❞❶★↔✦❺❃ç✞➙➐↕✞➂★➌✔➝✹❺✭➂➍Þ✱❸⑧❺❑➊✹➂➍❻➣❹✮➂★Þ✔❸➉❺✛→❇➪❆❹⑧➝✹↕✯➏ßÞ✌❺ ✞⑤↔✤❶✹❻❈➂★➌✯➜✼→➣❷✱Þ✔→➣❺✭à❅❷✱❺✿➌✌➙❃❺✒✑✔✓ ☎✖✕ →✭❾ ➏✭❾❈⑦✘✗✙✓ ➓✛✚✢✜✣✜✤✜✥✚ ✓ ➩ ✗

✠ß➀✱➎ß❻✣✑✤✦ ✇ ★ ✚★✧ ➓✔✩✣✪✤✪✣✪✫✩ ✦ ✇ ☞ ✚★✧ ➩✬✕✮✭ ➎ß❻✣✑✣✦ ➓✯✚★✧★➓✣✩✤✪✣✪✤✪✰✩ ✦ ➩ ✚★✧ ➩✬✕ ❾ã✹ã

Page 87: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

▼❊✴✘✄ ➇ ❯✜✿ ➆✾✽❧❯❫❬ ❯❁➆✂✽✂❯✸➆✘✸✪➅ ❨✘❲❱❯ ✆✎✸ ➇ ❯✜❬ ✹✼✻✍✌❧❨✫✌✗✿❘◗ ✿❘❲❱✸✺✿✚➅✙❨✘❬ ❬✗✹✼✻✵❨❁➅ ➇▼❊✴ ✳✵✴✪◆ ✻✢➆✵✸✺✿①➆✢➂☎✻✢➂✂❲ ✹✺❨✤➆✂✽❧✻✂❩ ❙❫❨✘✹✟✿❭❨✫✌✗◗❭❯❫❲✛✴ ❤➣➡ ✩❆➛★➟❁❵✰➢✒➡✌✩❬➝➉➡✞❲★➢✱❲✦✣â❵★✬✱✣❬➟✝✸✠✩❆➛★➟✖❴ ✇ ✬✯✧❆➟r➝➣❝ ➝➣❝✏✥ß❝ ✬❫➡✦✥❢❵✰➢✒➡✌✩❬➝➉➡✙❁

❲★➢✱❲✦✣☞✂♦✩❆➛★➟★✧❆➟r➟✆✝❢➝✤✣❃✩✴✩✈❇➜➢❁✣❬➟✺❑✱❲★➟▼➡✦❵✰➟✹✣➎➢❫➧➥➡★➢✱✧✿❪✍✬❃➠●➝✮✟✹✬✯✩❬➝➉➢✒➡ý❵✰➢❑➡✦✣❃✩✭✬❫➡✌✩✭✣✡➒ ❂ ❚ →✝✬■➡✦✥ ➒ ❈ ❚ →❊✬❫➡✦✥ ✬❚➧✽❲★➡✦❵✢✩❬➝➉➢✒➡ ➶ ✣★❝➇✩✹❝➠●➝✮❪✍❚✁� ② ➱ ✝✠✧✤➒❑➋❅❉ù❚❉⑥ ❂✱❚★➍✡✪ ❈ ❚ ✌ ✚✤→❨➑ ➶Ó➋✣✚➞➍ ✂✦✩❅➛★➟▼➡✦➶ ➝✤✣❆✩❅➛★➟✿❝❑❤ ✔✷❤♥✐✦❤❥❴ ❧ ✏✝❤❧❡✮✐✦❛✤❤①❷ ✣✲✐✦❤✡✝ ❴ ➢❫➧❑✩❅➛★➟❨➋q➡★➢✱✧✿❪❀✬❃➠●➝✲✟▼➟✹✥✸➍❪✍✬ ✝❸➝✮❪✴❲✵❪ ❉ù❚⑤❝➙➜➛★➟✾✩❆➛★➟▼➢✱✧✿✶➁➢❫➧◆✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵✷✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡✇➢❫➧◗➟✆✝✵✩✿✧❆➟★❪➬➟✹✣ ❇✷✬✱✣⑥➝➉➡❸➝✮✩❬➝✤✬✯✩❆➟✹✥s✶✞✶ ☞❞➝✰✣✛❵❆➛★➟★✧✷✬❫➡✦✥❨➙⑧➝✮✳✵✳✸➟★✩✿✩➜➝➉➡Ü✂✒✹✄✂✝◆✙✸

✬❫➡✦✥✇➧✽❲✵✧✿✩❆➛★➟★✧✴✥❸➟✮✵✒➟✰➠➉➢✱✳❁➟✹✥❽✶✌✶Ô➷☞➡★➟✹✥❸➟▼➡✰✯✒➢Ü✬❏✧❆➢✱❲★➡✦✥ ✂✺✹✆☎✞❥ ✂❇✣❬➟▼➟✡➧①➢✱✧✝➟✆✝✦✬✯❪✺✳❸➠➉➟❀✩❆➛★➟★✶❁➢❸➢✄✯✵✣❉✶✌✶✵➷✼✬❃➠✤✬✯❪✷✶❁➢✞✣➁➲✞✝▼➳❣➢✱✧✮➜➟✹✣❬➡❸➝✤❵✩✯❼➲✮✂✟✂❃➳⑧➢✱✧✼✩❆➛★➟✺✳✵✧❆➟✹✣➦➟▼➡✞✩✭✬❏✩❬➝➉➢✒➡✵➤❫➝❀✵✒➟▼➡❹✶✌✶ ✻ ❇➜➟▼➟★✩❬➝➉➡★➤❨➝➉➡❼➲✮✂✹❥■➳➣❝➬➙➜➛★➟★✶✸➟▼➛✦✬✺✵❑➝➉➢✱❲✵✧☎➢■➧◗✩❅➛★➟✺✩✭✬❃➝●➠❑✥❸➟★✩❆➟★✧✿❪➎➝➄➡★➟✹✣✩❆➛★➟✮➠●➝✲❪➎➝✲✩➦➝➄➡★➤❁✥❑➝✤✣❃✩✛✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡✃➶Ó➋✣✚➞➍❀➋❜✣❬➟▼➟✮➧①➢✱✧➜➟✆✝❯✬✯❪â✳❸➠➄➟➬➲✠✂❦✸✌✳❇❝✡✂✵✂ ✁ ➳❁➢✱✧✝➲✞✝❦✸✌✳❇❝★Ö✵✂✮❁qÖ☛✂❫➳★➧①➢✱✧❑❵✰➢✔❪✺✳❸➠➉➟★✩❆➟❆❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣✰➍✭❝➙➜➛★➟✡➠●➝✮❪✡➝✮✩❬➝➉➡★➤ ✥❑➝✤✣❃✩✿✧➦➝✻✶✵❲✵✩➦➝➄➢❑➡Ô➢❫➧✖✩❆➛★➟➬➡★➢✱✧✛❪✍✬❃➠●➝✮✟▼➟✹✥ù❪✍✬✎✝❢➝✮❪✴❲✵❪ ✣✿✬❏❪✺✳❸➠➉➟➬➛✦✬✱✣✝➢❑➡★➟✍➢■➧◗✩❅➛★➟✡➧❹➢■➠❐➠➉➢✢❇➜➝➉➡★➤❁✩❃✶✌✳❁➟✹✣ ✚ ✙P❤ ✚❤①➧ ✝✠✧▼➋✢❴ ✇ ✥✏✡✣✚➞➍❀✪ ✝♦✧❇➋✢❴ ✇ ✥✏✡❆➍ ➽ ✚ ❿ò☞ ➋❃■✾✥ ✁ ➍➜➧❹➢✔✧ ✡ ➽ ❸✕✔❻✸ß✩❆➛★➟▼➡Ô➶Ó➋✣✚➞➍➸➑➪➟✆✝ò✳✔➋ ⑥✜✚ ❿✵☞ ➍➜➧①➢✱✧✦✚❋✥ ✁ ✬❫➡✦✥➶Ó➋✣✚✤➍⑥➑ ✁ ➧❹➢✱✧ ✚ ✆ ✁ ✂✔✙✍❤♥❤ ✚✸❤ ➧ ✩❅➛★➟★✧❆➟➜➟✆✝❢➝✤✣❃✩✭✣❋✬❪❅❁➡❸➝✮✩❆➟ ✓✺✣★❝➇✩❅❝ ✝✠✧⑦➋✚❴ ✇ ✆ ✓✤➍❣➑ ✂✝✸✱✬■➡✦✥ ✝✠✧▼➋✢❴ ✇ ✥ ✓❈⑥✌☞✔✚➞➍❀✪ ✝♦✧❆➋✚❴ ✇ ✥✓❘⑥✍☞✰➍ ➽ ✚ ☞ ➧❹➢✱✧✎☞ ➽ ✁ ✸❈✩❆➛★➟▼➡ ➶Ó➋✣✚✤➍✔➑ ➟✆✝✵✳✝➋ ⑥☞➋✤⑥✜✚➞➍ ☞ ➍✮➧❹➢✔✧ ✚ ✌ ✁ ✬■➡✦✥Ô➶Ó➋✣✚➞➍✝➑ ✂➎➧❹➢✱✧✥✚ ★ ✁ ✂ ✙P❤♥❤♥❤ ✚✺❤①➧✝✠✧⑦➋✚❴ ✇ ✥ ✡ ❸ ✚✑✏➁➋✚❴ ✇ ⑥ ✡ ✧ ❴ ✇ ✥✍✡❆➍❆➍✡✪ ✝✠✧✰➋✚❴ ✇ ✥✍✡❅➍ ➽ ✍ ❿☞✣ ➧①➢✱✧ ✡ ➽ ❸✕✔❻✸❯✩❆➛★➟▼➡♠➶Ó➋✣✚✤➍⑥➑❼➟✆✝✵✳✝➋✤⑥ ✍ ❿✄✣ ➍⑥➧①➢✱✧✷✬❃➠●➠ ✚▲❝➙➜➛★➟☞➡★➢✱✧✿❪✍✬❺➠❐➝✮✟✹✬✯✩➦➝➄➢❑➡✝❵✰➢✒➡✦✣✫✩✭✬❫➡✌✩✭✣✻❂✱❚✴✬❫➡✦✥ ❈ ❚❆❪✡➝➉➤✒➛✌✩✓✶✸➟✒✣❬➟▼➟▼➡❀✧❆➟✹✣❃✳✸➟✹❵✢✩❬➝❀✵✒➟✰➠✮✶✝✬✔✣✸✬❆✣➦➛❸➝❐➧✽✩✷✬❫➡✦✥❀✬❆✣✿❵★✬❃➠●➝➉➡★➤✔➧ ✬✔❵✢✩❆➢✱✧✹❝➙➜➛★➟★✶✴✬✯✧❆➟➜➡★➢✱✩⑥➡★➟✹❵✰➟✹✣✿✣✿✬✯✧❬➝●➠✮✶✴❲★➡❸➝ ❑✱❲★➟ ✚✸✣➦➟▼➟➹➲✠✂✙✸✯✳❇❝✄✂ ✁ ✹❫➳❑➢✱✧➸➲✰✂✟✂✙✸✯✳❇❝✢◆✱✎❫➳❑➧❹➢✱✧✸✬✾✥❑➝✤✣✿❵✢❲✦✣✿✣➣➝➉➢✒➡r➢❫➧✦✩❆➛❸➝✤✣❈✳✸➢❫➝➉➡✞✩ ✂ ➷✒✬❃➠✤✬✯❪✷✶✸➢✞✣

✥❸➟✮✵✒➢✱✩❅➟✹✣✑✬✱❇➥➛★➢❫➠➉➟✺✣❬➟✹❵✢✩❬➝➉➢✒➡✵➢■➧❀➛❸➝✰✣▲✶✸➢❢➢ ✯❁✩❆➢✍✥❑➝✤✣✿❵✢❲✦✣✛✣➣➝➉➡★➤Ü✳✸➢✞✣✿✣➣➝❀✶❸➠➉➟✍❵❅➛★➢❫➝✤❵✰➟✹✣✡➲✞✝❦✸⑤✳❇❝✿Ö✒✝ ✰ ✎✱❥❫➳➐❝✖❤q➡✵➤✒➢❸➢✵✥❁❵★✬✱✣❬➟✹✣✉✸✤❂✔❚✬❫➡✦✥ ❈ ❚✍❵✰➢✱✧✿✧❆➟✹✣✫✳❁➢✒➡✦✥❭✩❆➢✺✩❆➛★➟ ➠❐➝✮❪✡➝✮✩❬➝➉➡★➤❡❪➬➟✹✬❫➡Ü✬■➡✦✥❘✵✙✬❏✧❬➝✤✬❫➡✦❵✰➟ ✂❇✣❬➟▼➟✪➲✰✂✟✂✲✸✦✳❇❝☛◆✆☎✝❁P◆✒Ö❫➳✤➧①➢✱✧✑❵✰➢❑➡✦✥❑➝✲✩➦➝➄➢❑➡✦✣✾✩❆➛✦✬✯✩➥➟▼➡✦✣❃❲✵✧❅➟✩❆➛✦✬✯✩❬❇➜➟❆❵★✬❫➡❡❲✦✣❬➟✼✩❆➛★➟❆❪➁➟✹✬❫➡❁✬❫➡✦✥◗✵✙✬❏✧❬➝✤✬❫➡✦❵✰➟❴✬✱✣✪✣✿❵★✬❃➠●➝➉➡★➤➬➧➣✬✱❵✢✩❆➢✱✧✢✣★❝✤Ï➛★➟▼➡❨➝✮✩✮➝✰✣✪✳❁➢✌✣✿✣➣➝❀✶❸➠➉➟❴✩❅➢✺✳✵✧❆➢✢✵✒➟❆❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✦✣✮➢✒➡❁✩❅➛★➟✼✩✭✬❃➝●➠♦✥❑➝✤✣❃✩✛✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡✟✸❇✣❃❲✦❵❅➛❁✬✱✣✑✬■➡❨➟✆✝ò✳✸➢✒➡★➟▼➡✞✩➦➝✰✬❺➠◆✩✭✬❺➝❐➠P✸⑤✩❆➛★➟

✬✱✣❃✶✌❪✺✳✵✩❆➢✔✩❬➝✤❵✾❪➬➟✹✬❫➡❁❵★✬❫➡❘✶✸➟❴❵✰➢✱❪✺✳✵❲✵✩❅➟✹✥❁✬✱✣ ✚✻❂✔❚➬➑ ➝➉➡❸➧❄➒ ✚ ✚ ✝✠✧▼➋✢❴ ✇ ★ ✚➞➍✮✆❛✂ ✪ ⑤❞→✞❝▼❊✴❘▼☎✴✁�✖✿ ❲❃➅✛✹✼❯ ✸❱❯ ✹✼❨✤➆✂✽✂✻❧❩ ❙❫❨✘✹✟✿❀❨✫✌ ◗❀❯❫❲✛✴ ❤➣➡❊✩❆➛❸➝✤✣❑❵★✬✔✣❬➟✝✸ ✺❒➡✦✥❸➟★✧✭✣➦➢✒➡✃➲✰✂❇➳❞➋❜✣❬➟▼➟✼✬❃➠✤✣❬➢❨➲✞✝✝✸✱✳❇❝ß✂✟✂ ✁ ✸❫➟✆✝ ❝✙◆❫➳①➍⑥➤✞✬✒✵✒➟✷✬

➡★➟✹❵✰➟✹✣✿✣✿✬❏✧✿✶✺❵✰➢✒➡✦✥❑➝✮✩❬➝➉➢✒➡✡➧①➢✱✧✠✩❆➛★➟➜➟✆✝❢➝✤✣❃✩❅➟▼➡✦❵✰➟❒➢❫➧☞❂✱❚❆✬■➡✦✥ ❈ ❚❆✣➍❝➇✩✹❝❇✩❅➛★➟➸➡★➢✔✧✿❪✍✬❃➠●➝✮✟▼➟✹✥✺✧✢✬❫➡✦✥❸➢✱❪⑨✵✙✬❏✧❬➝✤✬✢✶❸➠➉➟✝➋❅❉ô❚ ⑥ ❂✔❚★➍❀✪ ❈ ❚❵✰➢✒➡✲✵✒➟★✧❆➤✒➟✹✣◗✩❆➢✺✬✡➡★➢✒➡✙❁➣✥❸➟▼➤✒➟▼➡★➟★✧✭✬❏✩❆➟✝➠●➝✮❪✡➝✮✩❬➝➉➡★➤❁✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡ ✚ ✝♦✧❇➋✢❴ ✇ ➑ ❙✸➍✡✪ ✝✠✧✰➋✚❴ ✇ ✥ý❙✸➍ ➽ ✁ ✸✦❙ ➽ ✔ ✩➙➜➛★➟➥➟✆✝❸➝✤✣❃✩❆➟▼➡✦❵✰➟☞➢❫➧ ✬✷❝❑❤✘✔✷❤❥✐✦❤♥❴✔✓✴✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡r➝✤✣❋✬✼✣❃✩✿✧❆➢✒➡★➤✼✳✵✧❅➢✱✳❁➟★✧✿✩❃✶✝✸ ❇➥➛❸➝✤❵❆➛✡➝✤✣✘➡★➢✱✩❑✬❃➠❀❇✷✬❅✶ò✣ ✵❑➟★✧❬➝❑❅❁➟✹✥ ✂✒➝➉➡✍✣➦➢✱❪➬➟

❵★✬✱✣❬➟✹✣ ❇➜➟✼❵★✬❫➡✍✳✵✧❅➢ ✵❑➟✑✬❫❇➸➟✹✬ ✯✒➟★✧✸✧❆➟✹✣✫❲❸➠✲✩✮➢✒➡✍✩❅➛★➟❒➟✆✝❸➝✤✣❃✩❆➟▼➡✦❵✰➟✝➢❫➧◆✬■➡✎❜✢❡ ✖ ✔✍✌ ✐✒✝✝✐✦❤✞✟❆✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡✟✸❲❇➥➛❸➝✤❵❆➛❀❪✡➝➉➤✒➛✌✩➜➡★➢✱✩➝✮❪✺✳❸➠✮✶ ✬❚➠●➝✮❪✡➝✮✩❬➝➉➡★➤ ✥❑➝✤✣❃✩✛✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡❻✶✸➟✹❵★✬✯❲✦✣❬➟❨➢❫➧ ✝✦❲✦❵✢✩✛❲✦✬✯✩❬➝➉➢✒➡✦✣★❝ ✺☞➡Ô➟✆✝✦✬✯❪✺✳❸➠➉➟❨➢❫➧✾✩❆➛❸➝✤✣✡➛✦✬✯✳✵✳❁➟▼➡✦✣✽❇➥➛★➟▼➡ ✩❅➛★➟✖❴ ✇➧①➢❫➠●➠➄➢✢❇ ✬❨➤✒➟▼➢✱❪➁➟★✩✿✧❬➝✤❵✺✥❑➝✤✣❃✩✿✧❬➝❀✶✵❲✵✩❬➝➉➢✒➡ ✚ ✝♦✧▼➋✚❴ ✇ ➑ ❙✸➍✝➑ ❆ ❼ ➋✢✂④⑥✜❆➞➍➜➧❹➢✱✧✴❙ ★ ✁ ❝❨➙➜➛★➟▼➡②➝✮✩✔➝✤✣✼✳❁➢✌✣✿✣➣➝❀✶❸➠➉➟❊✩❆➢❁✳✵✧❆➢✢✵✒➟✩❆➛✦✬✯✩✁✝✠✧▼➒❳❉ ❚ ✌✖✕●➠➉➢✒➤ ➓ ✛✘✗ ⑤◗❸✚✙✜✛✒→ ✞ ➟✆✝✵✳ ✙ ⑥❢❆ ✝ ❿✡✢ ✦ ★☞✩ ★✤✣✦✥ ❚ ② ✝★✧ ✢ ✩✿➫⑧➟✹❵★✬✯❲✦✣❬➟✔➢❫➧✸✩❆➛★➟ ✝✦❲✦❵✢✩✿❲✦✬✯✩❬➝➉➡★➤❨➡✦✬✯✩✿❲✵✧❅➟✝➢❫➧✸✩❆➛★➟➧✽✧✭✬✱❵✢✩❬➝➉➢✒➡✦✬❃➠❇✳✦✬✯✧✛✩✝➒ ✡❆→✔➑✍✡ ⑥✩✕ ✡✪✛❦✸✦✩❅➛❸➝✰✣✮➟✆✝✵✳✵✧❆➟✹✣✿✣➣➝➉➢✒➡✇➢✞✣✿❵❅➝●➠●➠✰✬❏✩❆➟✹✣❈✶✸➟★✩✈❇➸➟▼➟▼➡✚✍ ❿✁✗ ✬ ✬■➡✦✥ ✍ ❿✫✗ ✬ ✿ ★ ❝

✂❧✴☎✄ ➇ ❯✙✿①➆✂✽✂❯❫❬ ❯✸➆✾✽❧❯❁➆✵✸ ➅✟❨✘❲✔❯✝✆ ✸ ➇ ❯ ❨✤➆❊❨✘◗❭❖✂✸✺✿✚➅✟❨✘◗✑❨✘❬✗❬ ✹✼✻✘❨❁➅ ➇☞★➢✔✧❣➝➣❝ ➝➣❝✏✥ß❝☎✵✯✬✯✧❬➝✤✬✢✶❸➠➉➟✹✣ ❴★✇❍✸ ❇➜➟➥➛✦✬✒✵✒➟ ✝✠✧⑦➒✺❴❨➓ ✥ý❙ ✧ ✩ ✩ ✩ ✧▲❴ ➩ ✥ý❙✸→✔➑Õ➋❱➐✔➒✺❴❚➓ ✥ý❙✸→✒➍ ➩ ❝❣➊✮➟▼➡✦❵✰➟✭✬❋ ➩ ➑ ❴✯✮ ➩ ✸✲❇➜➝✮✩❆➛❴✯✮ ➩✱✰ ✦✳✲★✴ ✂ ❼ ✰ ✝♦✧✶✵✼❴ ✥ý❙✸✷☛✲ ➩ ✦ ❼ ✣✫✩✭✬❫➡✦✥❑➝➉➡★➤➬➧①➢✱✧✝❈✎✹✑✬✔✥✵✬✯❪✍✬✯✧✭✥❀✳✵✧❅➢ò✥✌❲✦❵✢✩✭✣➍❝✏✑✡❦❢✒❴✎✐☛✡✲❢ ✏✝❤❧❡♠✐✦❛▼❤✻✺✝✣❦✐✦❤✞✝✝❴✧✝✽✼✰✐☛✡❦❢✎❴ ✇ ❤❧❡✰❜◗❡ ✣ ✔ ✝✾✼✿✓✝❢ ✝ ✔✷❢✺✐✦❛▼❤✡✟✝✏✝❤❧❡✮✐✦❛✤❤✦✺ ✣✲✐✦❤✡✝ ❴✙❡❁❀❖✩❆➛★➟✰➝✮✧☞➤✦❝ ➧✿❝⑥➝✤✣❂✬❴ ✰ ✦✳✲❃✴✙❂✡❄ ✰✶❅ ⑥

✎ ✦✳✲✵❇❆✦❈✄❉❋❊✾❈ ❪✜●❑❵ ❈✄❍✑❊✾■❁❏✁❍✔■❁❊ ❂☛✸ ✎ ❏✁❍✑❑ ✟⑤❝❨✴ ❈ ❇❫✸ ❆✦❈✄❉▼▲✤❍✳■ ●❖◆✄● ❉ ✟❲✸ ■◗P ●❙❘ ❈ ●❁❚❯❘ ▲ ● ❍✳■❲❱ ✦✁❳☛❨ ✬❴ ✰ ✦✳✲ ▲❩❊ ●✺❑✄❬ ❏❪❭✡■◗❈ ❂ ✚ ❳ ② ✵ ❿✑❫✵

❿✑❫ ✢ ✎✔❳❏✁❍✑❑ ❇❙●❴❘ ❏✁❍ ❘ ❈✄❵✌❛ ❬ ■ ● ❏ ❬ ❍✳▲✞❆✦❈✄❉◗❵❜❏✆❛✡❛✡❉◗❈ ✝ ▲✤❵❝❏✁■✽▲❞❈☛❍❡❈✁❆ ✬❋❣❢ ✰ ✦✳✲✆✚

✬❋ ❢ ✰ ✦✳✲★✴ ✰ ✟ ❈❪⑥✜❈☛✲✤✌ ❂☛❢✰◗✰ ✟❉⑥ ❅ ✲✤✌✞✲ ❢ ✰✶❅ ⑥ ✎ ❢ ✦✒✲ ✵ ❢❿ ❢ ② ❫ ❸ ✭ ✞ ❅

✰✶❅ ⑥✗✎ ❢ ✦✳✲ ✬ ✵❿✑❫ ✭ ❢ ✠ ✩

☞ ❉❤❈✄❵✐❍✡❈ ❇ ❈✄❍❡❏✌❥ ● ❭✞❭❦▲✤❍ ❁✚✮ ▲ ❘✱● ❏✁❛✡❛✡❉◗❈✔❏ ❘ P ❘ ❏✁❍ ✶✸●❴❬ ❊ ● ❑ ✸ ■◗❈✌❈ ✶ ■✶❏✫▲❞❍❧❴♠✫✵✔♥✞☎✶✵✡♦ ❅ ✷q♣✟❢✺✐☞❂ ❳ ✴ ❭✤❈ ◆ ⑤■❸✰ ✟✰⑥ ❅ ✲ ❭✤❈ ◆ ❭✤❈ ◆❈⑤◗⑥ ❭✤❈ ◆ ✏ ✰ ✟✡✲ ✂✓✐☛✡❦❢✺❴r✼ ✝✝❛❉❜✝❴ ✖✱❤❥❴❲✐✦❢s✓ ❢✺❛❲t

✝ ❉✰ ❉ ❳ ✆ ❂ ❳ ❸✉t✸✲❃✴ ❅

❭✤❈ ◆❅ ❄ ✎ ✍ ❿✡✈

✑ ✄ ★ ✄✁✇❩① ■✁② ✰✶❅ ❸ ① ✰❁❅ ✲◗✲✪✩ã✲✱

Page 88: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✗✴ �✖✿✂✁☎✿❀✸❱❨✘◗✑❲❱✸✺✹☎✄✝✆✟✸✞✄✂✹✺❯❫❲�✗✴ ✳✵✴✁�✪❯✭❬❧✸✞✟ ✿✡✠ ❨✪✸✺✹✟✿❀❯☎✴☞☛ ❈☛❍✑❊ ▲❩❑ ● ❉ ❏❣■◗❉✾▲ ●❬✶✡❬ ▲❦❭✤■❙❈✄❍ ⑤ ▲❞❍✑❑ ● ❛ ● ❍✑❑ ● ❍✔■❙❉✶❏✆❍✑❑✳❈✄❵ ❬ ❍✳▲✞❆✻❈✄❉❤❵ ✶ ▲❞❍✑❏✆❉✍✌✌❊ ●✺❑✄❬✡● ❍ ❘❁● ❊✎ ✇✌✧ ❅ ✆ ③✍✆ ⑤ ✸ ❈✁❆ ✁ ❏✁❍✑❑❅ ✏ �❣●▼❅ ❍ ● ✟ ❳ ❏✄❊q■◗P ● ❏ ✵✄● ❉✶❏ ◆☛● ❑ ● ❛✡■◗P ❈✁❆❲❏✁❍ ●✆✝ ■ ● ❉◗❍✑❏❪❭ ❍✡❈✡❑ ● ❱

❅ ☎✁❨ ✂ ■◗P✳▲❩❊ ❑☛❬ ❏✁❍✳■✾▲✤■✑✌▲❩❊✿❉ ● ❭❩❏✁■ ● ❑❡■❤❈❯■◗P ● ❍ ❬ ❵ ✶✑● ❉r❈✁❆ ❍✡❈✡❑ ● ❊ ✵ ▲ ❊s▲❞■ ● ❑✉❑ ❬ ❉✾▲✤❍ ◆ ❏❯❊ ❬✑❘❖❘❁● ❊◗❊ ❆ ❬ ❭ ❊ ● ❏✁❉ ❘ P ✏☞✒ P ● ❏✁❍✑❏❪❭✂✌✡❊ ▲❩❊✿❈✁❆ ✟ ❳ ❭ ● ❏☛❑✡❊✿■◗❈❘ ❈✄❍✑❊ ▲❩❑ ● ❉✾▲✤❍ ◆ ■◗P ● ❭ ● ❍ ◆ ■◗P✔✓ ✇ ✦ ☎ ❈✁❆ ■◗P ● ❭✤❈✄❍ ◆✄● ❊✾■✿❛✡❉ ●▼❅ ✝✉❘ ❈✄❵✜❵✌❈✄❍❡■❤❈❝■◗P ● ❊ ●✺❑☛❬✡● ❍ ❘❁● ❊ ✎ ✇ ❏✁❍✑❑ ✎ ☎ ✚ ✟ ❳ P✑❏✄❊❣■◗P ●❊◗❏✁❵ ● ❑☛▲ ❊✽■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍✯❏✄❊❙❵❝❏ ✝✑✵ ✓ ❫ ✦ ✟✤✧ ✩ ✩ ✩ ✧ ✓ ❫ ✦ ❳ ✷ ✏ ✺ ❭❞■❤P✡❈ ❬✡◆ P❡■❤P ● ✓ ✇ ✦ ☎ ❏✆❉ ● ❑ ● ❛ ● ❍✑❑ ● ❍✳■✗✖ ❇ ● ❊✽■✾▲✞❭❦❭★P✑❏✙✘ ●✝ ❉ ✵☎✟ ❳ ★ t✸✷❴✴ ❅

⑤❳⑧❢ ❛ ✟

✰ ⑥ ❅ ✲ ❢ ❄ ⑤ ❈ ❆ ❈ ✝ ❉ ✵ ✓ ❫ ✦ ✟ ★✍t ✧ ✩ ✩ ✩ ✧ ✓ ❫ ✦ ❢ ★✍t✸✷ ✩✰ ✂✳✲

✚✌✡❦❢✜✛❈❢✒❛✤❴ ✝✘✣❦❝♥❝❑❤ ✔ ✝ ✏✝❢✒❝✂✢✤✣ ❍ ■◗P✳▲❩❊❴❵✜❈✒❑ ● ❭✥✖ ✝ ❉ ✵ ✓ ❫ ✦ ✟ ★✐t ✧ ✩ ✩ ✩ ✧ ✓ ❫ ✦ ❢ ★✐t✸✷❡✴ ✰ ❆ ❢ ❸ ❄ ❢ ✲ ❼ ✏ �❣●▼❅ ❍ ● ✎✦ ❳ ✰ ✦✒✲❴✴✂ ❼ ☞ ✁ ✝ ❉ ✵ ✟ ❳ ★✍t✸✷✎✦ ❼ ✂ ■◗P ● ❉ ● ❭ ❏✆■✾▲✤❈✄❍✰ ✂✳✲ ❈✄❍ ✟ ❳ ■◗❉❁❏✁❍✑❊ ❭❩❏✁■ ● ❊ ▲❞❍✳■◗❈✌❏✁❍ ●✺❑☛❬ ❏✁■✾▲✤❈✄❍ ❈✄❍ ✎✦ ❳ ✰ ✦✳✲ ✖★✧❲P✳▲ ❘ P ◆ ▲✂✘ ● ❊❙❏❪❆✦■ ● ❉❊✾❈✄❵ ●❴❘ ❈✄❵✌❛ ❬ ■✶❏✁■✽▲❞❈☛❍✑❊

✎✦ ❳ ✰ ✦✳✲★✴ ❅✂★✩ ✝ ✟ ❿ ✡ ✛ ✟✑✪✬✫✂✭

❿ ✡ ✛✥✟❞❿✬✫✮✭ ✯ ❿ ✂✈❿✸❫ ✏ ✰ ✘✱✰ ❅ ✲❅ ✲ ✦ ✰ ❆✴✳ ✂ ✰ ❄☎✳ ✂ ✲ ✟ ✘ ✞ ❅ ✰ ✥ ✞ ❅✯ ✠ ✠ ✩✣ ❍ ■◗P ● ❏☛❊✵✌✔❵✜❵ ● ■◗❉✾▲ ❘❴❘ ❏☛❊ ● ✖ ✟ ❳ ❆✦❈✁❭✞❭✤❈✞✧ ❊ ❏✜❍✡❈✄❉◗❵ ❏❪❭ ❭✞▲✤❵✎▲✤■✾▲✤❍ ◆ ❑☛▲ ❊✽■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍✝✖✝✧ ▲❞■❤P ❏✄❊✵✌✳❵✌❛✡■◗❈☛■✾▲ ❘ ❵ ● ❏✁❍ ✟ ❳ ✞✰✶❅ ❄ ✑▼✲ ❭✤❈ ◆ ✯ ❏✁❍✑❑✶✘✁❏✁❉✾▲❩❏✁❍ ❘❁● ✂ ✟❳ ✞✸✷ ❭✤❈ ◆ ✯✺✹ ■◗P ●❯❘ ❈✄❍✑❊✾■❁❏✁❍✔■ ✷ ▲❩❊ ✰ ✑✄✟ ✲ ✑ ✟ ✲❤❄ ✑ ✡ ✖✺✧❙▲✤■◗P ✑ ✴ ✲ ❆ ❭✤❈ ◆ ❆ ✲ ❄ ❭✤❈ ◆ ❄❏✁❍✑❑ ✑✄✟ ✴✱❆ ❭✤❈ ◆ ✟ ❆ ✰ ❄ ❭✤❈ ◆ ✟ ❄ ✏✶✒ P ● ❛✡❉❤❈✔❈✁❆❲❉ ● ❭✞▲ ● ❊✎❈✄❍✼✻ ❈☛❍ ❘ P✑❏✁❉ ● ✘✾✽ ❊ ❘ ❈✄❍✑❑☛▲✤■✾▲✤❈✄❍✝✖ ❘ P✑❏✁❉❁❏ ❘ ■ ● ❉✾▲✂✿❁▲✤❍ ◆ ❏❡❍✡❈☛❉◗❵❝❏❪❭❑☛▲❩❊✾■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍ ❆✦❉◗❈✄❵✐▲✤■✶❊ ◆ ✏ ❆ ✏ ✚ ❭✞▲✤❵ ❳ �❀✭✚✍ ✳❂❁ ✌ ■ ✛ � ■ ✦ ❳ ✰ ✍ ❁ ✛ � ■ ✲ ✴✄✍ ❁ ✪ ✛ ✟ ✏ ✣ ❍ ■◗P ● ❊✵✌✳❵✌❵ ● ■❤❉✾▲ ❘❴❘ ❏✄❊ ● ✰❄❃ ✴❆❅r✴ ❅ ❄✫✂✳✲ ✖■◗P ● ✘✁❏✁❉✾▲❩❏✁❍ ❘❁● ▲❩❊ ✥ ✰✶❅ ✲ ✰ ✷ ✴ ✁ ✲ ✖✝✧❲P✳▲ ❘ P ❊ ❬✡◆✄◆✄● ❊✾■✶❊ ■◗P✑❏✁■☞✻❣❈✄❍ ❘ P✑❏✆❉ ● ✘✾✽✠❊ ❘ ❈✄❍✑❑☛▲✤■✾▲✤❈✄❍✍❑✳❈ ● ❊ ❍✡❈✄■❴P✡❈✆❭ ❑ ❏✁❍✑❑ ■◗P✑❏✁■✧ ● ❘ ❏✆❍✡❍✡❈✄■ ●✆✝ ❛ ●✟❘ ■ ❏ ❍✡❈✄❉❤❵❝❏❪❭ ❭✞▲✤❵✎▲✤■✾▲✤❍ ◆ ❑☛▲ ❊✽■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍ ✏ ✣ ❍✑❑ ●❖● ❑✴✖ ■❤P ● ❏✄❊❇✌✔❵✌❛✡■❤❈✄■✾▲ ❘ ❑☛▲❩❊✾■❤❉✾▲✂✕ ❬ ■✾▲✤❈✄❍ ✝✑❬✑❘ ■ ❬ ❏✆■ ● ❊❏ ❘❖❘ ❈✄❉❁❑☛▲❞❍ ◆ ■◗❈✎■◗P ● ❆✻❉✶❏ ❘ ■✾▲✤❈✄❍✑❏❪❭ ❛✑❏✁❉◗■❲❈✆❆ ❭✤❈ ◆ ✟ ✯ ✚ ✝ ❉ ✵☎✟ ❳❉❈ ❭✤❈ ◆ ✟ ✯❊✰ t✸✷ ✞ ●✆✝ ❛✰ ✲ ✂★❋ ✪✸❫✥✪✡✢ ✦ ★☞✩ ✪ ❳ ✧ ✲◗❄ ❭✤❈ ◆ ✂✞✩✚✌✡❍●❏■✶❑★▲✡✆ ✝★▼✙◆❖❑★P ✟◗❑✞❘❙●✞✢❚✣ ❍✌■◗P ● ❥ ❏✁❉ ✯ ❈✞✘✄▲❩❏✁❍✎❵✌❈✡❑ ● ❭✥✖✔■❤P ● ❍ ●✆✝ ■ ❊❇✌✔❵☞✕✑❈✆❭ ❑ ● ❛ ● ❍✑❑✡❊❃❈✄❍✌■◗P ● ❛✡❉ ● ✘✄▲✤❈ ❬ ❊ ❈✄❍ ● ❈✄❍✳❭✂✌ ✹

■◗P ● ❛✡❉◗❈☎✕✑❏✞✕✳▲✞❭❦▲✤■✵✌ ❃ ✫❖❯ ☎ ❈✁❆★❈★✕✡■✶❏✫▲❞❍✳▲✤❍ ◆ ■◗P ● ❭ ● ■◗■ ● ❉ ✩ ❏❪❆✦■ ● ❉❙■◗P ● ❭ ● ■❤■ ● ❉ ✎ ▲❩❊ ◆ ▲✂✘ ● ❍❱✕✬✌❡❏✎❵❝❏✆■◗❉✾▲ ✝❳❲ ✏ ✣ ■❙▲❩❊q❛✑❈✔❊◗❊s▲✮✕✳❭ ●■◗❈❱✧❲❉✽▲❞■ ● ❏✁❍ ●✗❨✄❬ ❏✆■✾▲✤❈✄❍✯❈✄❍✯■❤P ●✌◆ ✏ ❆ ✏ ❈✆❆ ■◗P ● ❑ ● ❛✡■❤P ✟ ❳ ❏✁❍✑❑✯❏❯❊s▲❞❵ ▲❦❭❩❏✁❉✌❏✁❍✑❏✫❭✮✌✡❊ ▲❩❊ ❱❬❩ ❨ ❊✾P✡❈✞✧ ❊❣■◗P✑❏✁■ ✟ ❳ ❏ ◆ ❏❪▲✤❍■ ● ❍✑❑✡❊ ■◗❈ ❏ ❍✡❈✄❉❤❵❝❏❪❭★❭✞▲✤❵✎▲✤■✾▲✤❍ ◆ ❑☛▲❩❊✾■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍✝✖❭✧ ▲❞■❤P✉❏❱✘✁❏✁❉✾▲❩❏✁❍ ❘❁● ❈✁❆ ❈✄❉❁❑ ● ❉✿❭✤❈ ◆ ✯ ✖ ●✆✝✑❘❁● ❛✡■✿❆✦❈✄❉❴■◗P ● ❊✵✌✔❵✜❵ ● ■◗❉✾▲ ❘▲✤❍✑❑ ● ❛ ● ❍✑❑ ● ❍✳■❴❵✌❈✡❑ ● ❭✥✖❪✧❲P ● ❉ ● ■◗P ● ✘✫❏✆❉✾▲❩❏✁❍ ❘❁● ▲❩❊❏❫ ✰✶❅ ✲ ✏�❵❴❄❛✴❴❉❜❝✠❡❞✾❢✺❣❤✠✐❢❵❥✙❞✾❦✺❧♠❣♦♥ ✆❝✟✾❣❪♣✂✁q✟♦r❱❞♦s✉t✈r✗❥✞♣♠❣✾❴ ✒ P ● ❏✁❛✡❛✡❉❤❈✔❏ ❘ P ❈ ❬ ■✾❭✞▲❞❍ ● ❑ ▲❞❍①✇ ●✟❘ ■✾▲✤❈✄❍ ☎ ✏ ❅ ❆ ❏❪▲✞❭ ❊❏✧qP ● ❍❈✄❍ ●✎❘ ❈✄❍✑❊ ▲❩❑ ● ❉✶❊q■◗P ● P ● ▲ ◆ P✳■ ❈✆❆ ❏✎■◗❉✾▲ ● ✖▼❑ ●◗② ❍ ● ❑ ❏☛❊❙■◗P ● ❵ ❏ ✝ ▲✤❵❝❏✫❭ ❑ ● ❛✡■◗P ❈✁❆ ❏❪❭✞❭❋❭ ● ❏✙✘ ● ❊ ✚④③ ❳ ✴ ❵❝❏ ✝▼✵ ✓ ✫❄❯ ☎ ✧ ❅ ❈✩ ✌ ✎ ❈ ✯ ✷ ✏⑤✒ P ●❴❘ ❏✁■ ❘ P❯P ● ❉ ● ▲❩❊q■◗P✑❏✁■❙■◗P ● ✘✁❏✁❉✾▲❩❏✞✕✳❭ ● ❊❣❏✁❉ ● ❍✡❈✄■ ●✆✝✑❘ P✑❏✁❍ ◆✄● ❏✞✕✳❭ ● ✏�❵❴✂⑥q❴✁�✜❣❂❢qr✞✟⑦❞♦s⑧t❡⑨✺♣♠✁✾♣♠r⑩t♦❧⑧❶⑩❣✬t♦❥✞✆☎✟❆r✗❥✙❣✬❣✾❴❷☛ ❈✄❍✑❊s▲ ❑ ● ❉❴❏❯❑☛▲ ◆ ▲✤■✶❏✫❭ ❊ ● ❏✁❉ ❘ P ■◗❉ ●❖● ✕ ❬ ▲✞❭✤■❴❈✄❍ ✯ ▲✤❍✑❑ ● ❛ ● ❍✑❑ ● ❍✳■✯✄● ✌✡❊❣▲✤❍ ■◗P ●❹❸❃● ❉◗❍✡❈ ❬ ❭✞❭✞▲❲❵✌❈✒❑ ● ❭ ✹ ❏☛❊q❆✻❈✄❉✎❏❯■◗❉✽▲ ● ✖ ❭ ● ■ ✟ ❳ ✕ ● ■◗P ● ❏✗✘ ● ❉✶❏ ◆✄● ❑ ● ❛✡■◗P ❈✁❆ ❏✆❍ ●✆✝ ■ ● ❉◗❍✑❏❪❭ ❍✡❈✡❑ ● ✖★❏✁❍✑❑❑ ●◗② ❍ ● ✙❉❺ ❳ ✰ t✸✲ ❏✄❊ ■◗P ● ❏✙✘ ● ❉❁❏ ◆✄● ❍ ❬ ❵☞✕ ● ❉ ❈✆❆ ▲✤❍✔■ ● ❉❤❍✑❏❪❭ ❍✡❈✡❑ ● ❊❲❏✁■ ❭ ● ✘ ● ❭ t ✏❭✒ P ● ❍ ✝ ❉ ✵ ✟ ❳ ✴ t✸✷✿✴ ✙✜❺ ❳ ✰ t✸✲◗❄ ✯ ✏✒ P ●✿◆✄● ❍ ● ❉❁❏✁■✾▲✤❍ ◆ ❆ ❬ ❍ ❘ ■✾▲✤❈✄❍ ❺ ❳ ✰ ✗ ✲✰✚✞✴ ✂ ❋ ☞❪❻ ✙❉❺ ❳ ✰ t✸✲ ✗ ❋ ❊◗❏✁■✾▲❩❊ ②✑● ❊q■◗P ● ❉ ●✟❘❁❬ ❉❤❉ ● ❍ ❘❁●❴●✗❨☛❬ ❏✁■✾▲✤❈✄❍❺ ❳ ✪✸❫ ✰ ✗ ✲★✴ ❅ ✰ ✗ ❳❼☎❾❽❪❻ ❿ ✯

✎♦➀ ❃☎➁ ❅ ❳ ✳ ➁❪✰ ❺ ➁ ✰✑➂ ✲ ✰ ❺❀➃ ✳ ➁ ✰✵➂ ✲◗✲❾➄✧❲P✡❈✔❊ ● ❊✾❈✁❭ ❬ ■✾▲✤❈✄❍ ❘ ❏✁❍➅✕ ●✎●◗➆ ❛✡❉ ● ❊❤❊ ● ❑ ▲✤❍ ■ ● ❉◗❵❝❊ ❈✁❆➈➇ ❋ ✰✑➂ ✲❃✴➊➉ ❋ ✪✸❫➁ ❽❪➋ ✰✶❅ ✲ ✰❖❃ ➁ ✰ ❅ ➁ ✲ ➂ ✲ ✏➍➌ ◆ ❏✫▲❞❍ ■◗P ● ❏☛❊✵✌✔❵✜❛✡■◗❈✄■✾▲ ❘❑☛▲❩❊✾■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍ ▲✤❍❡■◗P ● ❊✵✌✳❵✌❵ ● ■❤❉✾▲ ❘✿❘ ❏✄❊ ●❏➎✑❬✑❘ ■ ❬ ❏✁■ ● ❊④✧❙▲✤■◗P ✯ ✖✑❏✁❍✑❑❯❏ ❘❁● ❍✳■◗❉✶❏❪❭▼❭✞▲✤❵✎▲✤■✿■◗P ● ❈✄❉ ● ❵ ❘ ❏✁❍❱✕ ● ❛✡❉◗❈✞✘ ● ❑ ▲✤❍■◗P ● ❏✄❊❇✌✔❵✌❵ ● ■◗❉✾▲ ❘✿❘ ❏✄❊ ● ❱ ❅✗➏ ❨ ✏✒ P ●❉➐▼● ❵✌❛ ● ❭✂➑✵➒✡▲✂✘ ❏❪❭ ◆ ❈☛❉✾▲✤■◗P✡❵ ❆✻❈☛❉ ❑✡❏✁■❁❏ ❘ ❈✄❵✌❛✡❉ ● ❊◗❊s▲❞❈☛❍ ❘ ❏✆❍✔✕ ● ❵✌❈✡❑ ● ❭✞❭ ● ❑➓✕✬✌ ❏ ❑☛▲ ◆ ▲✤■✶❏❪❭❲❊ ● ❏✁❉ ❘ P ■◗❉ ●❖● ✕ ❬ ▲✞❭❞■❈✄❍ ▲✤❍✑❑ ● ❛ ● ❍✑❑ ● ❍✔■❉➔ ● ✌✒❊⑩✖✴✧qP ● ❍✉■◗P ● ❍ ❬ ❵☞✕ ● ❉ ✯ ❈✆❆ ❛✑❏✁❉✶❊ ● ❑✶✧❙❈✄❉✶❑✡❊q▲❩❊✉➔✳❍✡❈✞✧❲❍✝✖❋❏✁❍✑❑ ▲❞■❁❊✿❛ ● ❉✽❆✻❈✄❉❤❵❝❏✁❍ ❘❁●✌❘ ❏✁❍✔✕ ●●◗➆ ❛✡❉ ● ❊◗❊ ● ❑ ▲✤❍✚■ ● ❉◗❵ ❊❴❈✆❆ ❛✑❏✁❉✶❏✁❵ ● ■ ● ❉✶❊✿❈✆❆ ■◗P ● ■◗❉ ●❖● ❊ ❬✑❘ P✍❏☛❊❴■❤P ● ❏✙✘ ● ❉✶❏ ◆✄● ❑ ● ❛✡■◗P✚❈✁❆✿❏✁❍ ●◗➆ ■ ● ❉◗❍✑❏✫❭ ❍✡❈✡❑ ● ✏✔➌→✗➣

Page 89: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❑☛▲✁� ● ❉ ● ❍✔■❙❵✌❈✡❑ ● ❭ ❘ ❈✄❍✑❊ ▲❩❑ ● ❉✶❊❙■❤P✑❏✁■ ■◗P ● ❛ ● ❉❤■✾▲✤❍ ● ❍✔■❃▲✤❍✳❆✻❈☛❉◗❵❝❏✁■✾▲✤❈✄❍✜▲❩❊❙■◗P ● ❭ ● ❍ ◆ ■◗P ❈✁❆❋■◗P ● ❊ ●✗❨✄❬✡● ❍ ❘❁● ■◗❈☞✕ ● ❛✑❏✁❉❁❊ ● ❑ ✹❏ ◆ ❏✫▲❞❍ ■◗P✳▲❩❊ ❘ ❏✁❍✈✕ ● ❵✌❈✡❑ ● ❭❦❭ ● ❑①✕❍✌✉❏ ❑☛▲ ◆ ▲✤■✶❏❪❭✿❊ ● ❏✁❉ ❘ P✉■❤❉ ●❖● ✖★❍✡❈✞✧ ✧❙▲✤■◗P✄✂ ●✆☎❂●✙P ✂ ●✙P✞✝ ➔ ● ✌✒❊ ✏ ✣ ■✎▲❩❊r❛✑❈✔❊◗❊s▲✮✕✳❭ ● ■◗❈❛✡❉◗❈✞✘ ● ✰ ❊ ●❖● ❱ ❅✗➏ ❨✦✲ ■◗P✑❏✁■❲■◗P ● ❑☛▲❩❊✾■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍✯❈✆❆ ■◗P ● ❭ ● ❍ ◆ ■◗P❡❈✆❆ ❏✎❉✶❏✁❍✑❑✳❈✄❵ ❛✡P✡❉✶❏✄❊ ● ▲❩❊ ❏☛❊✵✌✔❵✜❛✡■◗❈✄■✾▲ ❘ ❏❪❭✞❭✂✌❯■◗P ● ❊❤❏✁❵ ●❏✄❊✜■◗P ● ❭✞▲✤❵✎▲✤■✾▲✤❍ ◆ ❑☛▲❩❊✾■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍ ❈✁❆❴■◗P ● ❑ ● ❛✡■❤P✚▲✤❍ ■◗P ●❱② ❉✶❊✽■✌❵✌❈✡❑ ● ❭✡✖✱✧❙▲✤■◗P ❏ ❑☛▲ ◆ ▲✤■✶❏❪❭❴❊ ● ❏✁❉ ❘ P✍■❤❉ ●❖● ✕ ❬ ▲✞❭✤■❯❈✄❍✟ ✴✡✠ ✯☞☛ ❭✤❈ ◆ ✯✍✌ ❍✡❈✡❑ ● ❊

✰P ● ❉ ● ❏ ◆ ❏✫▲❞❍ ☛ ❑ ● ❍✡❈✄■ ● ❊q■◗P ●✿● ❍✳■◗❉◗❈✄❛✬✌❝❈✆❆❋■◗P ● ❏✫❭❞❛✡P✑❏ ✕ ● ■✏✎ ☛ ✴ ✲ ❃

❭❞❈ ◆❃ ✲ ❅ ❭✤❈ ◆④❅✄✲ ✏�❵❴ �✺❴❉❜ ❧♠❣❍t♦⑨q❣❂❥①❣❂❧♠❣❪✆✞r✗♣✂❞q✠✸t♦❧✂✁❤❞✾❥✞♣♠r✞✟❵♥✈❴ ✒ P ● ❏❪❭ ◆ ❈✄❉✾▲✤■◗P✡❵ ❆✻❈☛❉✌■◗P ●❯● ❭ ●✟❘ ■✾▲✤❈✄❍ ❈✁❆❴❏ ❭✤❈✔❊ ● ❉✙✖ ❏✁❍✑❏✫❭✮✌✬✿ ● ❑✼✕❍✌✑ ❉❤❈✒❑☛▲✤❍ ◆✄● ❉✎▲✤❍✩❱

❅✄❅ ❨ ✖ ❘ ❏✁❍✈✕ ● ❑ ● ❏❪❭✤■✜✧❙▲✤■◗P ▲✤❍ ❏ ❊ ▲✤❵✎▲✞❭❩❏✁❉ ❵❝❏✁❍✡❍ ● ❉❡❱✓✒ ❨ ✏ ✒ P ● ❛✡❉✽▲❞❍ ❘ ▲✤❛✳❭ ● ❈✁❆✿■◗P ● ❏❪❭ ◆ ❈☛❉✾▲✤■◗P✡❵ ▲ ❊❏✄❊q❆✦❈✁❭✞❭✤❈ ✧❣❊✔✎ ➌ ■✿■◗P ● ✕ ●❖◆ ▲✤❍✡❍✳▲✤❍ ◆ ✖ ❏❪❭✞❭❙❛✳❭ ❏✙✌ ● ❉❁❊❴❏✁❉ ● ❏ ❘ ■✽▲✮✘ ● ✹ ❏✆■ ● ❏ ❘ P ❊✾■ ● ❛✝✖ ■❤P ● ❏ ❘ ■✾▲✂✘ ● ❛✳❭❩❏✙✌ ● ❉✶❊✿■❤P✡❉◗❈✞✧ ❏ ❘ ❈✁▲✤❍❉✶❏✁❍✑❑✳❈☛❵✎❭✂✌ ❏✆❍✑❑ ▲✤❍✑❑ ● ❛ ● ❍✑❑ ● ❍✳■✾❭✂✌✍❏✁❍✑❑ ■◗P ● ❊ ● ■✿❈✁❆ ❏ ❘ ■✾▲✂✘ ● ❛✳❭❩❏✙✌ ● ❉✶❊q❆✦❈✄❉❴■❤P ● ❍ ●◗➆ ■ ❊✽■ ● ❛ ▲❩❊ ●◗➆ ❏ ❘ ■✾❭✂✌✯■◗P✡❈✳❊ ● ✧❲P✡❈■◗P✡❉◗❈✞✧ ✝ ❑★◆✖✕ ✖▼❈☛❉❴❏❪❭✞❭ ■◗P ● ❆✻❈✄❉❤❵ ● ❉✿❛✳❭❩❏✗✌ ● ❉✶❊q▲✞❆q❏✫❭❦❭ ❈✆❆ ■◗P ● ❵ ■◗P✡❉❤❈ ✧✘✗ ●◗❑ ✂ ❘ ✹ ■◗P ● ❏❪❭ ◆ ❈☛❉✾▲✤■◗P✡❵ ● ❍✑❑✡❊✉✧❲P ● ❍ ❏❯❊ ▲✤❍ ◆ ❭ ●❛✳❭❩❏✙✌ ● ❉✿■◗P✡❉◗❈✞✧ ❊ ✝ ❑☎◆✙✕ ✏✉✒ P ● ❍ ❬ ❵☞✕ ● ❉✿❈✁❆ ❊✾■ ● ❛✑❊❣❉ ●✗❨☛❬ ▲✤❉ ● ❑✶✕✬✌❯■◗P ● ❏❪❭ ◆ ❈✄❉✾▲✤■◗P✡❵ ■❤❈ ❘ P✡❈✔❈✳❊ ● ❏✜❭✤❈✔❊ ● ❉❣▲❩❊❣■◗P ● P ● ▲ ◆ P✳■③ ❳ ❈✁❆ ■◗P ● ❭ ● ❆✦■◗❵✌❈✳❊✾■❲❭ ● ❏❪❆❙❈✁❆ ❏✜■◗❉✾▲ ● ✏ ✒ P ● ❏✁❍✑❏✫❭✮✌✡❊ ▲❩❊❏✕ ●❖◆ ▲❞❍✑❊❏✧ ▲❞■❤P ■❤P ● ❊✽■ ❬ ❑✬✌❯❈✁❆ ■◗P ●✚✑ ❈✁▲❩❊◗❊✾❈✄❍ ❵✌❈✡❑ ● ❭✥✖✴✧❲P ● ❉ ●■◗P ● ❍ ❬ ❵☞✕ ● ❉✌❈✁❆❀➔ ● ✌✡❊✿❆✦❈✁❭✞❭✤❈✞✧ ❊✌❏ ✑ ❈✆▲ ❊❤❊✾❈✄❍✚❑☛▲ ❊✽■◗❉✾▲✂✕ ❬ ■✾▲✤❈✄❍✝✖❙■◗P ● ❍ ◆ ❈ ● ❊❴❈☛❍✉■◗❈ ●◗➆ ■◗❉✶❏ ❘ ■r■◗P ● ❊✾■✶❏✁■✾▲❩❊✾■✽▲ ❘ ❊ ❆✦❈✄❉✎■◗P ●❸❃● ❉◗❍✡❈ ❬ ❭✞❭✞▲ ❵✜❈✒❑ ● ❭❭✕❍✌❯❏✜✛ ●✆☎✣✢★◆✂❘◗❘✔✢★P♦◆✥✤❙❑✦✝ ◆✙✢★P ♣✝●✏✧✚✧☞❑ ✏�❵❴✖★✴❴✪✩⑧❥✙❞✾❦qt♦❦✺♣❖❧❄♣❖❶ r✗♣❖✆➓✆✞❞✝✄✺✠♦r✗♣✡✠✾✁✺❴ ✒ P✳▲❩❊ ◆☛● ❍ ● ❉✶❏❪❭✞▲✂✿✟❏✁■✾▲✤❈✄❍ ❈✁❆ ❏✁❍❡❏❪❭ ◆ ❈✄❉✾▲✤■◗P✡❵ ✕✬✌✬✫❇❭❩❏✮✭✾❈✁❭ ● ■ ❏✁❍✑❑❯❥ ❏✁❉❤■✾▲✤❍✯❱✰✯ ❨ ✖❬ ❊ ▲✤❍ ◆ ❏✁❍❡❏✁❉◗❉✶❏✙✌✌❈✆❆❋▲✤❍✳■ ●❖◆✄● ❉✶❊❃▲✤❍✑❊✾■ ● ❏✄❑❯❈✁❆ ❏☞✕✳▲✤■◗❵❝❏✆❛✝✖✳▲❩❊❙❛✡❉ ● ❊ ● ❍✳■ ● ❑ ▲✤❍ ❱✰✱ ❨ ✏✲✴✳✖✵✷✶✖✳✖✸✺✹✼✻✔✽✿✾✞❀❂❁

❃✁❄❆❅❈❇❊❉✼❋✮●■❍❑❏▼▲✏❉❖◆◗P❙❘✔❚❯❘✓❱❲❘❨❳❬❩❂❭✿❪❑❍▼●■❫❴●❛❵✏❜❞❝❢❡✦●❣❪▼❤✿●■▲✏❍▼✐❦❥✖▲✏❍❧❜❦♠✆❝♥❜✔❏▼❏❧▲✔❥✞❋✮♦✁❏♣♠❆❍❑●■❪▼●❈❋✮♦✁❏❑❪▼❍❑♦✁q✿❡✿❪▼♦✁▲✏❉✿❏☞r❛♦✁❪❑❤❴❜❞s✿s✿❝✁♦♥♠■❜✔❪▼♦❢▲t❉✿❏✞❪▼▲❦❏❑▲t❫❴●❏❑❪▼▲✿♠❑❤✼❜✔❏❑❪▼♦♥♠❙s✿❍❑▲✿♠✆●❲❏❑❏❑●❲❏✉❘❣✈✮✇✔①✮②■③✼④✔⑤✷✇⑦⑥❊⑧❛⑨t⑨✺⑤❶⑩✙❷✆❸❺❹❣②✆✇✏❻✆④✏❻❲⑩♥⑤✰⑩❽❼◗❾✔❿t❵✏▲t❝◗❘ → ❿✣➀❨➁✏➂t➃✿❿✮s✿s✞❘ ➣✙➣ ❳✣❄✏❄✉➄✦❘❃✓➅➆❅❈❇❊❍▼❉✿▲✏❝♥❋➇◆➉➈❊❘✓❱■❿❧➈➊❜✔❝♥❜❞➋➌❍▼♦✁❏❑❤✿❉✺❜❞❉➍◆◗➎✴❘ ❱❲❿✷❜❞❉✺❋➏➎❊❜❞➐➌❜❞❍♣❜■➑■❜✬◆◗➒❦❘☞➎❦❘✓❱❲❘✼❳➓⑧→➔❧②✆➣✆❼↕↔✆✇✔①✮②✆➣✉❷➙⑩♥③➛✇❞②♣❸t❷■②❺➣✆❼❑④❨❼➉⑩✁➣✆❼◗⑩✙↔❆➣■❘✼❳➜❚➝♦✁❝❢●❲✐❏❑●❲❍❑♦✁●■❏❙♦✁❉❬➞☞❍▼▲✏q✺❜❞q✿♦✁❝❢♦✁❪➉✐❴❜❞❉✺❋❴➟✮❪✆❜✔❪▼♦❢❏▼❪❑♦♥♠✆❏❨❿✞➀✉➁t➁✏➠✦❘❃✓➄➆❅➢➡✦●■❝✁❝❢●❲❍❙◆✙❚❯❘✓❱■❘t❳➛⑧❙③➙➤■③✮❼➉②♣✇❨❸✔①✿↔❆❼◗⑩✙✇❞③✪❼❑✇❺❹➊②♣✇✏❻✆④t❻■⑩♥⑤❶⑩✁❼➉❾❬➥❂➦✿❷♣✇❞②■❾❴④✔③✼❸❴⑩❽❼✙➣❛⑧❛⑨✏⑨✼⑤✰⑩✙↔✆④➆❼◗⑩✙✇❞③✮➣■❘✮❳➧❚➝♦✁❝✁●■✐❴➨→➟✮▲✏❉✿❏❨❿✺➎➩●■r➭➫❣▲✏❍▼➋✣❿➀✉➁t➂✿➀t❿✮❵✏▲✏❝➉❘✮➅✿❘❃ ➯❞❅➢➡❂♦✁❝❢❝✍◆✙➲✺❘✓❱❲❿✿➳✪❜✔❤✿❫➙▲✏❡✺❋➵◆◗➒❦❘✓❱❲❿➌❜❞❉✺❋➸➟✮➺■s✺❜❞❉✿➋✏▲✔r❛❏▼➋✮♦✞◆✖❚❯❘✓❱■❘❨❳➝➻❛③➙❼✙➦✿❷❈❸❞⑩✁➣✆❼◗②❲⑩✙❻■①t❼➉⑩✙✇✔③➼⑥✉✇✔②➩❼✙➦✿❷❙❸✔①✮②♣④➆❼◗⑩✙✇❞③✪✇➉⑥❈④❺②✆④✔③✺❸t✇✔➽❺⑩✁➾✉❷✆❸⑤❢❷✆④t❸✏❷❲②↕❷■⑤✁❷✆↔✆❼➉⑩✙✇✔③✪④❞⑤✓➚✏✇✔②■⑩✁❼✖➦➌➽❺❘t❳➏➪✷●❨♠❑❤✦❉✿♦♥♠■❜✔❝☞➶❛●■s✼▲✏❍▼❪❛❉✿➹➌P❛➟✿➘➩➴➉➪❊➶➊➴ ➣✏➷ ➴⑦➬t➄✏➮✿❿t➞☞❡✿❍♣❋➱❡✿●↕✃❛❉✦♦❢❵t●■❍❑❏▼♦✁❪➉✐➌❿✣➀❨➁✏➁✏❐✦❘❃ ➷ ❅➢➡❂❝♥❜■➑✆▲✏❝✁●■❪➊◆➉➞☞❘ ❱❂❜✔❉✺❋❺➳✪❜❞❍❑❪❑♦✁❉➙◆◗❒➸❘t➎❦❘✓❱■❘❲❳❬➞☞❍▼▲✏q✺❜❞q✿♦✁❝❢♦✁❏▼❪❑♦♥♠❧♠✆▲t❡✿❉✮❪❑♦✁❉✿➐❦❜✔❝✁➐✏▲t❍❑♦✁❪❑❤✦❫❴❏✼❥✙▲t❍❮❋✦❜✔❪♣❜➼q✺❜❞❏❑●❛❜✔s✿s✦❝❢♦♥♠■❜❞❪❑♦✁▲✏❉✦❏✉❘✿✈✮✇✔①✮②■③✺④❞⑤✇➉⑥Ï❰❣✇✔➽➼⑨✺①t❼⑦❷❲②↕④❞③✺❸❺Ð✺❾❨➣✆❼❑❷■➽ÑÐ✣↔■⑩✙❷❲③✺↔✆❷❆➣❆❿✦❵✏▲t❝◗❘✮➄✿❄t❿✮❉✿➹➌➅✦❿✿Ò❙♠✆❪❑▲tq✺●■❍❺➀✉➁tÓ✏❐✿❿✮s✦s✞❘✣❄✉➮t➅❨❳➱➅t➬ ➣ ❘❃✓Ô➆❅➢➡❂❝♥❜■➑✆▲✏❝✁●■❪➊◆➉➞☞❤✿♦✁❝✁♦❢s✦s✺●✉❱Õ❜✔❉✺❋❺➟✮●✉❋✮➐t●■r❛♦♥♠▼➋❴◆➉➶❛▲✏q✼●■❍▼❪♣❱■❘❞❳❬➳✚●■❝✁❝✁♦✁❉↕❪▼❍♣❜❞❉✿❏➉❥✙▲t❍❑❫➙❏❮❜❞❉✺❋❺❜✔❏❑✐✮❫➙s✿❪❑▲t❪❑♦♥♠✆❏✉ÖØ×✺❉✿♦✁❪❑●❊❋✮♦❶Ù✣●■❍❑●❲❉✺♠✆●■❏❊❜❞❉✺❋➶❛♦♥♠✆●tÚ ❏❛♦✁❉✮❪❑●❲➐✏❍♣❜❞❝✁❏✉❘❧➥❂➦➱❷✆✇❞②♣❷❆❼◗⑩✙↔✆④❞⑤☞❰❣✇✔➽➼⑨✺①t❼⑦❷❲②➼ÐØ↔❲⑩✙❷■③✼↔♣❷❲❿✼❵✏▲t❝◗❘✼❄■➯t➯✺❿✮❉✿➹✿❄❆❳➱➅✦❿✮➲✏❡✿❉✿●➙➀✉➁✏➁t❐✿❿ts✿s✞❘❂❄✉➬✿❄❆❳Ø❄❨➅✔➯✺❘❃ → ❅➢❒❦❜❞❝❽❜❞❫➸q✺▲t❏❛◆✙➲✼❘✓❱■❘t❳❯➥❂➦➱❷❺④❨➣■❾✔➽❊⑨✦❼⑦✇➆❼◗⑩✖↔❙❼✖➦➱❷✆✇✔②❲❾❴✇➉⑥↕❷❆Û✉❼➉②♣❷❲➽➸❷➼➣✆❼⑦④➆❼◗⑩✁➣✆❼➉⑩✙↔❆➣❆❘t❳➏❚➝♦✁❝✁●■✐✮❿➌➎➩●■r➝➫➊▲✏❍❑➋✣❿✣➀❨➁✏➂✏Ó✦❘❃✓➮➆❅❈➲➌❜t♠■Üt❡✿●■❪✜◆◗➞☞❘✓❱➸❜❞❉✺❋➍➟✮➺■s✺❜❞❉✿➋✏▲✔r❛❏▼➋➌♦✴◆✙❚❯❘✓❱❲❘❂❳Ý❇❊❉✼❜✔❝✁✐✮❏❑♦✁❏➸▲✔❥↕❋✮♦✁➐✏♦✁❪✆❜✔❝❛❪❑❍▼♦✁●■❏❴r❛♦✁❪❑❤➝➳✪❜❞❍❑➋t▲✔❵➌♦♥❜❞❉➛❋✮●■s✼●■❉✺❋➱●■❉✺♠✆✐✮❘❊➤✆ÞÕÞ❧Þ➥✼②♣④❞③✮➣✉④✏↔❆❼◗⑩✙✇❞③✮➣↕✇✔③❴➤❲③■⑥✉✇❞②■➽➵④➆❼◗⑩✖✇✔③➧➥❂➦✿❷♣✇❞②■❾✔❿✮❵✏▲t❝➉❘✿➄ → ❿✮❉✦➹ ➷ ❿✣➀❨➁✏➁✦➀✏❿ts✿s✞❘✞❄❲➯ → ➬❨❳Ø❄❲➯ →t➷ ❘❃ ➣ ❅➢ß➼♦✁❍❑❏♣♠▼❤✿●❲❉✿❤✿▲✔❥✖●■❍✪◆➉➞☞❘ ❱❲❿✷➞❮❍❑▲✿❋✮♦✁❉✿➐✏●❲❍❴◆➉➒❦❘✓❱■❿➊❜✔❉✺❋➏➟✮➺❲s✺❜✔❉✿➋t▲✔r❛❏❑➋✮♦➼◆✙❚❯❘✓❱■❘✍❳à➒❛▲✔rá❪❑▲â♠✆▲t❡✿❉✮❪➵Üt❡✿♦♥♠▼➋✮❝✁✐✬❜❞❉✺❋➧❜t♠■♠✆❡✿❍✆❜✔❪❑●❲❝❢✐✣Ö❇ã❡✿❉✿♦❶×✺●✉❋❖❜✔❉✺❜❞❝❢✐✮❏▼♦❢❏➼▲✔❥❣s✦❍❑▲✏q✼❜✔q✿♦✁❝✁♦✁❏❑❪❑♦♥♠❙♠✆▲t❡✿❉✮❪❑♦✁❉✿➐❬❜❞❉✺❋✚▲t❪❑❤✿●■❍❙❍▼●■❝♥❜✔❪❑●❨❋✪s✿❍▼▲✏q✿❝✁●■❫➙❏✉❘✦ä➉❉â⑧❙①t❼⑦✇❞➽➵④➆❼⑦④➆å❛æ✍④❞③✮➚➆①✿④➆➚❞❷❆➣✆å❈④✔③✺❸❹❣②✆✇✆➚✔②♣④❞➽↕➽❺⑩♥③✮➚✔❿✮æ✞❷♣↔❆❼➉①➌②✆❷➩ç➢✇❨❼❑❷❆➣è⑩♥③❖❰❣✇✔➽➼⑨✺①t❼❑❷■②➩ÐØ↔■⑩✖❷■③✺↔✆❷❲❿✏s✦s✞❘✏➅✿❄t❄✆❳✿➅✏➅✏➅✦❘✆❳➏➀✉➁✏➁t➠✿❘✔➞☞❍▼▲➱♠❆●■●✉❋✮♦✁❉✿➐t❏❣▲❞❥Ø❪▼❤✿●❦❄ ➣ ❪❑❤➸ä❑P➊❇❈é❂➞P➊▲✏❉➱❥✙●■❍❑●❲❉✺♠✆●✏❘❃✁❄✉➬➆❅➢é✣▲t❡✺♠▼❤✺❜✔❍✆❋➙◆◗❒➸❘✓❱❂❜✔❉✺❋❺➟✮➺■s✺❜❞❉✿➋✏▲✔r❛❏▼➋✮♦✺◆✖❚❯❘✓❱■❘❲❳❴❇❊❵t●■❍♣❜❞➐✏●➊s✿❍❑▲❞×✺❝✁●❊❜✔❉✺❋➢❝❢♦✁❫➙♦❢❪▼♦✁❉✿➐è❋➱♦❢❏▼❪❑❍▼♦❢q✦❡✿❪❑♦✁▲✏❉✴❥✙▲t❍✷❜➼s✿❤✿❍✆❜✔❏❑●❛❏▼♦✁➺■●❛♦✁❉❦❪❑❤✿●é✣●❲❫❴s✼●■❝❶➴⑦ê✼♦✁❵➸s✺❜❞❍❑❏❑♦✁❉✿➐❴❜❞❝✁➐✏▲✏❍▼♦✁❪❑❤✿❫✜❘➆➤❆Þ❧Þ❧Þë➥✼②♣④✔③➱➣❲④t↔✆❼➉⑩✙✇❞③✮➣➢✇❞③❬➤❲③■⑥✉✇✔②❲➽➵④➆❼◗⑩✙✇❞③➧➥❂➦➱❷✆✇❞②■❾✔❿✮❵✏▲t❝◗❘t➯✺❄t❿✣➀✉➁t➁✏❐✿❿ts✿s✞❘✦➯ → ➮❨❳➌➯✮➮✏➮✦❘❃✁❄✏❄❆❅➢➞☞❍▼▲➱❋➱♦❢❉✦➐✏●■❍✴◆◗➒❦❘✓❱❲❘t❳ì➒➩▲✔rí❪▼▲↕❏▼●■❝✁●✉♠✆❪❦❜❦❝✁▲t❏❑●■❍❨❘✣î❈⑩❽➣❲↔❲②♣❷❆❼❑❷➼ïâ④❨❼✖➦➱❷❲➽➵④➆❼◗⑩✙↔❆➣■❿✿❵t▲✏❝➉❘✺❄❨➅✏➬✦❿✣➀✉➁✏➁tð✿❿ts✿s✞❘❂❄■➯ ➣ ❳Ø❄ ➷✗➣ ❘❃✁❄✉➅➆❅➢➶❛●❲❏❑❉✿♦♥♠▼➋✪◆➉➟✣❘✿ä■❘✓❱■❘t❳➍Þ❧Û❨❼◗②✆❷■➽➸❷✴ñ➆④❞⑤✰①✿❷✆➣✆å❣②✆❷⑦➚➆①✮⑤❢④❞②❊ñ✔④✔②■⑩✖④❨❼➉⑩✙✇✔③â④❞③✺❸✴⑨➱✇❞⑩♥③✮❼☞⑨✺②✆✇✉↔✆❷❆➣♣➣✉❷❆➣■❘t❳ì➟✮s✦❍❑♦✁❉✿➐✏●❲❍❛ò❧●■❍❑❝♥❜❞➐✺❿✣➀✉➁tÓ✏➂✦❘❃✁❄✉➄➆❅➢➟✮r➊●■●■❪▼♦❢❉✦➐❦◆✙➪❦❘❨➲✼❘ ❱❲❘✆❳➵Ò➼❉↕❋➱▲✏❫❬❜❞♦✁❉✿❏✺▲❞❥✿❡✿❉✿♦❶❥✙▲✏❍▼❫➝❝✁▲✿♠■❜✔❝✮❜✔❪❑❪▼❍♣❜t♠✆❪❑♦✁▲✏❉✴♦❢❉❙●✆❭✿❪▼❍❑●■❫➙●❧❵✏❜✔❝✁❡✿●❧❪▼❤✿●■▲t❍❑✐✮❘✉⑧❙③✿③✺④❞⑤✓➣è✇⑦⑥❧❹➊②♣✇✏❻✆④t❻■⑩♥⑤❶⑩✁❼➉❾✔❿❵✏▲t❝➉❘✣❄✉➄✿❿✮❉✦➹✿❄✏❿✞➀❨➁✏Ót❐✿❿ts✿s✞❘✣❄ ➣ Ô❨❳✿➅✏➬ ➷ ❘❃✁❄■➯❞❅➢➟✮➺■s✼❜✔❉✿➋t▲✔r❛❏❑➋✮♦❊◆✖❚❯❘✓❱■❘✍❳àÒ➼❉➧❪❑❤✦●❴❤✿●■♦✁➐t❤➌❪✴▲✔❥❈❋✮♦✁➐✏♦✁❪✆❜✔❝❧❪▼❍❑●■●■❏❴❜❞❉✺❋✜❍❑●❲❝❽❜❞❪❑●✉❋ìs✿❍❑▲tq✿❝✁●■❫❴❏❨❘✞⑧❙⑤✓➚✏✇✔②❲⑩✁❼✙➦✮➽↕⑩✖↔♣④❞❿✞❵t▲✏❝➉❘✞Ô✦❿☞❉✿➹➌➅✦❿➀✉➁t➁✿➀t❿✮s✿s✞❘✿➅ ➷ Ô❨❳✿➅ →✗→ ❘

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�✂✁☎✄✝✆✟✞✡✠☞☛✍✌✏✎✑✞✓✒✔✌✏✞✖✕✘✗✂✞✡✒✚✙✛✄✢✜✣✌✤☛☎✥✏✄✦✞★✧✪✩✦✕★✥✏✫✍✬✭✯✮✱✰★✲✝✳✴✰✶✵✯✷✹✸★✺✼✻✽✻

✾❀✿✣❁ ✘✏❂✼❃❅❄ ❁❇❆❉❈❋❊✛●■❍ ❂ ✿❏❆ ✖▲❑◆▼ ✿✣❆ ❂✼❃✍✕✯❖✯❃ ❈P❘◗ ❆✹❊ ✕✢❂✼❃✪❙ ➏ ✖★❙✏✱✿✱✮✒

❚ ❄❉❖✯❯❱❯❲▼✛❃ ❈ ✕ ❈❨❳✤❊ ❃ ❁ ❄❀✘✛▼ ✿❬❩ ❂✼❃❪❭ ❊ ❂⑩✘✏❂ ✿✯❫❴➸✵✡❵✹❛❨✻✔✽❏❜❝❛

➲t▲✏❤✿❉➍➟✮❤✺❜t♠❑➋t●■❝✁❝❣s✦❍❑▲✔❵✏●❲❏➵❜✜♠✆▲✏❉❨➑✆●✉♠✆❪▼❡✿❍❑●✚▲✔❥❈➒➼❜✔❍✆❋✮✐➌❿☞r❛❤✦♦❽♠▼❤➇❏❑❪♣❜❞❪❑●■❏➸❪▼❤✺❜✔❪❺❪❑❤✦●❴♦✁❉✮❵✏●■❍▼❏❑●➙❥✙❡✿❉✺♠❆❪❑♦✁▲✏❉➏▲❞❥❝❢▲t➐☞❝❢▲t➐❡❞❛❝✁▲t➐✷❝✁▲t➐✷❝✁▲t➐❡❞✜♦✁❏❦❉✿▲✏❪❺❜✔❏❑✐✮❫➙s✿❪❑▲t❪❑♦♥♠❙❪❑▲✜❜✔❉✮✐✪●✆❭✿s✮➴➉❝✁▲✏➐➙❥✙❡✿❉✺♠❆❪❑♦✁▲✏❉✞❘Ïä➉❉➏▲✏❍♣❋➱●■❍❦❪❑▲❖s✿❍❑▲✔❵t●➸❪❑❤✿♦✁❏✉❿❂❤✿●❡✿❏❑●■❏➼❤✿♦✁❏❣❪▼●✉♠▼❤✿❉✿♦♥Üt❡✿●❦▲❞❥✷❉✿●■❏▼❪❑●✉❋ ❥✙▲t❍❑❫❴❏❨❘

❢❤❴❱❣✐❤♦r✗❥✙❞ ⑨❦❥✡❧✞r✗♣✂❞✓❤❭❪▼✛❃ ❩✣❈ ✧♠▼♥❄ ❆♣♦ ❂ ② ❃❅❄ ❆q❆✹❊ ❄ ❆ ❖ ❩✣❈ ❄ ❈ ❄ ❆ ❂✼❯✂▼ ❆r❁ ◗ ▼✱sts ❈✉❆✹♦ ❂ ✿✯❊♥❆❉❁❇❊✏✿✉❊✛● ❂ ➆✯✈ ➑✽s ❊✏✇①● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❁❇✿✝❆✹♦ ❂ ◗ ❊✏✿✣❆ ❂ ➆✴❆q❊✛●

▼✏❄ ❈ ❯ ✈✯❆✹❊♥❆❉❁ ◗ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄ ❚③② ✖✔✒ ❫☞④❡⑤⑥♦ ❂⑦❄❉❂ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄✶▼✛❃✹❂⑤✕✯❖ ❁ s ❆ ❖ ✈⑧● ❃ ❊ ❯⑩⑨ ❊ ❃✡❶ ✕ ❈❷❆♣♦ ❂■❖✚❄❉❂ ❊✛●❪② ❂❸s ❩❹❊♥✈ ❂✼❃❅▼ ❆r❁❺❊♥✿ ❄⑩✖❂ ➆✯✈✚❊✏✿ ❂ ✿✣❆❉❁ ▼ ❆❉❁❇❊✏✿ ▼ ✿✚❩ s ❊✏✇ ▼✤❃ ❁❇❆✹♦ ❯ ④■❻ ➆ ▼✛❯ ✈ s❺❂⑦❄❀▼✛❃✹❂

❂ ➆✴✈✓❼❾❽ ✰ s ❊✏✇✢❼❾❽ ➋ ✰➀❿✼➁✣➂✹➂ ➄ ▼ ✿✚❩ s ❊✏✇✚❼ s ❊♥✇✯❼❾❽✯➃ ✰ ❂ ➆✯✈★❼ ❙✏✱✿✱✿✯ ❽ ➂✹➂❤✰➅➄✣➂❅➆❭❀❂➇❂⑦❄ ❆ ▼✞✕✣s ❁ ❄ ♦ ❂ ❩➈❆✹♦ ▼ ❆✍❆✹♦ ❂❪❄ ❁❇✇✏✿❱❊✛● ▼ ✿✣❈ ❂ ➆✯✈ ➑✽s ❊✏✇❷● ❖ ✿ ◗ ❆❉❁❇❊✏✿➈❁ ❄ ◗ ❊✏✿ ❄ ❆ ▼ ✿❏❆✶❁❇✿ ▼ ✿ ❂ ❁❺✇♥♦ ✕ ❊ ❖✯❃ ♦✯❊✣❊✴❩➈❊✛●★❁❇✿✬②✚✿✣❁❺❆❉❈✏④■⑤♠♦✣❁ ❄✈ ❃ ❊✏✈ ❂✼❃ ❆❉❈ ❯✂▼ ➔✏❂⑦❄✡❂ ➆✯✈ ➑✽s ❊✏✇❪● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄✍❂ ➆✯❆ ❃✹❂✼❯❱❂❸s ❈ ❖✚❄❉❂ ● ❖✣s ●➉❊ ❃ ❩✣❊✛❁❇✿✯✇ ▼✏❄ ❈ ❯ ✈✯❆♣❊✏❆❉❁ ◗ ❄ ④ ➌ s ❆✹♦✯❊ ❖ ✇✏♦ ❯✂▼ ✿✣❈❪● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄❊✏✿ ❂❱❂ ✿ ◗ ❊ ❖ ✿❏❆ ❂✼❃❸❄ ❁❇✿①✈ ❃❅▼ ◗ ❆r❁ ◗ ❂❋▼✛❃✹❂❱▼✏❄ ❈ ❯ ✈✯❆♣❊✏❆❉❁ ◗ ❆✹❊ ❄ ❊ ❯❱❂➈❂ ➆✴✈ ➑✽s ❊✏✇➊● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ✖✍❭❪▼✛❃ ❩✣❈ ◗ ❊✏✿ ✭❾❂ ◗ ❆ ❖✯❃✹❂ ❩①❆♣♦ ▼ ❆❷❆✹♦✣❁ ❄❁ ❄ ✿✯❊♥❆❘❆✹♦ ❂ ◗ ▼✏❄❉❂ ●➋❊ ❃ ❆✹♦ ❂ ❁❇✿ ✘✏❂✼❃❅❄❉❂ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿✦➌➇❼❾❽ ➂ ❊✛● s ❊✏✇ ➋ ❽ s ❊✏✇ ➃ ❽ ✖ ✧ ♦ ❂✼❃✹❂ ❆♣♦ ❂ ❁❇✿✚❩ ❂ ➆①❩ ❂ ✿✯❊✏❆ ❂⑦❄ ❁❺❆ ❂✼❃❅▼ ❆❉❁❇❊✏✿✡④④✣☞✿❊✏❆✹♦ ❂✼❃✱✧ ❊ ❃ ❩ ❄⑩✖ ➌✉❁ ❄ ❩ ❂ ②✚✿ ❂ ❩ ✕ ❈

s ❊✏✇ s ❊✏✇❀➌➇❼❾❽ ➂ s ❊✏✇ s ❊✏✇ s ❊♥✇➇➌➇❼❾❽ ➂✍➍ ❽ ➆➎❀❊ ✧ ❁❇❆❲❁ ❄✜➔ ✿✯❊ ✧ ✿ ❄ ❁❇✿ ◗ ❂ ➐✢❁❇❊ ❖❪✘ ❁ s➏s❇❂ ❚ ✯ ❫❪❆✹♦ ▼ ❆❲❆✹♦ ❂ ❁❇✿ ✘✏❂✼❃❅❄❉❂ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿➑➐❷❼❾❽ ➂ ❊✛●✪❽ s ❊✏✇◆❽➒❁ ❄ ✿✯❊♥❆ ▼ ✿ ❂ ➆✴✈ ➑✽s ❊✏✇● ❖ ✿ ◗ ❆❉❁❇❊✏✿✡④⑤✣☞✿➓♦✣❁ ❄ ❆ ▼✱s✮➔✶✇ ♦ ▼ ◗ ➔✏❂❸s➏s✟❄ ♦✯❊ ✧❪❄ ♦✯❊ ✧ ❆♣❊✂❩ ❂ ❩ ❖ ◗ ❂✪❭❪▼✛❃ ❩✣❈ ✽③❄ ◗ ❊✏✿ ✭❉❂ ◗ ❆ ❖✯❃✹❂ ● ❃ ❊ ❯ ❆✹♦✣❁ ❄➇❃✹❂⑦❄r❖✣s ❆✐④✣✑✿➔❊ ❃ ❩ ❂✼❃ ❆✹❊❘❩✣❊➇❆♣♦✣❁ ❄ ✖✬✇ ♦ ▼ ◗ ➔♥❂❸sts✯❖✚❄❉❂⑦❄ ♦✣❁ ❄ ❆ ❂ ◗ ♦✯✿✣❁❖❨ ❖✯❂ ❊✛●✚✿ ❂⑦❄ ❆ ❂ ❩ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄⑩✖✞✧ ♦✣❁ ◗ ♦ ✧➇▼✏❄ ❊ ❃ ❁❇✇✛❁❇✿ ▼✐s➏s ❈→❩ ❂⑦❄ ❁❺✇♥✿ ❂ ❩❆✹❊ ◗ ❊♥✿ ❄ ❆ ❃✹❖ ◗ ❆ ▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯✂❄ ●➉❊ ❃ ❩✣❊✤❁❺✿✯✇ ▼✏❄ ❈ ❯ ✈✯❆✹❊♥❆❉❁ ◗ ❄ ④ ➌ s ❆♣♦✯❊ ❖ ✇✏♦ ✇ ♦ ▼ ◗ ➔✏❂❸s➏s✟▼✱s➣❄ ❊ ❄ ✈✢❊ ➔✏❂❹▼✞✕ ❊ ❖ ❆➇❆✹♦ ❂⑦❄r❂ ❁ ❄✹❄❉❖✯❂⑦❄ ❁❇✿♦✣❁ ❄ ❆ ▼✐s✂➔✴✖✞✧◆❂④✧ ❁ s➏s ❊✏✿ s ❈ ❃♣❂ ◗ ▼✐s➏s ❆✹♦ ❂⑥❯✂▼ ❆ ❂✼❃ ❁ ▼✐s❪✧ ♦✣❁ ◗ ♦❹❁ ❄ ✿ ❂ ◗ ❂⑦❄✹❄✹▼✛❃ ❈❪❁❇✿❱❊ ❃ ❩ ❂✼❃ ❆♣❊❘✈ ❃ ❊ ✘✏❂⑥❭❘▼✤❃ ❩✣❈ ✽↔❄ ◗ ❊✏✿ ✭❾❂ ◗ ❆ ❖✯❃✹❂ ④ ✫ ❊ ❃❯ ❊ ❃♣❂ ❩ ❂ ❆ ▼ ❁ s↕❄❘▼✞✕ ❊ ❖ ❆➇❆✹♦ ❂❹▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯ ❁ ◗ ▼♥❄ ✈ ❂ ◗ ❆ ❄ ❊✛● ▼♥❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗ ❄⑩✖❪✧⑥❂❷❃✹❂ ● ❂✼❃ ❆✹❊ ❚ ❙☎✖ ➄ ✖✚➙❪✖✢➛❍✖♦❩❪✖✣✱❪✖✓❙ ➏ ✖✡❙✏❙★✖★❙ ➄ ❫☞④❛✾❴❲➜❲❤➒❤✴❣❪❶⑩r⑩❣❪⑨✈❣✣➝❵❢✝t★❤✝❶✗♣♠❞✡❤✝❶➞ ❂q❄ ❆ ▼✛❃ ❆ ✧ ❁❇❆✹♦ ❄ ❊ ❯❱❂ ❩ ❂ ②✚✿✣❁❇❆❉❁❇❊✏✿ ❄ ④✉➐ ❂ ❆❹➟♥➠ ▼ ✿✚❩➓➟✞➋❪➡ ❂q❂ ➆✯✈ ➑✽s ❊♥✇❱● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄❏✧ ♦✣❁ ◗ ♦❬❆ ❂ ✿✚❩❋❆✹❊ ✿✼❂✼❃ ❊✚④⑥➞ ❂q❄✹▼ ❈❆✹♦ ▼ ❆■➟ ➠ ▼ ✿✚❩❱➟ ➋ ▼✛❃✹❂❷➢ ✢✦✧❦☎❪❑★▲✵❑❏➤✔✕ ●❪❊ ❃ ❊✛●★❆✹♦ ❂❘❄✹▼✤❯❱❂➇▼✏❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗ ❄ ◗ ▼✐s❇❂✏➥ ❁➏●✡❆✹♦ ❂✼❃✹❂➇❂ ➆✣❁ ❄ ❆■✈✢❊ ❄ ❁❇❆❉❁❇➦ ❂ ❁❇✿✣❆ ❂ ✇ ❂✼❃❅❄ ✟ ▼ ✿✚❩✯ ✧ ❁❇❆✹♦①➟✏➠ ❈ ➟ ➃➋ ▼ ✿✚❩➓➟✞➋ ❈ ➟✢➧➠ ❼ ❃♣❂ ◗ ▼✐s➏s ❆✹♦ ▼ ❆❪❆✹♦ ❂ ✇ ❂✼❃♣❯✂❄ ❊✛● ❂ ➆✯✈ ➑✽s ❊♥✇❲● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄➔▼ ❆❀❁❺✿✬②✚✿✣❁❇❆❉❈➨●➋❊ ❃✹❯➩▼ ❆✹❊✏❆ ▼✐s➏s ❈❊ ❃ ❩ ❂✼❃♣❂ ❩☞② ❂❸s ❩ ➂ ④■⑤♠♦ ❂ ◗ ❊ ❯ ✈ ▼✛❃❅▼ ➡✣❁ s ❁❇❆❾❈ ❃✹❂❸s↕▼ ❆❉❁❇❊✏✿❲❁ ❄⑥▼ ✿ ❂ ❨ ❖ ❁❇➦ ▼✐s❇❂ ✿ ◗ ❂❹❃✹❂❸s↕▼ ❆❉❁❇❊✏✿ ▼ ✿✚❩ ✧⑥❂ ❩ ❂ ✿✯❊✏❆ ❂ ❆✹♦ ❂❪❂ ❨ ❖ ❁❺➦ ▼✐s❇❂ ✿ ◗ ❂◗ s↕▼✏❄✹❄ ❊✛●➫➟➭➡❏❈➲➯❡❼❉➟ ➂ ④➓⑤⑥♦ ❂❲❂ ❨ ❖ ❁❇➦ ▼✱s❺❂ ✿ ◗ ❂ ◗ s↕▼✏❄✹❄r❂⑦❄ ◗ ▼ ✿✦➡ ❂ ❊ ❃ ❩ ❂✼❃✹❂ ❩✦➡✣❈①➯✶❼❾➟♥➠ ➂→➳ ➯✶❼❾➟✞➋ ➂ ➥ ❁➏●⑧➟♥➠ ❈ ➟ ➧➋ ●➋❊ ❃q▼✐s➏s✈✚❊ ❄ ❁❇❆❉❁❇➦ ❂ ❁❇✿✣❆ ❂ ✇ ❂✼❃❅❄ ✯ ④

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Page 91: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➐ ❂ ❆ ❖✚❄❪▼✐s↕❄ ❊q❁❇✿✣❆ ❃ ❊✯❩ ❖ ◗ ❂ ❆✹♦ ❂ ◗ ❊♥✿ ◗ ❂ ✈✯❆❘❊✛● ✿⑩➑ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ④ ✇✏❖ ◗ ♦ ▼ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿➊❁ ❄ ❊✏✿ ❂ ❊✛●✍❆✹♦ ❂ ●➉❊ s➏s ❊ ✧ ❁❺✿✯✇ ✎✿✼❂ ➆✯✈ ➧ ❼✁� ➂✍➍ � ✳ ➧ ❼ ❂ ➆✯✈★❼✁� ➂ ✲ ❙ ✲ � ✲✄✂☎✂✆✂✗✲ � ➧✞✝ ✯✠✟➏➂ ➄✿❸s ❊✏✇ ➧ ❼✁� ➂✍➍ � ✳ ➧ ❼ s ❊✏✇✯❼ ❙ ✰ � ➂ ✲ � ✲✡✂✆✂☎✂✙✲ ❼ ✲ ❙ ➂ ➧ ✳ ➠ � ➧ ✝ ✯✓➂ ➄✿ ❁❇✿✣➦ ➧ ❼✁� ➂✍➍ � ✳ ➧ ❼ ❙ ✝ ❼ ❙ ✰ � ➂ ✲ ❙ ✰ � ✲✡✂✆✂☎✂✙✲ ❼ ✲ ❙ ➂ ➧ ✳ ➠ � ➧ ➂ ➄●➉❊ ❃❬▼ ✿✣❈✝❁❇✿❏❆ ❂ ✇ ❂✼❃ ✯☞☛ ➏ ④ ✣➉●✌�✹➠⑩➄ ➆⑦➆✐➆ ➄✍� ➃ ▼✤❃✹❂①❂ ➆✯✈ ➑✽s ❊♥✇✖● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄❝✧ ♦✣❁ ◗ ♦⑩❆ ❂ ✿✚❩ ❆✹❊ ✿✼❂✼❃ ❊ ➥❏✧⑥❂ ❩ ❂ ✿✯❊✏❆ ❂ ➡❏❈✎❪❼✁�✹➠⑩➄ ➆✐➆⑦➆ ➄✏� ➃ ➂ ❆✹♦ ❂❋❄❉❂ ❆q❊✛●➇● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄☞✧ ♦✣❁ ◗ ♦ ◗ ▼ ✿✉➡ ❂ ❊✏➡✯❆ ▼ ❁❇✿ ❂ ❩ ● ❃ ❊ ❯ �♣➠❙➄ ➆⑦➆✐➆ ➄✍� ➃ ➡❏❈ ❖✚❄ ❁❺✿✯✇ ▼ ❩✯❩♥❁❇❆❉❁❇❊✏✿ ➥◆❄r❖ ➡ ➑❆ ❃❅▼ ◗ ❆❉❁❇❊✏✿ ➥✣❯✪❖✣s ❆❉❁❇✈ s ❁ ◗ ▼ ❆❉❁❇❊✏✿ ▼ ✿✚❩ ▼ ✈✯✈ s ❁ ◗ ▼ ❆❉❁❇❊✏✿➨❊✛● ✿⑩➑ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ④ ✇ ♦ ▼ ◗ ➔✏❂❸s➏s ✈ ❃ ❊✱➦ ❂ ❩❱❆✹♦ ❂ ●➋❊ sts ❊ ✧ ❁❇✿✯✇❲❆✹♦ ❂ ❊ ❃✹❂✼❯ ❚ ❩ ❫☞④✑✓✒✕✔✗✖✙✘✚✔✜✛ ❙✗✢✤✣ ●✏✝❪➟ ➤✍●✔❑☎P ●✦✥■☎★✧✆✕❢✢✪✩✬✫✮✭✬P ➢ ✝ ◆✖✢★P✰✯ ✗ ◆ ➢❞✗ ✝ ●✗P ✂ ❘➛✝➉✢✼◆❖P✦✱ P❤◆✙✝✳✲✵✴☞✶ ✗ ●✗Pë✝ ✗ ●✙▲✵● ●✦✥ ◆♠❘➆✝☞●✮✥❲☎★✧♣✕✁✢✪✩

✫✮✭❍P ➢ ✝ ◆✖✢★P❪❘✷�♣➠❙➄ ➆⑦➆⑦➆ ➄✍� ➃ ✯❭◆✙✝ ✗ ➯✶❼✁�♣➠ ➂◆➳ ✂☎✂✆✂ ➳ ➯✶❼✁� ➃ ➂✍✸ ❘✮✭ ➢❞✗ ✝ ✗ ❑✿✝✍➟ ➢ ❑★P✦➤✍●☞●✮✥❲☎✾▲✵●⑩❘◗❘❙● ✂ ❑✞❘❘➟ ➍ ❂ ➆✴✈✜✹✐❼✹❼✻✺ ✰✡✼✣➂✻✽♠➂✍✸✯ ✗ ●✙▲✑● ❂ ➆✴✈✜✹❉◆♠❘❴✝ ✗ ●✓✾✿✧♣✝ ✗ ◆✖✝ ●✗▲✵❑✿✝ ● ✂ ●✮✥■☎✣✢★P♦●✙P✞✝ ◆❄❑✿✕ ✸ ✺✔◆♠❘⑧❑❱P✞✢★P➇✤⑩●✗▲✆✢ ➢ ✢★P ❘➆✝ ❑☎P✞✝ ✸❀✽ ◆✂❘⑧❑Ï☎✾▲✆✢ ✂ ✭ ➢ ✝❦✢❁✫⑧▲✵●❾❑✦✕✼☎Ø✢✵✯❭●✙▲✍❘✢❁✫⑧◆✖✝ ●✗▲✵❑✿✝ ● ✂ ✕✁✢❂✩★❑☎▲❾◆✖✝ ✗ ✧❷❘ ✸ ❑☎P ✂ ✼ ➤ ●✏✕✁✢★P❃✩✞❘➸✝➉✢✌✎❘❼✁�♣➠❙➄ ➆⑦➆✐➆ ➄✏� ➃ ➂ ✴⑤⑥♦ ❂☎❂ ➆✴✈ ❃✹❂⑦❄♣❄ ❁❇❊✏✿✪➟ ➍ ❂ ➆✯✈✜✹✐❼✹❼✻✺ ✰❄✼✣➂✻✽♠➂ ❁ ❄ ◗ ▼✐s➏s❇❂ ❩ ▼ ✿ ❂⑦❄ ❆ ❂ ❩⑧●➋❊ ❃✹❯ ❊✛● ➟✶④✙❅➨❊ ❃✹❂ ✇ ❂ ✿ ❂✼❃❸▼✐s➏s ❈ ➥ ❊♥✿ ❂ ◗ ▼ ✿ ❃✹❂ ◗ ❖✯❃❅❄ ❁❇➦ ❂❸s ❈◗ ❊ ❯ ✈ ❖ ❆ ❂ ✿ ❂⑦❄ ❆ ❂ ❩❲●➉❊ ❃✹❯❲❄ ●➋❊ ❃ �♣➠❙➄ ➆⑦➆✐➆ ➄✍� ➃ ④❇❆❪❊✛❁❇✿✯✇❲❆✹♦✣❁ ❄✼➥ ❊✏✿ ❂ ❊✏➡✯❆ ▼ ❁❇✿ ❄➇❄ ❊ ◗ ▼✐s➏s❇❂ ❩➓✿ ❂⑦❄ ❆ ❂ ❩ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄ ④ ✇ ♦ ▼ ◗ ➔✏❂❸s➏s

▼ ✿✚❩ ✇❏▼✐s ➦✣❈❋♦ ▼ ➦ ❂➫❄ ♦✯❊❉❈❀✿❋♦✯❊❉❈ ❆✹❊q❊✏➡✯❆ ▼ ❁❇✿ ▼✛❖ ❆✹❊ ❯✂▼ ❆❉❁ ◗ ▼✐s➏s ❈❋✿ ❂⑦❄ ❆ ❂ ❩ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄ ❊✛●✍❆✹♦ ❂ ● ❖ ✿ ◗ ❆r❁❺❊♥✿ ▼✐s ❁❇✿❏➦ ❂✼❃❅❄❉❂⑦❄ ❊✛●❂ ➆✯✈ ➑✽s ❊♥✇❱● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❚ ➛ ❫ ➥✯❯ ❊✯❩ ❖✣s ❊ ❄❉❖ ❁❇❆ ▼ ➡ s❇❂ ♦❏❈✣✈✚❊♥❆✹♦ ❂⑦❄❉❂⑦❄ ❊✏✿ ❂ ➆✴✈ ➑✽s ❊✏✇ ◗ ❊✏✿ ❄ ❆ ▼ ✿✣❆ ❄ ④⑥q❴❋❊❍●✴❣✔❶⑩❞✾❧ ❥✴r✗♣✂❞✓❤❡r⑩❞❏■ t♦❥✞⑨❀❑❇▲✂❶q❧✞❞✓❤◆▼ ❣✴❧ r✛❥ ❥✙❣❆ ❂ ✿✯❊✏❆ ❂ ➡✣❈✝➐ ❆✹♦ ❂ ❁❺✿✣➦ ❂✼❃❅❄r❂ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿✖❊✛●❹❽ s ❊♥✇◆❽ ➥⑥▼ ✿✚❩ ❃✹❂ ◗ ▼✐s➏s ❆✹♦ ▼ ❆➊➌ ➍ ❂ ➆✯✈ ➋ ➐ ❩ ❂ ✿✯❊♥❆ ❂⑦❄ ❆♣♦ ❂ ❁❇✿❏➦ ❂✼❃❅❄❉❂● ❖ ✿ ◗ ❆❉❁❇❊✏✿➓❊✛● s ❊✏✇ ➋ ❽ s ❊♥✇ ➃ ❽✓④■⑤⑥♦ ❂ ●➉❊ s➏s ❊❖❈⑥❁❇✿✯✇ s❇❂✼❯❱❯✂▼ ❁ ❄ ◗ ❃✹❖ ◗ ❁ ▼✐s ●➉❊ ❃ ❆♣♦ ❂ ✈ ❃ ❊❏❊✤●✟❊✛● ❭❪▼✛❃ ❩✣❈ ✽③❄ ◗ ❊✏✿ ✭❾❂ ◗ ❆ ❖✯❃✹❂ ④P❇✔✜✛◗✛❙❘ ❙✗✢ ✶ ✗ ●✙▲✑●☞◆♠❘⑧P✞✢✜●✮✥❲☎★✧♣✕✁✢❂✩✤✫✮✭❍P ➢ ✝ ◆✖✢★P❋➟ ❘✮✭ ➢❞✗ ✝ ✗ ❑✿✝❚ ➟ ✲ ➐ ❚ ❈ ❿ ✳✜❯✳❱ ➁ ➄

✫✔✢★▲⑧❑✿✕✖✕★❲ ➳ ➏ ✴❳❨✘✜✖❩✖❭❬ ✢ ➌ ❄♣❄❉❖✯❯❱❂ ❆♣♦ ▼ ❆ ❄❉❖ ◗ ♦ ▼ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿①➟ ❂ ➆✣❁ ❄ ❆ ❄ ④❀✣☞❆ ◗ ▼ ✿➓➡ ❂❱❄ ♦✯❊❖❈➇✿①❼ ❖✚❄ ❁❺✿✯✇❲❆✹♦ ❂❱❄✹▼✛❯➈❂ ✿✯❊✏❆ ▼ ❆❉❁❇❊✏✿ ❄➇▼✏❄ ❁❇✿❆✹♦ ❂❹▼ ➡✢❊✛➦ ❂ ❆✹♦ ❂ ❊ ❃✹❂✼❯ ➂ ➥ ❆✹♦ ▼ ❆➇❊✏✿ ❂ ◗ ▼ ✿✜②✚✿✚❩ ✼❋❪ ✎❘❼✁�♣➠❙➄ ➆⑦➆✐➆ ➄✍� ➃ ➂ ❄❉❖ ◗ ♦❋❆✹♦ ▼ ❆

➟ ➍ ❽s ❊✏✇⑥❽

❼ ❙ ✰❫✼✴➂❅➆➎❀❊❉❈ ❃✹❂ ✈ s↕▼ ◗ ❂❘▼✱sts ❆ ❂✼❃✹❯✂❄ ❁❺✿q❆✹♦ ❂ ➐ ▼✤❖✯❃✹❂ ✿❏❆ ❄r❂✼❃ ❁ ❂⑦❄✍❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿q❊✛● ✼ ❁❇✿❋� ➠ ➄ ➆✐➆⑦➆ ➄✏� ➃ ➥ ❈➇♦✣❁ ◗ ♦❱♦ ▼ ➦ ❂☎❂ ❨ ❖ ❁❇➦ ▼✐s❇❂ ✿ ◗ ❂ ◗ s➣▼♥❄✹❄❄❉❖ ✈ ❂✼❃ ❁❇❊ ❃ ❊ ❃✶❂ ❨ ❖✚▼✐s ❆✹❊❷➯✶❼ ❿ ❱ ➁ ➂ ➡✣❈ ✿✼❂✼❃ ❊✢④❵➐ ❂ ❆❋❴✼ ➡ ❂ ❆✹♦ ❂❘❄❉❂✼❃ ❁ ❂⑦❄✍❄ ❊❷❊✏➡✯❆ ▼ ❁❇✿ ❂ ❩ ▼ ✿✚❩q❩ ❂ ✿✯❊✏❆ ❂ ❴➟ ➍ ❼❾❽ ✝ s ❊♥✇■❽ ➂ ❼ ❙ ✰ ❴✼✣➂ ④⑤⑥♦ ❂ ✿ ❁❇❆ ◗ ▼ ✿➲➡ ❂✂❄ ♦✯❊❖❈➇✿ ❆✹♦ ▼ ❆ ❴➟ ❁ ❄❹▼ ✿ ❂ ➆✯✈ ➑✽s ❊✏✇❋● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ➥✍❄ ❊❋❆✹♦ ▼ ❆ ❯ ❊✯❩ ❖✣s ❊ ◗ ♦ ▼ ✿✯✇✛❁❇✿✯✇❵❲ ➥ ❈ ❂q❯✂▼ ❈ ▼✏❄♣❄❉❖✯❯❱❂❈⑥❁❇❆✹♦✯❊ ❖ ❆ s ❊ ❄✹❄ ❊✤●❡✇ ❂ ✿ ❂✼❃❅▼✐s ❁❇❆❉❈❋❆✹♦ ▼ ❆➇➯✶❼✁�♣➠ ➂❜❛ ✂✆✂☎✂ ❛ ➯✶❼✁� ➃ ➂❇❛ ➯✶❼ ❿ ❱ ➁ ➂ ④➎❀❊❉❈✝❁❇❆❀❁ ❄❀❂⑦▼✏❄ ❁ s ❈ ❄❉❂✼❂ ✿➨❆✹♦ ▼ ❆ ❚ ➟ s ❊✏✇◆➟ ✲ ❽ ❚ ➍ ❚ ➟ s ❊✏✇➇➟ ✲ ➐ s ❊✏✇❪➐ ❚ ❈ ❿ ✳✜❯✁❝❞❱ ➁ ➄●➉❊ ❃➫❄ ❊ ❯❱❂✪❄r❖ ❁❺❆ ▼ ➡ s❇❂ ❲✆❡↕④✉❸ ❖ ❆➫➟ s ❊✏✇⑥➟ ▼ ✿✚❩➨❽ ▼✛❃✹❂ ➡✚❊✏❆♣♦ ▼ ✿ ▼✐s ❈❏❆❉❁ ◗ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❁❇✿ ❽q➄ s ❊✏✇⑥❽✝➄ s ❊✏✇ ➋ ❽✝➄✏�✹➠❾➄ ➆⑦➆✐➆ ➄✍� ➃ ➥★❄ ❊❆✹♦ ▼ ❆✤❈ ❂➔❯q❖✚❄ ❆➇♦ ▼ ➦ ❂ ➟ s ❊✏✇◆➟ ➍ ❽✓④ ❸ ❖ ❆❪❆✹♦✣❁ ❄ ❁ ❄ ❁ ❯ ✈✢❊ ❄✹❄ ❁❇➡ s❇❂ ➡✣❈➅➐✢❁❇❊ ❖ ➦✏❁ s➏s❇❂★✽③❄ ❆♣♦ ❂ ❊ ❃✹❂✼❯ ④ ❭➇❂ ✿ ◗ ❂✏➥ ❈ ❂ ❊✏➡✯❆ ▼ ❁❇✿ ❂ ❩❆✹♦ ❂ ❩ ❂⑦❄ ❁ ❃✹❂ ❩ ◗ ❊✏✿✣❆ ❃❅▼ ❩♥❁ ◗ ❆r❁❺❊♥✿✡④✑✓✒✕✔✗✖✙✘✚✔✜✛ ➄ ✢ ✶ ✗ ●✙▲✵● ✂ ✢✙●⑩❘✉P✞✢✿✝➍●✮✥ ◆♠❘✔✝❭❑★P★✲❉●✦✥■☎★✧✆✕✁✢❂✩✤✫❢✭✬P ➢ ✝ ◆✙✢☎P❣✯ ✗ ◆ ➢✔✗ ◆✂❘⑧❑ ❘❢✲✮✧✴☎✷✝➉✢✿✝ ◆ ➢ ✝➉✢â✝ ✗ ●☞◆❄P♦▼✙●✗▲ ❘❙●❭✫❢✭✬P ➢ ✧✝ ◆✖✢★P➍✢❁✫ s ❊✏✇ ➋ ❽ s ❊✏✇ ➃ ❽✠✴

➮✏➅

Page 92: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❳❨✘✜✖❩✖❭❬ ✢ ✇ ❁❇✿ ◗ ❂ ➐ ➍ ❽ ✝ s ❊✏✇❀➐ ➍ ❽ ✝ ❼ s ❊✏✇■❽ ✲ s ❊♥✇ ➋ ➐ ➂ ➥ ❈ ❂ ♦ ▼ ➦ ❂➌ ➍ ❂ ➆✴✈ ➋ ❼❾❽ ✝ ❼ s ❊✏✇■❽ ✲ s ❊♥✇✁�✓➌ ➂✹➂❅➆➎❀❊❉❈ s❺❂ ❆✄✂❨➡ ❂✪▼✏❄ ❈ ❯ ✈✯❆✹❊♥❆❉❁ ◗ ❆✹❊➊➌ ➥✚❄ ❊q❆✹♦ ▼ ❆ s ❊♥✇☎✂ ✲ s ❊♥✇➇➌ ➍✝✆ ❼ ❙ ➂ ④✍⑤⑥♦ ❂ ✿s ❊✏✇☎✂ ✝ s ❊✏✇⑥➌ ➍ ❙ ✰✞✆ ❼ s ❊✏✇ ✳ ➠ ➌ ➂☎➍ ❙ ✰✞✆ ❼ ❂ ➆✯✈★❼✹❼✠✟ ✲ ❙ ➂ ❽ ✝ s ❊♥✇■❽ ➂✹➂ ➄●➉❊ ❃❘▼ ✿✣❈✡✟ ➳

➏ ④ ❭❀❂ ✿ ◗ ❂ ❚ s ❊✏✇ ➋ ✂ ✲ s ❊✏✇ ➋ ➌ ❚ ❛ ❂ ➆✯✈ ✳✜❯✳❱ ➁ ➄●➉❊ ❃❘▼✐s➏s ❲ ➳

➏ ④⑤❸☎❈❋❆✹♦ ❂❪s❇❂✼❯❱❯✂▼ ➥ ❁❇❆⑥●➉❊ s➏s ❊❉❈ ❄ ❆✹♦ ▼ ❆ s ❊✏✇ ➋ ✂ ◗ ▼ ✿✯✿✯❊✏❆❀➡ ❂❱▼ ✿ ❂ ➆✯✈ ➑✽s ❊♥✇❱● ❖ ✿ ◗ ❆❉❁❇❊✏✿✡④ ❭❀❂ ✿ ◗ ❂ ✿ ❂ ❁❇❆✹♦ ❂✼❃ ❁ ❄✂✡④⑤⑥♦✣❁ ❄ ❆✹♦ ❂ ❊ ❃✹❂✼❯ ❄ ♦✯❊❉❈ ❄ ❆✹♦ ▼ ❆❱❆♣♦ ❂➓❄ ◗ ▼✐s❇❂ ❊✛● ▼✱sts❪❂ ➆✴✈ ➑✽s ❊✏✇➲● ❖ ✿ ◗ ❆r❁❺❊♥✿ ❄ ❁ ❄ ✿✯❊✏❆ ❄r❖ ☛❨◗ ❁ ❂ ✿❏❆❲❆✹❊➀❩✣❊ ▼♥❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗

❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄ ❊✤●✍● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ▼✱s ❁❺✿✣➦ ❂✼❃❅❄r❂⑦❄ ④❹⑤⑥♦✣❁ ❄❹❄ ♦✯❊❉❈ ❄ ❆✹♦ ▼ ❆❘❊✏✿ ❂q❂⑦❄✹❄r❂ ✿❏❆❉❁ ▼✐s➏s ❈ ✿ ❂✼❂ ❩ ❄❷❯ ❊ ❃✹❂ ✇ ❂ ✿ ❂✼❃❸▼✐s❦▼♥❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗❄ ◗ ▼✐s❇❂⑦❄✼➥ ❊ ❃❱▼ ✿ ▼✐s ❆ ❂✼❃ ✿ ▼ ❆❉❁❇➦ ❂ ❈ ▼ ❈①❆♣❊ ❃♣❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ▼♥❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗ ❄❉❂✼❃ ❁ ❂⑦❄ ④ P ✿ ❂ ❊✛●❪❆✹♦ ❂ ◗ ▼ ✿✚❩♥❁↕❩ ▼ ❆ ❂⑦❄ ●➉❊ ❃❱❄❉❖ ◗ ♦ ▼ ✿▼✐s ❆ ❂✼❃ ✿ ▼ ❆❉❁❇➦ ❂ ❈ ▼ ❈❲❊✛● ❃♣❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆❉❁❇✿✯✇ ❄❉❂✼❃ ❁ ❂⑦❄ ❁ ❄✉✇ ♦ ▼ ◗ ➔✏❂❸s➏s✥✽③❄ ❆ ❂ ◗ ♦✯✿✣❁♠❨ ❖✯❂ ❊✤●✟✿ ❂⑦❄ ❆ ❂ ❩ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❄ ④✲✴✳✖✵✷✶✖✳✖✸✺✹✼✻✔✽✿✾✞❀❂❁❃✁❄❆❅➢❒❙●✉❋✦❋✮●■❏✚◆◗ß➼●■♦✁❪▼❤ Ò❺❘✓❱❺❜✔❉✺❋➇❒❙▲✏❉✿❉✦●■❪❴◆➉❒❦❜✔❏▼❪❑▲t❉➛➒❦❘✓❱❲❘❂❳ ❇Ñ❉✿●■r➜❜✔❝✁➐t▲✏❍❑♦✁❪▼❤✿❫➜❥✙▲t❍➵♠❆▲✏❫❴s✦❡✿❪❑♦✁❉✿➐✪❏▼✐✮❫➸q✺▲t❝❢♦♥♠✴❝✁♦❢❫➙♦✁❪❑❏❙❡✿❏➉➴♦✁❉✿➐❴❤✦♦❢●❲❍♣❜✔❍✆♠▼❤✿♦♥♠■❜✔❝❧❏▼●■❍❑♦✁●■❏❨❘✣ä➉❉➏❒❙♦♥❜✔❉✿❉✿♦Õ◆◗➞☞❘✓❱❙◆✖●✉❋✮♦✁❪❑▲t❍♣❱❲❿❧Ð✺❾✔➽➸❻✆✇✔⑤❶⑩✙↔➸④✔③✺❸Ï⑧❙⑤✓➚✏❷✉❻❲②♣④❞⑩✙↔➙❰❣✇✔➽➼⑨✺①t❼❑④❨❼➉⑩✙✇✔③✿❘❮æ✍❷✆↔❆❼◗①✮②♣❷✴ç❦✇❨❼❑❷✆➣❺⑩♥③❰❣✇✔➽➼⑨✺①t❼❑❷■②➢ÐØ↔■⑩✖❷■③✺↔✆❷❲❿✿❵t▲✏❝➉❘➌➄ ➷ ➮✦❿✮s✿s✞❘✮➯ ➣ ➬❨❳✮➯ ➣✏➷ ❘✔❳➧➎❛●❲r➭➫❣▲✏❍▼➋Ø❿✣➀❨➁✏Ót➁✿❘✮➞☞❍❑▲✿♠✆●■●❨❋✮♦✁❉✿➐✏❏➼ä❑➟✿➟✮❇❊P❙Ú✓➮✏➮✦❿✿➶❛▲✏❫➙●✏❘❃✓➅➆❅➢❒❙▲t❉✿❉✿●■❪❺◆◗❒✴❜✔❏❑❪▼▲✏❉➏➒❦❘✓❱❊❜❞❉✺❋✜❒❙❍❑❡✿❉✮❪▼➺❴◆➉➘❊▲t❫❴♦✁❉✿♦✁➋✿❱■❘t❳ëæ☞⑩♥➽↕⑩❽❼❦❰❣✇✔➽➼⑨✺①t❼⑦④➆❼◗⑩✖✇✔③➏⑩♥③➇❰❣✇✔➽➼⑨✺①t❼❑❷■②❦⑧❙⑤ ➚❞❷❨❻■②✆④✔❘➱❳❯➪✷●❨♠❑❤✦❉✿♦♥♠■❜✔❝➶❛●❲s✺▲t❍❑❪❊❉✦➹✿❄✉➮ → ❿✿❩☞➪❊➒❦❿✼ê✌☞❡✿❍❑♦♥♠▼❤✞❿✼➎❛▲✔❵✏●❲❫➸q✺●■❍❙➀✉➁t➁✏➠✦❘❃✓➄➆❅➢➒❊❜❞❍♣❋✮✐❖◆◗❒➸❘✼➒❦❘✓❱■❘t❳ ➻❛②♣❸t❷■②✆➣❦✇➉⑥❊➤❲③■➔❧③✿⑩❽❼◗❾✔❘✦❳➧P❛❜✔❫➸q✿❍▼♦❽❋➱➐✏●❊✃❛❉✦♦❢❵t●■❍❑❏▼♦✁❪➉✐❬➞☞❍▼●■❏❑❏❨❿❧➀✉➁✦➀✉➃✿❿❂❰❣④✔➽➸❻❲②■⑩✙❸❨➚✏❷➙➥✺②✆④✏↔❆❼✙➣❙⑩♥③✚ïâ④❨❼✖➦➱❷✎✍➽➸④❨❼➉⑩✙↔✆➣■❿✮❵t▲✏❝➉❘✣❄✉➅✦❘❃ ➯❞❅➢➒❊❜❞❍♣❋✮✐ì◆◗❒➸❘✞➒✴❘✓❱■❘✦❳✄➟✮▲✏❫➙●❦❍❑●❲❏❑❡✿❝✁❪❑❏❺♠✆▲✏❉✺♠❆●■❍❑❉✿♦✁❉✿➐❖❪❑❤✿●❺q✺●❲❤✺❜❨❵✮♦❢▲t❡✿❍❦❜✔❪❙♦✁❉✮×✺❉✿♦✁❪➉✐✚▲✔❥❛❜❴❍▼●✉❜✔❝➊❜✔❉✺❋✜♠✆▲✏❉✮❪▼♦❢❉✮❡✿▲t❡✿❏❙❏❑▲t❝❢❡✦❪❑♦✁▲✏❉▲✔❥❧❜✔❉✪❜✔❝✁➐t●■q✿❍♣❜❞♦♥♠❊❋✮♦❶Ù✣●■❍❑●■❉✮❪▼♦❽❜❞❝✞●✉Üt❡✺❜❞❪❑♦✁▲✏❉➙▲✔❥☞❪❑❤✿●➼×✺❍▼❏❑❪❊▲t❍♣❋✮●❲❍✉❘✣❹➊②♣✇❨↔♣❷✆❷✆❸✔⑩✥③✮➚✉➣❦✇➉⑥❙❼✖➦➱❷➢æ✞✇✔③✺❸t✇✔③✚ïâ④❨❼✖➦➱❷❲➽➸④❨❼➉⑩✙↔✆④✔⑤✣Ð✣✇✉↔❲⑩✙❷❆❼◗❾✔❿❵✏▲t❝➉❘✣❄✉➬✿❿✣➀❨➁✿➀t➀✏❿ts✿s✞❘✮➯ ➷ ❄✆❳✮➯➌Ô✏➮✦❘❃ ➷ ❅➢é✣♦✁▲t❡✿❵✮♦❢❝✁❝✁●➼◆✙➲✺❘✓❱❲❘t❳❖➟➱❡✿♦✁❪❑●❈❋➱❡❬➳✑✏●■❫➙▲✏♦✁❍❑●❛❏▼❡✿❍➊❝❽❜✴♠✆❝♥❜✔❏❑❏▼♦❶×Ø♠■❜✔❪▼♦✁▲✏❉❬❋➱●■❏❛❪❑❍✆❜✔❉✿❏✆♠✆●■❉✺❋✿❜❞❉✮❪❑●■❏➼●■❪❣❏▼❡✿❍➊❝❢●❲❏❛❍♣❜✏♠❆♦❢❉✦●■❏è❋➱●➢♠❆●■❍❑❪✆❜✔♦✁❉✿●■❏

✏●✉Üt❡✺❜❞❪❑♦✁▲✏❉✿❏➸●❲❉➏❥✙▲t❉✺♠✆❪❑♦✁▲t❉➏×✺❉✿♦✁●➙●✆❭✿s✿❝✁♦❽♠❆♦❢❪▼●✪❋✮●■❏❴♠✆▲✮●✓✒❬♠✆♦✁●■❉✮❪▼❏✉❘❈✈✮✇❞①➌②❲③✺④✔⑤❊❸t❷➙ïâ④❨❼✖➦✕✔❷❲➽➵④➆❼◗⑩✗✖❲①✿❷✆➣✚❹❣①✮②✆❷✆➣❬❷❆❼❈⑧❛⑨t⑨✺⑤❶⑩✗✖■①✘✔❷❨❷✆➣■❿❵✏▲t❝➉❘✿➄✿❿✣➀✉Ótð✏Ó✦❿✏s✿s❂❘ ➷ ➅t➄❨❳ ➷ ➯➌Ô✦❘❃✓Ô➆❅➢➟✿❜❞❝❢❵✮✐➙◆◗➈Õ❍❑❡✿❉✦▲➌❱■❘➱❳â⑧❙➣■❾✔➽❊⑨✦❼⑦✇➆❼◗⑩✙✖■①✿❷❺④✔①t❼⑦✇❞➽➵④➆❼◗⑩✙✖■①✿❷❦❷❆❼✺⑥✉✇❞③✺↔✆❼➉⑩✙✇❞③✮➣❙➚✚✔❷❲③✛✔❷❲②♣④❨❼➉②■⑩✙↔✆❷❆➣■❘❨❳✬➞☞❤✞❘✿➘❺❘t➪❛❤✿●■❏▼♦❢❏❨❿ ✏❩❧♠✆▲t❝❢●❙s✼▲✏❝✁✐✮❪❑●✉♠▼❤✮➴❉✿♦♥Üt❡✿●✏❿❂➀✉➁✏➁✦➀✏❘❃ → ❅➢➟✿❜❞❝❢❵✮✐✚◆➉➈❧❍▼❡✿❉✿▲➌❱❛❜❞❉✺❋❴➟➱❤✺❜✏♠▼➋✏●❲❝❢❝☞◆✖➲✏▲t❤✿❉✺❱■❘➱❳â❇❊❏▼✐✮❫❴s✿❪▼▲✏❪❑♦♥♠➩●✆❭✿s✺❜✔❉✿❏▼♦✁▲✏❉✿❏➊▲✔❥❂❥✙❡✿❉✺♠✆❪▼♦✁▲✏❉✺❜❞❝✣♦❢❉✮❵t●■❍❑❏▼●■❏✉❘✦ä➉❉❴❚➧❜✔❉✦➐➸◆◗➞☞❜✔❡✦❝✞➟✣❘✓❱◆✙●❨❋✮♦✁❪❑▲✏❍✆❱■❿➩Ð✺❾✔➽➵❻✆✇❞⑤✰⑩✙↔✚④✔③✼❸✚⑧❙⑤✓➚✏❷✉❻❲②♣④❞⑩✙↔✚❰❣✇❞➽❊⑨✼①✏❼❑④❨❼➉⑩✙✇❞③✿❘✞s✦s✞❘❣❄❨➄✏➬➆❳Ø❄✉➄ → ❘✼❳➜❇❊P❛➳ ➞❮❍❑●■❏▼❏✉❿❊➀❨➁✏➁t➠✿❘✞➞☞❍▼▲✿♠✆●■●✉❋✮♦✁❉✿➐t❏➸▲✔❥❊ä❑➟t➴➟✮❇❊P❙Ú ➣ ➅✦❿✿➈❧●❲❍❑➋✏●❲❝❢●❲✐➌❿✦➲✏❡✿❝✁✐â❄ ➣✗➣ ➅✿❘❃✓➮➆❅➢➟✮❤✺❜t♠▼➋✏●■❝✁❝➊◆✙➲t▲✏❤✿❉✺❱❲❘✦❳ ❒❙❍▼▲✔r❛❪❑❤✪●❲❏❑❪❑♦✁❫✚❜✔❪❑●❲❏❛❥✙▲t❍❊●✆❭✿s✮➴➉❝✁▲✏➐❺❥✙❡✿❉✼♠✆❪❑♦✁▲✏❉✦❏✉❘❧✈✮✇✔①✮②■③✺④❞⑤❮✇⑦⑥❦Ð✼❾✔➽➵❻✆✇✔⑤❶⑩✙↔✚❰❣✇❞➽❊⑨✼①t❼⑦④➆❼◗⑩✙✇❞③✿❿✼❵✏▲t❝◗❘❂❄✉➬✦❿➘➼●✉♠✆●■❫➸q✼●■❍❺➀✉➁✏➁t➃✿❿ts✿s✞❘✿Ô✦❄✏❄✆❳✿Ô✏➄t➅✿❘❃ ➣ ❅➢➟✮❤✺❜t♠▼➋✏●■❝✁❝❧◆✖➲✏▲t❤✿❉✺❱■❘t❳➛é✍♦✁❫❴♦✁❪❑❏❧▲❞❥❮é✍♦❢▲t❡✿❵✮♦✁❝❢❝✁♦♥❜✔❉✴❥✙❡✿❉✼♠✆❪❑♦✁▲✏❉✦❏✉❘t❳➧➞☞❍❑●■s✦❍❑♦✁❉✮❪✉❿☞➀✉➁t➁✿➀✏❘❃✁❄✉➬➆❅➢➟✮❤✺❜t♠▼➋✏●■❝✁❝☞◆✙➲t▲✏❤✿❉✼❱■❘t❳âä➉❉✮❵✏●❲❍❑❏❑●❲❏❊▲✔❥✷➒➼❜✔❍✆❋✮✐❬éØ➴✙❥✙❡✦❉✺♠✆❪❑♦✁▲t❉✿❏✉❘✢✜è①✮⑤♥⑤✁❷✆❼➉⑩♥③✪✇➉⑥➼❼✖➦➱❷➢æ✍✇❞③✺❸✏✇❞③✚ïâ④❨❼✖➦➱❷❲➽➵④➆❼◗⑩✖↔♣④❞⑤✼ÐØ✇❨↔■⑩✙❷❆❼➉❾✔❿✮❵✏▲✏❝➉❘✮➅ ➷ ❿➀✉➁t➁✏ð✦❿✮s✿s✞❘✣❄ ➷ ➬❨❳✣❄ ➷ Ô✦❘❃✁❄✏❄❆❅➢➟✮❤✺❜t♠▼➋✏●■❝✁❝☞◆✙➲t▲✏❤✿❉✼❱■❘t❳➧➶❛▲✏❏▼●■❉✿❝✁♦♥♠▼❤➌❪Õ×✺●■❝♥❋✮❏❨❘❧➥✼②♣④✔③➱➣❲④t↔✆❼➉⑩✙✇❞③✮➣➢✇⑦⑥❙❼✙➦✿❷❛⑧❙➽➸❷■②■⑩✖↔♣④❞③➙ï❖④➆❼✙➦✿❷■➽➸④❨❼➉⑩✙↔✆④✔⑤✼Ð✣✇✉↔❲⑩✙❷❆❼◗❾✔❿✦❵✏▲✏❝➉❘✮➄✏➄ ➷ ❿t❉ ➹ ➅✦❿➀✉➁t➁✏ð✦❿✮s✿s✞❘ ➷✗→✙➣ ❳ ➷✗➣✏➷ ❘❃✁❄✉➅➆❅❈❵✏❜✔❉✚❋✮●■❍❛➒❛▲✮●■❵t●■❉✜◆✙➲✺❘✓❱❲❘✔❳✬⑧➢➣■❾✔➽❊⑨✦❼⑦✇➆❼◗⑩✗✖❲①✿❷❦④✔①t❼❑✇✔➽➸④❨❼➉⑩✗✖❲①➱❷❲❘t❳✬➞☞❤✼➘➭❪❑❤✿●■❏▼♦✁❏✉❿ ✏❩❧♠✆▲t❝✁●❈➞❂▲✏❝✁✐✮❪❑●✉♠▼❤✿❉✦♦❽Üt❡✿●t❿✿➡✿❍✆❜✔❉✺♠✆●t❿✞➀✉➁t➁✏❐✦❘✔ä➉❉s✿❍▼●■s✺❜✔❍✆❜✔❪▼♦❢▲t❉✞❘

➮✏➄

Page 93: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➮✔➯

Page 94: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�❹✕★✥✛✌✂✁

✄❬✒☎✕★✠➉✬✆☎✛✎✝☎❋✞★✧✞✄ ✠✝✟✡✞✡✥♥✎➉✌✏✁✆✠✡☎❲✕★✒■✫☞☛①✕✢✌✏✕ ✆✶✌✏✥✏☛■✜✣✌✏☛■✥♥✄✌☎

Page 95: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 96: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ☎✱✎☞✒✆✟✂✁✍☛■✒☎✜✣✌✏✎✑✞✡✒☎✕ ✠ ✄ ✒☎✕ ✠ ✬✆☎✛✎✝☎❋✎✑✒ ✄☎✄❡✄✚✥♥✕ ✟✓✄✝✗✂✕ ☎✛✄ ✄ ✒■✕★✠ ✬✆☎✱✎ ☎✝✆✌✏✁■✄✟✞✡✠■✕ ✠☞☛☎✠✑✄ ✞★✧➔✌✤✁☎✄✍✌①✕★☛✆☎ ☎✏✎ ✄✢✫■☛■✜✣✌✏✎☞✞✡✒ ✄ ✠ ✟✡✞✡✥✏✎ ✌✤✁ ✠

✑✓✒✕✔✗✖✘✔✚✙✛✙♣✺✢✜✍✵✛✻↕✻✤✣✺✛✺✾❀✿✣❁❇➦ ❂✼❃❅❄ ❁❇❆✦✥❂ ❩ ❂❱❑◆▼✤❂ ✿❅ ▼ ❈ ❙✏✯✯➥★❙✏✱✿✱✿✯

❚ ❄❉❖✯❯❱❯❲▼✛❃ ❈❱➡✣❈✬✑✟❁ ❂✼❃✹❃✹❂ ➎♠❁ ◗ ❊✴❩★✧❂✼❯❱❂ ❫❴➸✵✡❵✹❛❨✻✔✽❏❜❝❛

➪❛❤✦●❊❒❦❜✔❡✿❏▼❏❑♦♥❜✔❉❴❜❞❝✁➐✏▲✏❍▼♦✁❪❑❤✿❫ ❫✚❜❨✐❈q✼●❊❵✮♦✁●■r➊●✉❋➸❜✔❏➊❜➼❥✙▲✏❍▼❫❬❜❞❝✏➐✏●❲❉✿●■❍♣❜❞❝✁♦❢➺❨❜✔❪❑♦✁▲t❉➸▲✔❥✣❪❑❤✿●❙❩☞❡✺♠✆❝✁♦♥❋✮●✉❜❞❉❴❜✔❝✁➐✏▲❞➴❍❑♦✁❪❑❤✿❫✜Ö✿♦✁❪✣❡✿❏▼●■❏❧❜✔❉❦●✆❭✿❪▼●■❉✿❏❑♦✁▲t❉❦▲✔❥✿❪❑❤✦●❧❍❑●✉❜❞❝✮❏❑❤✿♦❶❥✙❪✣▲ts✺●■❍✆❜✔❪▼▲✏❍✪✩➏❡✿❏❑●✉❋➢❥✙▲t❍✞♠✆▲✏❉✮❪❑♦✁❉✮❡✿●✉❋❈❥✙❍♣❜t♠✆❪❑♦✁▲✏❉✦❏✉❘❂❚➏●✷❏▼❪❑❡✺❋➱✐❪❑❤✿●❺❍♣❜❞❉✺❋✮▲✏❫✘❵✏❜✔❍▼♦❽❜❞q✿❝✁●✬✫❑❉✮❡✿❫➸q✼●■❍➼▲✔❥❛♦❢❪▼●■❍♣❜❞❪❑♦✁▲✏❉✦❏✮✭✬✯❛❿❂r❛❤✿●■❉✜❪❑❤✿●➸♦✁❉✿s✿❡✦❪➢❋✦❜✔❪♣❜✚❜❞❍❑●❴❋✮♦✁❏❑❪▼❍❑♦✁q✿❡✿❪▼●✉❋➏❜✔❝✁▲t❉✿➐❜✔❉➸♦✁❉✿♦✁❪❑♦♥❜✔❝✣❋✮●■❉✦❏❑♦✁❪➉✐➌❿✮❜✔❉✼❋➸r➊●➢❋➱●■❏♣♠✆❍▼♦✁q✺●❦❪▼❤✿●❊●❲❵✏▲✏❝✁❡✿❪▼♦✁▲✏❉❴▲❞❥✞❪❑❤✿●❦❋✿❜❞❪♣❜✴r❛❤✿♦✁❝✁●❛s✿❍❑▲✿♠✆●■❏▼❏❑♦✁❉✿➐➙❪❑❤✿●❦❜✔❝✁➐t▲✏❍❑♦✁❪▼❤✿❫â❘➪❛❤✿●❛❍❑●■❏▼❡✿❝✁❪❑❏❛❡✿❏▼●❊❏▼s✺●✉♠❆❪❑❍♣❜❞❝✣s✿❍❑▲ts✺●❲❍❑❪❑♦✁●■❏❛▲❞❥✍❜❈❥◗❜✔❫➙♦❢❝✁✐➼▲✔❥✷➶❛❡✦●■❝✁❝❢●❆➴⑦➳✪❜❨✐t●■❍❧▲ts✺●■❍✆❜✔❪▼▲✏❍❑❏✱✰✳✲✓✫❑♦✁❉✮❵✏●❲❍❑❪❑♦✁❉✿➐✴✭❙❪❑❤✿●❏❑❤✿♦❶❥✙❪➊▲✏s✼●■❍♣❜❞❪❑▲t❍✵✩↕❘☞➪❛❤✿●❙▲✏s✼●■❍♣❜❞❪❑▲t❍➊❥◗❜✔❫➙♦❢❝✁✐✵✰✳✲➼❋✮●✆×✺❉✦●■❏❈❜✴❡✿❉✿♦❶❥✙✐✮♦✁❉✿➐✴❥✙❍♣❜❞❫❴●■r➊▲✏❍▼➋➵❜❞❝❢❝✁▲✔r❛♦✁❉✿➐❦❜❺♠✆▲✏❫➙❫❴▲✏❉❜✔❉✺❜❞❝❢✐✮❏▼♦❢❏❛▲❞❥❣q✼▲✏❪❑❤✜❩☞❡✺♠✆❝✁♦♥❋â❜❞❉✺❋✪❒❦❜❞❡✿❏❑❏❙❜✔❝✁➐✏▲t❍❑♦✁❪❑❤✦❫❴❏✉❘➩➪❛❤✿♦✁❏❊r➊▲✏❍❑➋✚♦✁❏❈❜➙➐t●■❉✿●■❍✆❜✔❝✁♦✁➺✉❜✔❪▼♦❢▲t❉✚▲✔❥è❜➙♠✆▲✏❫➙❫❴▲✏❉r❣▲t❍❑➋➸r❛♦✁❪❑❤✪➒❛●❲❍❑❵✚✏●↕➘❙❜✔❡✺❋ ✏●➢❜❞❉✺❋❴➞❮❤✿♦✁❝❢♦✁s✿s✼●❦➡❂❝❽❜❲➑✆▲✏❝✁●■❪❙❃✓➅❲❅⑦❘

❢♦❴✌❊❍●✴❣✷✶❷❥✡❧★❧❄♣❖⑨q❣❍t★❤✼t★❤ ⑨✹✸❹t★❥✝❶✗❶✙♣✂t★❤✈t♦❧✗✺♦❞✴❥ ♣♠r❖●✺♥ ❶✇ ❆ ▼✛❃ ❆❉❁❇✿✯✇❱● ❃ ❊ ❯ ▼→s↕▼ ❆✹❆❉❁ ◗ ❂ ❁❇✿①❩♥❁ ❯➈❂ ✿ ❄ ❁❇❊✏✿ ➄ ➥✤✻ ➍✽✼ ➂✿✾ ✼❁❀ ➥ ❈♠❁❺❆♣♦➂ ➄ ❀✌❪❃❂ ✿✯❊✏❆ ◗ ❊ s➏s ❁❇✿ ❂⑦▼✛❃⑦➥ ❆♣♦ ❂✬❄➫▼✤❖✚❄✹❄ ❁ ▼ ✿

▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ②✚✿✚❩ ❄➇▼q❯ ❁❇✿✣❁ ❯✂▼✐s ➡ ▼✏❄ ❁ ❄ ❼ ✟ ➄✛❅ ➂ ❁❺✿❋❆♣♦ ❂❹❄❉❂ ✿ ❄❉❂ ❆♣♦ ▼ ❆⑥❆✹♦ ❂ ❆ ❃ ❁ ▼ ✿✯✇ s❇❂ ➡ ❖ ❁ s ❆❷❊✏✿ ❼ ✟ ➄✕❅ ➂ ♦ ▼✏❄ ✿✯❊❱❊♥➡✯❆ ❖✚❄❉❂▼ ✿✯✇ s❇❂ ④❷⑤⑥♦ ❂ ✈ ❃ ❊✏➡ s❇❂✼❯ ❁ ❄ ❁❇✿❏➦ ▼✛❃ ❁ ▼ ✿✣❆❷➡❏❈ ❄ ❁ ❯ ❁ s ❁❇❆ ❖ ❩ ❂

➂❃❆❇❉❈♦➂➥ ❈⑥❁❇❆✹♦

❈ ❪✷❂ ➥■▼ ✿✚❩➊❆✹♦ ❂✼❃✹❂ ●➉❊ ❃✹❂ ❆✹♦ ❂ ✈ ❃ ❊✏➡ s❇❂✼❯ ❊✏✿❼ ➂ ➄ ❀ ➂ ❁ ❄➇❂ ❨ ❖ ❁❇➦ ▼✐s❇❂ ✿✣❆❷❆✹❊q❆✹♦ ❂ ✈ ❃ ❊✏➡ s❇❂✼❯ ❊✏✿ ❼ ❙ ➄ ❀ ✝ ➂ ➂ ④✡⑤⑥♦ ❂ ❆ ❃ ❁ ▼ ✿✯✇ s❇❂ ➡ ❖ ❁ s ❆❷❊✏✿ ❼ ❙ ➄ ✼✣➂ ♦ ▼♥❄ ✿✯❊❱❊✏➡✯❆ ❖✚❄r❂❹▼ ✿✯✇ s❇❂⑦❄ ❁ �✼❋❪❋❊❍●❃■ ➥ ❈➇♦ ❂✼❃✹❂ ❊✝➍☞❏❉✼ ➄ ➏▲❑◆▼ ✼ ❑ ❙P❖❏➥✯▼ ✿✚❩ ■ ❁ ❄ ❆✹♦ ❂ ❩♥❁ ❄✵➔ ❊✤●❦❩♥❁ ▼✛❯❱❂ ❆ ❂✼❃ ❚ ➏ ➄ ❙ ❫✑④

◗❙❘❯❚❙❱❀✘✚✔❳❲ ✢ ➌ s↕▼ ❆✹❆❉❁ ◗ ❂ ▼ ✿✚❩✉❆❁❈⑥❊ ❊✛●❘❁❇❆ ❄ ➡ ▼✏❄❉❂⑦❄➈❃✹❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ❂ ❩✉➡✣❈✦❆✹♦ ❂ ✈ ▼✛❃❸▼✐s➏s❺❂❸s ❊✏✇ ❃❅▼✛❯ ❆✹♦ ❂ ❈❄ ✈ ▼ ✿✡④■⑤⑥♦ ❂ ② ❃❅❄ ❆➇➡ ▼♥❄ ❁ ❄ ❁ ❄❘❄✵➔♥❂ ❈ ➥ ❆✹♦ ❂✪❄❉❂ ◗ ❊♥✿✚❩❲❊✏✿ ❂ ❁ ❄❀❯ ❁❇✿✣❁ ❯❲▼✐s ❼ ❃✹❂ ❩ ❖ ◗ ❂ ❩ ➂ ④

⑤⑥♦ ❂▲❄➫▼✛❖✚❄♣❄ ❁ ▼ ✿ ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❁ ❄ ❆✹♦ ❂ ◗ ❊ ❯ ✈✢❊ ❄ ❁❇❆❉❁❇❊✏✿❋❊✛● ▼✪❄r❖ ◗✼◗ ❂⑦❄✹❄ ❁❇❊✏✿➓❊✤●▲❆ ❃❅▼ ✿ ❄ ●➉❊ ❃✹❯✂❄ ❊✛●❡❆❁❈⑥❊❹❆❉❈✣✈ ❂⑦❄✔✎❩❨❭❬❫❪ ❁❇✿❏➦ ❂✼❃ ➑❄ ❁❇❊✏✿❃❴ ❈⑥❁❇❆✹♦❃❴☎❼ ✼✣➂✍➍ ❙ ✝ ✼ ➥❵❨✮❬❯❬❛❪ ❆ ❃❸▼ ✿ ❄☞s↕▼ ❆❉❁❇❊✏✿❝❜❩❞ ➃ ❈⑥❁❇❆✹♦✢❜❷❼ ✼✴➂✍➍ ✼❢❡ ❙ ④❦➞✖❁❇❆✹♦✷❣⑧❼ ✼✣➂✍➍ ❙ ✝ ✼❁● ✠ ▼ ❼ ❙ ✝ ✼✣➂➉✌ ➥ ❆✹♦ ❂❄➫▼✤❖✚❄✹❄ ❁ ▼ ✿ ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❆ ❂✼❃✹❯ ❁❇✿ ▼ ❆ ❂⑦❄ ❈➇♦ ❂ ✿ ❂ ➦ ❂✼❃ ❣✿❤✐❼ ✼✣➂❙❪❝❊✷●✏■ ④ ➌ ✈✯✈ s ❈♥❁❇✿✯✇ ▼q❄❉❖ ❁❇❆ ▼ ➡ s❇❂ ❆ ❃❅▼ ✿ ❄ ●➉❊ ❃✹❯ ❜ ❞ ➃ ❈⑥❁❇❆✹♦▼ ◗ ❖ ❆ ❂ ➡ ▼♥❄ ❁ ❄✼➥✚❄ ❊❱❆♣♦ ▼ ❆

▼ ❼ ✼✴➂❇☛ ➏➥ ❁❇❆➇❁ ❄⑥❃✹❂⑦▼ ❩♥❁ s ❈ ❄❉❂✼❂ ✿❋❆✹♦ ▼ ❆⑥❁❇❆ ❄r❖ ☛❨◗ ❂⑦❄ ❆♣❊ ◗ ❊♥✿ ❄ ❁↕❩ ❂✼❃ ◗ ▼✏❄❉❂⑦❄ ❈➇♦ ❂✼❃♣❂ ✼❋❪✢■ ④⑤⑥♦ ❂❝❄➫▼✤❖✚❄✹❄ ❁ ▼ ✿ ▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯ ●➉❊ ❃➇s↕▼ ❆♣❆❉❁ ◗ ❂✪❃♣❂ ❩ ❖ ◗ ❆❉❁❇❊✏✿➨❁ ❄➔▼ ✇ ❂ ✿ ❂✼❃❅▼✐s ❁❥✐ ▼ ❆❉❁❇❊✏✿①❊✛●■❆♣♦ ❂ ❻ ❖ ◗ s ❁↕❩ ❂⑦▼ ✿ ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ●➉❊ ❃❦ ✿✚❩♥❁❇✿✯✇❋❆✹♦ ❂ ✇ ◗ ❩❲❊✛●✍❆❁❈⑥❊❹❁❇✿✣❆ ❂ ✇ ❂✼❃❅❄ ❁❺✿➨❆✹♦ ❂ ●➉❊ s➏s ❊❖❈⑥❁❇✿✯✇✌❈ ▼ ❈ ✎

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Page 97: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❻ ❖ ◗ s ❁➣❩ ❄➫▼✛❖✚❄✹❄❑ ❊♥✿❏❆❉❁❇✿ ❖✯❂ ❩ ✫ ❃❅▼ ◗ ❆❉❁❇❊✏✿ ❄ ➐ ▼ ❆♣❆❉❁ ◗ ❂✁�⑥❂ ❩ ❖ ◗ ❆❉❁❇❊✏✿➌ s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ✣✑✿✯✈ ❖ ❆ ✎ ❽ ❪ ❚ ➏ ➄ ❙ ❚ ❁❇✿✯✈ ❖ ❆ ✼❋❪✢■ ➍ ❩♥❁ ❄ ◗ ❊✛●✟❩♥❁ ▼✛❯❱❂ ❆ ❂✼❃ ❚

➏ ➄ ❙ ❚❈➇♦✣❁ s❇❂ ❽✄✂➍ ➏ ❈❀♦✣❁ s❇❂ ✼❋❪❋■❩✣❊✂❽ ➍ ❙ ✝ ❽ ● ✠ ❙ ✝ ❽ ✌ ❩✣❊ ✼q➍ ❙ ✝ ✼❩● ✠ ▼ ❼ ❙ ✝ ✼✣➂➉✌

⑤ ❂✼❃✹❯ ❁❺✿ ▼ ❆❉❁❇❊✏✿ ❆ ❂✼❃✹❯ ❁❇✿ ▼ ❆ ❂⑦❄ ❊✏✿ ⑨ ❆ ❂✼❃♣❯ ❁❇✿ ▼ ❆ ❂⑦❄ ❊✏✿ ❂✆☎❁❏ ❶ ☎ ⑨ ❖❈➇♦ ❂ ✿➓❆✹♦ ❂ ❁❇✿✯✈ ❖ ❆❪❁ ❄ ❁❇✿ ❶ ❈➇♦ ❂ ✿➨❆✹♦ ❂ ❁❇✿✯✈ ❖ ❆❪❁ ❄ ❁❇✿ ❂➞ ❂q▼✛❃✹❂ ❁❇✿✣➦ ❂⑦❄ ❆❉❁❇✇ ▼ ❆❉❁❇✿✯✇ ▼ ✇ ❂ ✿ ❂✼❃❅▼✐s ❁❥✐ ▼ ❆❉❁❇❊✏✿ ❊✛● ▼ ✈ ❃ ❊✏➡ s❇❂✼❯ ❄❉❂ ❆❪➡❏❈ ❄❷▼✛❖✚❄✹❄❪▼✛❃ ❊ ❖ ✿✚❩ ❙✞✝ ➏★➏ ●➉❊ ❃ ❆♣♦ ❂ ❻ ❖ ◗ s ❁↕❩ ❂⑦▼ ✿▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯➧✎✍❄ ❆ ▼✛❃ ❆r❁❺✿✯✇ ❈⑥❁❇❆✹♦ ▼ ❩ ❂ ✿ ❄ ❁❇❆❾❈❲➟❋❊✏✿ ❚

➏ ➄ ❙ ❫ ➥ ❈➇♦ ▼ ❆✍❁ ❄ ❆✹♦ ❂ ❩ ❂ ✿ ❄ ❁❇❆❉❈✠✟ ❤ ❚ ➟✢❫ ▼ ●➉❆ ❂✼❃ ✺✪❁❺❆ ❂✼❃❅▼ ❆❉❁❇❊✏✿ ❄ ❊✛● ❣ ➥ ❈⑥❁❇❆✹♦❣❷❼❉❽ ➂✍➍ ❙ ✝ ❽ ● ✠ ❙ ✝ ❽ ✌ ④■⑤♠♦ ❂ ✈✢❊ ❄✹❄ ❁❇➡ s❇❂❱▼ ✿❏❆ ❂ ◗ ❂ ❩ ❂ ✿❏❆ ❄ ❊✛●✍❽ ▼✛❃✹❂ ❊✛●❡❆✹♦ ❂ ●➋❊ ❃✹❯ ❙ ✝ ❼ ✟✹❡ ❽ ➂ ➥ ❈⑥❁❇❆✹♦ ✟ ☛ ❙✏➥✯▼ ✿✚❩✡✟ ❤▼ ✿✚❩☛✟ ❤✌☞ ➠ ▼✛❃✹❂ ◗ ❊♥✿✯✿ ❂ ◗ ❆ ❂ ❩❋➡✣❈ ✟ ❤✌☞ ➠ ❚ ➟✢❫➉❼❾❽ ➂❡➍ ❼➃✎✍ ➠ ❙❼ ✟ ❡ ❽ ➂ ➋ ✟ ❤ ❚ ➟✢❫✑✏ ❙✟ ❡ ❽✓✒ ➆❼ ❙ ➂✣✑✿✣❆ ❃ ❊✯❩ ❖ ◗ ❁❇✿✯✇✂❆♣♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃✕✔⑥➥ ❩ ❂ ❦ ✿ ❂ ❩➨➡❏❈

✔ ✲ ❚ ➟✢❫➉❼❾❽ ➂✍➍ ❼➃✎✍ ➠ ❙❼ ✟ ❡ ❽ ➂ ✲ ➟ ✏ ❙✟ ❡ ❽ ✒ ➄❼ ➄✣➂

❯✂▼ ✿✣❈❹✈ ❃ ❊✏✈ ❂✼❃ ❆r❁ ❂⑦❄ ❊✛●★❆✹♦ ❂ ❻ ❖ ◗ s ❁↕❩ ❂⑦▼ ✿ ▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯ ◗ ▼ ✿❱➡ ❂❪❂ ➆✴✈ ❃♣❂⑦❄✹❄❉❂ ❩➔❁❇✿❲❆ ❂✼❃✹❯✂❄ ❊✛● ❄ ✈ ❂ ◗ ❆ ❃❅▼✐s✗✖♥❖✚▼ ✿✣❆❉❁❇❆❉❁ ❂⑦❄☎❃✹❂❸s↕▼ ❆ ❂ ❩❆✹❊❲❆✹♦ ❂ ❊✏✈ ❂✼❃❸▼ ❆✹❊ ❃✁✔ ✲ ❼✁❈⑥❁❇❆✹♦✄✘ ◗ s ❊ ❄r❂ ❆♣❊ ➄✣➂ ✎ ❆♣♦ ❂✪❂ ➆✣❁ ❄ ❆ ❂ ✿ ◗ ❂ ❊✤● ▼→s ❁ ❯ ❁❇❆❱❩ ❂ ✿ ❄ ❁❇❆❉❈✙✟✛✚ ❚ ➟✢❫➉❼❉❽ ➂⑥➍ ➠✜ ✢✤✣ ➋ ➠➠ ☞ ➁ ◗ ❊ ❃✹❃✹❂⑩➑❄ ✈✢❊✏✿✚❩ ❄ ❆✹❊❱❆✹♦ ❂ ❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❂ ❁❇✇ ❂ ✿✣➦ ❂ ◗ ❆✹❊ ❃ ❊✛● ✔ ➋➔❼✁❈♠❁❺❆♣♦ ❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂ ❈ ➍ ❙ ➂✦✥ ❆✹♦ ❂➔❂ ➆✴✈ ❂ ◗ ❆ ▼ ❆❉❁❇❊✏✿ ❊✛●✍❆✹♦ ❂ ✿ ❖✯❯ ➡ ❂✼❃✧ ➧ ❊✛●✡❁❇❆ ❂✼❃❸▼ ❆❉❁❇❊✏✿ ❄ ❊✛●❡❻ ❖ ◗ s ❁↕❩❋❊✏✿✩★ ✝✫✪ ➦ ❂✼❃ ❁➏●➋❈♥❁❇✿✯✇ ❙ ❑ ★ ❛ ✪ ❑✭✬ ❁ ❄ ✇✤❁❺➦ ❂ ✿✂➡✣❈✂❻ ❚ ✧✯✮☎❫ ➍ ➠✥➋ ✜ ✢✤✣ ➋✰✲✱ s ❊♥✇✬ ❡✄✳ ❼ ❙ ➂ ➥❁❇✿➓❆❉❁❇✇✏♦✣❆ ❃✹❂❸s↕▼ ❆r❁❺❊♥✿ ❄ ♦✣❁❇✈❵❈♠❁❺❆♣♦

❈ ❡ ❼ ➄✣➂ ❼ ❈⑥❁❇❆✹♦ ❈ ❼✴✘ ➂ ❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂ ❊✤● ✔ ✲ ➂ ④➞ ❂ ❈⑥❁ sts ❩ ❂✼❃ ❁❺➦ ❂ ● ❃ ❊ ❯ ❆✹♦ ❂ ✈ ❃ ❊✏✈ ❂✼❃ ❆❉❁ ❂⑦❄ ❊✛●✚❆✹♦ ❂✵✔ ❊✏✈ ❂✼❃❸▼ ❆✹❊ ❃❅❄ ❆✹♦ ❂✷✶✼❄ ❆ ▼ ❆r❁❺❊♥✿ ▼✛❃ ❈✹✸➇❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿✠✟✛✚ ❚ ➟✢❫ ➥✛▼ ✿✚❩➔❆✹♦ ❂❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ❊✛●✍❆✹♦ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ✽ ❊✛●✶❁❇❆ ❂✼❃❅▼ ❆❉❁❇❊✏✿ ❄ ❊✛●✍❆✹♦ ❂ ❄➫▼✤❖✚❄✹❄ ❁ ▼ ✿ ▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯ ▼✐s ❊✏✿✯✇ ▼ ✿✣❈❱❁❇✿✣❁❇❆❉❁ ▼✐s ❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿➟✶④ ➐✢❁ ➔✏❂ ❆✹♦ ❂ ◗ ❊✏✿✣❆❉❁❇✿ ❖✯❂ ❩❨● ❃❅▼ ◗ ❆❉❁❇❊✏✿ ❂ ➆✴✈ ▼ ✿ ❄ ❁❇❊✏✿❋❊✛● ▼ ✿ ❖✯❯ ➡ ❂✼❃➇❖ ✿✚❩ ❂✼❃ ❆♣♦ ❂ ❻ ❖ ◗ s ❁↕❩ ❂⑦▼ ✿ ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯➓➥ ❈⑥❁❇❆✹♦ ✼ ➁ ❪✢■ ➥❈➇♦✣❁ ◗ ♦ ❁ ❯ ✈ s ❁ ❂⑦❄▼ ❼ ❙ ✝ ✼ ➁ ➂❬➳ ❙✏➥ ❈ ❂ ♦ ▼ ➦ ❂ ✼ ➁ ☞ ➠ ➍ ❙ ✝ ✼ ➁ ●ë✟ ➁ ➥ ❈⑥❁❇❆✹♦ ✟ ➁ ☛ ❙✏➥ ❈➇♦✣❁ ◗ ♦ ❁ ❄❲❂✞✖✏❖ ❁❇➦ ▼✐s❇❂ ✿❏❆ ❆✹❊✼ ➁ ➍ ❙ ✝ ❼ ✟ ➁ ❡❫✼ ➁ ☞ ➠ ➂ ➥✴▼ ✿✚❩❋✇✛❁❇➦ ❂⑦❄ ❆♣♦ ❂❷❂ ➆✴✈ ▼ ✿ ❄ ❁❺❊♥✿

✼✻✺⑥➍ ❙✟ ➠ ❡ ❙

✟ ➋ ❡ ❙④ ④ ④✟ ❤ ❡❫✼ ❤

➆❼ ② ➂

⑤⑥♦✣❁ ❄❲❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿ ❆ ❂✼❃✹❯ ❁❇✿ ▼ ❆ ❂⑦❄✂▼✏❄❲❄ ❊✣❊✏✿ ▼♥❄ ✼ ❤ ❪ ❊☞●✂■ ④ ⑤⑥♦ ❂ ✿ ✽ ❼ ✼✞✺❝➂❋➍ ✺ ➥ ✼✻✺①➍ ☛ ➃ ❼ ✼ ❤ ➂ ▼ ✿✚❩ ☛ ➃ ❼ ✼✣➂❯✂▼ ❈✔➡ ❂✉❂ ➆✴✈ ❃✹❂⑦❄♣❄❉❂ ❩ ❁❇✿➑❆ ❂✼❃✹❯✂❄ ❊✛●✂❆♣♦ ❂ ◗ ❊✏✿✣❆❉❁❇✿ ❖✚▼ ✿❏❆ ❄ ➇ ❤ ❼ ✟ ➠⑩➄ ✟ ➋◗➄ ➆✐➆⑦➆ ➄ ✟ ❤ ➂ ▼ ✿✚❩✽✼ ❤ ❼ ✟ ➠◗➄ ✟ ➋⑩➄ ➆⑦➆⑦➆ ➄ ✟ ❤ ➂✖➍➇ ❤ ❞ ➠ ❼ ✟ ➋ ➄ ➆✐➆⑦➆ ➄ ✟ ❤ ➂ ▼✏❄

☛ ➃ ❼ ✼✣➂✍➍ ✼ ❤ ❡❫✼ ✼ ❤ ❞ ➠➇ ❤ ❡❫✼ ➇ ❤ ❞ ➠❼ ✒ ➂●➉❊ ❃ ❚ ☛ ❚ ➍ ✺ ✥ ❆✹♦ ❂ ◗ ❊✏✿✣❆❉❁❇✿ ❖✚▼ ✿❏❆ ❄➇▼✛❃✹❂ ❩ ❂ ❦ ✿ ❂ ❩➊➡❏❈❲❆✹♦ ❂❹❃♣❂ ◗ ❖✯❃✹❃✹❂ ✿ ◗ ❂❹❂✞✖♥❖✚▼ ❆❉❁❇❊✏✿ ❄➇ ➧ ❼❾❽★➠◗➄❅❽♦➋ ➄ ➆⑦➆✐➆ ➄❅❽ ➧ ➂☎➍ ❽ ➧ ➇ ➧ ❞ ➠✹❼❉❽★➠❾➄ ➆⑦➆⑦➆ ➄❅❽ ➧ ❞ ➠ ➂★❡ ➇ ➧ ❞ ➋❸❼❾❽▲➠❾➄ ➆✐➆⑦➆ ➄❸❽ ➧ ➂ ➄

➮✏➮

Page 98: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

◗❙❘❯❚❙❱❀✘✚✔✁� ✢ ⑤⑥♦ ❂ ❩✣❊ ❯✂▼ ❁❇✿ ❄ ■✁✺ ☎★■ ➠ ➥■ ➠ ☎❵■ ➋ ➥ ■ ➋ ☎❵■ ➃ ➥ ■ ➃ ☎ ■ � ➥ ■ � ☎❵■✄✂❃✹❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ❂ ❩ ▼✱s ❆ ❂✼❃ ✿ ▼ ❆❉❁❇➦ ❂❸s ❈➲❁❺✿✝➡ s↕▼ ◗ ➔▼ ✿✚❩ ❈➇♦✣❁❇❆ ❂ ④ ❼❾⑤⑥♦ ❂➲s↕▼✛❃ ✇ ❂⑦❄ ❆ ❩♥❁ ❄✵➔ ❁ ❄■✁✺✆☎ ■ ❈❀♦✣❁ ◗ ♦ ❁ ❄ ❆✹♦ ❂ ❩♥❁ ❄❇➔ ❊✛●✪❩♥❁ ➑▼✛❯❱❂ ❆ ❂✼❃ ❚

➏ ➄ ❙ ❫☞④ ➂

Density

3

2.5

2

1.5

1

0.5

Im(z)

0

1

0.8

0.6

0.4

0.2

0

Re(z)

0

1

0.8

0.6

0.4

0.2

0

◗❙❘❯❚❙❱❀✘✚✔✞✝ ✢ ⑤♠♦ ❂ ◗ ❊♥✿✚❩♥❁❺❆r❁❺❊♥✿ ▼✐s ❁❇✿ ➑➦ ▼✛❃ ❁ ▼ ✿✣❆❷❩ ❂ ✿ ❄ ❁❇❆❾❈☛✟✛✚❱④

❈⑥❁❇❆✹♦ ➇ ✺♠➍ ❙✏➥❍➇ ➠❅❼❉❽★➠ ➂✍➍ ❽▲➠ ④✍⑤⑥♦ ❂ ✿ ➥ ❆✹♦ ❂❪❄❉❂ ❆■❊✛●✡✈✢❊✛❁❇✿❏❆ ❄ ✇✛❁❇➦♥❁❇✿✯✇ ❯ ❊ ❃✹❂ ❆✹♦ ▼ ✿ ✺➔❁❇❆ ❂✼❃❸▼ ❆❉❁❇❊✏✿ ❄ ❁ ❄ ❚ ✽ ❼ ✼✣➂✙☛ ✺ ❡ ❙ ❫ ➍✟✡✠ ☛☞✠ ❽ ❤ ☛ ❼ ■➈➂ ❈⑥❁❇❆✹♦ ☛ ❼ ■❱➂ ❆✹♦ ❂ ● ❖ ✿✚❩ ▼✛❯➈❂ ✿❏❆ ▼✱s ❩♥❁ ❄❇➔ ❊✤●▲❩♥❁ ▼✛❯❱❂ ❆ ❂✼❃ ☛ ❼✍✌ ➂✍➍ ❚ ✼ ❤ ✝ ➇ ❤ ➄❝❼✴✼ ❤ ❡ ✼ ❤ ❞ ➠ ➂ ✝ ❼ ➇ ❤ ❡ ➇ ❤ ❞ ➠ ➂ ❫➉④➞ ❂ ♦ ▼ ➦ ❂✄✎ ❚ ☛ ❼ ■❱➂ ❫ ➍✑✏✒✏ ☛✔✓✖✕✘✗ ➟✓❼ ✼✴➂✚✙ ❽ ✙✜✛➈➍✑✏✒✏ ✕ ❚ ☛ ❡ ❼ ✼✣➂ ❚ ➋ ➟✣✢ ☛ ❼ ✼✣➂✤✙ ❽ ✙✜✛ ➥ ❆✹♦ ❂❹❯❱❂⑦▼♥❄❉❖✯❃✹❂✥✎ ➡ ❂ ❁❇✿✯✇ ▼✏❄✹❄ ❊ ◗ ❁ ▼ ❆ ❂ ❩❈⑥❁❇❆✹♦❋❆✹♦ ❂ ❩ ❂ ✿ ❄ ❁❺❆❉❈➓➟ ➥✚▼ ✿✚❩ ➥✣❃✹❂✼❯❲▼✛❃✍➔ ❁❺✿✯✇➈❆✹♦ ▼ ❆➇❆✹♦ ❂ ❩♥❁ ❄✵➔✯❄ ☛ ❼ ■❱➂ ▼✤❃✹❂ ❩♥❁ ❄✖✭ ❊✤❁❺✿✣❆ ➥✚▼ ●➋❆ ❂✼❃⑥❂ ➆ ◗ ♦ ▼ ✿✯✇✛❁❇✿✯✇✂❆✹♦ ❂❹❄r❖✯❯ ▼ ✿✚❩❁❇✿❏❆ ❂ ✇ ❃❅▼✐s✟❄ ❁❺✇♥✿ ❄✼➥✦ ❤ ➍ ✑ ❃ ❚ ✽✡☛ ✺ ❡ ❙ ❫ ➍ ❙✎ ❼ ■➈➂ ❼✠ ☛☞✠ ❽ ❤ ✎ ❚ ☛ ❼ ■❱➂ ❫ ➍★✧✩✧ ✕ ❼ ❼✠ ☛☞✠ ❽ ❤ ❚ ☛ ❡ ❼ ✼✣➂ ❚ ➋ ➟✣✢ ☛ ❼ ✼✣➂✹➂✤✙ ❽ ✙✜✛✢➆❼ ✯ ➂✣✑✿✣❆ ❃ ❊✯❩ ❖ ◗ ❁❇✿✯✇✂❆♣♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃✫✪ ❤➋ ✲ ❚ ➟✚❫ ❚ ✼ ❫ ➍★✬ ✠ ☛☞✠ ❽ ❤ ❚ ☛ ❡ ❼ ✼✣➂ ❚ ✲ ➟✭✢ ☛ ❼ ✼✣➂ ➥ ❈ ❂ ♦ ▼ ➦ ❂

✑✓✒✕✔✗✖✙✘✚✔✜✛ ❙✗✢✯✮ ✢✱✰✳✲ ✂✱✴✶✵✸✷ ❬ ✝✳✲❹➟ ✸ ✝ ✗✜✴ ☎✹✰✆✢❏➤✺✲✣➤ ❬ ✕ ❬ ✝✳✲✪✢❁✫✚✧✥✲✼✻ ❬✽✵ ✩✜✧✚✢✱✰ ✴ ✝ ✗ ✲ ✵ ✺ ❬ ✝ ✴ ✰✾✲✿✝ ❬ ✢ ✵✤✷ ✢❁✫✚✝ ✗✜✴✣✿ ✲✵✭ ✷✔✷ ❬ ✲ ✵✲✿✕ ✩✿✢❀✰ ❬ ✝ ✗ ✧ ❬❁✷ ✦ ❤ ❚ ➟✢❫ ➍ ✏✒✏ ✕ ✪ ❤� ❚ ➟✢❫➉❼ ✼✣➂❂✙ ❽ ✙❃✛✏✒✏ ✕ ➟✓❼ ✼✴➂❂✙ ❽ ✙❃✛ ❄❬ ✫❴✝ ✗✜✴✪✂✱✴❅✵✤✷ ❬ ✝✳✲❷➟ ❬❁✷ ✭ ✵ ❬ ✫✔✢✱✰❨✧ ✸ ✝ ✗✜✴ ☎❆✰♣✢✣➤✺✲❏➤ ❬ ✕ ❬ ✝✳✲ ❬❇✷

✦ ❤ ❚ ➟✚❫ ➍ ❈➃❊❉ ❯●❋●❋●❋ ❯ ➃■❍ ❙➇ ➋❤ ❼ ➇ ❤ ❡ ➇ ❤ ❞ ➠ ➂ ➋ ➄✲ ✵❂✂ ✝ ✗✜✴✭✴ ✥■☎ ✴❅➢ ✝❏✲✿✝ ❬ ✢ ✵ ✢❁✫❴✝ ✗✜✴❑✵ ✭✺✧❱➤ ✴ ✰➸✢❁✫ ❬ ✝ ✴ ✰✾✲✿✝ ❬ ✢ ✵✤✷✡❬❇✷❻ ❚ ✽ ❫ ➍ ✯

✒❡ ❙✞✝ ➏▲ � ❈▼ ✍ ➠ ❙✙ ➋ ❈▼❖◆✤P◗◆ ➋ ▼ ❙❘ ➋ ➆

⑤⑥♦ ❂✼❃✹❂ ●➉❊ ❃✹❂❷▼✐s➏s ❆♣♦ ❂ ❊✏➡ ✭❾❂ ◗ ❆ ❄ ❈ ❂❘▼✛❃♣❂➫❄ ❆ ❖ ❩✣❈✏❁❇✿✯✇ ❯✂▼ ❈q➡ ❂❷❂ ➆✯✈ ❃✹❂⑦❄✹❄❉❂ ❩✌❈⑥❁❇❆✹♦ ✪ ✲ ❚ ➟✚❫ ❼ ✼✣➂✶➍★✬ ➃ ✍ ➠ ➠✠ ➃ ☞❃❙ ✠●❚ ➟✓❼ ➠➃ ☞❃❙ ➂▼ ✿✚❩ ❁❇❆ ❄ ♦✯❊ s ❊ ❯ ❊ ❃ ✈✯♦✣❁ ◗ ➦ ❂✼❃❅❄ ❁❇❊✏✿ ✔ ✲ ❚ ➟✢❫➉❼ ✼✣➂➔➍❯✬ ➃ ✍ ➠ ➠✓ ➃ ☞❃❙ ✗ ❚ ➟✓❼ ➠➃ ☞❃❙ ➂ ➥ ❆✹♦ ❂ ◗ s↕▼✏❄♣❄ ❁ ◗ ▼✐s �⑥❖✯❂❸s➏s❺❂⑩➑ ❅ ▼ ❈ ❂✼❃ ❊✏✈ ❂✼❃❸▼ ❆✹❊ ❃✔ ✲ ④⑥➞ ♦✣❁ s❺❂ ❁❇✿ ❆✹♦ ❂❹❖ ✿✣❁➏●➉❊ ❃✹❯ ◗ ▼✏❄r❂✏➥ ❆✹♦ ❂q❄ ❆ ❖ ❩✣❈❋❊✛● ✔ � ❁ ❄❷❄❉❖ ☛❨◗ ❁ ❂ ✿❏❆ ➥ ❁❇✿ ✇ ❂ ✿ ❂✼❃❅▼✐s ❁❺❆❪❁ ❄ ✿ ❂ ◗ ❂⑦❄✹❄✹▼✛❃ ❈❋❆✹❊ ❄ ❆ ❖ ❩✣❈❋❆✹♦ ❂◗ ❊ ❯ ✈ s❇❂ ❆ ❂ ● ▼✤❯ ❁ s ❈❋❊✤●✟❆✹♦ ❂✳✪ ✲ ④

➮ ➣

Page 99: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁â✩☎✄✝✆✂✞✠✟✡✄✝☛✌☞✍✟✡✎✏✆✒✑✓☛❖●✂✟✕✔➊❥✂✟✡✖✗✖✘✟✚✙✜✛✣✢✗❑✂✟✤✄✥✆✂✞✠✟✡✄✝✢✤☛✦✆✂✄✧✎★✢★❤✪✩✫✢✬✞✠✞✠✖✭☞✽❧✮✢✤☛✌☞✍✆✡❤✯☛✦✆✰☛❖●✂✟✱✢★❤✲✢✬✖ ❑✳✎✌☞✗✎★✆✬✑✴☛❖●✲✟✸✵✢★❥✶✎✝✎✌☞✍✢★❤✷✢✬✖❥✺✒✆✲✄✮☞✘☛❖●✠✸⑤⑥♦ ❂✠�♠❖✯❂❸sts❇❂⑩➑ ❅ ▼ ❈ ❂✼❃ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄✁✔ ✲ ▼✤❃✹❂ ❩ ❂ ❦ ✿ ❂ ❩✦❊✏✿①❆♣♦ ❂❨❄❉❂ ❆✏✹ ✚ ❼✻✺ ➂ ❊✛●➇♦✯❊ s ❊ ❯ ❊ ❃ ✈✯♦✣❁ ◗ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❊✏✿✼✺ ➥◗ ❊✏✿✣❆❉❁❇✿ ❖ ❊ ❖✚❄ ❊✏✿ ✺ ➥ ❈⑥❁❇❆✹♦✽✺ ➍☞❏ ❚ ✼❢● ❙ ❚ ❛ ➃ ➋ ❖❏➥ ●➉❊ ❃ ✘ ❈⑥❁❇❆✹♦ ▼ ❼✴✘ ➂■➳ ❙ ④■⑤⑥♦ ❂ ❈ ▼✛❃♣❂ ✿ ❖ ◗ s❇❂⑦▼✛❃ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❸❄ ❊✛●❡❊ ❃ ❩ ❂✼❃➏ ❼☞➦ ❂✼❃ ❈ ❄ ❁ ❯ ❁ s↕▼✛❃ ❆✹❊➔❁❇✿ ❦ ✿✣❁❇❆ ❂❷❯✂▼ ❆ ❃ ❁ ◗ ❂⑦❄ ➂✌✥ ▼ ●➋❆ ❂✼❃ ❆ ❃❅▼ ✿ ❄ ● ❂✼❃ ❁❇✿ ▼ ✿✯❊♥❆✹♦ ❂✼❃➇❭ ❁ s ➡ ❂✼❃ ❆ ❄ ✈ ▼ ◗ ❂✏➥ ❆✹♦ ❂ ❈ ▼✛❃♣❂ ❩♥❁ ▼ ✇✏❊✏✿ ▼✐s ❁ ❄✹▼ ➡ s❇❂❈⑥❁❇❆✹♦ ▼ ❩♥❁ ❄ ◗ ❃♣❂ ❆ ❂❘❄ ✈ ❂ ◗ ❆ ❃✹❖✯❯ ✥ ❯ ❊ ❃✹❂ ❊✛➦ ❂✼❃⑦➥ ❆♣♦ ❂ ❈ ▼✛❃✹❂ ✑ ❂✼❃✹❃ ❊✏✿ ➑❑✫✯❃ ❊♥➡ ❂ ✿✣❁ ❖✚❄ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄ ●➋❊ ❃ ✘ ➳ ❙✏➥ ♦ ▼ ➦♥❁❇✿✯✇ ▼❪❖ ✿✣❁ ✖✏❖✯❂❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂

❈ ❼✴✘ ➂ ④➌ ❄➇▼ ◗ ❊✏✿ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂✏➥ ❆ ❖✯❃ ✿✣❁❇✿✯✇✂➡ ▼ ◗ ➔ ❆✹❊q❆✹♦ ❂❹❖ ✿✣❁➏●➉❊ ❃✹❯ ◗ ▼♥❄❉❂✏➥ ❈ ❂ ♦ ▼ ➦ ❂ ❆✹♦ ❂ ❆✹♦ ❂ ❊ ❃♣❂✼❯ ④✑✓✒✕✔✗✖✙✘✚✔✜✛ ➄ ✢ ✶ ✗✜✴ ☎❆✰♣✢✣➤✺✲❏➤ ❬ ✕ ❬ ✝✳✲ ✦ ❤ ✗ ✲ ✷ ✲❣✩ ✴ ✢✿✧ ✴ ✝❏✰ ❬↕➢ ➤ ✴✔✗ ✲✿✾ ❬ ✢✵✭❃✰ ✸ ✦ ❤❁❀ ❘ ❈ ❤� ✸ ✯ ❬ ✝ ✗ ❈ �✵❂ ➏ ➆ ❙✏✱✦✱✮✒ ✲ ✵❂✂❘ ❂ ❙ ➆ ② ✴✶ ✗✜✴➙✂ ✲ ✵ ✲✿✧ ❬✽➢✚✂✱✴✶✵✸✷ ❬ ✝✳✲✷✟ ❤ ❼ ✼✴➂ ➢ ✢ ✵ ✾ ✴ ✰✳✩ ✴✒✷ ✝➉✢ ✲ ❨✑➢ ✢ ✵❂✂ ❬ ✝ ❬ ✢ ✵ ✲✿✕ ❪✳❬✍✵ ✾✶✲✱✰ ❬ ✲ ✵ ✝ ✂✱✴❅✵✤✷ ❬ ✝✳✲✷✟✛✚q❼ ✼✴➂ ☎✹✰✆✢❨☎Ø✢❀✰✉✝ ❬ ✢ ✵ ✲✦✕❧✝➉✢✏ ☞ ➠❞ ➠ ❼ ❙ ●✰❃ ➋ ➂✚❘ � ❼❉❽ ❡✰❄ ✛✚❃⑧➂❂✙✚❃❄✸ ✯ ✗✜✴ ✰ ✴ ❘ � ❬❁✷ ✝ ✗✜✴❖✂ ✢✿✧ ❬✍✵ ✲✿✝ ❬✽✵ ✩ ✴ ❬ ✩ ✴❅✵ ✾ ✴❸➢ ✝➉✢❀✰↕✢❁✫ ✔ � ✴✣✑✿➨❆✹♦ ❂ ✇ ❂ ✿ ❂✼❃❅▼✱s ◗ ▼✏❄❉❂✏➥ ❈ ❂ ♦ ▼ ➦ ❂ ❆✹❊ ❄ ❆ ❖ ❩✣❈✂✇ ❂ ✿ ❂✼❃❸▼✐s ❁ ✐ ❂ ❩ �⑥❖✯❂❸s➏s❇❂⑩➑ ❅ ▼ ❈ ❂✼❃ ❊♥✈ ❂✼❃❅▼ ❆♣❊ ❃❅❄ ❚③② ❫⑤⑥♦ ❂❋❄ ✈ ❂ ◗ ❆ ❃❅▼✐s ✈ ❃ ❊✏✈ ❂✼❃ ❆❉❁ ❂⑦❄ ❊✛●➇❆✹♦ ❂ ❊✏✈ ❂✼❃❸▼ ❆✹❊ ❃✥✪ ✲ ▼✛❃✹❂❲❂⑦❄✹❄❉❂ ✿✣❆❉❁ ▼✐s➏s ❈➀❆♣♦ ❂❨❄✹▼✤❯❱❂❨▼♥❄ ❆♣♦✯❊ ❄❉❂ ❊✛● ✔ ✲ ✥ ❆✹♦ ❂✼❃♣❂ ❁ ❄q▼❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂

❈ ❼✴✘ ➂ ▼ ✿✚❩ ▼ ❩✣❊ ❯ ❁❇✿ ▼ ✿❏❆ ❂ ❁❇✇ ❂ ✿✣➦ ❂ ◗ ❆✹❊ ❃ ❈➇♦✣❁ ◗ ♦ ❯✂▼ ❈❋➡ ❂❱❂ ➆✯✈ ❃✹❂⑦❄✹❄r❂ ❩ ❂⑦▼✏❄ ❁ s ❈➨❁❺✿✦❆ ❂✼❃✹❯❲❄ ❊✛●✔ ✲ ④ ❭ ❊❖❈ ❂ ➦ ❂✼❃⑦➥❏▼ ✿➊❁❇✿❏❆ ❂✼❃♣❂⑦❄ ❆❉❁❇✿✯✇q❁ ❯ ✈ ❃ ❊✛➦ ❂✼❯❱❂ ✿✣❆⑥❁ ❄ ✈✚❊ ❄✹❄ ❁❺➡ s❇❂ ❁❇✿ ◗ ▼✏❄r❂ ❊✛●❡● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❈⑥❁❇❆✹♦❋➦ ▼✱s❺❖✚▼ ❆❉❁❇❊✏✿ ❄ ④✑✓✒✕✔✗✖✙✘✚✔✜✛ ② ✢✯✮ ✢✱✰✳✲ ✵✷❬✽✵✤❬ ✝ ❬ ✲✿✕ ✂❀✴✶✵✤✷ ❬ ✝✳✲â✢❁✫✏✾✶✲✿✕ ✭❃✲✿✝ ❬ ✢ ✵ �✦❅①➟✓❼❾❽q➄ ✛ ➂◆➍ ❚ ✛ ❚ ❆ ✂ ❼❾❽q➄ ✛ ➂✍✸ ✯ ❬ ✝ ✗ ✂ ✂☎ ➏ ✢ ✵ ✝ ✗✜✴ ✰ ✴ ✲✦✕✲❖✥ ❬❁✷ ❅ ✝ ✗✜✴ ✲ ✷ ✲➌✧✴☎✷✝➉✢✦✝ ❬↕➢ ✲✿✕◆➤ ✴✔✗ ✲✿✾ ❬ ✢✵✭❃✰ ✷ ✢❁✫ ✦ ❤ ❚ ➟✚❫✳✲ ✵❂✂ ✟ ❤ ❚ ➟✢❫ ✂✱✴ ☎ ✴✶✵❂✂ ✢ ✵ ✝ ✗✜✴➧✂ ✢✿✧ ❬✍✵ ✲ ✵ ✝ ✷ ☎ ✴❅➢ ✝❏✰✾✲✿✕❛✢❏➤✗❇ ✴❸➢ ✝ ✷ ✢❁✫✔ � ☞ ➋ ❆✜❈ ✦ ❤ ❚ ➟✢❫ ❀ ❘ ❈ ❤� ☞ ➋ ❆❼ ➙ ➂✲ ✵❂✂ ✟✛✚ ❚ ➟✢❫➉❼ ✼✣➂ ❬❇✷ ☎✹✰✆✢❨☎Ø✢✱✰❨✝ ❬ ✢ ✵ ✲✿✕Õ✝➉✢ ❚ ✛ ❚ ❆ ✏ ☞ ➠❞ ➠ ❼ ❙ ●✰❃ ➋ ➂ ➠ ☞ ❆ ✂ � ☞ ➋ ❆ ❼❾❽ ❡✷❄ ✛✚❃❷➂✤✙❉❃ ✴❊✪✁✵❋☎✆✓❤▲❧●✖➉❥✪✎✌☞✍✆✡❤

⑤⑥♦ ❂⑦❄❉❂❷❃♣❂⑦❄❉❖✣s ❆ ❄⑥s❇❂⑦▼ ❩➊❆✹❊q❆❁❈◆❊ ❯✂▼ ❁❺✿ ▼ ✈✯✈ s ❁ ◗ ▼ ❆❉❁❇❊✏✿ ❄✔✎✫✒✰♣✢✦✧ ✿ ✲✵✭ ✷✔✷ ✝➉✢✵❍❙✭ ➢ ✕ ❬✖✂ ❈ ❆✹♦ ❂ ✿ ➥ ❈ ❂ ♦ ▼ ➦ ❂ � ❇ ❙✏➥❈ � ☞ ➋ ❆ ❇ ❈ ➋ ➍ ❙✏➥✯▼ ✿✚❩ ✂ � ☞ ➋ ❆ ❇ ✂ ➋ ➍ ➠✜ ✢✤✣ ➋ ➠➠ ☞ ❆ ✥✫✒✰♣✢✦✧ ✿ ✲✿✭ ✷ ✷ ✝➉✢ ✣✠✣❩✣ ❈ ◗ ❊✏✿ ❄ ❁↕❩ ❂✼❃ ❁❇✿✯✇ ❅➨➦ ❂ ◗ ❆✹❊ ❃❸❄❏■ ➠❾➄ ➆⑦➆⑦➆ ➄ ■ ➧ ❖ ✿✣❁➏●➋❊ ❃✹❯qs ❈❨❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆ ❂ ❩❲❁❇✿ ❊ ➧ ➥ ❆✹♦ ❂❘❖ ✿✣❁❇❆➇➡ ▼✱sts ❊✛●

❶ ➧ ➥ ❈⑥❁❇❆✹♦✽❑✍▲ ❆♣♦ ❂❪s❺❂ ✿✯✇♥❆✹♦✂❊✤●❡❆✹♦ ❂ ❄ ➑ ❆✹♦❲❊ ❃ ❆✹♦✯❊♥✇✏❊✏✿ ▼✐s ❁❥✐ ❂ ❩ ➥ ❆✹♦ ❂ ❁❇✿✣❁❺❆r❁ ▼✱s ❩ ❂ ✿ ❄ ❁❇❆❉❈✂♦ ▼✏❄ ➦ ▼✐s❇❖✚▼ ❆❉❁❇❊✏✿✏❅ ●▼❄✤● ❙♥➥✴▼ ✿✚❩❋❈ ❂◗ ▼ ✿ ▼ ✈✯✈ s ❈❋❊ ❖✯❃❀❃✹❂⑦❄❉❖✣s ❆ ❄ ❈⑥❁❇❆✹♦ ❖✚❄❉❂ ❊✤● ✔ ➋ ✓ ➠ ☞ ➧ ❞ ▲ ✗ ❚ ❙ ❫✑④➞ ❂✂❄ ♦✯❊❉❈ ❂ ❩➨♦✯❊❖❈ ❆✹❊ ✶ ❁❺✿✣➦ ❂✼❃❅❄r❂ ✸❋❆✹♦ ❂ ❊♥✈ ❂✼❃❅▼ ❆♣❊ ❃ ❣ ❊✤●◆❆✹♦ ❂☎❄➫▼✛❖✚❄♣❄ ❁ ▼ ✿ ▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ➡❏❈ ❖✚❄❉❂ ❊✛● ▼ ● ❖ ✿ ◗ ❆r❁❺❊♥✿ ▼✐s❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃✕✔ ✲ ④ ➌ ✿❋❊✏✈ ❂ ✿ ✖♥❖✯❂⑦❄ ❆❉❁❇❊✏✿❋❁ ❄ ❆✹♦ ❂ ✇ ❂ ✿ ❂✼❃❅▼✱s ❁❥✐ ▼ ❆r❁❺❊♥✿❬❊✤● ❄❉❖ ◗ ♦ ▼q❯❱❂ ❆♣♦✯❊✴❩❲❆✹❊➈❊✏❆✹♦ ❂✼❃❘▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯✂❄ ④✲✴✳✖✵✷✶✖✳✖✸✺✹✼✻✔✽✿✾✞❀❂❁❃✁❄✆❅↕➘❙❜✔❡✺❋ ✏●❊◆➉➒❦❘✓❱☞❜✔❉✺❋✴ò❣❜✔❝✁❝ ✏●■●➼◆◗➈➼❘✓❱■❘❨❳❴❇➼❉↕❡✿s✦s✺●■❍Õq✺▲t❡✿❉✺❋❺▲✏❉❺❪❑❤✦●❊❜❨❵✏●■❍✆❜✔➐✏●➊❉✮❡✿❫➸q✼●■❍☞▲✔❥✺♦✁❪❑●❲❍♣❜✔❪▼♦✁▲✏❉✿❏☞▲✔❥✣❪❑❤✦●❊é✞é✞é✚❜❞❝❢➐t▲✏❍▼♦❢❪▼❤✿❫â❘➥❂➦➱❷✆✇❞②♣❷❆❼◗⑩✙↔✆④❞⑤✞❰❣✇❞➽❊⑨✼①✏❼❑❷❲②❙ÐØ↔❲⑩✙❷■③✼↔♣❷❲❿✿❵t▲✏❝➉❘✼❄✉➅✏➄✦❿✮❉✿➹✺❄t❿✣➀✉➁t➁✦◆✺❿ts✿s✞❘ ➣✏➷ ❳Ø❄✏❄ ➷ ❘❃✓➅❨❅↕➘❙❜✔❡✺❋ ✏●➸◆◗➒➩●■❍❑❵ ✏●✉❱❲❿✷➡❂❝♥❜■➑✆▲t❝❢●❲❪❦◆◗➞❮❤✿♦✁❝❢♦✁s✿s✼●✉❱❲❿Ø❜❞❉✺❋✚ò❣❜❞❝✁❝ ✏●❲●➸◆◗➈Õ❍❑♦✁➐✏♦✁❪▼❪❑●✉❱❲❘✿❳ ❇❊❉➏❜✔❉✼❜✔❝✁✐✮❏❑♦✁❏❊▲❞❥❮❪▼❤✿●❴❒❦❜❞❡✿❏❑❏▼♦❽❜❞❉✪❜✔❝✁➐✏▲t❍❑♦✁❪❑❤✿❫á❥✙▲t❍❝♥❜✔❪▼❪❑♦♥♠✆●❺❍❑●✉❋✮❡✼♠✆❪❑♦✁▲✏❉❂❘✞ä➉❉➏❇❙❋✮❝✁●■❫❬❜❞❉➧◆➉é❧❘✓❱✴◆✙●✉❋✮♦✁❪▼▲✏❍♣❱❲❿❧⑧❙⑤✓➚✏✇✔②■⑩❽❼✙➦✮➽↕⑩✙↔✴ç❙①✮➽➵❻✆❷❲②✪➥❂➦➱❷✆✇✔②■❾ Ð✺❾✔➽❊⑨✿✇❨➣■⑩♥①✮➽❺❿❧æ✞❷✆↔✆❼➉①✮②♣❷➵ç➢✇❨❼❑❷❆➣❴⑩♥③❰❣✇✔➽➼⑨✺①t❼❑❷■②➼ÐØ↔❲⑩✙❷❲③✺↔✆❷■❿✦s✿s✞❘❂❄■➯✏➯❞❳Ø❄ ➷ ➮✿❘➆❳í➀✉➁✏➁❖◆✺❘✮➞☞❍❑▲✿♠✆●❲●✉❋✮♦✁❉✿➐✏❏➼▲✔❥❣⑧❙ç➸➥❂Ð✳P ◗❙❘✿❘❃✓➄❨❅❦ò❣❜❞❝❢❝ ✏●■●Ï◆◗➈➼❘ ❱❲❘✼❳ é✣●➸❍✦❚▲✏❝✁●➵❋➱●■❏❦▲✏s☎✏●■❍♣❜❞❪❑●■❡✿❍▼❏➵❋➱●❴➶❛❡✿●■❝✁❝✁●✆➴❑➳✪❜❨✐✏●❲❍❈➐✌✏●■❉☎✏●■❍✆❜✔❝✁♦✁❏ ✏●■❏❺❋✿❜✔❉✿❏✴❝◗Ú✓❜❞❉✺❜✔❝✁✐✮❏❑●❦●❲❉➏❫❴▲✔✐✏●❲❉✿❉✿●↕❋✮●❲❏↕❜✔❝✁➐✏▲❞➴❍❑♦✁❪▼❤✿❫❴●■❏❧❋✣Ú✓❩☞❡✼♠✆❝✁♦❽❋➱●❣●■❪❛❋✮●❊❒❦❜❞❡✿❏❑❏❨❘✔❳❬❒✴➶❊❩❂➫❦P❙❿✏➘✡✏●■s✺❜✔❍▼❪❑●■❫➙●■❉✮❪❣❋✣Ú ä➉❉✮❥✙▲t❍❑❫✚❜✔❪❑♦♥Üt❡✿●✏❿❨✃❛❉✿♦✁❵t●■❍❑❏▼♦❢❪ ✏●❈❋✮●❊P❛❜❞●■❉✞❿✼❄■➯✮➬✏➄✏➅❙P❛❜❞●■❉P➊●✉❋✮●❆❭✍❿✼➡✿❍✆❜✔❉✺♠❆●✏❘

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Page 100: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✄☎✄❡✄✢✥✏✕ ✟✡✄➭✗✂✕ ☎✛✄ ✄ ✒■✕★✠ ✬✆☎✱✎ ☎➓✞★✧q�❘✥♥✄✚✄✟✎❬✄✁�➓✥✏✎➉✌✏✎☞✒✆✟✝✆❡✬✆☎✐✌✏✄✌✠ ☎

✂☎✄ ✒✕✔↕✻ ✂ ✰✶✵✁✆ ✵✞✝✠✟➐ ✣❾⑤❦✑❳ ❖ ✿ ❂❋❙ ➄ ➥ ❙t✱✿✱✿✯

❚ ❄❉❖✯❯❱❯✂▼✛❃ ❈✂➡✣❈☛✡ ▼ ➦✏❁ ❂✼❃❩❄ ❊ ❖✯❃ ❩✣❊✏✿✯❫❴➸✵✡❵✹❛❨✻✔✽❏❜❝❛

❇ ➐t●■❉✿●■❍✆❜✔❝☞❪❑●❨♠❑❤✦❉✿♦♥Ü✏❡✦●↕♦✁❏❛s✿❍▼●■❏❑●■❉✮❪▼●✉❋✜❪❑▲➙●✉❜✔❏▼♦❢❝✁✐✚♠✆▲✏❫➙s✿❡✿❪❑●❙❪▼❤✿●❦▲✏❍✆❋✮●■❍➼▲✔❥❧❪❑❤✿●➸❜❨❵✏●❲❍♣❜✔➐t●❦♠✆▲✏❫➙s✿❝✁●✆❭✿♦❢❪➉✐▲✔❥❊❜✚❪❑❍▼●■●✚❍❑●■r❛❍▼♦❢❪▼♦✁❉✿➐✪❏❑✐✮❏▼❪❑●■❫ ❥✖❍❑▲✏❫ ♦✁❪❑❏✴❫❬❜✔❪▼❍❑♦❶❭â❍▼●■s✿❍❑●❲❏❑●■❉✮❪♣❜❞❪❑♦✁▲✏❉❂❘✪ä➉❪➸♠■❜✔❉➏q✼●❴❡✿❏▼●✉❋ì❥✙▲✏❍✴●✆❭✺❜✔❫❴s✦❝❢●❺❪❑▲s✿❍❑▲✔❵t●❊❪❑❤✼❜✔❪❛❪❑❤✦●↕❜❨❵✏●■❍✆❜✔➐t●➢♠❆▲✏❏❑❪❛▲❞❥❧❪❑❤✿●✌☞t➴➉❪❑❤✪❋✮♦❶Ù✣●■❍❑●■❉✮❪▼♦❽❜❞❪❑♦✁▲✏❉✚♦✁❏➊▲✔❥❧▲✏❍✆❋✮●■❍✎✍ ➠ ☞✦❤✑✏ ➋ ❘❢✒✁❱❣✐❤✬☛✌✄✝✆✶✩❦❥✡❧✮☛✌☞✘✆✓❤

➞ ❂⑥▼ ❁ ❯ ▼ ❆ ❄ ❆ ❖ ❩✣❈♥❁❺✿✯✇❷❆♣♦ ❂ ❊ ❃ ❩ ❂✼❃ ❊✛●✚❆✹♦ ❂■▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆❏❁❇❆❉❈❹❊✤● ❃✹❂ ✇ ❖✣s➣▼✤❃ ❆ ❃♣❂✼❂■❃✹❂ ❈ ❃ ❁❺❆r❁❺✿✯✇ ❄ ❈ ❄ ❆ ❂✼❯✂❄ ④✡➞ ❂ ❩ ❂⑦▼✐s❈⑥❁❇❆✹♦ ❄ ❁ ❯ ✈ s❇❂ ● ▼✤❯ ❁ s ❁ ❂⑦❄ ❊✛●✟❆ ❃✹❂✼❂⑦❄✓✒➈➥ ❁❇✿ ❆✹♦ ❂q❄❉❂ ✿ ❄❉❂ ❊✛●❜❅ ❂ ❁ ❃➫▼ ✿✚❩ ❅➨❊❏❊✏✿ ❚ ✒ ❫✑④➇⑤⑥♦ ❂ ◗ ❊ ❃✹❃♣❂⑦❄ ✈✚❊✏✿✚❩♥❁❇✿✯✇❋✇ ❂ ✿ ❂✼❃❸▼ ❆❉❁❇✿✯✇● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❼ ❄➵✫ ➂ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩➭➡❏❈ ❜❷❼ ✼✣➂➔➍ ✼✕✔ ❼✮❜❷❼ ✼✣➂♣➂ ❈➇♦ ❂✼❃✹❂ ✔ ❼ ✛ ➂ ❁ ❄❱▼ ✈✚❊ s ❈✣✿✯❊ ❯ ❁ ▼✐s ❈❀♦✯❊ ❄❉❂ ❅ ➑ ❆♣♦ ◗ ❊ ❂ ☛❨◗ ❁ ❂ ✿❏❆❁ ❄ ❆✹♦ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ◗ ❊♥✿ ❄ ❆ ❃✹❖ ◗ ❆✹❊ ❃❅❄ ❊✛● ▼✛❃ ❁❇❆❉❈ ❅✶④ ✫ ❊ ❃❋❂ ➆ ▼✛❯ ✈ s❇❂✏➥ ❆✹♦ ❂✍❄➸✫ ❊✛●✪➡✣❁❇✿ ▼✛❃ ❈ ❆ ❃♣❂✼❂⑦❄ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩ ➡❏❈❜❷❼ ✼✴➂✍➍ ✼ ❼ ❙ ❡ ❜ ➋ ❼ ✼✴➂✹➂❡➍ ✼✕✔ ❼✮❜❷❼ ✼✣➂♣➂ ❈♠❁❺❆♣♦ ✔ ❼ ✛ ➂✍➍ ❙ ❡ ✛ ➋ ④✖ ✷ ✲✮✧✴☎✷✝➉✢✿✝ ❬✽➢✒✷ ✢❁✫✢❜❷❼ ✼✴➂ ✴ ➞ ❂ ❩ ❂ ❦ ✿ ❂✘✗ ➳ ➏

▼✏❄ ❆✹♦ ❂✦❄ ❊ s❇❖ ❆❉❁❇❊✏✿✔❊✛● ✗ ✔ ❡ ❼ ✗ ➂ ●✙✔ ❼ ✗ ➂ ➍ ➏▼ ✿✚❩✄❈ ❂ ❩ ❂ ✿✯❊✏❆ ❂✚❱➍ ✗ ✝ ✔ ❼ ✗ ➂✍➍ ❙ ✝ ✔ ❡ ❼ ✗ ➂ ④✍⑤⑥♦ ❂ ✿ ✚ ❁ ❄ ❆✹♦ ❂ ❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❄ ❁❇✿✯✇ ❖✣s↕▼✛❃ ❁❇❆❉❈❋❊✛●❵❜❷❼ ✼✣➂ ❈⑥❁❇❆✹♦➨❆✹♦ ❂ ✑ ❖ ❁ ❄❉❂✼❖ ➆ ❂ ➆✯✈ ▼ ✿ ❄ ❁❇❊✏✿

❜❷❼ ✼✣➂✍➍ ✗ ● ✛ ➄✜✔ ❼ ✗ ➂✔ ❡ ❡ ❼ ✗ ➂ ✏ ❙ ● ✼✚ ✒ ➠ ✏ ➋❡ ❈➧ ✍ ➋ ✙ ➧ ✏ ❙ ● ✼✚ ✒ ➧ ✏ ➋

✫✯❃ ❊ ❯ ❄ ❁❇✿✯✇ ❖✣s↕▼✛❃ ❁❇❆❉❈ ▼ ✿ ▼✐s ❈ ❄ ❁ ❄✼➥ ❈ ❂ ❩ ❂ ❩ ❖ ◗ ❂ ❆✹♦ ❂❷❂⑦❄ ❆❉❁ ❯✂▼ ❆ ❂ ❊✛●✍❆✹♦ ❂ ❅ ➑ ❆✹♦ ◗ ❊ ❂ ☛❨◗ ❁ ❂ ✿❏❆❪❊✛● ❜⑧❼ ✼✣➂❚ ✼ ➧ ❫❥❜⑧❼ ✼✣➂✍➍ ✛ ✔ ❼ ✗ ➂➄✱▲✢✔ ❡ ❡ ❼ ✗ ➂ ✚ ❞ ➧ ❅ ❞ ➃ ✏ ➋ ✏ ❙ ❡✤✣ ✏ ❙❅ ✒✓✒ ➆✥ ❤✽✟✣➝✪✢✂✸ ✞✳✖✍✟✧✦✴✩✳☞✩★ ✟✤✄✝✟✚❤✒☛✌☞✘✢✤☛✌☞✍✆✡❤ ✆✒✑❏☛✌✄✝✟❉✟✤✎✿✁ ➌ ❆❾❈✣✈✣❁ ◗ ▼✐s✚❂ ➆ ▼✛❯ ✈ s❇❂ ❊✤● ▼ ❆ ❃✹❂✼❂❀❃✹❂ ❈ ❃ ❁❇❆❉❁❇✿✯✇ ❄ ❈ ❄ ❆ ❂✼❯ ❁ ❄ ●➋❊ ❃✹❯✂▼✐s❩♥❁ �✡❂✼❃✹❂ ✿❏❆r❁ ▼ ❆❉❁❇❊✏✿✡④✶➞ ❂ ❩ ❂⑦❄ ◗ ❃ ❁❇➡ ❂ ❆✹♦ ❂⑥▼ ◗ ❆❉❁❇❊✏✿q❊✛●✯❆✹♦ ❂ ❩♥❁ �✡❂✼❃✹❂ ✿✣❆❉❁ ▼ ❆❉❁❇❊✏✿ ▼ ✿✚❩ ◗ ❊✏✈✣❈❷❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄ ❊♥✿❹❆ ❃✹❂✼❂⑦❄ ◗ ❊✏✿ ❄ ❆ ❃✹❖ ◗ ❆ ❂ ❩❈⑥❁❇❆✹♦ ▼ ➡✣❁❇✿ ▼✛❃ ❈ ◗ ❊✏✿ ❄ ❆ ❃✹❖ ◗ ❆♣❊ ❃✫✪❱▼ ✿✚❩ ▼ ➦ ▼✤❃ ❁ ▼ ➡ s❇❂✭✬

❩✢❼ ✬ ➂ ❇ ✬ ◗ ✈★❼ ✬ ➂ ❇ ✬❩✢❼ ➂✯✮ ❀ ➂ ❇ ❩✢❼ ➂ ➂ ✮ ◗ ✈✡❼ ❀✯➂★❡ ❩✢❼ ❀ ➂ ✮ ◗ ✈✡❼ ➂ ➂ ◗ ✈★❼ ➂✰✮ ❀✯➂ ❇ ◗ ✈✡❼ ➂ ➂ ✮ ◗ ✈★❼ ❀✯➂✣➉●✌✱q❼ ✼✴➂ ❩ ❂ ✿✯❊✏❆ ❂⑦❄ ❆✹♦ ❂❝❄➵✫ ❊✛●◆➡✣❁❇✿ ▼✛❃ ❈➓❆ ❃✹❂✼❂⑦❄❝➥ ❆✹♦✣❁ ❄ ❆ ❃❅▼ ✿ ❄☞s↕▼ ❆ ❂⑦❄ ❁❺✿ ❆ ❂✼❃♣❯✂❄ ❊✛● ◗ ❊ ❄ ❆❪✇ ❂ ✿ ❂✼❃❅▼ ❆❉❁❇✿✯✇❲● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❁❇✿❆✹♦ ❂ ●➉❊ ❃✹❯ ✲✴✳❼ ✼✣➂✍➍ ✱q❼ ✼✣➂ ❡➀➄✿✼ ✱q❼ ✼✴➂ ✲✴✳ ❼ ✼✣➂✱❡➀➄✵✼ ✱q❼ ✼✣➂ ✲✴✵✷✶ ❼ ✼✴➂ ➄✲✴✵✷✶❼ ✼✣➂✍➍ ✱q❼ ✼✣➂ ❡➀➄✿✼ ✱q❼ ✼✴➂ ✲✴✵✷✶ ❼ ✼✣➂❸➆➣ ❄

Page 101: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❻ ✖♥❖ ❁❇➦ ▼✐s❇❂ ✿✣❆ s ❈ ➥ ❈ ❂ ♦ ▼ ➦ ❂ ❆✹♦ ❂❷❯✂▼ ❆ ❃ ❁ ➆ ❃✹❂ ✈ ❃✹❂⑦❄r❂ ✿❏❆ ▼ ❆❉❁❇❊✏✿✏ ✲✴✳ ❼ ✼✣➂✲✴✵✷✶❼ ✼✣➂ ✒ ➍ ✏ ➄✵✼ ✱→❼ ✼✣➂ ➄✵✼ ✱q❼ ✼✣➂➏ ➄✵✼ ✱q❼ ✼✣➂ ✒ ✏ ❘ ✲✴✳ ❼ ✼✣➂✲✴✵✷✶

❼ ✼✣➂ ✒ ❡ ✏ ✱q❼ ✼✣➂✱q❼ ✼✣➂ ✒ ➆❼ ❙ ➂⑤⑥♦ ❂❹❄ ❊ s❺❖ ❆r❁❺❊♥✿❋❁ ❄✲✴✳

❼ ✼✣➂✍➍ ✱q❼ ✼✣➂❼ ❙ ●①➄✿✼ ✱q❼ ✼✴➂✹➂ ➋ ➍ ✱q❼ ✼✣➂ ❼ ❙ ❡ ✱ ➋ ❼ ✼✣➂✹➂❼ ❙ ● ✱q❼ ✼✣➂✹➂ ➋ ❼ ❙ ❡ ✱→❼ ✼✣➂✹➂ ➋ ➄ ✲✴✵✷✶❼ ✼✣➂☎➍ ✱q❼ ✼✣➂ ❼ ❙ ❡ ✱ ➋ ❼ ✼✣➂✹➂❼ ❙ ● ✱q❼ ✼✴➂✹➂ ❼ ❙ ❡ ✱→❼ ✼✣➂✹➂ ➆� ❁❇✿ ◗ ❂ ✱q❼ ✼✣➂☎➍ ✼✕✔ ❼ ✱→❼ ✼✣➂✹➂ ❈♠❁❺❆♣♦ ✔ ❼ ❃❷➂✍➍ ❙ ❡✰❃ ➋

➥✞✗❋▼ ✿✚❩ ✚ ▼✛❃✹❂❪❂⑦▼✏❄ ❁ s ❈❬❩ ❂ ❆ ❂✼❃♣❯ ❁❇✿ ❂ ❩ ✎ ✗ ➍ ❙✏➥ ✚❱➍ ❙ ✝ ➄ ④✖ ✾ ✴ ✰✾✲☎✩ ✴❲➢ ✢✿✧✴☎✷✕ ✴ ✥ ❬ ✝✳✲✵✴ ⑤⑥♦ ❂ ◗ ❊ ❄ ❆ ❄➵✫✲✴✵✷✶

❼ ✼✣➂ ❈ ❃ ❁❇❆ ❂⑦❄➔▼✏❄ ✟➔❼ ✱→❼ ✼✣➂✹➂ ➥ ❈❀♦ ❂✼❃✹❂ ✟➔❼ ❃⑧➂ ❁ ❄❹▼➊❃❅▼ ❆❉❁❇❊✏✿ ▼✱s ● ❖ ✿ ◗ ❆❉❁❇❊✏✿✡④⑤⑥♦ ❂ ❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆❡✈✢❊ s❇❂ ❊✤● ✟➔❼ ❃⑧➂ ❁ ❄ ❃ ➍ ✗❹▼ ✿✚❩➫❁❺❆✓❁ ❄❡❄ ❁ ❯ ✈ s❺❂ ④ ➌ ✿ ▼ ✈✯✈ s ❁ ◗ ▼ ❆❉❁❇❊✏✿q❊✛●✚❆ ❃❅▼ ✿ ❄ ● ❂✼❃★s❇❂✼❯❱❯❲▼ ❊✛● ❄ ❁❇✿✯✇ ❖✣s↕▼✛❃ ❁❇❆❉❈▼ ✿ ▼✐s ❈ ❄ ❁ ❄ ❚ ➄ ❫★❆✹♦ ❂ ✿ s❇❂⑦▼ ❩ ❄ ❆✹❊q❆✹♦ ❂❷❂⑦❄ ❆❉❁ ❯✂▼ ❆ ❂

✲ ✵✷✶➧✂✁ ❘ ➠ ❅✬❈⑥❁❇❆✹♦ ❘ ➠ ➳ ➏ ●➋❊ ❃ ❆♣♦ ❂ ◗ ❊ ❄ ❆■❊✤●❡❆✹♦ ❂ ◗ ❊✏✈✣❈❱❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃ ❊✛➦ ❂✼❃❆ ❃✹❂✼❂⑦❄ ❊✛● ❄ ❁❥✐ ❂ ❅❡④ ➌ ❄ ●➉❊ ❃ ❆✹♦ ❂ ◗ ❊ ❄ ❆ ❄➵✫ ✲✴✳ ❼ ✼✣➂ ➥ ❁❇❆❜❈ ❃ ❁❇❆ ❂⑦❄➇▼✏❄☎▼❹❃❸▼ ❆❉❁❇❊✏✿ ▼✐s ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ▼✐s ❁❇✿ ✱q❼ ✼✣➂ ❈⑥❁❇❆✹♦✂❆♣♦ ❂ ❩✣❊ ❖ ➡ s❇❂❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆➇✈✢❊ s❇❂✰✗★➥✯▼ ✿✚❩ ❈ ❂ ❩ ❂ ❩ ❖ ◗ ❂✪▼ ✿ ▼ ➦ ❂✼❃❅▼ ✇ ❂➫▼♥❄ ❈ ❯ ✈✯❆✹❊✏❆❉❁ ◗ ➦ ▼✱s❺❖✯❂ ❊✛●✶❆✹♦ ❂ ●➉❊ ❃✹❯ ✲ ✳

➧ ✁ ❘ ➋ ❅ ➃ ✏ ➋ ➥ ❘ ➋ ➳ ➏ ④�✂✁ ✔★✟ ✺✓❥✶✖✍✢✬✄ ✄✝✟☎✄✵✄✧☞✍☛✌☞ ❤ ✺✷✎✮❑✳✎❖☛✦✟✬✸ ✎

⑤⑥♦ ❂ ❯✂▼ ❆ ❃ ❁ ➆ ❃✹❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ▼ ❆❉❁❇❊✏✿ ❼ ❙ ➂ ●➉❊ ❃ ❆✹♦ ❂ ◗ ❊ ❄ ❆ ❄➵✫✝✆③❄ ◗ ▼ ✿➒➡ ❂ ✇ ❂ ✿ ❂✼❃❅▼✱s ❁ ❄❉❂ ❩➒●➋❊ ❃❋▼✐s➏s❹❃✹❂ ✇ ❖✣s↕▼✛❃❲❃✹❂ ❈ ❃ ❁❺❆r❁❺✿✯✇❄ ❈ ❄ ❆ ❂✼❯✂❄ ❚ ❙ ❫✑④✑✓✒✕✔✗✖✙✘✚✔✜✛ ❙ ❼✏✛❜❘✟✞✠✘✤❘✡✠ ✘✚✔✟☛✜✘✚✔☎☞❖✔✟✌✍✞✗❘✟✞ ❘ ✖✎✌✄❬❉✖✙✘✡✘✚✔ ❚❙❱✑✏☎❘✙✘✡✘✚✔✓✒✬✘✤❘✔✞ ❘✕✌ ❚✖☞✘✗✙☞✚✞✠✔✜✛✛☞ ➂ ✢ ✶ ✗✜✴➇➢ ✢ ✷ ✝ ✿✫✮✢✜ ✷ ✢❁✫✢❨☎ ✴ ✰✾✲✿✝➉✢✱✰ ✷ ➟♥➠❙➄ ➆⑦➆⑦➆ ➄❅➟ ➧ ✢❁✫✥✲ ✰ ✴ ✩✵✭✼✕ ✲❀✰ ✷ ✲ ✷ ✝ ✴ ✧ ✷ ✲✿✝ ❬❇✷ ✫✮✲❑✲ ✷ ✲ ✷ ✝ ✴ ✧✡✢❁✫❴✝ ✗❃✴ ✫➆✢❀✰✉✧✣✤

✥✲✝✦ ❉ ❼ ✼✣➂✴✴✴✲✝✦★✧

❼ ✼✣➂

✩✫✪✬ ➍✮✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂✹➂ ✣✤✥

✲✝✦ ❉ ❼ ✼✣➂✴✴✴✲✝✦★✧❼ ✼✣➂

✩✫✪✬ ❡

✣✤✥❜ ✹ ❉ ❼ ✼✣➂✴✴✴❜ ✹✧❼ ✼✴➂

✩✫✪✬ ➄❼ ➄✣➂

✯ ✗✜✴ ✰ ✴ ✝ ✗✜✴ ✾❖▲ ✲✱✰ ✴ ✝ ✗✜✴ ✲✱✰ ❬ ✝ ❬✽✴✒✷ ✢❁✫✪✝ ✗✜✴ ➟✝▲ ✜ ✷ ✸ ✲ ✵✞✂ ✯ ✗✜✴ ✰ ✴ ✝ ✗✜✴❲➢ ✢ ✴✕✯✖➢✴❬✍✴❅✵ ✝❙✢❁✫✪✝ ✗✜✴✣✷✚✰ ✭❃✲✱✰ ✴ ✧✥✲✿✝❏✰ ❬ ✥ ✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂♣➂✲✱✰ ✴ ☎Ø✢✿✕ ✲ ✵ ✢✦✧ ❬ ✲✿✕ ✷✡❬✽✵ ✼ ✲ ✵❂✂ ❜❷❼ ✼✣➂ ✯ ❬ ✝ ✗ ✵ ✢ ✵ ✵ ✴ ✩✱✲✦✝ ❬ ✾ ✴❹➢ ✢ ✴✕✯✖➢✴❬✍✴❅✵ ✝ ✷ ✴⑤⑥♦ ❖✚❄✼➥ ❆✹♦ ❂❷❂ ➆✯✈ ❃✹❂⑦❄✹❄ ❁❺❊♥✿➓❊✛● ❂⑦▼ ◗ ♦ ◗ ❊ ❄ ❆ ❄➸✫ ❁ ❄✲✝✦★✱❼ ✼✣➂☎➍ ❩ ❂ ❆✚✲ ▲✴✳ ❼✥✣❾❩ ●✵✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂✹➂✹➂❩ ❂ ❆✼❼ ✣❾❩ ●✶✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂♣➂✹➂ ➄❼ ② ➂

❈➇♦ ❂✼❃✹❂ ✲ ▲✴✳ ✹✔❩ ❂ ✿✯❊♥❆ ❂⑦❄ ❆✹♦ ❂❘❯❲▼ ❆ ❃ ❁ ➆q❁❇✿✬❈➇♦✣❁ ◗ ♦❲❆✹♦ ❂ ❄ ➑ ❆✹♦ ◗ ❊ s❇❖✯❯ ✿❋❊✛●✳✹ ♦ ▼✏❄ ➡ ❂✼❂ ✿ ❄❉❖ ➡ ❄ ❆❉❁❇❆ ❖ ❆ ❂ ❩➈➡✣❈❱❆✹♦ ❂❪❃ ❁❇✇✏♦❏❆ ❯ ❊ ❄ ❆➦ ❂ ◗ ❆✹❊ ❃ ❊✤● ❂✞✖♥❖✚▼ ❆❉❁❇❊✏✿➲❼ ➄✣➂ ④✶➞ ❂ ❩ ❂ ❩ ❖ ◗ ❂✏➥★❄ ❁❇✿ ◗ ❂ ✼➔➍ ❜❷❼ ✼✣➂ ✝ ✔ ❼✮❜❷❼ ✼✣➂♣➂ ➥ ❆✹♦ ▼ ❆ ✲✷✦✸✱ ❼ ✼✣➂ ❈ ❃ ❁❇❆ ❂⑦❄➇▼✏❄✲✝✦ ✱❼ ✼✴➂✍➍ ✼ ▲ ❼✮❜⑧❼ ✼✣➂✹➂➇ ▲☞❼✮❜❷❼ ✼✴➂✹➂ ➄❈➇♦ ❂✼❃✹❂ ✼ ▲☞❼ ❃❷➂ ▼ ✿✚❩ ➇ ▲☞❼ ❃⑧➂ ▼✤❃✹❂ ✈✚❊ s ❈✣✿✯❊ ❯ ❁ ▼✐s↕❄ ④⑥⑤⑥♦ ❂✪▼ ➦ ❂✼❃❸▼ ✇ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆❏❁❇❆❉❈❋❊✛●✍❆✹♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃ ➟✝▲ ➥ ❩ ❂ ❦ ✿ ❂ ❩➨➡❏❈✲ ✦ ✱➧ ➍ ❚ ✼ ➧ ❫

✲✝✦ ✱❼ ✼✣➂❚ ✼ ➧ ❫❥❜ ✹✱❼ ✼✣➂ ➄

❁ ❄ ❩ ❂ ❆ ❂✼❃✹❯ ❁❺✿ ❂ ❩✝➡✣❈➀❆♣♦ ❂❋❃✹❂❸s↕▼ ❆❉❁❇➦ ❂ ✈✚❊ ❄ ❁❇❆❉❁❇❊✏✿✖❊✛● ✚ ❈⑥❁❇❆✹♦ ❃✹❂⑦❄ ✈ ❂ ◗ ❆❱❆✹❊ ❆✹♦ ❂➓❄❉❯✂▼✱sts❇❂⑦❄ ❆❲✈✚❊ ❄ ❁❇❆❉❁❇➦ ❂❬❄ ❊ s❺❖ ❆r❁❺❊♥✿ ✚✹✺ ❯ ▲⑥❊✛●➇ ▲☞❼✮❜❷❼ ✚ ✺ ❯ ▲ ➂✹➂✍➍ ➏ ❼ ❄❉❂✼❂ ❚ ❙ ❫ ➂ ④✑✓✒✕✔✗✖✙✘✚✔✜✛ ➄ ❼★✹✻✺❭✔✜✘ ❘ ❚❭✔✽✼✚✖✙☞✘✞ ✔☎☞✘✞ ❘✳✛❙❘✟✞✠✔ ➂ ✢ ✶ ✗✜✴ ✲✿✾ ✴ ✰✚✲✆✩ ✴q➢ ✢ ✷ ✝ ✷ ✲✿✝ ❬❇✷ ✱ ✴✒✷❼➉❁ ➂✿✾ ✫ ➇ ▲ ❼❭❜❷❼ ✼✣➂✹➂ ✂ ✢ ✴☞✷✄✵ ✢✿✝ ✾✶✲ ✵ ❬❁✷❨✗ ✢ ✵ ❼ ➏ ➄ ✚ ❫ ✸ ✝ ✗✜✴❅✵ ✲✦✸✱➧ ➍★❘ ➠ ❼ ❙ ❡ ✣ ❼ ❙ ✝ ❅ ➂✹➂ ❄❼➉❁➏❁ ➂ ❬ ✫ ✚➈➍ ✚ ✺ ❯ ▲ ✸ ✝ ✗❃✴✶✵ ✲

✦★✱➧ ➍★❘ ➋ ❅ ❤ ✏ ➋ ❼ ❙ ❡✤✣ ❼ ❙ ✝❁❀ ❅ ➂✹➂ ❄➣ ➅

Page 102: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❼➉❁➏❁➏❁ ➂ ❬ ✫ ✚❲➳✘✚ ✺ ❯ ▲ ✸ ✝ ✗❃✴✶✵ ✲✦★✱➧ ➍★❘ ➃ ❼ ✚ ✝ ✚ ✺ ❯ ▲ ➂ ➧ ❅✁� ☞ ➠ ✏ ➋ ❼ ❙ ❡ ✣ ❼ ❙ ✝ ❀ ❅ ➂✹➂✍✸✯ ❬ ✝ ✗ ❘ ➁ ➳ ➏ ✲ ✵❂✂ ✺ ✸ ✪ ☎Ø✢ ✷ ❬ ✝ ❬ ✾ ✴✳❬✽✵ ✝ ✴ ✩ ✴ ✰ ✷ ✴✣✑✿➲❆✹♦ ❂ ◗ ▼✏❄❉❂ ✚ ➍ ✚ ✺ ❯ ▲ ➥ ❈ ❂ ♦ ▼ ➦ ❂ ✺ ➍ ✘ ❡ ❙ ❈➇♦ ❂✼❃♣❂ ✘q❁ ❄ ❆✹♦ ❂❱❯q❖✣s ❆❉❁❇✈ s ❁ ◗ ❁❇❆❉❈➀❊✤●◆❆✹♦ ❂ ● ▼ ◗ ❆✹❊ ❃ ❼✮❜❷❼ ✼✣➂❵● ✗ ➂ ❁❇✿➇ ▲☞❼✮❜❷❼ ✼✣➂✹➂ ④

❊ ✁ ❋☎✆ ✸✕✞❦❥✲☛✦✢✤☛✌☞✍✆✡❤✷✆✒✑ ☛❖●✂✟✱✆✲✄✮✩✪✟✤✄✏✆✒✑ ☛❖●✂✟✽✢✄✂✂✟✡✄✝✢✦✺✬✟ ❧✮✆✲✎❖☛✣✑❆➈❁ ❄ ✈✢❊ ❄✹❄ ❁❇➡ s❇❂ ❆✹❊✦❩ ❂✼❃ ❁❇➦ ❂ ❩♥❁ ❃♣❂ ◗ ❆ s ❈✉● ❃ ❊ ❯ ❆✹♦ ❂➨❯✂▼ ❆ ❃ ❁ ➆ ✭ ❼ ✼ ➄ ❜⑧❼ ✼✣➂✹➂ ❆✹♦ ❂ ❊ ❃ ❩ ❂✼❃ ❊✛●➫❆♣♦ ❂❬▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❄ ❆❱❊✛●❆✹♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❸❄ ❊✛● ▼➲❃✹❂ ✇ ❖✣s↕▼✛❃➓❄ ❈ ❄ ❆ ❂✼❯ ④⑩⑤⑥♦ ❂①❄❉❖ ➡ ❄ ❆ ▼ ✿ ◗ ❂ ❃✹❂❸s ❁ ❂⑦❄ ❊✏✿ ✫✯❃ ❊✏➡ ❂ ✿✣❁ ❖✚❄ ❆♣♦ ❂ ❊ ❃ ❈✉❊✛● ❯✂▼ ❆ ❃ ❁ ◗ ❂⑦❄ ❈⑥❁❇❆✹♦✿✯❊✏✿✯✿ ❂ ✇ ▼ ❆❉❁❇➦ ❂ ◗ ❊ ❂ ☛❨◗ ❁ ❂ ✿✣❆ ❄ ❼ ❄❉❂✼❂ ●➉❊ ❃ ❁❇✿ ❄ ❆ ▼ ✿ ◗ ❂ ❚ ✯ ❫ ➂ ④ ⑤⑥♦ ❂ ✇ ❂ ✿ ❂✼❃❅▼✐s ❆ ❂ ◗ ♦✯✿✣❁ ✖♥❖✯❂ ✈ ❃ ❊ ◗ ❂✼❂ ❩ ❄➈▼✏❄ ●➋❊ s➏s ❊❖❈ ❄ ④ ✫ ❁ ❃❅❄ ❆ ➥❩ ❂ ◗ ❊ ❯ ✈✢❊ ❄❉❂ ✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂✹➂ ❁❇✿❏❆✹❊✦❩♥❁ ▼ ✇✏❊✏✿ ▼✐s ➡ s ❊ ◗ ➔✯❄ ❊✛●❀❁ ❃♣❃✹❂ ❩ ❖ ◗ ❁❇➡ s❺❂➲❯✂▼ ❆ ❃ ❁ ◗ ❂⑦❄ ❼✻❆ ❂ ❦ ✿✣❁❇❆❉❁❇❊✏✿ ❙ ➂ ➥ ❆✹♦ ❂ ✿✡❈⑥❊ ❃ ➔ ❊✏✿❂⑦▼ ◗ ♦❲❁ ❃✹❃✹❂ ❩ ❖ ◗ ❁❇➡ s❇❂ ➡ s ❊ ◗ ➔ ④❊✪✁➉❢✒✁❱❣✦✄✮✄✌✟✤✩❦❥▲❧✿☞✆☎✠✖✘✟ ✸✱✢✤☛✌✄✧☞➣➝✖❧✮✢✬✎❖✟✲✁✝❋✔✜❬ ❘✕✌★❘✡✞ ❘ ✖✎✌ ❙✗✢ ➌ ❄ ✖♥❖✚▼✛❃✹❂❪❯✂▼ ❆ ❃ ❁ ➆ ✭ ❁ ❄✓❬ ✰ ✰ ✴✉✂ ✭ ➢ ❬ ➤✔✕ ✴ ❁➏●❡❆♣♦ ❂✼❃✹❂ ❩✣❊ ❂⑦❄ ✿✯❊✏❆ ❂ ➆❏❁ ❄ ❆ ▼ ✿❏❈q✈ ❂✼❃✹❯q❖ ❆ ▼ ❆❉❁❇❊✏✿ ❯✂▼ ❆ ❃ ❁ ➆✼ ❄r❖ ◗ ♦❋❆✹♦ ▼ ❆ ✼ ❞ ➠ ✭ ✼ ➍ ❼✟✞ ✺✠☛✡ ➂ ❈⑥❁❇❆✹♦ ✹ ➥ ✱ ▼ ✿✚❩

✲❄ ✖✏❖✚▼✤❃✹❂❷❯✂▼ ❆ ❃ ❁ ◗ ❂⑦❄ ④✣✑✿➨❊✏❆✹♦ ❂✼❃ ❆ ❂✼❃✹❯✂❄✼➥✯▼ ✿➊❁ ❃♣❃✹❂ ❩ ❖ ◗ ❁❇➡ s❺❂➈❯✂▼ ❆ ❃ ❁ ➆❲❁ ❄❘▼✏❄♣❄ ❊ ◗ ❁ ▼ ❆ ❂ ❩❲❆✹❊ ▼❱❄ ❆ ❃ ❊✏✿✯✇ s ❈ ◗ ❊✏✿✯✿ ❂ ◗ ❆ ❂ ❩❋✇ ❃❅▼ ✈✯♦✡④❭✣ ●■❆✹♦ ❂❷❯✂▼ ❆ ❃ ❁ ➆✭ ❼ ✼ ➄ ❜⑧❼ ✼✣➂✹➂ ❁ ❄ ❁ ❃✹❃✹❂ ❩ ❖ ◗ ❁❇➡ s❇❂✏➥ ❆✹♦ ❂ ❊ ❃ ❩ ❂✼❃ ❊✛●✍❆✹♦ ❂❹▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❯ ✈ s❺❂ ➆✣❁❇❆❉❈❋❊✛●✟❆♣♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄⑥▼✛❃✹❂❷❂⑦▼♥❄ ❁ s ❈❲●➉❊ ❖ ✿✚❩★④✑✓✒✕✔✗✖✙✘✚✔✜✛ ② ✢✤✣✘✴ ✝ ❏ ➟✝▲ ❖ ➤ ✴ ✲ ✷ ✴ ✝❬✢ ✫í✢❨☎ ✴ ✰✾✲✿✝➉✢✱✰ ✷ ✢ ✫ ✲ ✰ ✴ ✩✵✭✼✕ ✲❀✰ ✰ ✴ ✯ ✰ ❬ ✝ ❬✍✵ ✩ ✷ ✲ ✷ ✝ ✴ ✧ ✰ ✴ ☎✹✰ ✴✒✷✒✴✶✵ ✝ ✴❨✂ ➤✮✲ ✲ ✵❬ ✰✔✰ ✴❨✂ ✭ ➢✴❬ ➤❞✕ ✴ ✧ ✲✦✝❏✰ ❬ ✥ ✭ ❼ ✼ ➄ ❜❷❼ ✼✴➂✹➂ ✴ ✶ ✗✜✴✶✵ ✲✦✕✙✕❙✝ ✗✜✴ ✚ ✺ ❯ ▲✳✲✱✰ ✴✁✴ ✰ ✭❃✲✿✕❙✝➉✢➝✝ ✗✜✴ ✷ ✧✥✲✿✕✖✕ ✴✒✷ ✝❛☎✣✢ ✷ ❬ ✝ ❬ ✾ ✴ ✰✆✢t✢✿✝ ✚ ✺ ✢❁✫✬✝ ✗❃✴✴ ✰ ✭❃✲✿✝ ❬ ✢ ✵ ❩ ❂ ❆✼❼ ✾ ✂ ● ✭ ❼ ✼ ➄ ❜⑧❼ ✼✣➂✹➂✹➂❪➍ ➏

❨ ✝❏✲✼✻ ✴ ✚ ✺→➍ ❡✌☞ ❬ ✫â✝ ✗✜✴ ✰ ✴✢❬❇✷❑✵ ✢❖☎Ø✢ ✷ ❬ ✝ ❬ ✾ ✴❑✷ ✢✿✕ ✭✺✝ ❬ ✢ ✵ ❪ ✴✄✶ ✗✜✴ ✰ ✴ ✕✖✲✿✝ ❬ ✾ ✴☎Ø✢ ✷ ❬ ✝ ❬ ✢ ✵ ✢❁✫ ✚ ✺ ✯ ❬ ✝ ✗ ✰ ✴✒✷ ☎ ✴❸➢ ✝➊✝➉✢ ✚ ❬❇✷➵✂❀✴ ✝ ✴ ✰❨✧ ❬✍✵ ✴✉✂ ✫ ✰✆✢✿✧✡✝ ✗❃✴❬✂ ✢✿✧ ❬✍✵ ✲ ✵ ✝ ✴✴❬ ✩ ✴✶✵ ✾❅✲✿✕ ✭ ✴ ✾♥❼ ✚ ➄ ✗ ➂ ✢❁✫ ✭ ❼ ✚ ➄ ✗ ➂ ✴✎✍ ✴✗ ✲✿✾ ✴ ✾♥❼ ✚ ➄ ✗ ➂✠❛ ❙ ❬ ✏ ✚ ✺❀➳✘✚ ➄ ✾✏❼ ✚ ➄ ✗ ➂✡➍ ❙❝❬ ✏ ✚ ✺♠➍ ✚ ➄ ✾♥❼ ✚ ➄ ✗ ➂❡➳ ❙❝❬ ✏ ✚✹✺✷❛✘✚★➆➞ ♦ ❂ ✿❵✾♥❼ ✚ ➄ ✗ ➂✶➍ ❙✏➥ ❊ ❃➇❂✞✖✏❖ ❁❇➦ ▼✐s❇❂ ✿❏❆ s ❈ ✚✹✺➇➍ ✚ ➥ ❁❇❆❀❁ ❄ ✈✢❊ ❄✹❄ ❁❇➡ s❇❂ ❆✹❊❱✇ ❂ ❆➇❆♣♦ ❂❹❂ ➆✯✈✚❊✏✿ ❂ ✿✣❆❘❊✤●❙❅➨❁❇✿➨❆✹♦ ❂❹❂⑦❄ ❆r❁ ❯❲▼ ❆ ❂❼➉❁➏❁ ➂ ❊✤●❦⑤⑥♦ ❂ ❊ ❃✹❂✼❯ ❙ ④✍⑤⑥♦✣❁ ❄ ❁ ❄ ❆✹♦ ❂ ✈✢❊ s ❈❏✿✯❊ ❯ ❁ ▼✱s ◗ ▼✏❄r❂ ④✑✓✒✕✔✗✖✙✘✚✔✜✛ ✒ ✢✤✣✘✴ ✝ ❏ ➟ ▲ ❖ ➤ ✴ ✲ ✷ ✴ ✝❬✢ ✫í✢❨☎ ✴ ✰✾✲✿✝➉✢✱✰ ✷ ✢ ✫ ✲ ✰ ✴ ✩✵✭✼✕ ✲❀✰ ✰ ✴ ✯ ✰ ❬ ✝ ❬✍✵ ✩ ✷ ✲ ✷ ✝ ✴ ✧ ✰ ✴ ☎✹✰ ✴✒✷✒✴✶✵ ✝ ✴❨✂ ➤✮✲ ✲ ✵❬ ✰✔✰ ✴❨✂ ✭ ➢✴❬ ➤❞✕ ✴ ✧✥✲✿✝❏✰ ❬ ✥ ✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂✹➂ ✴ ✾ ✫✜✝ ✗✜✴➏✂ ✢✿✧ ❬✽✵ ✲ ✵ ✝ ✴✴❬ ✩ ✴✶✵ ✾❅✲✿✕ ✭ ✴ ✢❁✫ ✭ ❼ ✚ ➄ ✗ ➂ ❬❇✷❱❙ ✸ ✝ ✗✜✴❅✵ ✝ ✗✜✴ ➟✝▲ ✜ ✷✚✗ ✲✿✾ ✴ ✲ ✵✲✿✾ ✴ ✰✾✲☎✩ ✴q➢ ✢✿✧✴☎✷✕ ✴ ✥ ❬ ✝✳✲❋✯ ✗✝❬↕➢❞✗✏❬❁✷ ✕ ❬✽✵ ✴ ✲✱✰↕✢❀✰❴✢❁✫❴✢✱✰ ✂✱✴ ✰✿❅ ➃ ✏ ➋ ✴⑤⑥♦ ❂ ◗ ▼✏❄r❂ ❅ ➃ ✏ ➋ ❊ ◗✼◗ ❖✯❃❅❄ ❊✏✿ s ❈➈❁❺✿➨❆✹♦ ❂ ❩ ❂ ✇ ❂ ✿ ❂✼❃❅▼ ❆ ❂ ◗ ▼✏❄r❂ ❈➇♦ ❂✼❃✹❂ ✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂♣➂ ❩✣❊ ❂⑦❄ ✿✯❊✏❆➇❩ ❂ ✈ ❂ ✿✚❩➓❊♥✿✢❜❷❼ ✼✣➂ ④❊✪✁✗�✂✁❝✸ ✟✢❤✲✟✤✄✝✢✬✖⑥❧✮✢✬✎✦✟✂✁ ✣✑✿❋❆✹♦ ❂ ✇ ❂ ✿ ❂✼❃❸▼✐s ◗ ▼✏❄❉❂✏➥ ❈ ❂❹❄ ❆ ▼✛❃ ❆☎➡❏❈ ❦ ✿✚❩♥❁❇✿✯✇ ▼ ✈ ❂✼❃✹❯q❖ ❆ ▼ ❆❉❁❇❊✏✿ ❯✂▼ ❆ ❃ ❁ ➆ ✼ ❄❉❖ ◗ ♦❋❆✹♦ ▼ ❆✼ ❞ ➠ ✭ ✼ ❈ ❃ ❁❇❆ ❂⑦❄❀▼✏❄➇▼ ➡ s ❊ ◗ ➔ ❩♥❁ ▼ ✇✏❊♥✿ ▼✐s✡❯✂▼ ❆ ❃ ❁ ➆ ➥✯❂⑦▼ ◗ ♦❋➡ s ❊ ◗ ➔ ➡ ❂ ❁❇✿✯✇❋❊✛●❡❆♣♦ ❂ ●➉❊ ❃✹❯

✱ ➍✣✤✤✥✹ ➠ ➏④ ④ ④ ④ ④ ④④ ④ ④ ④ ④ ④ ✹ ❤

✩✫✪✪✬ ➄

❈➇♦ ❂✼❃✹❂q❂⑦▼ ◗ ♦✰✹ ▲ ➍ ✹ ▲✑❼ ✼ ➄ ❜❷❼ ✼✣➂✹➂ ❁ ❄❹▼ ✿➓❁ ❃✹❃♣❂ ❩ ❖ ◗ ❁❺➡ s❇❂➓❄ ✖♥❖✚▼✛❃✹❂ ➡ s ❊ ◗ ➔ ④q➞ ❂✂▼✐s↕❄ ❊❋✿ ❂✼❂ ❩ ❆✹♦ ❂ ◗ ❊✏✿ ❄ ❆ ❃❅▼ ❁❺✿✣❆❷❆✹♦ ▼ ❆❪●➉❊ ❃▼✐s➏s ❄❇❛✒✑ ➥ ❆✹♦ ❂q❄❉❖ ➡ ❯✂▼ ❆ ❃ ❁ ➆➓❊✛● ✱ ❈➇♦✯❊ ❄❉❂❪s ❁❇✿ ❂⑦❄❹▼✛❃♣❂ ❆✹♦✯❊ ❄r❂ ❊✛● ✹ ➁ ▼ ✿✚❩ ◗ ❊ s❇❖✯❯ ✿ ❄❷▼✤❃✹❂ ❆✹♦✯❊ ❄❉❂ ❊✛● ✹ ▲✡❁ ❄ ✿✯❊✏❆❁✐ ❂✼❃ ❊✚④❑ ❊✏✿ ❄ ❁➣❩ ❂✼❃ ❁❺✿✯✇ ❆✹♦ ❂ ✇ ❃❸▼ ✈✯♦ ❃✹❂ ✈ ❃✹❂⑦❄r❂ ✿❏❆ ❂ ❩➨➡✣❈ ❆✹♦ ❂❱❯✂▼ ❆ ❃ ❁ ➆ ✭ ➥ ❆✹♦✣❁ ❄ ❆ ▼✏❄❇➔ ◗ ▼ ✿①➡ ❂✂▼ ◗ ♦✣❁ ❂ ➦ ❂ ❩ ❆✹♦ ▼ ✿ ➔✯❄ ❆♣❊➓⑤ ▼✛❃⑦✭r▼ ✿▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ❊✏✿ ❄ ❆ ❃ ❊✏✿✯✇ s ❈ ◗ ❊♥✿✯✿ ❂ ◗ ❆ ❂ ❩ ◗ ❊ ❯ ✈✚❊✏✿ ❂ ✿✣❆ ❄ ❼ ❄❉❂✼❂ ❚③② ➥ ✈✯✈✡④ ✒✦✒✚❙✔✓✺✒✿✒ ✝ ❫✯●➉❊ ❃➇❂ ➆ ▼✛❯ ✈ s❇❂ ➂ ④➎❀❊❉❈ ➥⑥❂⑦▼ ◗ ♦ ➡ s ❊ ◗ ➔ ❊✛●❹❆✹♦ ❂ ●➋❊ ❃✹❯ ✱ ◗ ▼ ✿ ➡ ❂ ◗ ❊✏✿ ❄ ❁↕❩ ❂✼❃✹❂ ❩✝❁❇✿✚❩ ❂ ✈ ❂ ✿✚❩ ❂ ✿❏❆ s ❈✏④✸➐ ❂ ❆ ✲✷✦

✕ ❼ ✼✣➂ ➡ ❂①▼ ◗ ❊ ❄ ❆ ❄➵✫▼✏❄✹❄ ❊ ◗ ❁ ▼ ❆ ❂ ❩➨❆✹❊ ▼ ✿➓❁ ❃✹❃♣❂ ❩ ❖ ◗ ❁❺➡ s❇❂➓❄ ✖♥❖✚▼✛❃✹❂ ➡ s ❊ ◗ ➔ ✹✗✖ ④q❻✺➆✯✈ ❃✹❂⑦❄✹❄ ❁❇❊✏✿✉❼ ② ➂ ❆♣❊✏✇ ❂ ❆✹♦ ❂✼❃ ❈⑥❁❇❆✹♦①⑤⑥♦ ❂ ❊ ❃✹❂✼❯ ② ❄ ♦✯❊❖❈➑❆✹♦ ▼ ❆❆✹♦ ❂ ✈✚❊ ❄ ❁❇❆❉❁❇❊✏✿✂❊✤● ✚✹✺ ❯ ➁ ❁ ❄ ❆✹♦ ❂❘❄❉❯❲▼✐s➏s❺❂⑦❄ ❆✍✈✚❊ ❄ ❁❇❆❉❁❇➦ ❂❪❃ ❊✣❊✏❆✶❊✛● ➉ ✖ ▲✙✘✢➠ ❩ ❂ ❆❝❼✥✣❾❩ ● ✹ ▲ ➂ ④✍⑤⑥♦ ❖✚❄✼➥ ❁➏● ✚ ▲✚❩ ❂ ✿✯❊✏❆ ❂⑦❄ ❆✹♦ ❂➇❄❉❯✂▼✱sts❇❂⑦❄ ❆✈✚❊ ❄ ❁❇❆❉❁❇➦ ❂q❃ ❊❏❊♥❆➇❊✛●■❩ ❂ ❆✼❼✥✣❾❩ ● ✹ ▲ ➂ ➥ ●➋❊ ❃➇❂⑦▼ ◗ ♦✛✚ ➥ ❈ ❂ ✿ ❂✼❂ ❩➨❆✹❊ ◗ ❊ ❯ ✈ ▼✛❃✹❂ ✚ ✖❜❈♠❁❺❆♣♦ ❯ ❁❇✿✡➠✢✜✚▲✣✜✤✖ ❞ ➠ ✚ ▲✓❁❇✿ ❊ ❃ ❩ ❂✼❃ ❆✹❊➈✇ ❂ ❆➣ ➄

Page 103: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❆✹♦ ❂ ❊ ❃ ❩ ❂✼❃ ❊✛●■❆✹♦ ❂✪▼ ➦ ❂✼❃❸▼ ✇ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆✣❁❇❆❾❈➨❊✛●■❆✹♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄ ➟ ➁ ④✱✣✑✿➨● ▼ ◗ ❆ ➥ ⑤⑥♦ ❂ ❊ ❃✹❂✼❯ ② ▼✏❄✹❄r❂✼❃ ❆ ❄ ❆✹♦ ▼ ❆➇❆✹♦✣❁ ❄ ❆ ▼♥❄✵➔◗ ▼ ✿❋➡ ❂✪▼ ◗ ♦✣❁ ❂ ➦ ❂ ❩❋➡✣❈ ◗ ❊ ❯ ✈ ▼✛❃ ❁❇✿✯✇❲❊✏✿ s ❈❋❆✹♦ ❂ ❩✣❊ ❯ ❁❇✿ ▼ ✿✣❆ ❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂⑦❄ ✾✦▲☞❼ ✚ ➄ ✗ ➂ ❊✛●❡❆✹♦ ❂ ✹✓▲☞❼ ✚ ➄ ✗ ➂ ✆③❄ ④✣✑✿➨❆✹♦ ❂ ✈✢❊ s ❈❏✿✯❊ ❯ ❁ ▼✐s ◗ ▼✏❄❉❂✏➥ ❆✹♦ ❂❹❯q❖✣s ❆❉❁❇✈ s ❁ ◗ ❁❺❆❉❈ ❊✛●✍❆✹♦ ❂ ● ▼ ◗ ❆✹❊ ❃ ❼✮❜❷❼ ✼✴➂ ● ✗ ➂ ❁❇✿ ❆✹♦ ❂ ❩ ❂ ✿✯❊ ❯ ❁❇✿ ▼ ❆✹❊ ❃ ❊✛●✍❆✹♦ ❂ ◗ ❊ ❄ ❆❄➵✫ ❁ ❄ ❊✏➡✯❆ ▼ ❁❇✿ ❂ ❩❱➡✣❈ ▼ ❩✯❩♥❁❇✿✯✇q❆✹♦ ❂❪❯✪❖✣s ❆❉❁❇✈ s ❁ ◗ ❁❇❆❉❁ ❂✱❄ ❊✛●✡❆✹♦✣❁ ❄ ● ▼ ◗ ❆✹❊ ❃ ❁❇✿✂❆♣♦ ❂ ❩ ❂ ❆ ❂✼❃♣❯ ❁❇✿ ▼ ✿❏❆ ❄ ❩ ❂ ❆❝❼✥✣❾❩ ● ✹✓▲ ➂ ➥ ❈♥❁ ❂❸s ❩♥❁❇✿✯✇❆✹♦ ❂❷❂ ➆✯✈✚❊✏✿ ❂ ✿✣❆❪❊✛●❙❅➊❁❇✿ ❂✞✖♥❖✚▼ ❆❉❁❇❊✏✿➲❼➉❁➏❁ ➂ ❊✛●✶❆✹♦ ❂ ❊ ❃✹❂✼❯ ➄ ④❊✪✁✘❊ ✁✬✶➇➝ ✢✂✸✕✞✠✖✘✟✤✎✿✁

✶ ✰ ✴✔✴ ✷✉✗ ✭✁� ✴ ✴ ➞ ❂ ◗ ❊✏✿ ❄ ❁↕❩ ❂✼❃ ➡✣❁❺✿ ▼✤❃ ❈❋❆ ❃✹❂✼❂⑦❄ ❊✝➍ ✬ ❡ ✆ ❼ ❊ ➄ ❊➇➂ ▼ ✿✚❩❲❊♥✈ ❂✼❃❅▼ ❆♣❊ ❃❅❄ ➟ ▼ ✿✚❩ ✂❨❩ ❂ ❦ ✿ ❂ ❩➨❊✏✿ ❊➋ ➡✣❈

➟✡❼ ✬ ➄ ✬ ➂ ❇ ✬ ➟✡❼ ✆ ❼ ➂ ➄ ❀ ➂ ➄ ✬ ➂ ❇ ✆ ❼ ➂ ➄ ❀ ➂ ➟✓❼ ✬ ➄ ✆ ❼ ➂ ➄ ❀ ➂✹➂ ❇ ✂★❼ ➂ ➄ ❀✯➂✂ ❼ ✬ ➄ ✬ ➂ ❇ ✬ ✂★❼ ✆ ❼ ➂ ➄ ❀✯➂ ➄ ✬ ➂ ❇ ✂ ❼ ➂ ➄ ❀ ➂ ✂ ❼ ✬ ➄ ✆ ❼ ➂ ➄ ❀ ➂✹➂ ❇ ✂★❼ ➂ ➄ ❀✯➂

➟✡❼ ✆ ❼ ➂ ❙ ➄ ❀ ❙ ➂ ➄ ✆ ❼ ➂ ➄ ➄ ❀✣➄✣➂❉➂ ❇ ✆ ❼❾➟✓❼ ➂ ❙ ➄ ➂ ➄✣➂ ➄❅➟✓❼ ❀ ❙ ➄ ❀❏➄✴➂❾➂✂★❼ ✆ ❼ ➂ ❙ ➄ ❀ ❙ ➂ ➄ ✆ ❼ ➂ ➄ ➄ ❀✣➄✣➂❉➂ ❇ ✆ ❼❾➟✓❼ ➂ ❙ ➄ ➂ ➄✣➂ ➄✓✂✢❼ ❀ ❙ ➄ ❀✣➄✣➂✹➂⑤⑥♦ ❂❷❯✂▼ ❆ ❃ ❁ ➆ ❃♣❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ▼ ❆❉❁❇❊✏✿➨❊✛●❡❆✹♦ ❂q❄ ♦ ❖✄✂❲❂ ❁ ❄✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂♣➂✡➍ ✏ ➄✿✼ ➋ ❜ ➋ ❼ ✼✣➂ ➄✿✼ ➋

✼ ➋ ❜ ➋ ❼ ✼✣➂ ✼ ➋ ❜ ➋ ❼ ✼✣➂✱❡➀➄✵✼ ➋ ✒ ➆⑤⑥♦✣❁ ❄☎❯✂▼ ❆ ❃ ❁ ➆q❁ ❄ ❁ ❃✹❃✹❂ ❩ ❖ ◗ ❁❇➡ s❇❂ ④➇⑤⑥♦ ❂➇❂ ❁❇✇ ❂ ✿✣➦ ▼✐s❇❖✯❂⑦❄ ❊✛● ✭ ❼ ✚ ➄ ✗ ➂ ▼✛❃✹❂➔❙❘▼ ✿✚❩ ❙ ✝ ✒✚➥ ❆♣♦ ❖✚❄ ❈ ❂❪▼✛❃✹❂ ❁❇✿❲❆✹♦ ❂ ✈✚❊ s ❈✣✿✯❊ ❯ ❁ ▼✐s◗ ▼✏❄❉❂ ❈♠❁❺❆♣♦ ▼➔s ❁❇✿ ❂⑦▼✛❃❷▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆✣❁❺❆❉❈❋❊✛●✍❆✹♦ ❂ ❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃❅❄ ➟ ▼ ✿✚❩ ✂✡④

✮ ✢✱✰❨✧ ✲✦✕ ✂ ❬ ✏✩✴ ✰ ✴✶✵ ✝ ❬ ✲✿✝ ❬ ✢ ✵ ✴ ⑤⑥♦ ❂ ◗ s↕▼✏❄✹❄ ❁ ◗ ▼✱s ●➋❊ ❃♣❯✂▼✐s ❩✣❊ ❖ ➡ s❇❂ ❩♥❁ �▲❂✼❃♣❂ ✿❏❆❉❁ ▼ ❆r❁❺❊♥✿①❊✏✿ ❖ ✿ ▼✛❃ ❈ ➑ ➡✣❁❇✿ ▼✛❃ ❈ ❆ ❃✹❂✼❂⑦❄✫✒ ❈⑥❁❇❆✹♦◗ ❊✏✿ ❄ ❆ ❃✹❖ ◗ ❆✹❊ ❃❅❄ ✪✯➥✆☎✞✝✠✟➓▼ ✿✚❩ ▼ ➦ ▼✛❃ ❁ ▼ ➡ s❇❂ ♦ ▼✏❄ ❆✹♦ ❂❷❯✂▼ ❆ ❃ ❁ ➆ ❃♣❂ ✈ ❃✹❂⑦❄❉❂ ✿✣❆ ▼ ❆❉❁❇❊✏✿

✭ ❼ ✼ ➄ ❜❷❼ ✼✣➂♣➂✡➍ ✣✥ ✼✓❡✉➄✵✼ ❜❷❼ ✼✣➂ ➏ ➏➄✵✼ ❜❷❼ ✼✣➂★❡❏✼ ✼✓❡✉➄✵✼ ❜❷❼ ✼✣➂ ➏➄✵✼ ❜❷❼ ✼✣➂★❡➀➄✵✼ ✒ ✼ ❜❷❼ ✼✣➂★❡➅➄✵✼ ✼✓❡➅➄✿✼ ❜❷❼ ✼✣➂

✩✬ ➆⑤⑥♦ ❂ ❩♥❁ ▼ ✇✏❊✏✿ ▼✐s ◗ ❊ ❂ ☛❨◗ ❁ ❂ ✿✣❆ ❄ ❊✤● ✭ ❼ ✚ ➄ ✗ ➂ ▼✛❃✹❂ ❊✏✿ s ❈ ❙✓✆↔❄✼➥ ❆✹♦ ❖✚❄ ❈ ❂■▼✛❃✹❂ ❁❺✿➔❆✹♦ ❂ ✈✚❊ s ❈✣✿✯❊ ❯ ❁ ▼✐s ◗ ▼✏❄❉❂ ❈⑥❁❇❆✹♦❹❆♣♦ ❃✹❂✼❂ ➡ s ❊ ◗ ➔✴❄❊✛●⑥❁ ❃✹❃✹❂ ❩ ❖ ◗ ❁❇➡ s❇❂ ❯✂▼ ❆ ❃ ❁ ◗ ❂⑦❄ ❊✏✿➀❆♣♦ ❂ ❩♥❁ ▼ ✇✏❊♥✿ ▼✐s✑➥✟▼✱sts ✇✛❁❇➦♥❁❇✿✯✇ ▼ ◗ ❊✏✿✣❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿✦❆✹❊➨❆✹♦ ❂ ❊ ❃ ❩ ❂✼❃ ❊✛●❪❆✹♦ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆✣❁❇❆❾❈✏④⑤⑥♦ ❖✚❄✼➥ ❆✹♦ ❂❱▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❯ ✈ s❇❂ ➆✣❁❇❆❾❈ ❊✛●⑥❆✹♦ ❂ ❩✣❊ ❖ ➡ s❇❂ ❩♥❁ �✡❂✼❃✹❂ ✿❏❆r❁ ▼ ❆❉❁❇❊✏✿①❊✏✈ ❂✼❃❅▼ ❆✹❊ ❃ ❁ ❄ ❘ ❅ ➋ ④☛✡☎❈➓❁❇✿✚❩ ❖ ◗ ❆❉❁❇❊✏✿➲❊✏✿ ✺ ➥ ❁❇❆◗ ▼ ✿❋➡ ❂ ✈ ❃ ❊✛➦ ❂ ❩❲❆✹♦ ▼ ❆➇❆✹♦ ❂❹▼ ➦ ❂✼❃❅▼ ✇ ❂ ◗ ❊ ❄ ❆➇❊✛●❡❆✹♦ ❂ ✺ ➑ ❆✹♦➓❩♥❁ �✡❂✼❃✹❂ ✿❏❆r❁ ▼ ❆❉❁❇❊✏✿❋❁ ❄ ❊✛●❡❊ ❃ ❩ ❂✼❃ ❅ ❤ ✏ ➋ ☞ ➠ ④✲✴✳✖✵✷✶✖✳✖✸✺✹✼✻✔✽✿✾✞❀❂❁❃✁❄✆❅↕P➊❤✿▲ts✿s✮✐â◆➉P➊❤✿❍❑♦✁❏▼❪❑♦✁❉✿●✉❱❲❿✞ß❙❜✔s✿❝♥❜✔❉ì◆◗➟✮❪ ✏●■s✿❤✺❜❞❉✿●✉❱■❿☞❜✔❉✼❋â➟✮▲t❍❑♦♥❜✚◆➉➳✚♦♥♠▼❤✌☞●■❝✁●✉❱■❘Ø❳ P➊▲t❫❴s✿❝✁●✆❭✿♦✁❪➉✐❬❜❞❉✺❜✔❝✁✐✮❏❑♦✁❏❊▲❞❥❣❪❑●❲❍❑❫ ❍▼●■r❛❍❑♦✁❪▼♦❢❉✦➐❏❑✐✮❏▼❪❑●■❫➙❏✉❘❧➥❂➦➱❷✆✇❞②♣❷❆❼◗⑩✙↔✆④❞⑤☞❰❣✇✔➽➼⑨✺①t❼⑦❷❲②❙ÐØ↔❲⑩✙❷❲③✺↔✆❷■❿✦❵✏▲t❝◗❘✮Ô → ❿✣➀✉➁tÓ✏➁✿❿ts✿s✞❘✼➅✏Ô✦❄✆❳➱➅t➮✏➅✦❘❃✓➅❨❅↕➡❂❝♥❜■➑✆▲✏❝✁●■❪➙◆◗➞❮❤✿♦✁❝❢♦✁s✿s✼●✉❱❺❜✔❉✺❋➍Ò❙❋✮❝✁✐✮➺■➋✏▲➍◆✖❇❊❉✺❋➱❍❑●■r ➳➏❘✓❱❲❘❂❳ ➟✮♦✁❉✿➐t❡✿❝♥❜✔❍▼♦❢❪➉✐➏❜✔❉✼❜✔❝✁✐✮❏❑♦✁❏➸▲✔❥❙➐✏●■❉✿●❲❍♣❜✔❪▼♦✁❉✿➐✜❥✙❡✿❉✺♠❆❪❑♦✁▲✏❉✿❏❨❘❛Ð➌➤▼⑧❙ï✈✮✇✔①✮②■③✺④❞⑤✞✇✔③❖î❈⑩✁➣✉↔❲②♣❷❆❼⑦❷❈ï❖④➆❼✙➦✿❷■➽➸④❨❼➉⑩✙↔❆➣■❿✿❵✏▲t❝➉❘➌➄✦❿✮❉ ➹ ➅✦❿✣➀✉➁✏➁t➃✿❿✮s✿s❂❘✿➅✿❄✉Ô➆❳➱➅❞➯➌➬✿❘❃✓➄❨❅↕➡✦❍❑▲✏♦♥❋✮●❲❵✏❜✔❡✮❭❦◆➉P➊❤✿❍❑♦✁❏❑❪▼♦✁❉✿●✉❱■❿t❒❦❜✔❡✺❋➱●■❝✿◆➉➳✪❜✔❍▼♦❢●❆➴⑦P➊❝♥❜✔❡✼❋✮●✉❱■❿✔❜❞❉✺❋❦➟✮▲t❍❑♦♥❜➼◆◗➳✚♦♥♠▼❤✍☞●■❝✁●✉❱❲❘❲❳✬➥✼❾✆⑨➱❷❆➣è❸✏❷❛❸t✇✔③✿③✛✔❷✉❷❆➣❈❷✆❼✷④❞⑤✓➚✏✇✔②■⑩❽❼✙➦✮➽➵❷❆➣■❘▼❳➳✪♠■❒➢❍♣❜❨r➊❳➱➒➩♦✁❝❢❝➉❿✏➞☞❜❞❍❑♦✁❏✉❿❂➀✉➁✏➁t➃✿❘❃ ➯✔❅↕➳✚●■♦✁❍❙◆✖❇↕❘✓❱❊❜❞❉✺❋✚➳✚▲✮▲✏❉➏◆✖➲✺❘✿❚→❘ ❱❲❘✮❳➝Ò❊❉❖❪❑❤✿●↕❜❞❝✁❪❑♦✁❪❑❡✺❋➱●❈▲❞❥❧❉✿▲✿❋✮●■❏❊♦✁❉✪❍✆❜✔❉✺❋➱▲✏❫Ñ❪❑❍❑●❲●■❏✉❘➊❰❣④✔③✼④✏❸✔⑩✖④✔③➧✈✮✇✔①✮②■③✺④❞⑤✷✇⑦⑥❦ïâ④❨❼✖➦➱❷✎✍➽➸④❨❼➉⑩✙↔✆➣■❿✮❵t▲✏❝➉❘➌➄t➬✿❿✣➀❨➁✏➂✏Ó✦❿✏s✦s✞❘ ➣✙➣✗→ ❳✣❄✉➬✦❄ ➷ ❘❃ ➷ ❅↕➳✚♦✁❉✺♠➢◆◗➒❛●❲❉✿❍❑✐✮➋✿❱■❘t❳➧ç❦✇✔③✿③✼❷➉➚✏④❨❼➉⑩♥ñ✔❷❙➽➸④❨❼➉②■⑩✙↔✆❷✆➣■❘❞❳â➲✺❘✮❚ ♦❢❝✁●■✐❺❜✔❉✺❋Ï❏❑▲✏❉✦❏✉❿✿➎❛●❲r➝➫❣▲t❍❑➋✣❿✼➀✉➁✏ÓtÓ✿❿✏✎❴⑩♥⑤✁❷■❾❺⑩♥③✮❼❑❷❲②✆➣✉↔■⑩✙❷❲③✺↔✆❷➼➣✉❷❲②■⑩✙❷❆➣⑩♥③✪❸✔⑩❽➣❲↔❲②♣❷❆❼❑❷❦➽➸④❨❼✖➦➱❷❲➽➵④➆❼◗⑩✖↔✆➣↕④✔③✼❸❴✇✆⑨✦❼◗⑩✥➽↕⑩✁➾✉④➆❼◗⑩✙✇❞③✿❘

➣ ➯

Page 104: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✛✒✡✌✏✄✚✥ ✄▲✕★✠ ✄ ✠✝✟✡✞✡✥♥✎➉✌✏✁✆✠ ✧✹✞✡✥☎✎❬✕★✒☎✫■✞ ✠ ✁➀☛ ✠✄✂➇✄✢✥☎✌ ✄✢✒■✄✚✥♥✕✚✌✏✎☞✞✡✒☎✝✵✝✆✦✮ ✒ ✝✟✞➈✮✡✠✹✰★✔

❄❘❃❅▼ ❩ ❖✚▼ ❆ ❂ �❏◗ ♦✯❊✣❊ s ❊✤●❵✣✑✿✣●➉❊ ❃✹❯✂▼ ❆❉❁❇❊✏✿ � ❈ ❄ ❆ ❂✼❯✂❄✼➥⑤⑥♦ ❂ ✾❀✿✣❁❺➦ ❂✼❃❅❄ ❁❇❆❉❈❋❊✛●❦❻ s❇❂ ◗ ❆ ❃ ❊ ➑❉❑ ❊ ❯❱❯q❖ ✿✣❁ ◗ ▼ ❆❉❁❇❊✏✿ ❄✼➥⑤✓❊ ➔ ❈✏❊ ➥ ❳ ▼ ✈ ▼ ✿❳ ❖ ✿ ❂❋❙ ➄ ➥ ❙t✱✿✱✿✯

❚ ❄r❖✯❯❱❯✂▼✛❃ ❈➈➡❏❈☞☛➇❁❇✿ ◗ ❂ ✿✣❆ ❆ ❖✯❯❲▼✏❄ ❫

❢✒✁❱❣✐❤✬☛✌✄✝✆✶✩❦❥✡❧✮☛✌☞✘✆✓❤⑤⑥♦✣❁ ❄ ❆ ▼✐s✂➔ ❁ ❄ ➡ ▼✏❄❉❂ ❩q❊♥✿ ▼➢✭ ❊✛❁❇✿✣❆⑥✈ ▼ ✈ ❂✼❃ ❈⑥❁❇❆✹♦❋⑤ ❂ � ❖ ✿ ❭❘▼ ✿ ❚ ❙ ❫✑④q✣✑❆⑥✈ ❃✹❂⑦❄❉❂ ✿✣❆ ❄⑥▼ ✿ ✶ ❁❇✿✣❆ ❂✼❃ ➦ ▼✐s▲▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ✸➔❆✹♦ ▼ ❆

❄ ❊ s ➦ ❂⑦❄ ❆✹♦ ❂ ✈ ❃ ❊✏➡ s❇❂✼❯ ❊✛●➇✇ ❂ ✿ ❂✼❃❅▼ ❆❉❁❇✿✯✇ ▼❋❃❅▼ ✿✚❩✣❊ ❯ ✿ ❖✯❯ ➡ ❂✼❃✍✌ ❈⑥❁❇❆✹♦✉❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿✄✎ ➍ ❼ ✪ ➠❾➄ ✪ ➋⑩➄ ➆✐➆⑦➆ ➄ ✪ ✮ ➂ ❼➉❁✑④ ❂ ④✑ ❃ ❚ ✌ ➍ ✺✣❫ ➍ ✪ ❤ ➥☎❙ ❑ ✺ ❑ ✬ ➂ ● ❃ ❊ ❯ ❁❇✿✚❩ ❂ ✈ ❂ ✿✚❩ ❂ ✿✣❆❱❁↕❩ ❂ ✿✣❆❉❁ ◗ ▼✐s➏s ❈✉❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆ ❂ ❩✦❆♣❊ ❄✹❄❉❂⑦❄ ❈⑥❁❇❆✹♦ ▼ ✿ ✭ ➑ ◗ ❊✛❁❇✿➀❊✛●❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ✞ ➍ ❼ ★★➠❾➄ ★❤➋⑩➄ ➆✐➆⑦➆ ➄ ★✑✏ ➂ ④✍⑤⑥♦✣❁ ❄ ✈ ❃ ❊✏➡ s❇❂✼❯ ❈ ▼✏❄■❄r❂ ❆◆➡✣❈ � ❊ ◗ ♦ ❂ ❚ ➄ ❫✓❼✑➦ ▼✛❃ ❁ ▼ ✿❏❆ ❄ ❊✛●❡❆✹♦✣❁ ❄ ✈ ❃ ❊✏➡ s❇❂✼❯ ❈ ❂✼❃✹❂❄ ❆ ❖ ❩♥❁ ❂ ❩➨➡✣❈➓➦✏❊✏✿ ➎ ❂✼❖✯❯❲▼ ✿✯✿ ➥ ❻ s ❁ ▼♥❄✼➥ ❍❪✿ ❖ ❆♣♦ ▼ ✿✚❩✟✒ ▼ ❊ ➂ ④➇⑤⑥♦ ❂q❂ ☛❨◗ ❁ ❂ ✿ ◗ ❈➓❊✤●■❆✹♦ ❂✪▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❁ ❄❪❯❱❂⑦▼✏❄❉❖✯❃✹❂ ❩➊➡❏❈✽✔✓ ➥ ❈➇♦✣❁ ◗ ♦➈❁ ❄ ❆✹♦ ❂❪❂ ➆✴✈ ❂ ◗ ❆ ❂ ❩❲✿ ❖✯❯ ➡ ❂✼❃ ❊✛●✡❆✹❊ ❄✹❄❉❂⑦❄❦❃✹❂✞✖♥❖ ❁ ❃♣❂ ❩❲❆✹❊❹✇ ❂ ✿ ❂✼❃❸▼ ❆ ❂✕✌ ④ � ❊ ◗ ♦ ❂ ✈ ❃ ❊✛➦ ❂ ❩→❆✹♦ ▼ ❆⑥❆✹♦ ❂ ❊✏✈✯❆r❁ ❯❲▼✐s▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ❄ ♦✯❊ ❖✣s ❩ ❄♣▼ ❆❉❁ ❄ ●➉❈ ✎ ✖ ❼✗✎ ➂✖ ❼ ✞ ➂

❑ ✽ ✓ ❑ ✖ ❼✗✎ ➂ ❡ ➟✓❼ ✞ ➂✖ ❼ ✞ ➂ ➄❈➇♦ ❂✼❃✹❂

✖ ❁ ❄ ❆✹♦ ❂❷❂ ✿❏❆ ❃ ❊✏✈✣❈❱● ❖ ✿ ◗ ❆❉❁❇❊✏✿①❼ ❄❉❂✼❂ ➌ ✈✯✈ ❂ ✿✚❩♥❁ ➆ ➂ ▼ ✿✚❩➟✓❼ ✞ ➂■➍ s ✿★❼ ❿ ✝ ★✑✘✚✙ ✛ ➂ ➄ ❈➇♦ ❂✼❃✹❂ ★✑✘✚✙ ✛ ➍ ❯ ❁❺✿➠ ✜ ➁ ✜✜✏ ★ ➁ ➆⑤⑥♦ ❂❷❖ ✈✯✈ ❂✼❃ ➡✚❊ ❖ ✿✚❩❨❁ ❄❀❄✹▼ ❆❉❁ ❄ ❦ ❂ ❩➊➡❏❈ ▼ ✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁ ❄ ❆❉❁ ◗ ▼✱s ✇♥❊ ❃ ❁❇❆✹♦ ❯ ④❭❪▼ ✿ ▼ ✿✚❩ ❭ ❊ ❄ ♦✣❁❡✈ ❃ ❊♥✈✚❊ ❄❉❂q▼ ✿ ✶ ❁❇✿✣❆ ❂✼❃ ➦ ▼✱s✟▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ✸q❆✹♦ ▼ ❆ ❄✹▼ ❆r❁ ❄ ❦ ❂⑦❄ ❆✹♦ ❂❹❖ ✈✯✈ ❂✼❃ ➡✢❊ ❖ ✿✚❩✬❈♠❁❺❆♣♦

➟✓❼ ✞ ➂✍➍ s ✿ ❚ ➄ ❼ ✭❉● ❙ ➂ ❫ ❡ ☛ ❼ ★✢✘✤✣✦✥ ➂❙ ● ★✑✘✧✣✦✥ ➄ ❈➇♦ ❂✼❃✹❂ ★✑✘✧✣✦✥ ➍ ❯✂▼ ➆➠✢✜ ➁ ✜★✏ ★ ➁ ➄

❈⑥❁❇❆✹♦ ☛ ❼ ★ ➂✍➍✽● ★ s ✿ ★ ● ❼ ❙ ● ★ ➂ s ✿★❼ ❙ ● ★ ➂ ④✍➎➇❊ ◗ ♦✯❊✛❁ ◗ ❂ ❊✤●✡● ❖ ✿ ◗ ❆r❁❺❊♥✿❬➟ ❄r❂✼❂✼❯✂❄ ❆✹❊❱➡ ❂❷❂⑦❄✹❄❉❂ ✿✣❆❉❁ ▼✐s➏s ❈❋➡ ❂ ❆✹❆ ❂✼❃ ❆✹♦ ▼ ✿▼ ✿✣❈ ❊✏❆✹♦ ❂✼❃ ❊♥✿ ❂ ④❨⑤♠♦ ❂❨▼✏❄♣❄❉❖✯❯❱❂ ❩ ❄❉❖ ✈ ❂✼❃ ❁❇❊ ❃ ❁❇❆❉❈➀❊✤●◆❆✹♦ ❂ ❁❇✿❏❆ ❂✼❃ ➦ ▼✐s➇▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❁ ❄ ❆✹♦ ▼ ❆❷❁❇❆➔❁ ❄❖✂✱✴ ✝ ✴ ✰✉✧ ❬✽✵✤❬❇✷ ✝ ❬✽➢❋▼ ✿✚❩✴ ✲ ✷ ✲❖✝➉✢ ❬ ✧✴☎✷✕ ✴ ✧ ✴✶✵ ✝➉④

�✂✁✂❣✐❤✬☛✦✟✤✄ ✂✤✢✬✖ ✢✬✖✗✺✬✆✲✄✮☞✍☛❖●✳✸➐ ❂ ❆ ✞ ➡ ❂ ❆✹♦ ❂ ❊ ❃ ❁❇✇✛❁❇✿ ▼✐s ❩♥❁ ❄ ❆ ❃ ❁❺➡ ❖ ❆r❁❺❊♥✿✡④⑤➐ ❂ ❆ ❖✚❄ ❦ ➆ ▼ ✈ ▼✛❃ ❆r❁❺❆r❁❺❊♥✿❱❊✛● ❚ ➏ ➄ ❙ ➂ ▼ ◗✼◗ ❊ ❃ ❩♥❁❇✿✯✇❷❆✹❊ ✞ ➥ ❆✹♦ ▼ ❆✓❁ ❄✍▼❷❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂✩✑✺❀➍ ➏ ❛✪✩ ➠ ❛ ✂☎✂✆✂ ❛✄✩ ✏ ➍ ❙ ➄

❄❉❖ ◗ ♦❋❆✹♦ ▼ ❆ ✩ ➁ ●✫✩ ➁ ❞ ➠ ➍ ★ ➁ ●➉❊ ❃➇▼✐s➏s ✑ ④✍➎❀❊❉❈ ▼ ✿✣❈➈❁❺✿✣❆ ❂✼❃ ➦ ▼✐s ❚ ✬ ➄ ■ ➂ ❯❲▼ ❈➈➡ ❂ ✈ ▼✤❃ ❆❉❁❇❆❉❁❇❊✏✿ ❂ ❩➈❁❇✿❏❆♣❊❱❆✹♦ ❂❹❄❉❖ ➡✣❁❇✿✣❆ ❂✼❃ ➦ ▼✱s➣❄✬ ➁ ❼ ❚ ✬ ➄ ■ ➂✹➂ ➥✚❙ ❑ ✑ ❑ ✭ ➥ ❈⑥❁❇❆✹♦✬ ➁ ❼ ❚ ✬ ➄ ■ ➂♣➂✡➍ ❚ ✬ ❡ ❼ ■ ● ✬ ➂✗✩ ➁ ❞ ➠❾➄ ✬ ❡ ❼ ■ ● ✬ ➂✗✩ ➁ ➂❅➆➣✏➷

Page 105: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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◗❙❘❯❚❙❱❀✘✚✔ ❲ ✢ ❻✺➆ ▼✛❯ ✈ s❇❂ ❊✛● ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❼✴✧ ➧ ➂ ❼ ✞ ➍ ❼ ❙ ✝ ➄ ➄ ❙ ✝ ➄✴➂ ➥ ✎ ➍ ❼ ❙ ✝ ② ➄ ❙ ✝ ② ➄ ❙ ✝ ② ➂♣➂ ④➐ ❂ ❆ ✎ ➡ ❂ ❆♣♦ ❂ ❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ❈ ❂ ❈ ▼ ✿❏❆⑥❆✹❊❱✇ ❂ ✿ ❂✼❃❅▼ ❆ ❂ ④ ✫ ❁ ➆ ▼ ✈ ▼✛❃ ❆r❁❺❆r❁❺❊♥✿✁ ✺⑥➍ ➏ ❛ ✁ ➠ ❛ ✂☎✂✆✂ ❛ ✁ ✮ ➍ ❙

❊✛● ❚ ➏ ➄ ❙ ➂ ▼ ◗✼◗ ❊ ❃ ❩♥❁❇✿✯✇✂❆✹❊ ✎✦❼ ✁ ❤ ● ✁ ❤ ❞ ➠ ➍ ✪ ❤ ➂ ➥✚▼ ✿✚❩ ❄❉❂ ❆✄✂ ❤ ➍ ❚ ✁ ❤ ❞ ➠✍➄ ✁ ❤ ➂ ④⑤⑥♦ ❂ ❁❇✿✣❆ ❂✼❃ ➦ ▼✱s❦▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩ ▼✏❄ ●➉❊ s➏s ❊❉❈ ❄✔✎❼ ❙ ➂ ❄❉❂ ❆❁❅ ➍➏▼ ✿✚❩ ✧ ✺☎➍ ❚ ➏ ➄ ❙ ➂✦✥❼ ➄✣➂ ❁t●✎✧ ➧✆☎ ✂ ❤ ●➉❊ ❃➇❄ ❊ ❯❱❂ ✺ ➥ ❆✹♦ ❂ ✿ ❄ ❆♣❊✏✈✂❆♣♦ ❂✪▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯ ▼ ✿✚❩ ❄❉❂ ❆ ✌ ➍ ✺ ✥❼ ② ➂ ❂❸s➣❄r❂ ➎✯❁❇✈➑❆✹♦ ❂ ✭ ➑ ◗ ❊✛❁❇✿ ❼✁❈⑥❁❇❆✹♦ ✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❾❈➑❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ✞ ➂ ④ ⑤♠♦ ❂①❃✹❂⑦❄❉❖✣s ❆➨❁ ❄❬▼ ✿ ❖✯❯ ➡ ❂✼❃ ✭ ➧ ❪❏ ❙ ➄ ➆✐➆⑦➆ ➄ ✭ ❖ ④ � ❂ ❆ ✧ ➧ ☞ ➠ ➍ ✬ ✏

✧❼✤✧ ➧ ➂ ▼ ✿✚❩❋✇♥❊✪❆♣❊❋❼ ➄✣➂ ④⑤⑥♦✣❁ ❄ ✈ ❃ ❊ ◗ ❂ ❩ ❖✯❃♣❂ ❁ ❄ ❁ s➏s❺❖✚❄ ❆ ❃❅▼ ❆ ❂ ❩➊❁❇✿ ✫ ❁❇✇ ❖✯❃♣❂❱❙ ④➞✝❁❇❆✹♦ ✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❾❈➨❊✏✿ ❂ ❆✹♦✣❁ ❄❷▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❆ ❂✼❃✹❯ ❁❺✿ ▼ ❆ ❂⑦❄ ❁❇✿ ❦ ✿✣❁❇❆ ❂ ❆❉❁ ❯❱❂✏➥ ▼ ✿✚❩➓✇ ❂ ✿ ❂✼❃❅▼ ❆ ❂⑦❄❪▼❲❃❅▼ ✿✚❩✣❊ ❯ ✿ ❖✯❯ ➡ ❂✼❃

✌✉➥ ❈➇♦✣❁ ◗ ♦➓❁ ❄❪▼ ❩ ❂ ❆ ❂✼❃✹❯ ❁❇✿✣❁ ❄ ❆❉❁ ◗ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❊✛●✞✝ ➍ ✧✡✚q④❀➐ ❂ ❆✠✟➑➡ ❂ ❆✹♦ ❂q❄❉❂ ❆➇❊✛● ▼✐s➏s ✈✚❊ ❄♣❄ ❁❇➡ s❺❂ ➦ ▼✐s❇❖✯❂⑦❄ ❊✛●✡✝❋④ ✡■❈◗ ❊✏✿ ❄ ❆ ❃✹❖ ◗ ❆❉❁❇❊✏✿ ➥ ✟ ❁ ❄➇▼ ✈ ▼✛❃ ❆r❁❺❆r❁❺❊♥✿❋❊✛● ❚

➏ ➄ ❙ ➂ ➥✣▼ ✿✚❩ ▼ ✿✣❈ ✛✌❪ ✟ ❯❲▼ ❈➈➡ ❂ ❊✏➡✯❆ ▼ ❁❺✿ ❂ ❩ ❈⑥❁❇❆✹♦❋✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❈ ❚ ✛ ❚ ❼ ❈➇♦ ❂✼❃✹❂❚ ✛ ❚ ❩ ❂ ✿✯❊✏❆ ❂⑦❄ ❆♣♦ ❂➇s❇❂ ✿✯✇✏❆✹♦❲❊✛●✡❁❇✿✣❆ ❂✼❃ ➦ ▼✐s ✛ ➂ ④✺✣✑✿ ◗ ❊✏✿ ❄r❂✞✖✏❖✯❂ ✿ ◗ ❂✏➥ ❈ ❂ ● ▼✐s➏s ❁❇✿☛✂ ❤ ❈⑥❁❇❆✹♦❲✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❈ ❚ ✂ ❤ ❚ ➍ ✪ ❤ ➥ ❈➇♦✣❁ ◗ ♦❯❱❂⑦▼ ✿ ❄ ❆✹♦ ▼ ❆ ✌ ♦ ▼✏❄ ❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ✎ ▼♥❄■❂ ➆✯✈ ❂ ◗ ❆ ❂ ❩★④➎❀❊❉❈ ❩ ❂ ✿✯❊✏❆ ❂ ➡❏❈ ✽ ❆✹♦ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛●✡❆✹❊ ❄✹❄❉❂⑦❄ ✿ ❂ ◗ ❂⑦❄✹❄✹▼✛❃ ❈❱❆✹❊❹✇ ❂ ❆ ✌ ④ ✫✯❃ ❊ ❯ ➡ ▼✏❄ ❁ ◗ ❃✹❂⑦❄❉❖✣s ❆ ❄ ❊✏✿ ❂ ✿❏❆ ❃ ❊✏✈❏❈➔❁❇✿❲❆ ❃✹❂✼❂▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯✂❄✼➥ ❈ ❂ ✇ ❂ ❆⑥❆✹♦ ▼ ❆

✽ ✓ ➍ ❻♠❼ ✽⑥➂✍➍✖ ❼☞✝ ➂✖ ❼ ✞ ➂ ➆

❅➨❊ ❃✹❂ ❊✛➦ ❂✼❃⑦➥✣❄ ❁❇✿ ◗ ❂✍✌ ❁ ❄❘▼ ❼❾❩ ❂ ❆ ❂✼❃✹❯ ❁❇✿✣❁ ❄ ❆❉❁ ◗ ➂ ● ❖ ✿ ◗ ❆r❁❺❊♥✿➓❊✛●✡✝ ➥ ❆♣♦ ❂ ✿✖ ❼☞✝ ➂❜☛ ✖ ❼ ✌ ➂✓➍ ✖ ❼✗✎ ➂ ➥ ❈➇♦✣❁ ◗ ♦➓❈♥❁ ❂❸s ❩ ❄

✽ ✓ ☛✖ ❼✗✎ ➂✖ ❼ ✞ ➂ ➆

❊ ✁✍✌ ✞✠✞✠✟✡✄✛☎✠✆✓❥❡❤✪✩✣✑✿❲❊ ❃ ❩ ❂✼❃ ❆✹❊❹✇ ❂ ❆ ▼ ✿ ❖ ✈✯✈ ❂✼❃ ➡✚❊ ❖ ✿✚❩❲❊✏✿ ✖ ❼✎✝ ➂ ❼ ▼ ✿✚❩q❆✹♦ ❂ ✿❲❊✏✿ ✽ ✓ ➂ ➥ ❆✹♦ ❂❷▼✛❖ ❆✹♦✯❊ ❃❅❄ ❁❇✿✣❆ ❃ ❊✯❩ ❖ ◗ ❂❹▼ ✿ ❂ ❈ ➦ ▼✤❃ ❁ ▼ ➡ s❇❂✏ ➥✚❄❉❖ ◗ ♦➓❆✹♦ ▼ ❆❼ ❙ ➂ ✏ ❁ ❄❪▼ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❊✛●✑✝ ✥❼ ➄✣➂ ✏ ♦ ▼✏❄ ➄ ❼ ✭ ● ❙ ➂ ✈✚❊ ❄✹❄ ❁❇➡ s❇❂ ➦ ▼✱s❺❖✯❂⑦❄ ✥ ➣ Ô

Page 106: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❼ ② ➂ ◗ ❊✏✿✚❩♥❁❇❆❉❁❇❊✏✿ ▼✐s➏s ❈➓❊✏✿ ❼ ✏ ➄ ✌ ➂ ➡ ❂ ❁❇✿✯✇ ❂✞✖✏❖✚▼✐s ❆✹❊ ❄ ❊ ❯➈❂ ❼ ❃ ➄✪✺ ➂ ➥ ❈ ❂ ♦ ▼ ➦ ❂✝ ✁ ❄❘❂ ❊ ❯ ❼ ★ ✘✧✣✦✥ ➂ ➄❈➇♦ ❂✼❃✹❂ ❄❘❂ ❊ ❯ ❼ ★ ➂ ❩ ❂ ✿✯❊✏❆ ❂⑦❄ ❆✹♦ ❂ ✇ ❂ ❊ ❯❱❂ ❆ ❃ ❁ ◗ ❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ❊✛●✶✈ ▼✛❃❅▼✛❯❱❂ ❆ ❂✼❃ ★ ✎✑ ❃ ❚ ❄❘❂ ❊ ❯ ❼ ★ ➂✍➍ ❄ ❫ ➍ ❼ ❙ ● ★ ➂ ★ ▲ ➆

⑤⑥♦ ❂ ✿ ❈ ❂ ❈⑥❁ s➏s ✇ ❂ ❆➇❆✹♦ ▼ ❆ ✎✖ ❼☞✝ ➂✍➍ ✖ ❼☞✝ ➄ ✏ ➄ ✌ ➂✓➍ ✖ ❼ ✌ ➂✤❡ ✖ ❼ ✏ ❚ ✌ ➂✤❡ ✖ ❼☞✝ ❚ ❼ ✏ ➄ ✌ ➂✹➂ ➥ ❈⑥❁❇❆✹♦

✖ ❼ ✌ ➂✶➍ ✖ ❼✗✎ ➂ ➄ ✖ ❼ ✏ ❚ ✌ ➂ ❑ s ✿ ❚ ➄ ❼ ✭ ● ❙ ➂ ❫✥➄ ✖ ❼☞✝ ❚ ❼ ✏ ➄ ✌ ➂✹➂ ❑ ✖ ❼ ❄❪❂ ❊ ❯ ❼ ★✑✘✧✣✦✥ ➂✹➂✍➍ ☛ ❼ ★✢✘✤✣✦✥ ➂❙ ● ★✑✘✧✣✦✥ ➄

❈➇♦✣❁ ◗ ♦➓❈♥❁ ❂❸s ❩ ❄ ❆✹♦ ❂❹▼ ✿✯✿✯❊ ❖ ✿ ◗ ❂ ❩❋➡✢❊ ❖ ✿✚❩★④✣✑✿ ❊ ❃ ❩ ❂✼❃ ❆✹❊❋❩ ❂ ❦ ✿ ❂ ✏ ➥ ❄r❂ ❆ ✌ ➍ ✺ ▼ ✿✚❩ ◗ ❊♥✿ ❄ ❁↕❩ ❂✼❃ ❆✹♦ ❂ ✈✚❊ ❄✹❄ ❁❺➡ s❇❂ ➦ ▼✐s❇❖✯❂⑦❄ ❊✛● ✝ ➥ ❆✹♦ ▼ ❆❀❁ ❄❷▼✐s➏s ❆✹♦ ❂ ❁❇✿✣❆ ❂✼❃ ➦ ▼✱s➣❄✛ ❪ ✟ ❄r❖ ◗ ♦ ❆✹♦ ▼ ❆ ✛ ☎✂ ❤ ④⑧➞ ❂q❯✂▼ ❈❋❊ ❃ ✇ ▼ ✿✣❁❥✐ ❂ ❆✹♦ ❂✼❯ ▼✏❄ ●➉❊ s➏s ❊❖❈ ❄ ④❹⑤⑥♦ ❂✼❃♣❂ ❁ ❄❷▼❲❖ ✿✣❁ ✖♥❖✯❂✂❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❊✛●◆❆♣❊ ❄✹❄❉❂⑦❄❼ ✭ ➧ ➂ ❄r❖ ◗ ♦❲❆✹♦ ▼ ❆ ➥ ●➉❊ ❃⑥▼✐s➏s ❅ ➥ ✧ ➧ ➍ ❚ ➯❭➄❂❲ ➂ ❈⑥❁❇❆✹♦✂➯ ❑ ✁ ❤ ❞ ➠ ▼ ✿✚❩ ❲ ➳ ✁ ❤ ❞ ➠■❼ ❃✹❂⑦❄ ✈✡④✠❈⑥❁❇❆✹♦✡④✍➯ ❛ ✁ ❤ ▼ ✿✚❩ ❲ ☛ ✁ ❤ ➂ ✎❆✹♦✣❁ ❄ ❁ ❄ ❆✹♦ ❂ ✭❞☎ ✯ ✲✱✰ ✂✖❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❼ ❃♣❂⑦❄ ✈✡④ ❆✹♦ ❂➝✂ ✢✵✯ ✵ ✯ ✲✱✰ ✂✉❄❉❂✞✖✏❖✯❂ ✿ ◗ ❂ ➂ ▼✏❄✹❄ ❊ ◗ ❁ ▼ ❆ ❂ ❩➲❆✹❊ ✂ ❤ ✥ ❁❇❆➔❁ ❄ ❦ ✿✣❁❺❆ ❂ ❊✏✿ s ❈ ❁➏●➯ ➍ ✁ ❤ ❞ ➠❹❼ ❃♣❂⑦❄ ✈✡④➈❁t●❨❲ ➍ ✁ ❤ ➂ ●➋❊ ❃✪❄ ❊ ❯➈❂ ✧ ➧ ④❲➎➇❊❖❈ ▼ ✿❏❈ ✈✚❊ ❄✹❄ ❁❇➡ s❇❂ ➦ ▼✐s❇❖✯❂ ❊✛● ✝ ◗ ❊ ❃♣❃✹❂⑦❄ ✈✚❊♥✿✚❩ ❄ ❆♣❊ ▼❋❖ ✿✣❁ ✖✏❖✯❂✏➥❦ ✿✣❁❇❆ ❂✪❄r❂✞✖✏❖✯❂ ✿ ◗ ❂ ❊✛●❡❆♣❊ ❄✹❄❉❂⑦❄ ❼ ✭ ➧ ❼ ✛ ➂✹➂✴✺ ✜ ➧ ✜ ➧ ✓✄✂✔✗ ➥✯▼ ✿✚❩ ❈ ❂ ◗ ▼ ✿ ◗ ♦ ❂ ◗ ➔ ❆♣♦ ▼ ❆✭ ➧ ❼ ✛✯➂✍➍ ✭ ➧ ➄ ➏ ❑ ❅ ❛ ❅✓❼ ✛ ➂

❁ ❄ ➦ ▼✐s ❁↕❩❋●➉❊ ❃ ❼ ✭ ➧ ➂ ❂✞✖✏❖✚▼✱s ❆✹❊ ❂ ❁❇❆✹♦ ❂✼❃ ❆✹♦ ❂❷❖ ✈❃❈ ▼✤❃ ❩ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❊ ❃ ❆♣♦ ❂ ❩✣❊❉❈❀✿✗❈ ▼✛❃ ❩ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ④✫ ❊ ❃❹▼ ✇✛❁❇➦ ❂ ✿ ✛ ➥✶❄❉❂ ❆ ❄ ❁❺✇♥✿✡❼ ✛ ➂❷➍ ❖ ✈❃❈ ▼✤❃ ❩➲❼ ❃✹❂⑦❄ ✈✡④ ❄ ❁❇✇✏✿✓❼ ✛✯➂❷➍ ❩✣❊❉❈❀✿✗❈ ▼✛❃ ❩ ➂ ❁➏● ✛ ❩ ❂✼❃ ❁❇➦ ❂⑦❄ ● ❃ ❊ ❯ ▼ ✿ ❖ ✈❃❈ ▼✛❃ ❩

❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❼ ❃♣❂⑦❄ ✈✡④ ▼ ❩✣❊❖❈➇✿✗❈ ▼✛❃ ❩ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ➂ ➥ ▼ ✿✚❩ ✭ ❼ ✛ ➂✍➍✮✭ ➧ ✓✄✂ ✗ ❼ ✛ ➂ ❼✑❆✹♦ ❂ ➦ ▼✐s❇❖✯❂ ❊✛●❡❆♣♦ ❂❪s➣▼♥❄ ❆⑥❆✹❊ ❄✹❄ ❆✹♦ ▼ ❆ ❄ ❆♣❊✏✈ ❄❆✹♦ ❂ ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ▼ ❆ ✛ ➂ ④ P ✿ ❂ ◗ ▼ ✿ ◗ ♦ ❂ ◗ ➔ ❆✹♦ ▼ ❆q❁➏● ❄ ❁❇✇✏✿✓❼ ✛✯➂❲➍ ❖ ✈❃❈ ▼✛❃ ❩✝❼ ❃✹❂⑦❄ ✈✡④✝❁t● ❄ ❁❺✇♥✿✡❼ ✛ ➂✂➍ ❩✣❊❉❈❀✿✗❈ ▼✛❃ ❩ ➂ ➥❆✹♦ ❂ ✿ ✭ ❼ ✛✯➂ ◗ ▼ ✿✯✿✯❊♥❆✪➡ ❂✂❂✞✖♥❖✚▼✐s ❆✹❊ ❙ ❼ ❃✹❂⑦❄ ✈✡④ ✭ ❼ ✛✯➂ ◗ ▼ ✿✯✿✯❊✏❆➔➡ ❂❲❂✞✖✏❖✚▼✐s ❆✹❊ ✭ ➂✌✥ ❁❇✿ ◗ ❊✏✿ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂✏➥ ❆✹♦ ❂✼❃✹❂❲▼✛❃✹❂❊✏✿ s ❈ ➄ ❼ ✭ ● ❙ ➂ ✈✚❊ ❄✹❄ ❁❺➡ s❇❂ ➦ ▼✐s❇❖✯❂⑦❄ ●➉❊ ❃ ❼ ❄ ❁❺✇♥✿★❼ ✛✯➂ ➄ ✭ ❼ ✛✯➂♣➂ ④❷➞ ❂❱❯❲▼ ❈➨✿✯❊❖❈ ❩ ❂ ❦ ✿ ❂ ❆✹♦ ❂ ✿ ❂ ❈ ❃❅▼ ✿✚❩✣❊ ❯ ➦ ▼✤❃ ❁ ▼ ➡ s❇❂✏ ➍ ❼ ❄ ❁❇✇✏✿★❼✎✝ ➂ ➄ ✭ ❼☞✝ ➂♣➂ ❈➇♦✣❁ ◗ ♦q❊✏➡✣➦♥❁❺❊ ❖✚❄☞s ❈ ❄✹▼ ❆r❁ ❄ ❦ ❂⑦❄ ✈ ❃ ❊♥✈ ❂✼❃ ❆❉❁ ❂⑦❄ ❼ ❙ ➂ ▼ ✿✚❩q❼ ➄✣➂ ④❩❅➨❊ ❃✹❂ ❊✛➦ ❂✼❃⑦➥ ❁t● ✌ ➍ ✺ ▼ ✿✚❩ ✏ ➍❼✴✘☎➄ ✟➨➂ ➥ ❆✹♦ ❂ ✿ ▼✱sts ❆✹♦ ❂ ✈✚❊ ❄✹❄ ❁❇➡ s❇❂ ➦ ▼✱s❺❖✯❂⑦❄ ❊✛● ✝ ❩ ❂✼❃ ❁❇➦ ❂ ● ❃ ❊ ❯ ❆✹♦ ❂➫❄♣▼✛❯❱❂➇❖ ✈❃❈ ▼✛❃ ❩➈❊ ❃ ❩✣❊❖❈➇✿❃❈ ▼✛❃ ❩ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❼ ✭ ➧ ➂ ➥▼ ✿✚❩➊❆✹♦ ❂ ❈ ❯✂▼ ❈✂➡ ❂ ❊ ❃ ❩ ❂✼❃✹❂ ❩❨❁❺✿ ▼❲❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❼ ✛✆☎➣➂ ❄❉❖ ◗ ♦➓❆✹♦ ▼ ❆❩❅✓❼ ✛✝☎➣➂ ❁ ❄❷❄ ❆ ❃ ❁ ◗ ❆ s ❈❲❁❇✿ ◗ ❃✹❂⑦▼♥❄ ❁❇✿✯✇✚④❀✣☞✿ ◗ ❊♥✿ ❄❉❂✞✖✏❖✯❂ ✿ ◗ ❂✏➥❆✹♦ ❂ ❁❇✿✣❆ ❂✼❃ ➦ ▼✱s❦▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯ ❈♥❁ ❂❸s ❩ ❄ ✛✝☎ ❈⑥❁❇❆✹♦❋✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❺❆❉❈★★❼ ✛ ☎ ➂✍➍ ✣✥ ➧ ✓✄✂✟✞ ✗ ❞ ➠✠

➧ ✘ ✺ ★ ✏ ✧ ✩✬ ★ ➃ ➄❈➇♦✣❁ ◗ ♦❋❁ ❯ ✈ s ❁ ❂⑦❄ ❆✹♦ ▼ ❆✎★★❼ ✛ ☎ ➂ ❑ ★ ✘✧✣✦✥ ★★❼ ✛ ☎ ❞ ➠ ➂ ✎ ✈ ❃ ❊✏✈ ❂✼❃ ❆❉❈➨❼ ② ➂ ❯❲▼ ❈➈➡ ❂ ❩ ❂ ❩ ❖ ◗ ❂ ❩➊● ❃ ❊ ❯ ❆✹♦✣❁ ❄ ❁❺✿ ❂✞✖♥❖✚▼✐s ❁❇❆❉❈✏④

✡✳✁✵❋☎✆✓❤▲❧●✖➉❥✪✎✌☞✍✆✡❤⑤⑥♦ ❂ ❁❺✿✣❆ ❂✼❃ ➦ ▼✐s ▼✐s ✇✏❊ ❃ ❁❺❆♣♦ ❯⑩❯✂▼ ❈❪➡ ❂➇▼ ❩ ▼ ✈✯❆ ❂ ❩❹❆♣❊➇✇ ❂ ✿ ❂✼❃❅▼ ❆ ❂ ❆✹♦ ❂ ❦ ❃❅❄ ❆✪❅❱❆ ❂✼❃♣❯✂❄ ❊✤● ▼ ❦ ✿✣❁❇❆ ❂❘❄ ❆ ▼ ❆ ❂■❄ ✈ ▼ ◗ ❂ ❅ ▼✛❃✍➔ ❊✛➦◗ ♦ ▼ ❁❇✿ ✥ ❆♣♦ ❂→▼ ➦ ❂✼❃❸▼ ✇ ❂ ◗ ❊ ❄ ❆ ✽ ✓ ✝ ❅➲❁ ❄ ❆✹♦ ❂ ✿ ▼✏❄ ❈ ❯ ✈✯❆♣❊✏❆❉❁ ◗ ▼✐s➏s ❈❬❊♥✈✯❆❉❁ ❯✂▼✐s ④☞✣✑✿✚❩ ❂ ✈ ❂ ✿✚❩ ❂ ✿❏❆q❁↕❩ ❂ ✿✣❆❉❁ ◗ ▼✐s➏s ❈➀❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆ ❂ ❩❆✹❊ ❄♣❄❉❂⑦❄ ❈⑥❁❇❆✹♦ ▼ ✿ ✭ ➑ ◗ ❊✛❁❇✿ ❯❲▼ ❈ ▼✐s↕❄ ❊❱➡ ❂❹❃✹❂ ✈ s↕▼ ◗ ❂ ❩➊➡❏❈ ▼ ❅ ▼✛❃✍➔ ❊✱➦ ◗ ♦ ▼ ❁❇✿✡④✥ ✞✠✞✠✟✚❤✪✩✳☞➣➝✎✦ ☎ ✢✬✎✌☞✽❧✽✞✠✄✝✆✲✞✠✟✤✄✝☛✌☞✘✟✤✎✏✆✬✑✴☛❖●✂✟ ✟✢❤✬☛✌✄✝✆✲✞ ❑✰✑♣❥❡❤✡❧✮☛✌☞✍✆✡❤⑤⑥♦ ❂❷❂ ✿✣❆ ❃ ❊✏✈✣❈❲❊✛● ▼ ❩♥❁ ❄ ❆ ❃ ❁❺➡ ❖ ❆r❁❺❊♥✿ ✢ ➍ ❼ ✬ ▲ ➂ ▲☞☛✍✌➔❼✁❈➇♦ ❂✼❃✹❂ ✬➈❁ ❄ ◗ ❊ ❖ ✿✣❆ ▼ ➡ s❇❂ ➂ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩❋➡✣❈ ✎✖ ❼ ✢ ➂✍➍✽● ❈ ▲☞☛✍✌ ✬ ▲ s ✿ ✬ ▲ ➆

⑤⑥♦ ❂ ✿✯❊✏❆ ▼ ❆r❁❺❊♥✿✖ ❼ ✹ ➂ ❁ ❄⑥▼✐s↕❄ ❊ ❖✚❄❉❂ ❩q❁➏● ✹➒❁ ❄⑥▼⑧❃❅▼ ✿✚❩✣❊ ❯ ➦ ▼✛❃ ❁ ▼ ➡ s❇❂ ❈⑥❁❇❆✹♦❋❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ✢ ④❭✣ ● ❑◆▼✛❃ ❩ ❼ ✬ ➂✍➍ ✼ ➥ ❆✹♦ ❂ ✿✖ ❼ ✹ ➂✍➍ ✖ ❼ ✢ ➂ ❑ s ✿✷✼q④ ➣✗→

Page 107: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ❁❇✿ ◗ ❂✪▼ ✈ ▼ ❁ ❃ ❊✛● ❃❅▼ ✿✚❩✣❊ ❯ ➦ ▼✤❃ ❁ ▼ ➡ s❇❂⑦❄ ❼ ✹❷➄✑✱ ➂ ❁ ❄❀▼❹❃❸▼ ✿✚❩✣❊ ❯ ➦ ▼✛❃ ❁ ▼ ➡ s❺❂✏➥ ❊✏✿ ❂❪❯✂▼ ❈ ▼✐s↕❄ ❊ ◗ ❊♥✿ ❄ ❁↕❩ ❂✼❃ ❆✹♦ ❂❷❂ ✿✣❆ ❃ ❊✏✈✣❈✖ ❼ ✹❷➄✑✱ ➂ ④✈✣➉●✭✱ ➍ ➟✡❼✻✹ ➂ ❼ ❈➇♦ ❂✼❃✹❂ ➟➒❁ ❄ ❩ ❂ ❆ ❂✼❃✹❯ ❁❺✿✣❁ ❄ ❆r❁ ◗ ➂ ➥ ❆✹♦ ❂ ✿✖ ❼ ✹ ➂ ☛ ✖ ❼ ✱ ➂ ❼✑✿✯❊✏❆❉❁ ◗ ❂ ❆♣♦ ▼ ❆q❁❇❆❱❁ ❯ ✈ s ❁ ❂⑦❄✖ ❼ ✹❷➄✑✱ ➂✍➍ ✖ ❼ ✹ ➂✹➂ ④✣✑✿➈❆✹♦ ❂ ✇ ❂ ✿ ❂✼❃❅▼✱s ◗ ▼✏❄❉❂✏➥ ❩ ❂ ✿✯❊✏❆ ❂ ➡❏❈✥✹ ✝ ✱ ➍ ■ ❆♣♦ ❂ ❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿❋❊✛●✶✹ ◗ ❊✏✿✚❩♥❁❇❆❉❁❇❊✏✿ ❂ ❩❲❊✏✿ ✱ ➍ ■ ❼➉❁❇❆✍❁ ❄■▼✏❄♣❄❉❖✯❯❱❂ ❩❆✹♦ ▼ ❆❦✑ ❃ ❼ ✱ ➍ ■ ➂■➳

➏ ➂ ④ � ❂ ❆❷➟✓❼ ■ ➂❡➍ ✖ ❼✻✹ ✝ ✱ ➍ ■ ➂ ④✍⑤⑥♦ ❂ ✿❋❊♥✿ ❂❹❯✂▼ ❈✂❩ ❂ ❦ ✿ ❂✖ ❼ ✹ ❚ ✱ ➂❡➍ ❻ ❚ ➟✓❼ ✱ ➂ ❫✥➄❈➇♦✣❁ ◗ ♦ ❄✹▼ ❆r❁ ❄ ❦ ❂⑦❄✔✎ ✖ ❼ ✹ ❚ ✱ ➂✍➍ ✖ ❼ ✹❷➄✑✱ ➂ ● ✖ ❼ ✱ ➂ ④➎❀❊❉❈ ➥ ◗ ❊✏✿ ❄ ❁➣❩ ❂✼❃ ❆❁❈⑥❊❋❩♥❁ ❄ ❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿ ❄ ✢ ➍ ❼ ✬ ▲ ➂ ▲ ✍ ➠ ▼ ✿✚❩ ☎ ➍ ❼ ■ ▲ ➂ ▲ ✍ ➠ ❊ ❃ ❩ ❂✼❃✹❂ ❩➊❁❺✿①❩ ❂ ◗ ❃✹❂⑦▼♥❄ ❁❇✿✯✇➓✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❁ ❂⑦❄❼ ✬ ▲ ☛ ✬ ▲ ☞ ➠ ▼ ✿✚❩ ■ ▲ ☛ ■ ▲ ☞ ➠ ➥ ●➋❊ ❃♠▼✱sts ❄❉➂ ④✍⑤⑥♦ ❂ ✈ ▼✛❃ ❆❉❁ ▼✐s ❊ ❃ ❩ ❂✼❃ ❁❇✿✯✇ ✢ ✁ ☎ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩➨➡✣❈ ✎➁❈ ▲✙✘✢➠ ✬ ▲ ☛ ➁❈ ▲ ✘✢➠ ■ ▲✵➄ � ✑✌☛ ❙ ➆✣➉● ✢ ✁ ☎ ➥ ❆✹♦ ❂ ✿

✖ ❼ ✢ ➂ ❑ ✖ ❼ ☎ ➂ ❼☞❆✹♦✣❁ ❄ ❁ ❄ ❁❇✿✚❩ ❂✼❂ ❩➨➦ ▼✐s ❁↕❩➊●➋❊ ❃♠▼✱sts ❆✹♦ ❂ ◗ ❊✏✿ ◗ ▼ ➦ ❂✏➥✚❄ ❈ ❯❱❯❱❂ ❆ ❃ ❁ ◗ ● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ➂ ④✲✴✳✖✵✷✶✖✳✖✸✺✹✼✻✔✽✿✾✞❀❂❁❃✁❄✆❅↕➒❊❜❞❉➧◆✖➪☞●➵➟✮❡✼❱❦❜✔❉✺❋✜➒❛▲t❏❑❤✿♦➩◆◗➳✪❜❞❫❴▲✏❍▼❡✺❱■❘✦❳ãä➉❉➌❪▼●■❍❑❵✏❜❞❝❣❜✔❝✁➐t▲✏❍❑♦✁❪▼❤✿❫Ñ❥✙▲✏❍❙❍✆❜✔❉✺❋✮▲t❫➜❉✮❡✿❫➸q✺●❲❍❈➐t●■❉✿●■❍✆❜✔❪▼♦❢▲t❉✞❘✼❳ ➳✪❜❨✐➏➀✉➁t➁✏❐✦❘➞☞❍▼●■s✿❍❑♦✁❉✮❪✉❘❃✓➅❨❅↕➶❛▲✿♠▼❤✿●✚◆✖➲✺❘☞➶❦❘✓❱■❘✼❳✘Þ✂✁➝↔■⑩✙❷❲③✮❼❙➚✏❷■③✺❷❲②♣④➆❼◗⑩✖✇✔③➛✇⑦⑥❴②✆④✔③✺❸t✇✔➽ ñ➆④❞②■⑩✙④t❻■⑤✁❷✆➣❛⑥■②♣✇❞➽à❻❲⑩✙④❨➣✉❷✆❸✜↔♣✇❞⑩♥③✮➣■❘✍❳➓➈Õ●■❝✁❝❣➪☞●✉♠▼❤✿❉✦♦❽♠❲❜✔❝❛➶❛●■s✼▲✏❍▼❪❉✿➹✏➅t➬✏➮ → ➮✿❿✮❇❧➪❊➨➼➪íé❂❜✔q✼▲✏❍✆❜✔❪❑▲t❍❑♦✁●■❏❨❿✞➀✉➁t➁✏➠✦❘

➣ ➮

Page 108: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✄ ✠ ✟✡✞✡✥✏✎ ✌✤✁ ✠✔✎✑✜ �❱✥✏✞✧✂☎✠✑✄ ✠✡☎✂✎☞✒ ✁✦✞✡✒✁�⑦✗✂✕✚✂■✠☞✄✚✫ ✁✦✄✯✌ �✂✞✓✥✄✂ ☎☎⑥✰★✔✽✻ ✔✝✆✞✆■✺❱✭✯✵✯✷✠✟ ✝✢✺ ✙✣❾➎ � ✣ ➌ � ❊ ◗ ✖✏❖✯❂ ✿ ◗ ❊ ❖✯❃ ❆✫✯❂ ➡ ❃✹❖✚▼✤❃ ❈ ➙ ➥✡❙✏✱✿✱✿✯

❚ ❄❉❖✯❯❱❯✂▼✛❃ ❈✂➡✣❈☛✡ ▼ ➦✏❁ ❂✼❃❩❄ ❊ ❖✯❃ ❩✣❊✏✿✯❫❴➸✵✡❵✹❛❨✻✔✽❏❜❝❛

➘➼❡✿●❖❪❑▲➧❪▼❤✿●✜❏❑s✼●✉♠✆♦❶×Ø♠✜❉✺❜❞❪❑❡✿❍▼●â▲❞❥↕❍♣❜t❋✮♦✁▲➧❉✿●■❪➉r➊▲✏❍▼➋✮❏✉❿➼❪❑❤✿●➏♠▼❤✺❜✔❉✿❉✦●■❝❦❜✏♠■♠✆●❲❏❑❏✪♦✁❉➝❍✆❜✏❋✮♦✁▲➧❝✁▲✿♠■❜❞❝❈❜✔❍▼●✉❜❉✿●■❪➉r➊▲✏❍❑➋✮❏❛◆➉é✣❇❙➎❊❱☞♦✁❏❧❋✮♦❶ÙØ●❲❍❑●■❉✮❪Õ❥✙❍❑▲t❫✄♠■❜❞q✿❝✁●✉❋➸é✣❇❙➎❦❘✔➪❛❤✿●❊➒➩ä❑➞❧❩❧➶➼é✣❇❈➎ ❏❑❪♣❜❞❉✺❋✿❜❞❍♣❋❺❥✖▲✏❍☞❍♣❜t❋✮♦✁▲❈❉✦●■❪➉r❣▲t❍❑➋✮❏r❛♦❢❝✁❝❨s✿❍❑▲✔❵✮♦♥❋✮●❧❜❛➅✔➯✮➳✚q✿s✿❏☞❋✿❜✔❪✆❜➊❍♣❜❞❪❑●❧❪▼❍♣❜✔❉✦❏❑❫❴♦✁❏▼❏❑♦✁▲✏❉✞❘✼ä➉❪✣❤✺❜❞❏✷❜➊❏▼s✺●✉♠❆♦❽❜❞❝✔❥✙●❨❜✔❪❑❡✦❍❑●✏❿✏♠❲❜✔❝✁❝✁●✉❋❙❜✏♠✆❪▼♦❢❵t●☞❏❑♦✁➐✏❉✺❜❞❝✁❝❢♦✁❉✿➐✼❿r❛❤✿♦♥♠❑❤✚♠■❜✔❉✚q✼●❦❡✿❏▼●✉❋✚❪❑▲❺s✿❍▼▲✔❵➌♦♥❋✮●❦❜❞❉❬●✎✒❬♠✆♦✁●■❉✮❪❊♠❑❤✼❜✔❉✿❉✿●❲❝✷❜✏♠❲♠✆●■❏❑❏❙❫➙●✉♠▼❤✺❜✔❉✿♦✁❏▼❫â❘

❢✬✁ ✥ ❧✮☛✌☞✙✂✂✟✱✎✌☞✗✺✡❤✂✢✬✖✭✖✗☞➉❤★✺⑤⑥♦ ❂ ◗ ♦ ▼ ✿✯✿ ❂❸s✪▼ ◗✼◗ ❂⑦❄✹❄ ❁❇✿ ❃❅▼ ❩♥❁❇❊✈➐ ➌ ➎ ❄ ♦ ▼✏❄ ❆✹❊ ● ▼ ◗ ❂①❄ ✈ ❂ ◗ ❁ ▼✱s ✈ ❃ ❊✏➡ s❇❂✼❯✂❄ ④ ✾➇✿ s ❁ ➔✏❂ ❈⑥❁ ❃✹❂ ❩⑦➐ ➌ ➎ ❄✼➥ ✿✯❊✴❩ ❂⑦❄◗ ▼ ✿✯✿✯❊✏❆❷➡ ❖ ❁ s ❩ ▼ ◗ ❊ ❯ ✈ s❇❂ ❆ ❂ ♦✣❁ ❄ ❆✹❊ ❃ ❈➓❊✛●⑥❆✹♦ ❂ ✿ ❂ ❆❁❈◆❊ ❃✍➔ ● ❃ ❊ ❯ ❆✹♦ ❂ ● ❃❸▼ ✇ ❯❱❂ ✿✣❆ ❄ ❊✛●✍● ❂✼❂ ❩✣➡ ▼ ◗ ➔ ❆✹♦ ❂ ❈➨❊✏➡✯❆ ▼ ❁❇✿ ● ❃ ❊ ❯❆✹♦ ❂ ◗ ♦ ▼ ✿✯✿ ❂❸s ④■⑤⑥♦✣❁ ❄ ● ❂⑦▼ ❆ ❖✯❃✹❂❷❯❲▼✞➔✏❂⑦❄ ❆✹♦ ❂ ◗ ❊ s➏s ❁ ❄ ❁❇❊✏✿①❩ ❂ ❆ ❂ ◗ ❆r❁❺❊♥✿❋❆ ❂ ◗ ♦✯✿✣❁ ✖♥❖✯❂⑦❄ ❁❇✿ ❃❅▼ ❩♥❁❺❊➈✿ ❂ ❆✻❈⑥❊ ❃ ➔✴❄ ❩♥❁ �✡❂✼❃✹❂ ✿✣❆⑥● ❃ ❊ ❯◗ ▼ ➡ s❇❂ ❩❋✿ ❂ ❆❁❈⑥❊ ❃✍➔✯❄ ④⑤⑥♦ ❂➇▼ ◗ ❆❉❁❇➦ ❂⑥❄ ❁❇✇✏✿ ▼✐s➏s ❁❇✿✯✇❹● ❂⑦▼ ❆ ❖✯❃♣❂ ❊✤●✚❆✹♦ ❂■❃❅▼ ❩♥❁❺❊⑧➐ ➌ ➎ ❄ ❆ ▼ ✿✚❩ ▼✛❃ ❩ ❭ ✣♣✑☎❻ � ➐ ➌ ➎✝✈ ❃ ❊✛➦♥❁➣❩ ❂⑦❄✍▼ ✿ ❂ ☛❨◗ ❁ ❂ ✿✣❆ ◗ ♦ ▼ ✿✯✿ ❂❸s

▼ ◗✼◗ ❂⑦❄✹❄⑧❯❱❂ ◗ ♦ ▼ ✿✣❁ ❄❉❯ ④❉✣☞❆ ◗ ❊✏✿ ❄ ❁ ❄ ❆ ❄ ❁❇✿ ❃✹❂✞✖♥❖ ❁ ❃ ❁❇✿✯✇ ❂⑦▼ ◗ ♦➲✿✯❊✴❩ ❂ ❆✹♦ ▼ ❆❄❈ ▼ ✿✣❆ ❄ ❆✹❊ ▼ ◗✼◗ ❂⑦❄✹❄ ❆✹♦ ❂ ◗ ♦ ▼ ✿✯✿ ❂❸s ❆✹❊ ❄r❂ ✿✚❩ ▼◗ ❂✼❃ ❆ ▼ ❁❺✿ ❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❊✛●■❊✏✿✞✡⑦❊ � ✆③❄➇▼♥❄❘▼ ✈ ❃✹❂⑦▼✛❯ ➡ s❇❂ ❆✹❊ ❂⑦▼ ◗ ♦➨✈ ▼ ◗ ➔♥❂ ❆❘❆ ❃❸▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿✡④❷⑤⑥♦✣❁ ❄❷❄❉❂✞✖♥❖✯❂ ✿ ◗ ❂ ❁ ❄❪❂ ✿ ◗ ❊✯❩ ❂ ❩▼ ◗✼◗ ❊ ❃ ❩♥❁❺✿✯✇❲❆✹❊ ▼→❃❅▼ ✿✚❩✣❊ ❯ ✈ ▼ ❆✹❆ ❂✼❃ ✿✬❈➇♦✯❊ ❄❉❂ ❩ ❂ ❆ ▼ ❁ s↕❄ ❈⑥❁ s➏s ➡ ❂ ❩ ❂⑦❄ ◗ ❃ ❁❇➡ ❂ ❩ s↕▼ ❆ ❂✼❃ ④◆⑤♠♦ ❂ ❊✏➡ ✭❉❂ ◗ ❆❉❁❇➦ ❂ ❁ ❄ ❆✹❊ ❖✚❄❉❂ ❆✹♦ ❂⑦❄❉❂✈ ▼ ❆✹❆ ❂✼❃ ✿ ❄ ❆✹❊ ❄❉❂❸s❇❂ ◗ ❆❷❼ ❈⑥❁❇❆✹♦ ▼ ♦✣❁❇✇✏♦❋✈ ❃ ❊♥➡ ▼ ➡✣❁ s ❁❇❆❉❈ ➂ ❊✏✿ s ❈✂❊♥✿ ❂ ✿✯❊✯❩ ❂❹❄ ❊q❆✹♦ ▼ ❆☎✿✯❊ ◗ ❊ sts ❁ ❄ ❁❇❊✏✿ ❊ ◗✼◗ ❖✯❃❅❄ ❩ ❖✯❃ ❁❇✿✯✇❱✈ ▼ ◗ ➔✏❂ ❆❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿✡④■⑤♠♦ ❂ ✈ ▼ ❆✹❆ ❂✼❃ ✿ ❄⑥▼✛❃♣❂➫▼✐s↕❄ ❊➔● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄ ❊✛●❡❆✹♦ ❂❷▼ ◗✼◗ ❂⑦❄✹❄ ✈ ❃ ❁❺❊ ❃ ❁❇❆❾❈ ▼✏❄✹❄ ❁❺✇♥✿ ❂ ❩❲❆✹❊q❆✹♦ ❂ ✈ ▼ ◗ ➔✏❂ ❆✐④❇❆ ❖✯❃ ❁❇✿✯✇❆✹♦ ❂ ❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿➨❊✛●✍❁❇❆ ❄ ✈ ▼ ❆✹❆ ❂✼❃ ✿ ▼ ✿✚❩ ❈➇♦ ❂ ✿➨❁❺❆❪❁ ❄ ❁❇✿ ❆✹♦ ❂ ✶ ❊ � ✸❹✈ ❂✼❃ ❁❇❊✴❩ ➥ ❆✹♦ ❂ ✿✯❊✴❩ ❂❱❄❉❂ ✿ ❄r❂⑦❄ ❆✹♦ ❂ ◗ ♦ ▼ ✿✯✿ ❂❸s❑✎ ❁➏●❁❇❆➫❩ ❂ ❆ ❂ ◗ ❆ ❄❷▼ ✿✣❈✂❊✏❆♣♦ ❂✼❃➫❄ ❁❇✇✏✿ ▼✱s ➥ ❆♣♦ ❂ ✿❬❆♣♦ ❂ ✿✯❊✯❩ ❂→❄ ❆✹❊✏✈ ❄ ❁❇❆ ❄ ✈ ▼ ❆♣❆ ❂✼❃ ✿❋❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿ ▼ ✿✚❩➨❩ ❂ ● ❂✼❃❅❄❀❖ ✿✣❆❉❁ s ❆✹♦ ❂ ✿ ❂ ➆✯❆▼ ❆✹❆ ❂✼❯ ✈✯❆⑦④

�✲✁ ■➨❣✔✩✡✶✴✔☞☛ ✥✍✌ ✢✚❧✮☛✌☞ ✂✂✟✕✎✝☞❥✺✓❤✲✢✬✖✗✖✗☞➉❤★✺ ✞ ✢✤☛✦☛✦✟✡✄♥❤✫✎✦✟✤✖✍✟✴❧✮☛✌☞✍✆✡❤⑤⑥♦ ❂ ❭ ✣✆✑■❻ � ➐ ➌ ➎ ▼ ◗ ❆r❁❺➦ ❂ ❄ ❁❺✇♥✿ ▼✐s➏s ❁❇✿✯✇✝✈ ▼ ❆✹❆ ❂✼❃ ✿➭❁ ❄ ❩♥❁❺➦♥❁↕❩ ❂ ❩✝❁❇✿❏❆♣❊➀❆❁❈⑥❊ ◗ ❊✏✿ ❄❉❂ ◗ ❖ ❆r❁❺➦ ❂ ✈✯♦ ▼✏❄❉❂⑦❄✼➥ ❆♣♦ ❂ ▼ ◗✼◗ ❂⑦❄✹❄✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ ▼✏❄✹❄❉❂✼❃ ❆r❁❺❊♥✿❋✈✯♦ ▼✏❄❉❂✪▼ ✿✚❩❲❆✹♦ ❂ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿❋✈✯♦ ▼✏❄❉❂ ④�✲✁➉❢✒✁❋❊❍●✂✟✯✢✚❧✏❧✮✟✤✎✌✎ ✞✠✄✮☞✘✆✂✄✧☞✍☛✪❑ ✢✬✎✌✎✦✟✤✄✝☛✌☞✘✆✓❤ ✞❭●✲✢✬✎❖✟✲✁ ⑤⑥♦ ❂ ❦ ❃❸❄ ❆ ❄☞s ❊✏❆ ❄ ❊✛●❘❆✹♦ ❂ ✈ ▼ ❆✹❆ ❂✼❃ ✿ ▼✤❃✹❂ ❩ ❂ ❩♥❁ ◗ ▼ ❆ ❂ ❩✉❆✹❊

✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ ❄ ❁❇✇✏✿ ▼✐s➏s ❁❺✿✯✇✢④⑤⑥♦ ❂ ✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈➓✈✯♦ ▼♥❄❉❂ ◗ ❊✏✿ ❄ ❁ ❄ ❆ ❄ ❁❺✿ s❺❂⑦▼ ➦♥❁❇✿✯✇ ▼ ◗ ❂✼❃ ❆ ▼ ❁❺✿ ✿ ❖✯❯ ➡ ❂✼❃ ❊✤●■❁↕❩ s❇❂ ❼✑❊ � ➂ ❄☞s ❊✏❆ ❄ ➡ ❂ ●➉❊ ❃✹❂ ❊✏✿ ❂ ➡ ❖✚❄ ❈✦❼✑❊✏✿ ➂❄☞s ❊✏❆⑦④❲⑤⑥♦✣❁ ❄ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄☞s ❊✏❆ ❄ ❁ ❄⑧❂✞✖✏❖✚▼✱s ❆✹❊ ✯ ❼ ❯✂▼ ➆✣❁ ❯✪❖✯❯ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛●➇✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ s❇❂ ➦ ❂❸s↕❄ ➂ ❯ ❁❇✿ ❖✚❄ ❆✹♦ ❂ ✈ ❃ ❁❺❊ ❃ ❁❇❆❾❈s❇❂ ➦ ❂❸s ④①⑤⑥♦ ❂ ✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ ▼✏❄✹❄❉❂✼❃ ❆❉❁❇❊✏✿➀✈✯♦ ▼♥❄❉❂✂❂ ✿✚❩ ❄ ❈⑥❁❇❆✹♦✦❆✹♦ ❂ ❦ ❃❅❄ ❆q➡ ❖✚❄ ❈ ❄❾s ❊♥❆ ❂ ✿ ◗ ❊ ❖ ✿✣❆ ❂✼❃✹❂ ❩ ➥ ◗ ▼✱sts❇❂ ❩➭❆✹♦ ❂ ✈ ❃ ❁❺❊ ❃ ❁❇❆❾❈✈ ❖✣s↕❄❉❂ ④❷⑤⑥♦ ❂✼❃✹❂ ●➉❊ ❃✹❂✏➥ ❊♥✿ s ❈➨❆✹♦ ❂ ◗ ❊♥✿❏❆ ❂ ✿✚❩ ❂✼❃❸❄ ❈⑥❁❇❆✹♦➨❆✹♦ ❂ ♦✣❁❇✇✏♦ ❂⑦❄ ❆ ▼ ◗✼◗ ❂⑦❄✹❄ ✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ s❺❂ ➦ ❂❸s◆❄❉❖✯❃ ➦♥❁❺➦ ❂ ❆✹❊❲❆✹♦ ❂ ✈ ❃ ❁❺❊ ❃ ❁❇❆❾❈▼✏❄✹❄r❂✼❃ ❆❉❁❇❊✏✿❲✈✯♦ ▼✏❄❉❂ ④ ✫ ❁❇✇ ❖✯❃✹❂q❙❷❄ ♦✯❊❖❈ ❄■▼ ✿ ❂ ➆ ▼✛❯ ✈ s❇❂ ❈➇♦ ❂✼❃✹❂ ✿✯❊✯❩ ❂ ✡ ➥ ❊✏✿ ▼ ◗✼◗ ❂⑦❄✹❄ ✈ ❃ ❁❇❊ ❃ ❁❺❆❉❈ s❇❂ ➦ ❂❸s ② ➥ ➡ ❂⑦▼ ❆ ❄ ✿✯❊✴❩ ❂ ➌❊✏✿ ▼ ◗✼◗ ❂⑦❄♣❄ ✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ s❇❂ ➦ ❂❸s ➄ ④ ➣✗➣

Page 109: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

s✿❍▼♦❢▲t❍❑♦✁❪➉✐➸s✿❡✿❝✁❏▼●■❏◆✙❇❯❋➱▲➌●❲❏❊❉✿▲t❪❛❪❑❍♣❜❞❉✿❏❑❫➙♦✁❪❧♦✁❪❑❏❛q✿❡✿❍▼❏❑❪✆❱

✁✁✂

●❲❉✺❋✚▲✔❥s✦❍❑●■❵✮♦✁▲✏❡✿❏➼s✺❜✏♠▼➋t●■❪

s✼❜✔❪❑❪▼●■❍❑❉❖▲✔❥✷❉✦▲➱❋➱●➢➈s✼❜✔❪❑❪▼●■❍❑❉❖▲✔❥✷❉✦▲➱❋➱●❈❇

◗❙❘❯❚❙❱❀✘✚✔ ❲ ✢❷❭ ❊❉❈ ❆✹❊ ❈⑥❁❇✿❋✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ ◗ ❊✏✿❏❆ ❂ ✿❏❆❉❁❇❊✏✿�✲✁✗�✂✁❋❊❍●✂✟➀❧✮✆✓❤✬☛✦✟✚❤✒☛✌☞✘✆✓❤ ✞❭●✂✢✬✎✦✟✂✁ ⑤⑥♦ ❂ ◗ ❊♥✿❏❆ ❂ ✿✣❆❉❁❇❊✏✿❋✈✯♦ ▼✏❄r❂ ❁ ❄ ❩♥❁❇➦✏❁↕❩ ❂ ❩➊❁❇✿❏❆✹❊❲❆❁❈⑥❊ ◗ ❊♥✿ ❄❉❂ ◗ ❖ ❆❉❁❇➦ ❂ ✈ ▼✛❃ ❆ ❄❝➥ ❆✹♦ ❂❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿✉✈ ▼✛❃ ❆ ▼ ✿✚❩ ❆✹♦ ❂ ❆ ▼ ❁ s➇❄❉❂❸s❇❂ ◗ ❆❉❁❇❊✏✿✦✈ ▼✛❃ ❆⑦④❱⑤⑥♦ ❂➈❃ ❊ s❇❂ ❊✤●◆❆✹♦ ❂❱❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿✉✈ ▼✤❃ ❆❪❁ ❄ ❆♣❊ ❄❉❂❸s❇❂ ◗ ❆ ▼❋❄r❯✂▼✐s➏s✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄❉❖✯❃ ➦♥❁❇➦✏❊ ❃❅❄ ● ❃ ❊ ❯ ▼➔s↕▼✛❃ ✇ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ◗ ❊✏✿❏❆ ❂ ✿✚❩ ❂✼❃❅❄ ④■⑤⑥♦ ❂ ❆ ▼ ❁ s✟❄❉❂❸s❇❂ ◗ ❆❉❁❇❊✏✿➓✈ ▼✤❃ ❆➇❆ ❃ ❁ ❂⑦❄ ❆♣❊ ❄❉❂❸s❇❂ ◗ ❆➇❊✏✿ s ❈❊✏✿ ❂❷❄❉❖✯❃ ➦♥❁❇➦✏❊ ❃ ● ❃ ❊ ❯ ▼✪❄r❯✂▼✐s➏s ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ◗ ❊✏✿❏❆ ❂ ✿✚❩ ❂✼❃❅❄ ❈⑥❁❇❆✹♦ ▼ ♦✣❁❺✇♥♦❋✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❾❈✏④➍✣➉● ❯ ❊ ❃✹❂ ❆✹♦ ▼ ✿❲❊✏✿ ❂❷❄❉❖✯❃ ➦♥❁❺➦♥❊ ❃❁ ❄❘❄r❂❸s❺❂ ◗ ❆ ❂ ❩ ▼ ❆➇❆♣♦ ❂❷❂ ✿✚❩❋❊✛●✍❆✹♦ ❂ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿❋✈✯♦ ▼✏❄❉❂✏➥✚▼ ◗ ❊ s➏s ❁ ❄ ❁❇❊✏✿➲❊ ◗✼◗ ❖✯❃❅❄ ④✶ ✗✜✴✥✴ ✕ ❬ ✧ ❬✍✵ ✲✿✝ ❬ ✢ ✵ ☎ ✗ ✲ ✷ ✴ ✴❚✣☞❆ ◗ ❊✏✿ ❄ ❁ ❄ ❆ ❄ ❁❇✿ ❂ ✿ s↕▼✛❃ ✇✛❁❇✿✯✇❲❆✹♦ ❂ ✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈❲✈ ❖✣s➣❄r❂ ❈⑥❁❇❆✹♦ ▼➔❃❅▼ ✿✚❩✣❊ ❯ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄☞s ❊✏❆ ❄ ④❻ ▼ ◗ ♦ ✿✯❊✯❩ ❂→❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂⑦❄ ❁❇❆ ❄ ✈ ❖✣s↕❄❉❂ ❁❺✿✚❩ ❂ ✈ ❂ ✿✚❩ ❂ ✿❏❆ s ❈✦❊✛●■❆✹♦ ❂ ❊✏❆♣♦ ❂✼❃ ✿✯❊✯❩ ❂⑦❄❹▼ ✿✚❩ ▼ ◗✼◗ ❊ ❃ ❩♥❁❇✿✯✇❋❆✹❊ ▼ ✇ ❂ ❊ ❯➈❂ ❆ ❃ ❁ ◗ ❩♥❁ ❄❇➑❆ ❃ ❁❇➡ ❖ ❆❉❁❇❊✏✿➨❊✛●✍✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❾❈✯★ ➍ ❙ ✝ ➄ ④✟⑤♠♦ ❂✼❃✹❂ ●➋❊ ❃✹❂ ❆✹♦ ❂ ✈ ❖✣s↕❄❉❂ ❁ ❄☎s↕▼✛❃ ✇ ❂✼❃ ❆♣♦ ▼ ✿❣✺ ❄☞s ❊✏❆ ❄ ❈⑥❁❇❆✹♦❋✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❈ ❙ ✝ ➄ ❤⑦④➌ ●➋❆ ❂✼❃ ❆✹♦ ❂❷❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂ ❩q✈ ❖✣s↕❄❉❂⑦❄✼➥ ❆✹♦ ❂ ✿✯❊✯❩ ❂❀s❺❂⑦▼ ➦ ❂⑦❄⑥▼ ✿→❁➣❩ s❇❂❹❄☞s ❊✏❆ ➥ ◗ ▼✱sts❇❂ ❩❲❆✹♦ ❂✡✷ ✭✜✰ ✾ ❬ ✾✶✲✿✕✒✾ ✴ ✰ ❬ ✱ ➢ ✲✿✝ ❬ ✢ ✵✣✷ ✕✁✢✿✝❭❈➇♦ ❂✼❃✹❂❁❇❆ ❄❉❂ ✿ ❄r❂⑦❄ ❆✹♦ ❂ ◗ ♦ ▼ ✿✯✿ ❂❸s ④ P ✿ s ❈ ❆✹♦ ❂ ◗ ❊✏✿✣❆ ❂ ✿✚❩ ❂✼❃❅❄ ❈➇♦✣❁ ◗ ♦ ❄ ❁ ❯q❖✣s ❆ ▼ ✿ ❂ ❊ ❖✚❄☞s ❈❬♦✯❊ s ❩➲❆✹♦ ❂ ♦✣❁❇✇✏♦ ❂⑦❄ ❆ ▼ ◗✼◗ ❂⑦❄✹❄ ✈ ❃ ❁❺❊ ❃ ❁❇❆❾❈s❇❂ ➦ ❂❸s❹▼ ✿✚❩ ❄❉❂❸s❇❂ ◗ ❆✂❆♣♦ ❂❲s ❊♥✿✯✇ ❂⑦❄ ❆ ❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂ ❩✦✈ ❖✣s↕❄❉❂❬❄r❖✯❃ ➦✏❁❇➦ ❂ ❆✹❊①❆✹♦ ❂❋❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿ ✈ ▼✛❃ ❆⑦④ ✫ ❁❇✇ ❖✯❃✹❂ ➄ ❄ ♦✯❊❉❈ ❄❱▼ ✿❂ ➆ ▼✛❯ ✈ s❇❂ ❈➇♦ ❂✼❃♣❂ ✿✯❊✴❩ ❂ ➌ ❈⑥❁❇❆✹♦ ❄ ❆ ❃✹❂ ❆ ◗ ♦ s❇❂ ✿✯✇✏❆♣♦➓❊✛● ❙➔❄☞s ❊✏❆☎❁ ❄❀❂❸s ❁ ❯ ❁❇✿ ▼ ❆ ❂ ❩➨➡❏❈❲✿✯❊✯❩ ❂ ✡ ❈♠❁❺❆♣♦ ❄ ❆ ❃✹❂ ❆ ◗ ♦ s❇❂ ✿✯✇✏❆✹♦❋❊✛●➄ ❄☞s ❊✏❆ ❄ ④

✄✄☎

✆✝

❏❑❪▼❍❑●■❪✆♠▼❤✿●✉❋s✿❡✿❝✁❏▼●✆ ✞

❏❑❡✿❍▼❵✮♦❢❵✏❜❞❝❵✏●■❍▼♦❶×Ø♠■❜✔❪▼♦✁▲✏❉❴❏▼❝✁▲✏❪❇❯❋➱●■❪❑●✉♠❆❪❑❏❙s✿❡✿❝✁❏❑●❙▲❞❥Õ➈ ❜✔❉✺❋➙❋✮●✆❥✙●■❍▼❏●■❉✼❋❴▲❞❥s✿❍▼♦✁▲✏❍❑♦✁❪➉✐➙s✺❜✔❍▼❪

s✺❜t♠▼➋✏●■❪

❫❴♦♥❋❺s✺❜❞❪❑❪▼●■❍❑❉✪▲❞❥✷❉✿▲✿❋✮●✴❇❫❴♦♥❋❺s✺❜❞❪❑❪▼●■❍❑❉✪▲❞❥✷❉✿▲✿❋✮●❺➈

◗ ❘ ❚❙❱❀✘✚✔✆� ✢❷❭ ❊❖❈ ❆✹❊❋❈⑥❁❇✿➓❆♣♦ ❂❷❂❸s ❁ ❯ ❁❇✿ ▼ ❆r❁❺❊♥✿❬✈ ▼✤❃ ❆

✶ ✗✜✴ ✝❏✲ ❬ ✕ ✷✒✴ ✕ ✴❅➢ ✝ ❬ ✢ ✵ ☎ ✗ ✲ ✷✒✴ ✴ ⑤⑥♦✣❁ ❄ ✈✯♦ ▼✏❄❉❂ ❁ ❄❋▼✐s↕❄ ❊ ◗ ▼✐s➏s❇❂ ❩ ❆✹♦ ❂✆✶ ❈♥❁ ❂❸s ❩✹✸✉✈ ▼✛❃ ❆ ▼ ✿✚❩✦●➉❊ s➏s ❊❖❈ ❄➙✭❉❖✚❄ ❆ ▼ ●➉❆ ❂✼❃ ❆✹♦ ❂❄❉❖✯❃ ➦♥❁❇➦ ▼✐s ➦ ❂✼❃ ❁ ❦ ◗ ▼ ❆r❁❺❊♥✿ ❄☞s ❊✏❆⑦④⑥⑤⑥♦ ❂ ✿✯❊✴❩ ❂⑦❄ ❈➇♦✣❁ ◗ ♦ ❄❉❖✯❃ ➦♥❁❇➦ ❂ ❩❋❆✹❊➈❆✹♦ ❂❹❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿ ✈ ▼✛❃ ❆ ▼ ✇ ▼ ❁❇✿ ❄r❂❸s❺❂ ◗ ❆ ▼q❃❅▼ ✿✚❩✣❊ ❯✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄☞s ❊✏❆ ❄q▼ ◗✼◗ ❊ ❃ ❩♥❁❇✿✯✇①❆✹❊ ▼ ✇ ❂ ❊ ❯❱❂ ❆ ❃ ❁ ◗ ❃❅▼ ❆ ❂ ❙ ● ✾✬❈♠❁❺❆♣♦❏✾ ➍ ❙ ✝ ✝ ④ ✡ ❖ ❆❹❁❇✿ ❄ ❆ ❂⑦▼ ❩①❊✤●❘❆ ❃❅▼ ✿ ❄r❯ ❁❇❆✹❆❉❁❇✿✯✇➡ ❖✚❄ ❈ ❄❾s ❊♥❆ ❄■▼ ✇ ▼ ❁❇✿ ▼✏❄ ❈♠❁❺❆♣♦❱❆✹♦ ❂❷❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂ ❩q✈ ❖✣s↕❄❉❂ ✈ ❃ ❊ ◗ ❂ ❩ ❖✯❃✹❂✏➥ ❆✹♦ ❂ ◗ ❊♥✿❏❆ ❂ ✿✚❩ ❂✼❃❸❄ ❆ ❂✼❃✹❯ ❁❺✿ ▼ ❆ ❂ ❆✹♦ ❂ ❁ ❃ ✈ ▼ ❆✹❆ ❂✼❃ ✿❋❈⑥❁❇❆✹♦▼ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛●■❁↕❩ s❇❂❋❄☞s ❊✏❆ ❄❪❂✞✖♥❖✚▼✐s ❆✹❊❋❆✹♦ ❂ ❁ ❃❹❃♣❂⑦❄ ✈ ❂ ◗ ❆❉❁❇➦ ❂ ✿ ❂ ❈ ❄❉❂❸s❇❂ ◗ ❆ ❂ ❩①✿ ❖✯❯ ➡ ❂✼❃❅❄ ④✪⑤⑥♦ ❖✚❄ ❁➏● ▼ ✿✯❊✴❩ ❂ ❩ ❂ ❆ ❂ ◗ ❆ ❄ ✿✯❊❄ ❁❇✇✏✿ ▼✐s ❩ ❖✯❃ ❁❇✿✯✇q❁❇❆ ❄⑥❄ ❁ s❇❂ ✿✣❆➇✈ ❂✼❃ ❁❇❊✯❩ ➥ ❆✹♦ ❂ ✿❲❆✹♦ ❂ ✿✯❊✴❩ ❂ ❆ ❃❸▼ ✿ ❄❉❯ ❁❇❆ ❄ ❁❺❆ ❄ ✈ ▼ ◗ ➔✏❂ ❆✐④ P ❆♣♦ ❂✼❃ ❈⑥❁ ❄❉❂✏➥ ❆✹♦ ❂ ✿✯❊✯❩ ❂ ❩ ❂ ● ❂✼❃❅❄☎❖ ✿✣❆❉❁ s❆✹♦ ❂ ✿ ❂ ➆✯❆ ▼ ◗✼◗ ❂⑦❄✹❄ ◗ ❈ ◗ s❺❂ ④⑤⑥♦ ❂✼❃✹❂ ●➉❊ ❃✹❂✏➥ ❊♥✿ s ❈➔❆✹♦ ❂ ✿✯❊✴❩ ❂⑦❄ ❈➇♦✯❊ ❄❉❂ ✈ ▼ ❆✹❆ ❂✼❃ ✿ ❄✍❄ ❁ ❯✪❖✣s ❆ ▼ ✿ ❂ ❊ ❖✚❄☞s ❈q✈ ❃✹❂⑦❄❉❂ ✿✣❆✍❆✹♦ ❂ ♦✣❁❺✇♥♦ ❂⑦❄ ❆ ▼ ◗✼◗ ❂⑦❄✹❄ ✈ ❃ ❁❇❊ ❃ ❁❺❆❉❈ s❺❂ ➦ ❂❸s ➥❆✹♦ ❂qs ❊✏✿✯✇ ❂⑦❄ ❆ ❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂ ❩ ✈ ❖✣s↕❄❉❂❋▼ ✿✚❩➨❆✹♦ ❂✂❄ ♦✯❊ ❃ ❆ ❂⑦❄ ❆ ✶ ❈✏❁ ❂❸s ❩✹✸➨✈ ▼✛❃ ❆❷✇ ▼ ❁❇✿①❆♣♦ ❂✪❃ ❁❺✇♥♦❏❆➔❆✹❊❋❆ ❃❅▼ ✿ ❄r❯ ❁❇❆❷❆✹♦ ❂ ❁ ❃ ✈ ▼ ◗ ➔✏❂ ❆⑦④

❄✉➬✏➬

Page 110: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄s✺❜t♠❑➋t●■❪

✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄ ✄

●❲❉✺❋➙▲✔❥●■❝✁♦❢❫➙♦✁❉✺❜✔❪▼♦❢▲t❉↕s✼❜✔❍❑❪ ❇❯❋➱●■❪❑●✉♠❆❪❑❏❙s✺❜✏♠▼➋t●■❪❛▲✔❥❣➈➝❜❞❉✺❋❴❋✮●❆❥✙●■❍❑❏

●❲❉✺❋✚▲✔❥☞s✺❜✔❪▼❪❑●■❍▼❉s✦❝❢❡✦❏❛s✺❜✏♠▼➋✏●❲❪❛▲✔❥❧❉✿▲✿❋✮●❦➈

●❲❉✺❋✚▲✔❥☞s✺❜✔❪▼❪❑●■❍▼❉✪▲✔❥☞❉✿▲✿❋✮●❙❇

◗ ❘❯❚❵❱✕✘ ✔ ✝ ✢❷❭ ❊❖❈ ❆✹❊❋❈♠❁❺✿➨❆✹♦ ❂ ❆ ▼ ❁ s✟❄r❂❸s❺❂ ◗ ❆r❁❺❊♥✿➓✈ ▼✛❃ ❆

✫ ❁❇✇ ❖✯❃✹❂ ② ❄ ♦✯❊❖❈ ❄■▼ ✿ ❂ ➆ ▼✤❯ ✈ s❇❂ ❈➇♦ ❂✼❃♣❂ ✿✯❊✯❩ ❂ ✡ ❈♠❁❺❆♣♦✂❈♥❁ ❂❸s ❩ s❇❂ ✿✯✇✏❆♣♦✂❊✛● ➄ ❄☞s ❊✏❆ ❄ ❁ ❄☎❄❉❂❸s❇❂ ◗ ❆ ❂ ❩❲➡ ❂ ●➉❊ ❃✹❂ ✿✯❊✯❩ ❂ ➌ ❈⑥❁❇❆✹♦❈♥❁ ❂❸s ❩ s❇❂ ✿✯✇✏❆✹♦➨❊✛● ② ❄☞s ❊✏❆ ❄ ④

❊✪✁â✩✴✟✤✄✝✑ ✆✂✄✿✸✱✢★❤✡❧✮✟ ✟✟✂✤✢✬✖ ❥✂✢✤☛✌☞✘✆✓❤✫✆✬✑❄■➓❣✔✩▲✶ ✔ ☛ ✥✍✌ ✢✚❧ ☛✌☞✙✂✂✟ ✎✌☞✗✺✡❤✂✢✬✖✭✖✗☞ ❤ ✺ ❧✵●✂✢★❤✶❤✲✟✤✖ ✢✚❧✏❧✮✟✤✎✌✎⑤⑥♦ ❂ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿ ✈✯♦ ▼✏❄❉❂ ♦ ▼✏❄❷▼ ◗ ❂✼❃ ❆ ▼ ❁❺✿ s❺❂ ✿✯✇♥❆✹♦ ➥ ◗ ▼✐s➏s❇❂ ❩ ❊✛➦ ❂✼❃ ♦ ❂⑦▼ ❩★④ � ❆ ▼✤❃ ❆❉❁❇✿✯✇ ❈♠❁❺❆♣♦❍❅ ◗ ❊♥✿❏❆ ❂ ✿✚❩ ❂✼❃❸❄❷▼ ❆❷❆✹♦ ❂

❄✹▼✛❯➈❂ ♦✣❁❇✇✏♦ ❂⑦❄ ❆❷✈ ❃ ❁❇❊ ❃ ❁❺❆❉❈ s❇❂ ➦ ❂❸s✑➥ ❈ ❂ ✈ ❃ ❊✛➦ ❂ ❆✹♦ ▼ ❆➇❆♣♦ ❂→▼ ➦ ❂✼❃❸▼ ✇ ❂ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿➓❊✛➦ ❂✼❃ ♦ ❂⑦▼ ❩❲❁ ❄⑥s ❊✏✇ ➋ ❅ ❡ ✣ ❼ ❙ ➂ ④ ➌ s➣❄ ❊ ➥❈➇♦ ▼ ❆ ❂ ➦ ❂✼❃ ❆♣♦ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ◗ ❊✏✿❏❆ ❂ ✿✚❩ ❂✼❃❅❄✼➥ ❆✹♦ ❂➔❃✹❂⑦❄ ❁↕❩ ❖✚▼✐s ◗ ❊ s➏s ❁ ❄ ❁❇❊✏✿ ❃❅▼ ❆ ❂ ❊✏✿➨✈ ▼ ◗ ➔♥❂ ❆❘❆ ❃❸▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿➊❁ ❄❀s❺❂⑦❄♣❄ ❆✹♦ ▼ ✿② ➆ ✯✁� ④❊✪✁➉❢✒✁ ✥ ❤✲✢✬✖ ❑✪☛✌☞✽❧ ✟✄✂✤✢✬✖ ❥✲✢✤☛✌☞✍✆✡❤ ✆✒✑✽☛❖●✂✟ ✟✤✖✭☞ ✸ ☞➉❤✂✢✤☛✌☞✘✆✓❤ ✞❭●✲✢✬✎❖✟✲✁ ❄ ❁❺➦ ❂ ✿ ❅ ◗ ❊✏✿✣❆ ❂ ✿✚❩ ❂✼❃❅❄❲▼ ❆❲❆✹♦ ❂ ♦✣❁❇✇✏♦ ❂⑦❄ ❆✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ s❇❂ ➦ ❂❸s✑➥ ❈ ❂ ❩ ❂ ✿✯❊✏❆ ❂ ➡❏❈✢❴ ➧ ❆♣♦ ❂➫▼ ➦ ❂✼❃❅▼ ✇ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄❉❖✯❃ ➦♥❁❺➦♥❊ ❃❅❄⑥▼ ●➉❆ ❂✼❃ ❆✹♦ ❂❪❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿➓✈✯♦ ▼♥❄❉❂✏➥ ✽ ➧ ❆✹♦ ❂

▼ ➦ ❂✼❃❅▼ ✇ ❂♠❄ ❆ ❃✹❂ ❆ ◗ ♦ ❂ ❩➔✈ ❖✣s➣❄r❂➇s❇❂ ✿✯✇✏❆✹♦❲❊✛●★❆✹♦ ❂⑦❄❉❂❘❄❉❖✯❃ ➦✏❁❇➦✏❊ ❃❸❄✼➥❏▼ ✿✚❩ ★ ➧ ❆✹♦ ❂ ✈ ❃ ❊♥➡ ▼ ➡✣❁ s ❁❇❆❉❈❱❊✛●✡♦ ▼ ➦♥❁❺✿✯✇ ▼❷❄ ❁❇✿✯✇ s❇❂❹❄❉❖✯❃ ➦♥❁❇➦✏❊ ❃ ④➞✝❁❇❆✹♦✯★❋❆✹♦ ❂ ✇ ❂ ❊ ❯❱❂ ❆ ❃ ❁ ◗ ❄ ❆ ❃✹❂ ❆ ◗ ♦✣❁❇✿✯✇❱✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❈ ▼ ✿✚❩ ✪ ➍ ❙ ● ★ ➥ ❆✹♦ ❂ ●➉❊ s➏s ❊❉❈♠❁❺✿✯✇ ❃✹❂ ◗ ❖✯❃❅❄ ❁❇❊✏✿ ❄ ♦✯❊ s ❩ ✎❴ ➧ ➍ ❅ ✪ ➧ ❡ ➧❈❤ ✘✢➠

✂ ❅✺☎✄ ★ ❤ ✪ ➧ ❞ ❤ ❴ ❤ ➄

★ ➧ ➍ ➧❈❤ ✘✢➠✂ ❅✺ ✄ ★ ❤✻✪ ➧ ❞ ❤ ★ ❤ ➄

✽ ➧ ➍ ❙ ● ✪✐➧ ❡ ➧❈❤ ✘✢➠✂ ❅✺ ✄ ★ ❤ ✪✐➧ ❞ ❤ ✽ ❤ ➆

�⑥❂ ● ❂✼❃✹❃ ❁❇✿✯✇ ❆✹❊➓❆♣♦ ❂ ✇ ❂ ✿ ❂✼❃❅▼✐s⑥❯❱❂ ❆✹♦✯❊✯❩✣❊ s ❊✏✇✏❈ ❖✚❄❉❂ ❩ ❁❇✿➀❆✹♦ ❂❋▼ ✿ ▼✐s ❈ ❄ ❁ ❄ ❊✛● ▼✐s ✇✏❊ ❃ ❁❇❆✹♦ ❯✂❄ ❼✑❆ ❃❅▼ ✿ ❄☞s↕▼ ❆❉❁❇✿✯✇❋❁❇✿✦❆ ❂✼❃✹❯✂❄ ❊✛●✇ ❂ ✿ ❂✼❃❅▼ ❆❉❁❇✿✯✇❹● ❖ ✿ ◗ ❆❉❁❇❊✏✿ ❄✼➥ ❆✹♦ ❂ ✿ ❖✚❄ ❁❇✿✯✇❋❅ ❂❸sts ❁❇✿➓❆ ❃❅▼ ✿ ❄ ●➉❊ ❃✹❯✂❄ ❆♣❊ ❂⑦❄ ❆❉❁ ❯✂▼ ❆ ❂ ♦ ▼✛❃✹❯ ❊✏✿✣❁ ◗ ❄❉❖✯❯❲❄✼➥❏❄❉❂✼❂ ❚ ❙ ❫✢●➋❊ ❃✍❂✝✆ ▼✛❯ ✈ s❺❂ ➂s❇❂⑦▼ ❩ ❄ ❆✹❊q❆✹♦ ❂ ●➉❊ s➏s ❊❉❈♠❁❺✿✯✇ ❃✹❂⑦❄❉❖✣s ❆⑦④

✑✓✒✕✔✗✖✙✘✚✔✜✛ ❙✗✢ ✖ ✷ ✲✟✞✡✠☞☛✍✌✎☛ ❬✽➢ ✲✑✏✒✏ ✲ ✸❴ ➧ ➍ ✪★ s ❊✏✇✢❼ ❙ ✝ ★ ➂ ❡ ✼❦➠ ✏ s ❊✏✇✵❅

s ❊♥✇✯❼ ❙ ✝ ★ ➂ ✒ ❡✤✣ ❼ ❙ ✝ ❅ ➂ ➄★ ➧ ➍ ✪

s ❊♥✇✚❼ ❙ ✝ ★ ➂ ❡ ✼✔✓ ✏ s ❊✏✇✵❅s ❊✏✇✢❼ ❙ ✝ ★ ➂ ✒ ❡✘✣ ❼ ❙ ✝ ❅ ➂ ➄

✽ ➧ ➍ s ❊♥✇ ❅s ❊♥✇✚❼ ❙ ✝ ★ ➂ ❡

➯s ❊✏✇✚❼ ❙ ✝ ★ ➂ ● ❙➄ ❡ ✼ ➃ ✏ s ❊♥✇ ❅

s ❊♥✇✚❼ ❙ ✝ ★ ➂ ✒ ❡✤✣ ❼ ❙ ✝ ❅ ➂❅➆✶✖✕ ✴ ✼ ▲☞❼❾❽ ➂ ✜ ✷ ✲❀✰ ✴❷❙ ✧✗✠ ✴ ✰ ❬ ✌✙✘ ❬↕➢ ✫✮✭ ✵✢➢ ☛ ❬ ✌ ✵✤✷ ✯ ❬ ☛✚✕ ✲✎✞✡✠☞✏ ❬ ☛✳✭✛✘ ✴ ✌❁✫✜✌✱✰✢✘ ✴ ✰ ❂✝✆ ✈✡❼ ● ▲ ✓ ✝ s ❊✏✇✯❼ ❙ ✝ ★ ➂✹➂✍✸ ✲ ✵ ✘❪➯ ❬❇✷ ☛✚✕ ✴ ❍❙✭✛✏ ✴ ✰➢ ✌ ✵✤✷ ☛❏✲ ✵ ☛✁✴ ✣

➬✣

Page 111: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✯❊ ❃ ★ ➍ ❙ ✝ ➄ ➥ ❆✹♦ ❂ ✼✪▲☞❼❾❽ ➂ ✆③❄ ♦ ▼ ➦ ❂ ▼✛❯ ✈ s ❁❇❆ ❖ ❩ ❂①s❇❂⑦❄✹❄ ❆♣♦ ▼ ✿ ❙✂✁ ❞ ✂ ➥❪▼ ✿✚❩✹❴ ➧ ❂ ❙ ➆☎✄✆✄ ➥ ★ ➧ ❂ ✁ ➆ ➛ ➄ ➥ ✽ ➧ ❂s ❊✏✇ ✓ ❅ ❡ ✁ ➆ ②♥② ④❘⑤⑥♦ ❂⑦❄r❂→▼ ✈✯✈ ❃ ❊ ✆ ❁ ❯✂▼ ❆ ❂ ➦ ▼✱s❺❖✯❂⑦❄➔▼✛❃✹❂✯✖♥❖ ❁❺❆ ❂ ✇♥❊❏❊✯❩➊●➋❊ ❃ ❅ ☛✔➄ ✁ ④✞✝ ❄❪❂✝✆ ✈ ❂ ◗ ❆ ❂ ❩ ➥ ❆✹♦ ❂ ❈ ❄ ♦✯❊❖❈➑❆✹♦ ▼ ❆❆✹♦ ❂❷❂❸s ❁ ❯ ❁❇✿ ▼ ❆❉❁❇❊✏✿①✈✯♦ ▼♥❄❉❂❹❄❉❂❸s❇❂ ◗ ❆ ❄❪▼❱❄❉❯✂▼✐s➏s ✿ ❖✯❯ ➡ ❂✼❃ ❊✤● ❄❉❖✯❃ ➦✏❁❇➦✏❊ ❃❸❄ ● ❃ ❊ ❯ ▼⑧s↕▼✛❃ ✇ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ◗ ❊♥✿❏❆ ❂ ✿✚❩ ❂✼❃❸❄ ④❊✪✁✗�✂✁ ✥ ❤✲✢✬✖ ❑✪☛✌☞✽❧✏✟✄✂✤✢✬✖➉❥✂✢✤☛✌☞✘✆✓❤ ✆✬✑ ☛❖●✂✟ ✟✢❤✬☛✌☞✗✄✝✟✂❧✮✆✡❤✒☛✦✟✚❤✬☛✌☞✍✆✡❤✱✞✙●✂✢✬✎✦✟✂✁ ⑤⑥♦✣❁ ❄ ❆❉❁ ❯❱❂✏➥ ❴ ➧ ➥ ✽ ➧ ▼ ✿✚❩ ★ ➧ ❩ ❂ ✿✯❊✏❆ ❂❆✹♦ ❂q❄✹▼✛❯❱❂✁✖♥❖✚▼ ✿✣❆❉❁❇❆❉❁ ❂⑦❄❘▼✏❄ ➡ ❂ ●➉❊ ❃✹❂ ➡ ❖ ❆➇❆ ▼✠✟♥❂ ✿ ▼ ❆➇❆♣♦ ❂❷❂ ✿✚❩➓❊✤●✟❆✹♦ ❂❷❂ ✿✣❆❉❁ ❃✹❂ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿❋✈✯♦ ▼✏❄❉❂ ④⑥➞✝❁❇❆✹♦ ❙ ● ✾➔❆✹♦ ❂✇ ❂ ❊ ❯➈❂ ❆ ❃ ❁ ◗ ❃❅▼ ❆ ❂ ❁❇✿➨❆✹♦ ❂ ❈✏❁ ❂❸s ❩➨✈ ▼✛❃ ❆ ➥ ❆✹♦ ❂❷❂ ✿✣❆❉❁ ❃✹❂ ◗ ❊✏✿❏❆ ❂ ✿❏❆❉❁❇❊✏✿❋✈✯♦ ▼♥❄❉❂❷s❇❂⑦▼ ❩ ❄ ❆✹❊q❆✹♦ ❂ ●➉❊ s➏s ❊❖❈⑥❁❇✿✯✇ ❃✹❂ ◗ ❖✯❃❅❄ ❁❇❊✏✿ ❄☛✡

❴ ➧ ➍ ❅✚✾❙ ● ❼ ❙ ● ✾ ➂ ➧ ✪✐➧ ❡ ➧❈❤ ✘✢➠

✂ ❅✺ ✄ ★ ❤ ✪✐➧ ❞ ❤ ❴ ❤ ➄

★ ➧ ➍ ❅✚✾♥❼ ❙ ● ✾ ➂ ➧ ❞ ➠❙ ● ❼ ❙ ● ✾ ➂ ➧ ✪ ➧ ❡ ➧❈❤ ✘✢➠

✂ ❅✺ ✄ ★ ❤ ✪ ➧ ❞ ❤ ★ ❤ ➄

✽ ➧ ➍ ❙ ❡❼ ❙ ● ✾ ➂ ➧

❙ ● ❼ ❙ ● ✾ ➂ ➧ ✪ ➧ ❡ ➧❈❤ ✘✢➠✂ ❅✺ ✄ ★ ❤ ✪ ➧ ❞ ❤ ✽ ❤ ➆

➎❀❊✏❆❉❁ ◗ ❂ ❆✹♦ ▼ ❆❋❆✹♦ ❂✄✖♥❖✚▼ ✿❏❆r❁❺❆r❁ ❂⑦❄ ➧ ✹➠ ❞ ✓ ➠ ❞ ✹ ✗ ✧➥ ➧

✹ ✓ ➠ ❞ ✹ ✗ ✧☞ ❉➠ ❞ ✓ ➠ ❞ ✹ ✗ ✧

▼ ✿✚❩✓ ➠ ❞ ✹ ✗ ✧➠ ❞ ✓ ➠ ❞ ✹ ✗ ✧

▼✛❃✹❂ ❆✹♦ ❂①▼ ➦ ❂✼❃❅▼ ✇ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ▼✐s➏s ❊❖❈ ❂ ❩❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿ ❄✼➥ ❆✹♦ ❂ ✈ ❃ ❊♥➡ ▼ ➡✣❁ s ❁❇❆❉❈✖❊✤●❘♦ ▼ ➦✏❁❇✿✯✇✦❊✏✿ s ❈➀❊✏✿ ❂ ❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❺❊♥✿ ▼ ✿✚❩✦❆✹♦ ❂➓▼ ➦ ❂✼❃❸▼ ✇ ❂ ✿ ❖✯❯ ➡ ❂✼❃ ❊✛● ❄❾s ❊♥❆ ❄➡ ❂ ●➉❊ ❃✹❂ ❦ ❃❸❄ ❆➇❆ ❃❅▼ ✿ ❄❉❯ ❁ ❄✹❄ ❁❇❊✏✿➊❁❺✿ ▼ ❈♥❁ ❂❸s ❩ ◗ ❊✏✿✣❆ ❂ ✿✣❆❉❁❇❊✏✿❲❁❇✿❏➦✏❊ s ➦♥❁❇✿✯✇ ❅ ◗ ❊✏✿❏❆ ❂ ✿✚❩ ❂✼❃❅❄✼➥✯❃✹❂⑦❄ ✈ ❂ ◗ ❆❉❁❇➦ ❂❸s ❈✏④✑✓✒✕✔✗✖✙✘✚✔✜✛ ➄ ✢ ✖ ✷ ✲✟✞✡✠☞☛✍✌✎☛ ❬✽➢ ✲✑✏✒✏ ✲ ✸❴ ➧ ➍ ✪

s ❊✏✇✚❼ ❙ ✝ ★ ➂ ❈❤ ✍ ✺✾♥❼ ❙ ● ✾ ➂ ❤

❙ ● ❼ ❙ ● ✾ ➂ ❤ ✪ ❡ ✼✍➠ ✏ s ❊✏✇❁❅s ❊✏✇✢❼ ❙ ✝ ★ ➂ ✒ ❡✤✣ ❼ ❙ ✝ ❅ ➂ ➄

★ ➧ ➍ ✪s ❊✏✇✚❼ ❙ ✝ ★ ➂ ❈❤ ✍ ✺

✾♥❼ ❙ ● ✾ ➂ ❤❙ ● ❼ ❙ ● ✾ ➂ ❤✦☞ ➠ ✪ ❡ ✼✔✓ ✏ s ❊♥✇ ❅

s ❊✏✇✢❼ ❙ ✝ ★ ➂ ✒ ❡✤✣ ❼ ❙ ✝ ❅ ➂ ➄✽ ➧ ➍ s ❊✏✇❁❅

s ❊✏✇✚❼ ❙ ✝ ★ ➂ ❡➯

s ❊✏✇✢❼ ❙ ✝ ★ ➂ ● ❙➄ ● s ❊✏✇✍✌✏✎ ❤ ✍ ✺ ❼ ❙ ● ❼ ❙ ● ✾ ➂ ❤ ✪ ➂✒✑s ❊✏✇✯❼ ❙ ✝ ★ ➂ ❡ ✼ ➃ ✏ s ❊✏✇❁❅

s ❊✏✇✚❼ ❙ ✝ ★ ➂ ✒ ❡✤✣ ❼ ❙ ✝ ❅ ➂❅➆✶✖✕ ✴ ✼ ▲✑❼❉❽ ➂ ✜ ✷ ✲❀✰ ✴q❙ ✧ ✠ ✴ ✰ ❬ ✌✙✘ ❬✽➢ ✫❢✭ ✵✚➢ ☛ ❬ ✌ ✵✤✷ ✯ ❬ ☛✚✕✁✲✎✞✡✠☞✏ ❬ ☛✳✭ ✘ ✴ ✌❁✫ ✌❀✰ ✘ ✴ ✰ ❂✝✆ ✈★❼ ● ▲ ✓ ✝ s ❊✏✇✯❼ ❙ ✝ ★ ➂✹➂ ✴�✯❊ ❃ ❆♣♦ ❂ ➦ ▼✐s❇❖✯❂ ★ ➍ ❙ ✝ ➄ ▼ ✿✚❩✡✾ ➍ ❙ ✝ ✝✯➥ ❈ ❂ ❊♥➡✯❆ ▼ ❁❇✿✉❆✹♦ ❂❲s❇❂⑦▼ ❩♥❁❇✿✯✇➀❆ ❂✼❃✹❯✂❄ ❁❇✿☞❴ ➧ ➥ ★ ➧ ▼ ✿✚❩ ✽ ➧ ❂✞✖♥❖✚▼✐s ❆✹❊❙ ➆ ✁ ② ✁ ➄➇➆✐➆✼➆ ➥✓✁ ➆✕✔ ➛✣❙ ② ➆✐➆✼➆ ➥✯▼ ✿✚❩ s ❊✏✇ ✓ ❅ ❡ ➛ ➆ ❙ ② ✔ ② ➆⑦➆✼➆ ❃✹❂⑦❄ ✈ ❂ ◗ ❆❉❁❇➦ ❂❸s ❈✏④❊✪✁✘❊ ✁ ✌ ✟✚☛ ✄✏✆✂✄✗✖ ✞✠✟✤✄✌✑ ✆✲✄●✸✱✢★❤▲❧✮✟▼✢★❤✲✢✬✖ ❑✳✎✝☞✭✎●✁ ✝ ❄♠❂✝✆ ✈ ❂ ◗ ❆ ❂ ❩ ➥ ❆♣♦ ❂✼❃✹❂ ❁ ❄➇▼ ♦✣❁❇✇✏♦➨✈ ❃ ❊✏➡ ▼ ➡✣❁ s ❁❇❆❉❈➓❆✹♦ ▼ ❆⑥❆✹♦ ❂ ◗ ❊✏✿✙✘❆ ❂ ✿✣❆❉❁❇❊✏✿①✈✯♦ ▼✏❄r❂→❄r❂❸s❺❂ ◗ ❆ ❄ ❊♥✿ s ❈ ❊✏✿ ❂❱❄❉❖✯❃ ➦✏❁❇➦✏❊ ❃ ④❱⑤⑥♦ ❂❱❄ ❁❥✐ ❂ ❊✛●⑥❆✹♦ ❂ ❊✛➦ ❂✼❃ ♦ ❂⑦▼ ❩➊❁ ❄❪s ❊✏✇ ✓ ❅ ❡ ✣ ❼ ❙ ➂ ❈➇♦ ❂✼❃✹❂ ❅➲❁ ❄ ❆✹♦ ❂✿ ❖✯❯ ➡ ❂✼❃ ❊✤● ◗ ❊✏✿✣❆ ❂ ✿✚❩ ❂✼❃❅❄ ❈⑥❁❇❆✹♦❋❆✹♦ ❂ ♦✣❁❇✇✏♦ ❂⑦❄ ❆➇✈ ❃ ❁❇❊ ❃ ❁❇❆❉❈ s❇❂ ➦ ❂❸s ④◆⑤⑥♦ ❂ ❆♣♦ ❃ ❊ ❖ ✇✏♦✯✈ ❖ ❆❘⑤♠♦ ❃ ➧ ❁ ❄ ❩ ❂ ❦ ✿ ❂ ❩➊➡❏❈

⑤⑥♦ ❃ ➧ ➍★ ➧ ✻✽ ➧ ❡ ✻ ❡ ❙

➄❈➇♦ ❂✼❃✹❂❝✻ ❁ ❄ ❆✹♦ ❂✂▼ ➦ ❂✼❃❅▼ ✇ ❂ ✈ ▼ ◗ ✟✏❂ ❆ ❄ ❁❥✐ ❂ ④✚�✯❊ ❃ ❅✦✿✯❊✏❆q❆✹❊✣❊ s➣▼✤❃ ✇ ❂ ❼ ❄✹▼ ❈✷❅

❑ ② ➄✴➂ ▼ ✿✚❩ ●➉❊ ❃q▼ ❆❉❈❏✈✣❁ ◗ ▼✐s ➦ ▼✐s❇❖✯❂ ❊✛●✻ ➍✛✄ ✁✯➥ ❆✹♦ ❂ ❆✹♦ ❃ ❊ ❖ ✇✏♦✯✈ ❖ ❆➔❁ ❄❹❃♣❂❸s➣▼ ❆❉❁❇➦ ❂❸s ❈ ❄ ❆ ▼ ➡ s❇❂❨▼ ❆ ▼ ➦ ▼✐s❇❖✯❂ ◗ s ❊ ❄❉❂ ❆✹❊ ✁ ➆ ✝ ④❋⑤⑥♦✣❁ ❄ ❊ ❖ ❆ s ❁❺✿ ❂⑦❄ ❆✹♦ ❂ ❁ ❯ ✈✚❊ ❃ ❆ ▼ ✿✣❆➡ ❂ ✿ ❂ ❦ ❆❪❊✏➡✯❆ ▼ ❁❺✿ ❂ ❩➈● ❃ ❊ ❯ ▼ ◗ ❆❉❁❇➦ ❂❹❄ ❁❇✇✏✿ ▼✱sts ❁❇✿✯✇ ▼ ◗✼◗ ❂⑦❄✹❄⑥❄ ◗ ♦ ❂✼❯❱❂⑦❄ ❊✛➦ ❂✼❃ ✈ ❖✯❃✹❂ ◗ ▼✤❃✹❃ ❁ ❂✼❃➇❄❉❂ ✿ ❄❉❂❹❄ ◗ ♦ ❂✼❯❱❂⑦❄ ❼ ❑ � ❅✜✝ ➂ ➥✣▼✏❄❖✚❄❉❂ ❩➊➡❏❈❋❻✍❆✹♦ ❂✼❃ ✿ ❂ ❆ ✡ ❆✹♦ ❂ ❆✹♦ ❃ ❊ ❖ ✇✏♦✯✈ ❖ ❆⑥❁❇✿ ❑ � ❅✜✝ ❃❅▼ ✈✣❁↕❩ s ❈ ◗ ❊ sts↕▼ ✈ ❄r❂⑦❄ ❆✹❊ ✁ ④✢✤✣✦✥★✧✦✣✦✩✫✪✭✬✯✮✆✰✓✱✳✲✴✣✵✞✶✳✷✹✸✻✺✽✼✂✷✿✾✻❀❂❁❄❃❆❅☎❇❈✸✯❉✫❊●❋✠✾❍❊✠■✂✾✻❏▲❑✹▼❖◆P❁❘◗❙❅☎❇✻❅❯❚✜❱❂❑✿■✂❑✿❀❲✸☛✷✆❳✒✾✏✸☛❨❲▼❖❩P❀❖❨✒✾✻✾✻❳❬❨❖✾✻❭✠❑❪❳❖❑✿❀✒✾✏❊✙❅❴❫✗❵✒❛❝❜❡❞✗❢☛❣✠❤✻✐✫❥✯❦❆❢✯✐♠❧♥❢☛♦q♣✭❣❯r❄s✹✐✉t✇✈①❭✂✼✂✷❘❅

✣② ✈❉ ➹✂③ ✈✆④q⑤①■✂⑤✆❳❖❀❙⑥✏⑦✂⑧❯⑨✆✈❯⑩✆⑩✓❅✭❶✯❷✗❸✇❚✉❶❯❹✂❶✆❅ ✣

❺✂❻

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❄❆❅ � ❄✒✝ �✙❇✤❈✲✖✜❉✤❊✌❋✑❈❂❇✜❉✤●■❍❏▲❑✺▼✧◆ ✔✤❖★P✂✔✆✔✜◗❘❚❙ ❉✤❯❱❯ ❑ ● ▼❳❲❨▼❩❏❭❬ ●■❊ ❬❫❪❴❪ ❊✠�✧❵❊✌❛✜❋ ❬ ❊✌●❝❜

❞✒✁❱❡❣❢✬☛✌✄✝✆✶✩✐❤✗❥✮☛✌☞✘✆❦❢� ❍❝● ❬ ❋✤❛ ❙ ❊ ❑ ●❧❈■♠ ❬ ❋✤❛♥❈ ❑ ❋ ❲ ❊♦❛✜❊✌❋✤❊✌● ❑❣❪❴❬q♣ ❊✺r▲❍❝❇✄✶❂❯♦❉ ❪ ❍ ❬ r ❬ ❯❳❊✌❋ ❙ ❬ ❇✜❋ ❑❣❪ ❙ ❊ ❑ ●❧❈■♠ ✸ ❇✜●✯✶❂❯♦❉ ❪ ❍ ❬ r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ❑❣❪✆s✑❑ ❍■❍❝❊✌●❝❋❯ ❑ ❍❂❈❝♠ ❬ ❋✤❛ ✸ ✡ ❑ ❯♦❉ ❪ ❍ ❬ r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ❑❣❪✢s✑❑ ❍❝❍■❊✌●❝❋ ❖ ★ ❖ ❯❱❇ ❙ ❍✆❇✔t✉❍❝❊✌❋ ❑ ❋ ❑ ●■● ❑❣▼✈❑ ❋✑r✧❉ ❙ ❉ ❑❣❪❴❪q▼ ❈❂❇✜❋✤❋✤❊✺❈❂❍❝❊✺r ❑ ❋✑r❩❈❂❇✜❋❨✇①❊✝✆ ❖❬ ❙✱❙ ❊ ❑ ●❧❈■♠✤❊✺r ❬ ❋ ❑ ❯♦❉ ❪ ❍ ❬ r ❬ ❯❱❊✌❋ ❙ ❬ ❇①❋ ❑❣❪②❑ ●❝● ❑❣▼ ❖ ❍❝♠✤❊❩❍❝❊✝✆✤❍ ❖✓③❧④ ✝ ❙ ❍❝●❝❇✜❋✤❛ ❬ ❋⑤❍❝❊✌●❝❊ ❙ ❍ ❑✔s✤s ❊ ❑ ●❝❊✺r⑥●❝❊✺❈❂❊✌❋❨❍ ❪⑦▼ ❘⑨⑧ ❖ ◆ ❖✄ ❜ ④ ❅ ❇①❍ ❑✔❲⑤❪q▼ ❖ ❍❝♠✤❊②r⑤❉✤❊ ❪✆s✑❑ ● ❑ r ❬ ❛✜❯ ❬ ❯ s ●❝❇✔✇✜❊ ❙ ❑ ✇✜❊✌● ❑ ❛✜❊ ❑ ❋✑r♥⑩✙❇✜● ❙ ❍ ✘ ❈ ❑ ❙ ❊❶❈❂❇①❯ s⑤❪ ❊✝✆ ❬ ❍ ▼ ❇✔t s✑❑ ❍❝❍❝❊✌●❝❋❷❯ ❑ ❍❧❈■♠ ❬ ❋✤❛ ④❸ ❋✤❇✔⑩ ❬ ❋✤❛✚t❹❇✜●✢❊ ❑ ❈❝♠ s ❇ ❙ ❬ ❍ ❬ ❇✜❋✧❇✔t ❙ ❊ ❪ t ✘ ❇✔✇✜❊✌● ❪❺❑❻s❼❑ ❯ ❬ ❙ ❯ ❑ ❍❧❈■♠ ❬ ❋✤❛ s ❇ ❙ ❬ ❍ ❬ ❇✜❋⑤❽❾❍❝♠✤❊❱❿✢➀ ☛ ✵ ✴☞✷✔✷☎❽ ❑❣❪❴❪ ❇➁⑩ ❙ ❍❝❇➂❊ ❪❴❬ ❯ ❬ ❋ ❑ ❍❝❊❇✜❋✤❊❱❇❻t➃❍❝♠✤❊❱❍➄⑩✙❇❩❈ ❑ ❋✑r ❬ r ❑ ❍❝❊ ❙ ❲❨▼ ❇✜❋✤❊✱➅①❉✤❊ ❙ ❍ ❬ ❇✜❋⑤❽❾❍❝♠✤❊ ✘✜➆ ✴ ✏ ④❩➇ ❋✤❊ ❙ ❍❝❉✑r ❬ ❊ ❙ ♠✤❊✌●❝❊ s✑❑ ❍❝❍■❊✌●❝❋ s ❊✌● ❬ ❇✤r ❬ ❈ ❬ ❍ ❬ ❊ ❙ ❑ ❋✑r❙ s✑❑ ❈❂❊❱❈❂❇✔✇✜❊✌● ❬ ❋✤❛ ❙ ④➂➇ ❋✤❊ s ●❝❇ s ❇ ❙ ❊ ❙ ❑✧s ❊✌● ❬ ❇✤r▲r⑤❊❂➈✑❋ ❬ ❍ ❬ ❇✜❋➉✇ ❑❣❪❴❬ r ❬ ❋ ❑ ❋ ▼ r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ❑ ❋✑r❷❈❂❇✜❋ ❙ ❬ ❙ ❍❝❊✌❋⑤❍➂⑩ ❬ ❍❝♠▲❍❝♠✤❊❯❱❇✜●■❊②❛①❊✌❋✤❊✌● ❑❣❪ r⑤❊❂➈✑❋ ❬ ❍ ❬ ❇✜❋ ❙ ❬ ❋➉r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ P✜❖ ❬ ④ ❊ ④ ❇✜❋▲⑩✙❇✜●❧r ❙ ④✚➊ ❊ s ●■❇➁✇①❊②♠✤❊✌●■❊❱❍❝♠ ❑ ❍ ❑✧s ❊✌● ❬ ❇➋r ❬ ❈ s✑❑ ❍❝❍■❊✌●❝❋ ❬ ❙❛✜❊✌❋✤❊✌● ❑ ❍❝❊✺r ❲❨▼▲❑ ❙ ❉ ❲✤s✑❑ ❍❝❍❝❊✌●❝❋ ❖ ❑ ❋✑r❷❍❝♠✤❊ ❙ ❉ ❲✤s✑❑ ❍❝❍❝❊✌●❝❋ ❖ ❑ ❙ ⑩✙❊ ❪❴❪➃❑ ❙ ❍■♠✤❊②❛①❊✌❋✤❊✌● ❑ ❍ ❬ ❋✤❛ ❪✼❑ ⑩ ❑ ❋✑r❷❍❝♠✤❊ ❪❴❬ ❋✙✟➌❍❝❇✧❍❝♠✤❊●❝❊✌❛✜❉ ❪✼❑ ●❱r ❬ ❙ ❍❝● ❬⑦❲ ❉✤❍ ❬ ❇①❋➍❇✔t s ❊✌● ❬ ❇✤r ❙ ❖ ❬ ❙ ❊✝✆✤♠ ❬⑦❲⑤❬ ❍❝❊✺r ④➌➎ ♠✤❊❱❊✝✆➏❈❂❊ s ❍ ❬ ❇①❋ ❙ ❍❝❇♥❍■♠ ❬ ❙ ●❝❊✌❛①❉ ❪❺❑ ● ❬ ❍ ▼ ❖ ❍■♠✤❊✱r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍■❊✺rs ❊✌● ❬ ❇✤r ❙ ❖ ❑ ●❝❊ ❬ ❋❨❍■❊✌● s ●❝❊✌❍❝❊✺r ❑ ❙✱➐ ❲ ❇✜●❧r⑤❊✌●♦❊❂➑✗❊✺❈❂❍ ❙❝➒ ④✱➎ ♠✤❊ ▼ r⑤❊✌● ❬ ✇①❊❱t✉●❝❇✜❯ ❙ ❇✜❯❱❊❱●■❊✌❛✜❉ ❪✼❑ ● ❬ ❍ ▼ ❇❻t➓❍■♠✤❊✱❛✜❊✌❋✤❊✌● ❑ ❍ ❬ ❋✤❛❙ ❉ ❲✤s✑❑ ❍■❍❝❊✌●❝❋ ❖ ❑☛❲✑❑ ❙ ❬ ❈ s ♠✤❊✌❋✤❇✜❯❱❊✌❋✤❇✜❋ ❬ ❋❱r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ P✜④➔➎ ♠ ❬ ❙ ❑➁❪❫❪ ❇✔⑩ ❙ t✉❇✜● ❑ ❈ ❪✼❑ ❙❝❙ ❬ ➈✠❈ ❑ ❍ ❬ ❇✜❋❱❇✔t s ❊✌● ❬ ❇➋r ❬ ❈ ❬ ❍ ❬ ❊ ❙ ✇ ❑➁❪❫❬ r❬ ❋ ❑ ❋ ▼ r ❬ ❯❱❊✌❋ ❙ ❬ ❇①❋ ❖ ❑ ❋✑r♥r⑤❊✌❍ ❑➁❬❫❪ ❊✺r ❬ ❋➌r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ◆ ④ ❅ ❇✜❍ ❑✔❲⑤❪q▼ ❖ ❍❝♠✤❊✚❋❨❉✤❯ ❲ ❊✌●✾❇✔t s ❊✌● ❬ ❇➋r ❬ ❈ ❬ ❍ ▼ ❈ ❪❺❑ ❙❝❙ ❊ ❙ ❑✔s✤s ❊ ❑ ●❪❴❬ ❋✤❊ ❑ ● ❬ ❋→❍❝♠✤❊✱r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ④ ✝☛❪ ❙ ❇ ❖ ❇✜❋✤❊ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❑ t✉❉ ❪❴❪ ❈■♠ ❑ ● ❑ ❈❂❍■❊✌● ❬q♣✺❑ ❍ ❬ ❇✜❋➌❇✔t ❙ ❇✜❉✤●❧❈❂❊ ❙ s ❇ ❙ ❬ ❍ ❬ ❇✜❋ ❙ ❖ ❬ ❋✑❈ ❪ ❉✑r ❬ ❋✤❛❍❝♠✤❊➌r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍❝❊✺r❀❇✜❋✤❊ ❙ ❍❝♠ ❑ ❍ ❑ ●❝❊▲❊ ❙❝❙ ❊✌❋⑤❍ ❬✼❑❣❪ ❍❝❇➍❍❝♠✤❊➌r⑤❊ ❙ ❬ ❛✜❋ ❑ ❋✑r✏❈❂❇✜●❝●■❊✺❈❂❍❝❋✤❊ ❙❝❙ ❇✔t ◆✜➣↔s✑❑ ❍■❍❝❊✌●❝❋❀❯ ❑ ❍❧❈■♠ ❬ ❋✤❛❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ ❙ ④✾➎ ♠ ❬ ❙ ❈❂❇①❋ ❙ ❬ r⑤❊✌● ❑✔❲⑤❪q▼ ●❝❊❂➈✑❋✤❊ ❙ ❑ ❋✑r ❑ ❈❝♠ ❬ ❊✌✇✜❊ ❙ ❍❝♠✤❊ s ●❝❊✌✇ ❬ ❇✜❉ ❙ ❈ ❪✼❑ ❙❝❙ ❬ ➈✠❈ ❑ ❍ ❬ ❇①❋ ❲⑤▼ ❘ P ❜ ❖ ❑ ❋✑r❭❊✌✇✜❊✌❋▲❍❝♠✤❊❊✝✆✤❍❝❊✌❋✑r⑤❊✺r✶●❝❊ ❙ ❉ ❪ ❍ ❙ ❬ ❋ ❘ ✄ ❜ ❖ ❑ ❋✑r ❑❣❪❴❪ ❇✔⑩ ❙ t❹❇①● ❑ ❈ ❪✼❑ ❙❝❙ ❬ ➈✠❈ ❑ ❍ ❬ ❇✜❋➍❇❻t ❙ s✑❑ ❈❂❊❼❈❂❇✔✇✜❊✌● ❬ ❋✤❛ ❙ ❖ ⑩✭♠✤❊✌●❝❊✧❋✤❇✜❋ ✘ r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍■❊✺rs ❊✌● ❬ ❇✤r ❬ ❈ ❬ ❍ ❬ ❊ ❙ ❑✔s✤s ❊ ❑ ●❩❊ ❙❝❙ ❊✌❋⑤❍ ❬✼❑❣❪ ④✂➇ ❋✤❊▲❊✝✆✤♠ ❬⑦❲⑤❬ ❍ ❙ ●❝❊ ❪✼❑ ❍ ❬ ❇①❋ ❙ ♠ ❬qs✏❲ ❊✌❍➄⑩✙❊✌❊✌❋❀❍❝♠✤❊ s ❊✌● ❬ ❇✤r ❙ ❇✔t ❑➌s✑❑ ❍■❍❝❊✌●❝❋ ❑ ❋✑r❍❝♠✤❊ s ❇ ❙❝❙ ❬q❲⑤❪ ❊ ❙ s✑❑ ❈❂❊✱❈❂❇✔✇✜❊✌● ❬ ❋✤❛ ❙ ❲⑤▼ ❍■♠✤❊ ❙ ❑ ❯❱❊ s✑❑ ❍❝❍❝❊✌●❝❋ ④❷➎ ♠ ❬ ❙ ❬ ❙ ●❝❊ ❪ ❊✌✇ ❑ ❋⑤❍ ❲ ❇✜❍❝♠✶❍❝❇❷❍❝♠✤❊✱r⑤❊✌● ❬ ✇ ❑ ❍ ❬ ❇✜❋➍❇✔t✭❍❝♠✤❊❍❝♠✤❊✌❇✜●■❊✌❍ ❬ ❈ ❑❣❪ ❈❂❇✜❯ s⑤❪ ❊✝✆ ❬ ❍ ▼ ❇❻t✐↕ ✘ r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ❑❣❪✢s✑❑ ❍❝❍❝❊✌●■❋❩❯ ❑ ❍❧❈■♠ ❬ ❋✤❛ ❑ ❋✑r✧❍❝❇ ❑➁❪ ❛①❇✜● ❬ ❍❝♠✤❯ ❬ ❈ ❬ ❙❝❙ ❉✤❊ ❙ ④➎ ♠✤❊ ❙ ❬ ❯ s⑤❪ ❊➂●❝❊✌❯ ❑ ● ✟②❍■♠ ❑ ❍✆❍❝♠✤❊ ❙ ❊✌❍✙❇✔t ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊➂✇✜❊✺❈❂❍❝❇✜● ❙ ❑❣❪ ❯❱❇ ❙ ❍✆♠ ❑ ❙ ❑ ❯❱❇✜❋✤❇❣➙ ➛❺r ❙ ❍❝●■❉✑❈❂❍❝❉✤●❝❊ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝♠✤❊❪❴❬ ❋✙✟❶❍❝❇✭❍■♠✤❊✆⑩✙❊ ❪❴❪ ❙ ❍❝❉✑r ❬ ❊✺r s ❊✌● ❬ ❇✤r ❬ ❈✓t❹❉✤❋✑❈❂❍ ❬ ❇①❋ ❙ ❬ ❋❱➜✭➝ ④✢➞ ❙ ❬ ❋✤❛✾❍■♠✤❊ ❬ ● s ●❝❇ s ❊✌●❝❍ ❬ ❊ ❙ ❪ ❊ ❑ r ❙ ❍❝❇ ❑ ❛✜●■❊ ❑ ❍ ❙ ❬ ❯ s⑤❪❴❬ ➈✠❈ ❑ ❍ ❬ ❇✜❋❇✔t✆❍❝♠✤❊ s ●❝❇⑤❇✔t✙❇✔t s ●❝❊✌✇ ❬ ❇①❉ ❙ ●❝❊ ❙ ❉ ❪ ❍ ❙ ❬ ❋➌❍■♠✤❊ ❑ ●❝❊ ❑ ④ ✝ r✤r ❬ ❍ ❬ ❇✜❋ ❑❣❪❴❪q▼ ❖ ❬ ❍ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝❇⑤❇ ❪ ❙ t✉❇✜● ❑ ❛✜❊✌❋✤❊✌● ❑❣❪❴❬q♣✺❑ ❍ ❬ ❇✜❋✶❍❝❇❑ ❋ ▼ r ❬ ❯❱❊✌❋ ❙ ❬ ❇①❋ ④ �❦❬ ❋ ❑➁❪❫❪q▼ ❖ ❍❝♠✤❊ s✑❑❻s ❊✌● s ●❝❇✔✇ ❬ r⑤❊ ❙ ✟❨❋✤❇✔⑩ ❪ ❊✺r⑤❛✜❊➂❍❝❇✧r⑤❊✌● ❬ ✇✜❊❶❊❂➟❼❈ ❬ ❊✌❋⑤❍ s✑❑ ❍❝❍❝❊✌●❝❋ s ●❝❊ s ●■❇➋❈❂❊ ❙❝❙ ❬ ❋✤❛ ④ ❄ ❋s✑❑ ●❝❍ ❬ ❈❂❉ ❪✼❑ ● ❖ ❍❝♠✤❊②❈■♠ ❑ ● ❑ ❈❂❍■❊✌● ❬q♣✺❑ ❍ ❬ ❇✜❋▲❇✔t✢❯ ❬ ❋ ❬ ❯ ❑❣❪ ❛✜❊✌❋✤❊✌● ❑ ❍ ❬ ❋✤❛ ❙ ❉ ❲✙✘✉s✑❑ ❍❝❍❝❊✌●❝❋ ❙ ●❝❊✺r⑤❉✑❈❂❊ ❙✚➠ s✑❑ ●❝❍ ❬✼❑❣❪❴❪q▼✑➡✭s ❊✌● ❬ ❇➋r ❬ ❈ ❬ ❍ ▼❑ ❋✑r✧⑩ ❬ ❍❝❋✤❊ ❙■❙ ❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋✱❍■❇②⑩✙❊ ❪❴❪ ✟⑤❋✤❇✔⑩✭❋ s ●■❇ ❲⑤❪ ❊✌❯ ❙ ❇✜❋❩⑩✙❇✜●❧r ❙ ④➔➎ ♠ ❬ ❙ ❑❣❪❴❪ ❇✔⑩ ❙ t✉❇✜●✙❉ ❙ ❬ ❋✤❛❱❍❝♠✤❊ ❪✼❑ ●❝❛①❊➂❍❝❇❨❇ ❪ ✟ ❬ ❍❇✔t P ➣➢❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❙ ❍❝❇✱r⑤❊✌❍❝❊✌●❝❯ ❬ ❋✤❊ s ❊✌● ❬ ❇✤r ❬ ❈ ❬ ❍ ❬ ❊ ❙ ④ ✝✩s ●❝❊ ❪❴❬ ❯ ❬ ❋ ❑ ● ▼ ✇✜❊✌● ❙ ❬ ❇✜❋❩❇✔t✢❍❝♠ ❬ ❙ ⑩✙❇✜●✻✟ ❑✔s✤s ❊ ❑ ●❝❊✺r ❬ ❋ ❘❚➤ ❜ ④➥✠➦✧➧✗➨★➩✜➫▲➭✑➯✸➲✼➳❻➫

➵✭➸✔➺ ➀✼➻➽➼ ✌✎☛✉➸✑☛ ➀ ✌✜➾➏➺➪➚ ✝ ↕ ✘ r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋ ❑➁❪➔s✑❑ ❍❝❍❝❊✌●■❋②➶ ❬ ❙ ❑ ↕ ✘ r ❬ ❯❱❊✌❋ ❙ ❬ ❇①❋ ❑❣❪➹❑ ●❝● ❑✺▼ ⑩✭♠✤❇ ❙ ❊✾✇ ❑❣❪ ❉✤❊ ❙ ● ❑ ❋✤❛✜❊➘❇✜❋ ❙ ❇✜❯❱❊❑❣❪qs ♠ ❑✔❲ ❊✌❍➷➴ ④✙➬ ❬ ✇✜❊✌❋ ❑ ✇✜❊✺❈❂❍❝❇①●❼➮➂ ❖ ⑩✙❊❶r⑤❊✌❋✤❇✜❍❝❊➌➮➂ ❘❚➱ ❜✠❇①●❼➮➂✤✃ ❬ ❍ ❙✭➱ ✘ ❍■♠♥❈❂❇❨❇✜●❂r ❬ ❋ ❑ ❍❝❊ ④✆❐ ❊✌❍➂❒ ❲ ❊❶❍❝♠✤❊ ❙ ❊✌❍☛❇✔t➹✇①❊✺❈❂❍❝❇✜● ❙➮➂ ❙ ❉✑❈❝♠❷❍❝♠ ❑ ❍❶❮☎➮➂ ❘⑨➱ ❜❆❮①❰❾Ï ✃ ⑩✭♠✤❊✌●■❊❶Ï ✃ ❬ ❙➘❙ ❇✜❯❱❊ ❬ ❋⑤❍❝❊✌❛✜❊✌● ❖ ❈ ❑❣❪❴❪ ❊✺r❷❍❝♠✤❊ ➱ ✘ ❍❝♠♥r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋▲❇✔t✗➶ ④✣❺✺Ð

Page 113: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ➬ ❈ r ❊ t ❛ ♠ ❑ ✁ ❈ r ❊ t ❛ ♠ ❑✂ ➣ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯❛ ♠ ➸ ❲ ❈ r ❊ t ❛ ♠ ❑ ✁ ❈ r ❊ t ❛❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯❊ t ❛ ♠ ➭ ❲ ❈ r ❊ t ❛ ♠ ❑ ✁ ❈ r ❊❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ☎ ❪ ❯❈ r ❊ t ❛ ♠ ➭ ❲ ❈ r ❊ t ❛ ♠ ❑ ✆ ❈❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯ ❋ ❬ ✄ ✟ ❪ ❯❑ ❲ ❈ r ❊ t ❛ ♠ ➸ ❲ ❈ r ❊ ✝ ❛ ➬ ✆✞✠✟☛✡✌☞✎✍✑✏✓✒✕✔✗✖☛❑ r ❬✼❑ ❋❨❍ ❲⑤❬qs ❊✌● ❬ ❇✤r ❬ ❈ s✑❑ ❍❝❍❝❊✌●■❋✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜ P ✔ ➎ ⑩✙❇▲✇✜❊✺❈❂❍❝❇✜● ❙ ➮★ ❑ ❋✑r ➮✩ ❑ ●❝❊ ❙ ❑❣❬ r ❬ ❋❾❍❝♠✤❊ ❙ ❑ ❯❱❊♥r ❬ ●❝❊✺❈❂❍ ❬ ❇①❋ ❬ t ❑ ❋✑r➍❇①❋ ❪⑦▼→❬ t ❖ t✉❇✜● ❑ ❋ ▼ ➱ ✡➮★ ✃ ✪ ➮✩ ✃✬✫ ✁ ④ ✝ ✇✜❊✺❈❂❍❝❇✜●❱➮★ ✘✑✌✎✞ ➀ ➾✫➸✎☛✢✭✌➺➃❑ ✇✜❊✺❈❂❍❝❇✜●♦➮✩ ❬ ❋❩❍■♠✤❊ ❙ ❑ ❯❱❊✾r ❬ ●❝❊✺❈❂❍ ❬ ❇✜❋ ❬ t ❑ ❋✑r❳❇✜❋ ❪q▼♦❬ t ❖ t✉❇✜● ❑ ❋ ▼ ➱ ❖ ❮✦➮✩ ✃ ❮⑤❰ ❮☎➮★ ✃ ❮ ④✝ ✇✜❊✺❈❂❍❝❇✜●❩➮★ ❬ ❙ ❯ ❬ ❋ ❬ ❯ ❑❣❪❦❬ t ❬ ❍➂r⑤❇❨❊ ❙ ❋✤❇✜❍✾r⑤❇✜❯ ❬ ❋ ❑ ❍■❊ ❑ ❋ ▼ ✇✜❊✺❈❂❍❝❇①● ④➊ ❊ ❑ ●■❊ ❬ ❋⑤❍❝❊✌●❝❊ ❙ ❍❝❊✺r ❬ ❋ ❙ ♠ ❬ t✉❍ ❙✭❙ ❉✑❈❝♠❷❍❝♠ ❑ ❍✙❍❝♠✤❊➂❍➄⑩✙❇✈❈❂❇ s⑤❬ ❊ ❙ ❑ ●❝❊❶❈❂❇①❋ ❙ ❬ ❙ ❍❝❊✌❋⑤❍ ❬ ❋♥❍■♠✤❊➂❇➁✇①❊✌● ❪✼❑✔s✤s⑤❬ ❋✤❛ ❑ ●■❊ ❑ ④✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜➌◆✮✔❂✝ ✇✜❊✺❈❂❍❝❇✜●▲➮★ ❬ ❙ ❑ ❋❾➀ ➾✮✯❣➸✛✰ ➀ ➸✜➾ ➻ ✭ ✇✜❊✺❈❂❍❝❇✜●➘t✉❇✜●✭➶ ❬ t ❑ ❋✑r▲❇✜❋ ❪q▼❷❬ t ❖ t✉❇✜● ❑ ❋ ▼ ➮✩✲✱ ❒ ❖ ❇✜❋✤❊❳♠ ❑ ❙➶ ❘ ➮✩✴✳ ➮★ ❜✶✵ ➶ ❘ ➮✩ ❜ ④ ✝ ❈❂❇✜❉ s⑤❪ ❊ ➠ ➮★ ➄ ➮✩ ➡ ❇✔t ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊❩✇✜❊✺❈❂❍❝❇✜● ❙ ❬ ❙❱❙ ❑❣❬ r ❑ ❋❀➀ ➾✷✯✺➸✛✰ ➀ ➸①➾ ➻ ✭ ➻ ✌✜➆ ✠☞✏✸✭✧❬ t ❑ ❋✑r→❇✜❋ ❪q▼▲❬ t✹✻✺ ✡✛✼✾✽✆❮ ★ ✽ ❮ ✳ ❮ ✩ ✽ ❮⑤❰❾Ï ✽ ④ ❄ ❍ ❬ ❙✆❙ ❬ ❯ s⑤❪ ❊ ❬ t➂➮★ ❑ ❋✑r➌➮✩ ❑ ●■❊➓❈❂❇ ❪❫❪❴❬ ❋✤❊ ❑ ● ④✙➎ ♠✤❊ ❙ ❊ ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊✾✇①❊✺❈❂❍❝❇✜● ❙ ❑ ●■❊ ❙ ❑❣❬ r ➺ ➀ ✞✡✠☞✏✸✭ ④➊ ❊➂❋✤❇✜❍■❊❀✿✱❍❝♠✤❊ ❙ ❊✌❍✭❇✔t ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊♦✇✜❊✺❈❂❍❝❇✜● ❙ ④ ❁❦➦❃❂➢➭✑➲✦❢⑥➩❅❄✤➳✔❤✗➯✥❆✺➳

❇✗➸✎☛✍☛ ➀✸➻ ✭ ✘ ➀ ➺ ☛✢✰ ➀ ✁✌➆ ☛ ➀ ✌①➾ ✌❉❈ ➀ ➾✮✯❣➸✛✰ ➀ ➸✜➾ ➻ ✭❊✯❋✭ ➻ ☛✍✌✛✰■➺➪➚ ❄ t ❑❶s✑❑ ❍❝❍❝❊✌●❝❋♦➶ ❑ r⑤❯ ❬ ❍ ❙ ❑ ❋✤❇✜❋ ✘ ❙ ❬ ❯ s⑤❪ ❊ ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊❶❈❂❇①❉ s⑤❪ ❊ ❖ ❬ ❍❬ ❙✾❙ ❑❣❬ r ✁ ➀ ✠●✭❋✰ ➀ ✌✙✘ ➀✸➻ ➠❆❙ ❊✌❊ �❦❬ ❛①❉✤●❝❊ P ➡ ④➔➊ ❊➂♠ ❑ ✇①❊✆✡✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜ ⑧ ✔ ➬ ❬ ✇✜❊✌❋ ❑♦❪✼❑ ❍■❍ ❬ ❈❂❊■❍✰⑩ ❬ ❍❝♠ ❲✑❑ ❙ ❬ ❙➂➠ ➮★ ➄ ➮✩ ➡ ❖ ⑩✙❊②r⑤❊✌❋✤❇✜❍❝❊❑❏❀▲❑▼◆P❖ ▼◗ ✵❙❘✛❚➃➮★❑✳❱❯ ➮✩✣❲ ✁♦❰❳❚ ➄ ❯❱❨➢PP❩❨④✝❭❬❈✘✉s✑❑ ❍❝♠ ❬ ❙ ❑ ❈■♠ ❑❣❬ ❋ ➮❪❴❫ ✪❅✪❋✪ ➮❪❛❵ ❇✔t➔✇①❊✺❈❂❍❝❇✜● ❙ ❬ ❋❱➶ ❙ ❉✑❈■♠✧❍❝♠ ❑ ❍ ❖ t✉❇✜● ❑ ❋ ▼ ➱ ❖ ❊ ❬ ❍❝♠✤❊✌●❀➮❪ ✃✥❜ ❫✣❝ ➮❪ ✃ ❇✜●➍➮❪ ✃ ❝ ➮❪ ✃✥❜ ❫ ❬ ❙ ❬ ❋❬ ④➽➬ ❬ ✇✜❊✌❋▲❍➄⑩✙❇❱✇✜❊✺❈❂❍❝❇✜● ❙➂➠ ➮★ ➄ ➮✩ ➡ ❖ ❍❝♠✤❊ ❈❞✰❡✭❢✭❑❣✐❤✜➾✮✭ ❏❊❥❴▼◆P❖ ▼◗ ❬ ❙ ❍❝♠✤❊ ❙ ❊✌❍➘❇✔t s ❇ ❬ ❋⑤❍ ❙ ➮❪ ❬ ❋❩➶ ❙ ❉✑❈❝♠❷❍❝♠ ❑ ❍➘❍❝♠✤❊✌●❝❊♦❊❢❦ ❬ ❙ ❍ ❙❋✤❇ ➠ ➮★ ➄ ➮✩ ➡❖✘✉s✑❑ ❍❝♠ ❬ ❋❨❍■❊✌● ❬ ❇✜●✭❍❝❇✱❒➢❍■❇❃❏❀▲ ▼◆P❖ ▼◗ ④✆➎ ♠✤❊❴❧ ✭❅✰ ➀ ❤✙✘ ➀✼➻❣➀♥♠✢♦ ✘✛❤✛♣♦➸ ➀ ➾❷❬ ❙ ➶ ❝ ❏❊❥ ▼◆P❖ ▼◗ ④✢➎ ♠✤❊ ✁q❤✛✰✢✘✛✭❋✰➽❬ ❙ ✡r ✵➉➶ ❝ts ▼✉❅❖ ▼✈✐✇✐①✻② ❘➂➮❪ ❮ ➠ ➮❪t✳ ➮③ ➄ ➮❪t✳ ➮④ ➡ ✱ ➶✮⑤ ➄ ↕ ➱⑦⑥①➠ ➮❪ ➡ ✵ ↕ ➱⑦⑥①➠ ➮③ ➡ ✵ ↕ ➱⑧⑥①➠ ➮④ ➡ ❩ ✪⑨❶⑩✎✏✻✧✌✍✣✏✕❷ P ✔✶❇✦✭ ♠✤➶ ✁❸✭✙✁ ➀❹❧ ✭❋✰ ➀ ❤ ✘ ➀✼➻ ➚❻❺✦❤✛✰➂➸①➾ ♦❱➀ ➾✮✯❣➸✛✰ ➀ ➸✜➾ ➻ ✭ ➻ ❤✜➆ ❧✣❼ ✭ ➠ ➮★ ➄ ➮✩ ➡❴✭✐❽ ➀ ➺ ♠ ➺❶➸ ❼ ➸ ♠✢♠✉➀✸➻ ✭ ❍ ➺✌➆ ➻❿❾✾♠☛❾ ➸ ♠⑧➀

✿➂➁➃❍ s r s ❏❊❥✗▼◆P❖ ▼◗ ➄➠ P ➡❿➄❾ ✭❅✰➅✭❀r ➀ ➺ ♠☛❾ ✭❃✁q❤✛✰✢✘✛✭❅✰❀❤❡❈ ❍ ➚✶➆✥❈ ❍ ➸✎✘➇♣ ➀☛♠ ➺ ♠✉❿ ❤❳➺ ➀ ♣ ❧✑❼ ✭❑✯❋✭ ➻❋♠ ❤✛✰■➺❢➈ ♠☛❾ ✭✺➾✓➉ P❞➊ ✰❡✭✝✘✜➆ ➻ ✭✌➺ ♠ ❤ ➀

✿➋➁➌❍ s r ✪➠ ◆⑤➡➠ ➮★ ➄ ➮✩ ➡ ➀ ➺♥➺✌➸ ➀ ✘❾➸ ❋✤❇①❋ ✘ r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍❝❊✺r ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊➍❈❂❇✜❉ s⑤❪ ❊ ➸①➾ ✘ ❍↔➀ ➺▲➺✌➸ ➀ ✘➍➸❀➾✷❤✜➾✕➍✢✘✛✭➅➎➇✭✺➾✷✭❋✰➄➸ ♠ ✭✝✘ ❼ ➸ ♠✢♠✉➀✸➻ ✭✔➚➐➏❧ ➸ ♠✢♠ ✭❋✰❂➾➉➸✎✘➇♣ ➀☛♠ ➺❱➸ ♠ ♣■❤❻➺ ♠ ❤①➾✮✭❱➾✷❤✜➾✕➍✢✘✛✭➅➎➇✭✺➾✷✭❋✰➄➸ ♠ ✭✝✘ ❼ ➸ ♠✢♠✉➀✼➻ ✭✐➈ ➻ ➸ ❼♥❼ ✭✝✘ ♠☛❾ ✭ ❈ ❑ ❋✤❇✜❋ ❬ ❈ ❑❣❪✢❪✼❑ ❍■❍ ❬ ❈❂❊ ➸✜➾ ✘ ✘✛✭❣➾✮❤ ♠ ✭✝✘ ❍ ▼➑ ❖ ▼➒❿➄❾ ✭❅✰➅✭ ➠ ➮➓❉➄ ➮❏ ➡ ➀ ➺❱➸❱✁■➸✔➺ ➀ ➺✺➚→➔ ❾ ✭ ➀ ➾✮✯✺➸➇✰ ➀ ➸✜➾ ➻ ✭✙✯❅✭ ➻❅♠ ❤✛✰❝➺ ➀ ➾❙➣✿✲✵❭✿ ❝ r ▼➑ ❖ ▼➒ ➸✛✰❡✭❩➾✫➸✛♣❑✭ ✘ ♠☛❾ ✭❩➾✮❤✜➾↔➍ ✘✛✭❡➎✛✭❣➾✮✭❅✰❆➸ ♠ ✭ ✘➀ ➾✮✯✺➸➇✰ ➀ ➸✜➾ ➻ ✭❶✯❅✭ ➻❅♠ ❤✛✰■➺➪➚ ➶✶➀ ➺➂➺✌➸ ➀ ✘✱➸✧➾✮❤①➾✕➍ ✘➇✭➅➎➇✭✺➾✮✭❅✰➄➸ ♠ ✭ ✘➋✁ ➀↕❧ ✭❋✰ ➀ ❤✙✘ ➀✸➻✶❧ ➸ ♠✢♠ ✭❅✰❧➾★➚�❦❬ ❛✜❉✤●❝❊ P s ●❝❇✔✇ ❬ r⑤❊ ❙ ❑ ❋♥❊❢❦ ❑ ❯ s⑤❪ ❊♦⑩✭♠✤❊✌●❝❊ ➮➓ ✵ ❘ ✄ ➄ ✄ ❜ ❑ ❋✑r ➮❏➙✵ ❘❚➤ ➄❂◆ ❜ ④ ❄ ❍ ❬ ❙ ⑩➃❇①●❝❍❝♠❩❋✤❇✜❍ ❬ ❈ ❬ ❋✤❛❩❍❝♠ ❑ ❍ ❑❳❲✑❑ ❙ ❬ ❙❬ ❙ ❋✤❇✜❍❱❋✤❊✺❈❂❊ ❙■❙ ❑ ● ❬❴❪q▼ ❯ ❑ r⑤❊❩❇✔t ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊❷✇✜❊✺❈❂❍❝❇✜● ❙ ✡❱❍❝♠ ❬ ❙ ❬ ❙ ❬ ❋⑤❍❝● ❬ ❋ ❙ ❬ ❈ ❑❣❪❴❪q▼✏◆✜➣ ④➜➛ ❬ ❯ ❬❴❪❺❑ ● s ♠✤❊✌❋✤❇✜❯❳❊✌❋ ❑ ❇✤❈✌❈❂❉✤●❇✜❋ ❑ ❋ ▼ ❙ ❊✌❍➂❇✔t➃❈❂❇ ❪❴❪❴❬ ❋✤❊ ❑ ●♦✇✜❊✺❈❂❍❝❇✜● ❙ ✡✙❊ ④ ❛ ④ ❑ ●❝❊✌❛✜❉ ❪✼❑ ●❶r ❬ ❙ ❍■● ❬q❲ ❉✤❍ ❬ ❇✜❋➉❇❻t ❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊✱✇①❊✺❈❂❍❝❇✜● ❙ ❑ ❋✑r ❑ r⑤❊✌❛①❊✌❋✤❊✌● ❑ ❈ ▼s✑❑ ● ❑ r ❬ ❛①❯ ④ ✣

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Page 114: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✭❅✰ ➀ ❤✂✁ ➀✼➻❣➀♥♠✢♦❱➻❅❼ ➸✔➺❧➺ ➀ ✄➃➻ ➸ ♠✉➀ ❤①➾✠➚ ✝➢s✑❑ ❍❝❍❝❊✌●■❋ ❬ ❙ ✡➠ P ➡✧➾✮❤✜➾↔➍ ❧ ✭❅✰ ➀ ❤✂✁ ➀✼➻P➀✳❋✤❇ ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊❱❈❂❇✜❉ s⑤❪ ❊➠ ◆⑤➡➋♣■❤①➾✮❤ ❧ ✭❋✰ ➀ ❤☎✁ ➀✼➻P➀✢❊❢❦ ❬ ❙ ❍ ❙ ❇①❋✤❊ ❙ ❬ ❯ s⑤❪ ❊ ❬ ❋⑤✇ ❑ ● ❬❺❑ ❋✑❈❂❊✈❈❂❇①❉ s⑤❪ ❊ ❲ ❑❣❪❴❪✗❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊❱❈❂❇✜❉ s⑤❪ ❊ ❙ ❑ ●❝❊ ❙ ❬ ❯ s⑤❪ ❊ ④➠❆⑧ ➡ ✁ ➀↕❧ ✭❋✰ ➀ ❤✂✁ ➀✸➻ ➀ ❊❢❦ ❬ ❙ ❍✗❇①❋✤❊✆❋✤❇✜❋ ✘ ❙ ❬ ❯ s⑤❪ ❊ ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊✙❈❂❇✜❉ s⑤❪ ❊ ④ ❄ t✤❍❝♠✤❊ ❑ ❙❝❙ ❇➋❈ ❬✼❑ ❍❝❊✺r ❪✼❑ ❍❝❍ ❬ ❈❂❊ ❬ ❙ ❋✤❇①❋ ✘ r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍❝❊✺r ❖❍❝♠✤❊ s✑❑ ❍❝❍❝❊✌●■❋ ❬ ❙☛❙ ❑❣❬ r❩❋✤❇✜❋ ✘ r⑤❊✌❛①❊✌❋✤❊✌● ❑ ❍❝❊✺r ❲⑤❬⑦s ❊✌● ❬ ❇➋r ❬ ❈ ④ ❄ ❍✾r ❬ ✇ ❬ r⑤❊ ❙ ❬ ❋⑤❍❝❇❱❍➄⑩✙❇ ❙ ❉ ❲ ❈ ❪✼❑ ❙❝❙ ❊ ❙ ✡➠ ❑⑤➡✶❈ ➆⑤➾✆✁✜➸➇♣■✭❣➾ ♠ ➸ ❼ ✁ ➀↕❧ ✭❋✰ ➀ ❤✂✁ ➀✸➻❶❇①● ❼ ➸ ♠✢♠✉➀✸➻ ✭ ❧ ✭❋✰ ➀ ❤☎✁ ➀✸➻ ➀ ❑❣❪❴❪✗❪✼❑ ❍❝❍ ❬ ❈❂❊❶✇①❊✺❈❂❍❝❇✜● ❙ ❑ ●❝❊ ❬ ❋⑤✇ ❑ ● ❬❺❑ ❋✑❈❂❊②✇①❊✺❈❂❍❝❇✜● ❙ ④➠ ❲★➡❩➾✮❤✜➾❴❈✌➆❨➾✝✁✜➸✛♣❑✭✺➾ ♠ ➸ ❼ ✁ ➀❹❧ ✭❋✰ ➀ ❤☎✁ ➀✼➻➘❇✜● ✰➄➸✞✁ ➀ ➸✜➾ ♠✷❧ ✭❋✰ ➀ ❤✂✁ ➀✸➻ ➀ ❑❣❪❴❪★❬ ❋⑤✇ ❑ ● ❬✼❑ ❋❨❍ ❪❺❑ ❍❝❍ ❬ ❈❂❊➂✇✜❊✺❈❂❍❝❇✜● ❙ ❑ ●❝❊ ❬ ❋❩❍❝♠✤❊❙ ❑ ❯❱❊❶r ❬ ●❝❊✺❈❂❍ ❬ ❇✜❋ ④✟ ❤✛✰✠✁ ❧ ✰❡❤ ❧ ✭❋✰ ♠✉➀ ✭➪➺➪➚↔❄ ❍ ❑✔s✤s ❊ ❑ ● ❙ t✉●❝❇✜❯✏❇✜❉✤●❦❊❢❦ ❑ ❯ s⑤❪ ❊❂✟ ❬ ❋✑r➽❇✔t ❑ ⑩➃❇①●❧r✭●■❊ s ❊✌❍ ❬ ❍ ❬ ❇✜❋ ④ ❄ ❋ P ➣ ❖ ❯ ❬ ❋ ❬ ❯ ❑❣❪ ❛✜❊✌❋✤❊✌● ❑ ❍❝❇✜● ❙❑ ❋✑r s ❊✌● ❬ ❇✤r ❙ ❑ ●❝❊ ❲✑❑ ❙ ❊✺r❳❇✜❋ s ● ❬ ❯ ❑❣❪❴❬ ❍ ▼ ❋✤❇✜❍ ❬ ❇①❋✱❇✜❋✧⑩✙❇✜●❧r ❙ ④ ✝ ❦➋❍❝❊✌❋✑r ❬ ❋✤❛❱❍■♠ ❬ ❙ ❧ ✰ ➀ ♣②➸ ❼❫➀☛♠✢♦❱❋✤❇①❍ ❬ ❇✜❋✱❍■❇②r ❬ ❯❱❊✌❋ ❙ ❬ ❇✜❋◆ ④ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❑ ❋ ❑➁❪ ❍■❊✌●❝❋ ❑ ❍ ❬ ✇✜❊ s ❇ ❬ ❋⑤❍✾❇✔t✢✇ ❬ ❊✌⑩✩❍■❇❱❍❝♠✤❊②❈■♠ ❑ ● ❑ ❈❂❍❝❊✌● ❬q♣✺❑ ❍ ❬ ❇✜❋❩❇✔t✠✿ ❑ ❙ ❑ ❙ ❉ ❲ ❙ ❊✌❍➘❇✔t ❑✚❪✼❑ ❍❝❍ ❬ ❈❂❊✙❍☛✡ ▼➑ ❖ ▼➒✆☞s⑤❪ ❉ ❙ ❬ ❍ ❙ ❲ ❇✜●❧r⑤❊✌● r ✡ ▼➑ ❖ ▼➒✌☞ ④ ✝ ❙ ❑ ❯ ❑P✄ ❇✜● ❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❬ ❈❳❈❂❇✜❋ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊ ❖ ❬ ❍ ❑❣❪❴❪ ❇✔⑩ ❙ t✉❇✜●➘❉ ❙ ❬ ❋✤❛ P ➣ ❑❣❪ ❛✜❇①● ❬ ❍❝♠✤❯ ❙ ❍❝❇❙ ❊ ❑ ●❂❈❝♠✧t✉❇✜● s ❊✌● ❬ ❇➋r ❬ ❈ ❬ ❍ ❬ ❊ ❙ ❖ ♠✤❊✌❋✑❈❂❊✚⑩ ❬ ❍❝❋✤❊ ❙❝❙ ❊ ❙ ④ ✝✭❪ ❙ ❇ ❖ ❬ ❍ ❙ ❬ ❯ s⑤❪❴❬ ➈✑❊ ❙ ❍❝♠✤❊ s ●❝❇❨❇❻t ❙➘❘✎✍ ❜ ④✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜ ✄ ✔ ❐ ❊✌❍★➶ ❲ ❊ ❑ ❋✤❇✜❋ ✘ r⑤❊✌❛✜❊✌❋✤❊✌● ❑ ❍❝❊✺r ❲⑤❬qs ❊✌● ❬ ❇✤r ❬ ❈ s✑❑ ❍❝❍❝❊✌●❝❋ ④✳❐ ❊✌❍ ➠ ➮➓❉➄ ➮❏ ➡✫❲ ❊ ❑ t✉❉✤❋✑r ❑ ❯❱❊✌❋⑤❍ ❑❣❪✤❲✑❑ ❙ ❬ ❙❙ ❉✑❈■♠✱❍■♠ ❑ ❍ ❑ t❹❉✤❋✑r ❑ ❯❳❊✌❋❨❍ ❑➁❪✤❪❺❑ ❍❝❍ ❬ ❈❂❊➷❈❂❊ ❪❴❪ ❏❀▲ ▼➑ ❖ ▼➒ ❬ ❙ ❬ ❋✧❍❝♠✤❊ s ❊✌● ❬ ❇✤r ❬ ❈ ❬ ❍ ▼ r⑤❇✜❯ ❑❣❬ ❋ ④ ➣ ❊✌❋✤❇①❍❝❊ ➱ ❬ ❍ ❙ r ❬ ●❝❊✺❈❂❍ ❬ ❇①❋ ❖ ❑ ❋✑r✺ ❍❝♠✤❊➂❇✜❍❝♠✤❊✌●➘r ❬ ●■❊✺❈❂❍ ❬ ❇✜❋ ④✾❐ ❊✌❍✑✏❊✵✓✒❊▲✕✔ ➠ ➮➓ ✽ ➄ ➮❏ ✽ ➡➃❑ ❋✑r✾❍ ✵ ❬ ❋⑤tP❘✗✖ ✫✙✘ ❲ ✖➂➮✚ ✃ ✱ ❍ ▼➑ ❖ ▼➒ ❩❨④ ➣ ❊❂➈✑❋✤❊✚t✉❇✜● ❑ ❋ ▼ ➠ ❚ ➄ ❯ ➡❬ ❋ ❘ ✘ ✪❋✪❅✪ ❍ ❝➍P ❜✜✛ ❘ ✘ ✪❅✪❋✪ ✏ ❝➍P ❜ ❖ ➮❪✣✢ ❖ ✤ ❑ ❙ ❍❝♠✤❊✚❇✜❋ ❪q▼ ✇①❊✺❈❂❍❝❇✜● ❬ ❋ ❏❀▲ ▼➑ ❖ ▼➒ ❙ ❉✑❈■♠❩❍❝♠ ❑ ❍☎✥

➮❪✣✢ ❖ ✤ ❝ ➠ ❚❶➮✚ ✃ ✳❱❯ ➮✚ ✽ ➡ ✱ ❍ ▼➑ ❖ ▼➒ ✪❐ ❊✌❍➂➶ ✢ ❖ ✤ ❲ ❊♦➶ ❘ ➮❪✣✢ ❖ ✤ ❜ ❲ ❪ ❊✌❍✧✦ ✤ ❲ ❊❩❍❝♠✤❊ s ● ❬ ❯ ❬ ❍ ❬ ✇✜❊❩⑩✙❇✜●❧r ❑ ❙❝❙ ❇➋❈ ❬✼❑ ❍❝❊✺r→❍❝❇❷❍❝♠✤❊✱⑩✙❇✜●❂r♥➶✆★ ❖ ✤☎✩ ❫ ✪❋✪❋✪ ➶ ①✪✩ ❫ ❖ ✤☎✩ ❫❧④▲➎ ♠✤❊❙ ❊✺➅①❉✤❊✌❋✑❈❂❊ ➠ ✦ ✤ ➡ ❫✠✫ ✤ ✫✪✬ ❬ ❙ ❍❝♠✤❊✙❼❴➀ ➾✮✭❂➸✛✰ ➻ ➸①➾✮❤✜➾ ➀✼➻ ➸ ❼ ➎➇✭✺➾✷✭❋✰➄➸ ♠ ❤✛✰✐❬ ❋ r ❬ ●❝❊✺❈❂❍ ❬ ❇✜❋ ➱ ④✖ ❊✌❯ ❑ ●✮✭▲❍❝♠ ❑ ❍➘❍❝♠✤❊❱❊❢❦ ❬ ❙ ❍❝❊✌❋✑❈❂❊ ❑ ❋✑r▲❉✤❋ ❬ ➅✜❉✤❊✌❋✤❊ ❙❝❙ ❇✔t❾➮❪✣✢ ❖ ✤ ❬ ❙ ❑ r ❬ ●❝❊✺❈❂❍❱❈❂❇✜❋ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊✧❇✔t ✝✐❉✑❈ ❪❫❬ r✰✯ ❙ ❍❝♠✤❊✌❇①●❝❊✌❯❑ ❋✑r✧❍❝♠ ❑ ❍ ➠ ➮➓❉➄ ➮❏ ➡❖✘✉s ❊✌● ❬ ❇✤r ❬ ❈ ❬ ❍ ▼❷❬ ❯ s⑤❪❴❬ ❊ ❙ ❍■♠ ❑ ❍ ➠ ✦ ✃ ➡✢❬ ❙ ❬ ❋✑r⑤❊ s ❊✌❋✑r⑤❊✌❋❨❍➂❇✔t✢❍❝♠✤❊➘t✉❉✤❋✑r ❑ ❯❱❊✌❋⑤❍ ❑❣❪➔❲✑❑ ❙ ❬ ❙ ❈■♠✤❇ ❙ ❊✌❋ ④⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ◆✮✔✶❇✦✭ ♠✔➶ ✁❸✭➘➸♦➾✮❤✜➾↔➍✱✁✛✭❡➎✛✭❣➾✮✭❅✰❆➸ ♠ ✭✲✁❶✁ ➀❹❧ ✭❋✰ ➀ ❤☎✁ ➀✼➻➜❧ ➸ ♠✢♠ ✭❋✰❂➾✕➈✳➸✜➾✆✁ ➠ ✦ ✃ ➡ ❫✠✫ ✃✴✳ ✬ ✁❸✭ ♠☛❾ ✭➂➸✔➺❂➺✐❤ ➻✺➀ ➸ ♠ ✭✵✁ ❼❴➀ ➾✮✭❂➸✛✰➎✛✭❣➾✮✭❅✰❆➸ ♠ ❤✛✰ ➚ ➔ ❾ ✭✺➾↔➈➹➸✜➾ ♦ ✯❋✭ ➻❋♠ ❤➇✰ ➮❪ ➀ ➾ ♠☛❾ ✭ ❧ ✭❋✰ ➀ ❤☎✁ ➀✸➻✺➀☛♠✢♦ ✁✛❤✛♣♦➸ ➀ ➾➌➸✜➾✝✁ ➀ ➾ ♠☛❾ ✭✚➺ ➸✛♣❑✭✶✁ ➀ ✰❡✭ ➻❅♠✉➀ ❤✜➾❷➺✌➸ ♠✉➀ ➺ ✄ ✭✌➺ ➀

➶ ❘ ➮❪ ❜✣✵✷✦ ✤ ➠ ❚②❯❱❇✤r♥❮✸✦ ✤ ❮ ➡➠❆⑧ ➡❿➄❾ ✭❅✰➅✭ ➠ ❚ ➄ ❯ ➡ ➀ ➺✕✁✛✭ ✄ ➾✷✭✲✁❃✁ ♦✙♠☛❾ ✭✙✭✵✹✺➆⑤➸ ♠✉➀ ❤✜➾ ➮❪➌❝ ➮❪✺✢ ❖ ✤ ✱ ❍ ▼➑ ❖ ▼➒ ➚✼✻✭➾✷✭ ❾ ➸❻➺ ❍✓✵✷✒❊▲✕✽ ➠ ❮✸✦ ✤ ❮ ➡ ✵ ✾ ➒✆✿❁❀❂❄❃ ❀❅ ✾✬ ➚❄ ❋⑤❍❝❉ ❬ ❍ ❬ ✇✜❊ ❪q▼ ❖ ❑✧❲⑤❬qs ❊✌● ❬ ❇✤r ❬ ❈ s✑❑ ❍❝❍❝❊✌●❝❋❩➶ ❬ ❙ ❯ ❑ r⑤❊②❇❻t❆✏ s✑❑ ❍❝❍❝❊✌●❝❋ ❙ ❍❝♠ ❑ ❍➂●■❊ s ❊ ❑ ❍ ❬ ❋✑r⑤❊❂➈✑❋ ❬ ❍❝❊ ❪q▼ ❖ ❊❢❦✑❈❂❊ s ❍❶❯ ❑❣▼⑤❲ ❊t✉❇✜●✾❍■♠✤❊ ❲ ❇✜●❧r⑤❊✌● ❙ ✥✾●■❇➁⑩ ❙➂➠ ❇①●➷❈❂❇ ❪ ❉✤❯❱❋ ❙ ➡ ➱ ❖ ➱ ✱ ❘ P ✪❅✪❋✪ ✏ ❩ ❑ ●❝❊ ❪❴❬ ❋✤❊ ❑ ●②❈❂❇✜❋✑❈ ❑ ❍❝❊✌❋ ❑ ❍ ❬ ❇✜❋ ❙ ❇✔t ❙ ❍❝● ❬ ❋✤❛ ❙ ✦✂❇✃ ❑ ❋✑r❷●❝❇✔⑩✺ ✳ ✏ ❬ ❙ ❊✺➅✜❉ ❑➁❪ ❍❝❇❶●❝❇✔⑩ ✺ ❙ ♠ ❬ t❹❍■❊✺r ❲⑤▼ ❙ ❇✜❯❱❊✙✇ ❑➁❪ ❉✤❊✕❈ ④ ❄ ❋❊❉ ❬ ❛✜❉✤●❝❊ P✜❖ ⑩✙❊➃♠ ❑ ✇✜❊✑✏ ❫ ✵✷✏ ⑤ ✵ ◆✚❑ ❋✑r❋✦ ❫ ✵✷●■❍❑❏✌↕ ✚☎▲✪▼✆◆❑ ❋✑r❊✦ ⑤ ✵ ➱ ✺ ✖✤ÏP❖❊◗ ④

� ❤❻➺ ➀☛♠✉➀ ❤①➾❃❤❡❈☛➺❞❤✜➆ ✰ ➻ ✭➪➺➪➚ ④✳➊ ❊✭●❝❊✌❯ ❑ ●✮✭❶❍■♠ ❑ ❍ ➠➄⑧ ➡ ♠✤❇ ❪ r ❙ t✉❇✜● ❑ ❋ ▼ ➮❪ ❬ t✑➶ ❬ ❙ t✉❉✤❋✑r ❑ ❯❱❊✌❋⑤❍ ❑❣❪✑❲⑤❬qs ❊✌● ❬ ❇✤r ❬ ❈ ④✙➊ ❊ ❙ ♠✤❇✔⑩❍❝♠ ❑ ❍ ❬ t ❑ ✇✜❊✺❈❂❍❝❇①●✏➮❪ ❬ ❋ ❍ ▼➑ ❖ ▼➒❙❘❊❚ ❬ ❙ ❋✤❇①❍ ❑ ❋ ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊✧✇✜❊✺❈❂❍❝❇✜●➂❍■♠✤❊✌❋➉❒❑▼❯ ❈❂❇✜❋⑤❍ ❑❣❬ ❋ ❙ ❑✧s ❇ ❬ ❋❨❍✚❍❝♠ ❑ ❍ ✯ ➀ ❤ ❼ ➸ ♠ ✭✌➺➠ ➮➓❊➄ ➮❏ ➡ ❧ ✭❋✰ ➀ ❤☎✁ ➀✸➻✺➀☛♠✢♦✗✥♦❈ ❑✔s⑤❬ ❍ ❑❣❪ ❈❝♠ ❑ ● ❑ ❈❂❍❝❊✌● ❙ ❬ ❋❱❉ ❬ ❛✜❉✤●❝❊ P✜④ ✝➄❦✤❍❝●❝❊✌❯ ❑❣❪ ❙ ❉✑❈❝♠ s ❇ ❬ ❋❨❍ ❙ ❖ ❘ P✺◗ ➄❂◆ ❜ ➄ ❘ P ➤ ➄ ✘ ❜ ❑ ❋✑r ❘ P ➄✲❲ ❜ ❖❪ ❊ ❑ r❩❍■❇❱❍❝♠✤❊➂❊❢❦✑❈ ❪ ❉ ❙ ❬ ❇①❋ ❇❻t ❘ ❲ ➄ ✘ ❜ ➄ ❘ ➤ ➄❝◆ ❜ ❑ ❋✑r ❘ ✘ ➄✲❲ ❜➏t❹●❝❇①❯ ✿ ➠ ●❝❊ s ●■❊ ❙ ❊✌❋❨❍■❊✺r ❲⑤▼✱❲ ❇ ❪ r⑤❊✺r ➭ ➡ ④❳ ➸ ❽ ➀ ♣②➸ ❼✰❨ ❤✛✯❋✭❅✰ ➀ ➾✻➎❻➺ ❨✠❼ ➸✔➺❂➺ ➀ ✄✙➻ ➸ ♠✉➀ ❤✜➾★➚ ➇ ❋✤❊ s ●❝❇✔✇✜❊ ❙ ❍■♠ ❑ ❍➔❍➄⑩✙❇➂❈❂❇ s⑤❬ ❊ ❙ ❇✔t❨➶ ❙ ♠ ❬ t✉❍❝❊✺r ❲❨▼ ➮★ ❑ ❋✑r▲➮✩ ❑ ●❝❊✆❯♦❉✤❍❝❉ ❑❣❪❴❪q▼❈❂❇✜❋ ❙ ❬ ❙ ❍■❊✌❋❨❍ ❬ t ❑ ❋✑r▲❇✜❋ ❪q▼❷❬ t❼➮★❃❝ ➮✩ ❬ ❙ ❑ ❋ ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊✧✇✜❊✺❈❂❍❝❇✜●➂❇✜●✭➶ ▼◆ ❘ ➶✬▼◗ ✵❬❩ ④❱➇ ❋✤❊✧r⑤❊❂➈✑❋✤❊ ❙ ❑ ➠ ➮★ ➄ ➮✩ ➡✒✘✸❪✼❑ ❍■❍ ❬ ❈❂❊❈❂❇✔✇✜❊✌● ❬ ❋✤❛ ❑ ❙ ❑ ❙ ❊✌❍✱❇✔t ❬ ❋❨❍❝❊✌● ❪ ❊ ❑ ✇✜❊✺r ➮★ ✘ ❇➁✇①❊✌● ❪✼❑✔s✤s⑤❬ ❋✤❛ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ❙ ⑩✭♠✤❊✌●❝❊▲❍➄⑩✙❇➌❋✤❊ ❬ ❛✜♠ ❲ ❇✜❉✤● ❬ ❋✤❛ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊ ❙ ❑ ●❝❊❙ ♠ ❬ t✉❍❝❊✺r ❲⑤▼ ➮✩✫④ ❄ ❍ ❬ ❙ ✰❡✭❡➎✜➆ ❼ ➸➇✰✳❬ t✱➮★❑✳ ➮✩ ✱ ❚ ❖ ❊ ❪ ❙ ❊ ❬ ❍ ❬ ❙✾❙ ❑➁❬ r ✭✐❽ ♠ ✭✺➾✆✁➇✭✲✁ ④ ❄ ❍ ❙ ❍❝❊ ❑ r ❬❴❪q▼ t✉❇ ❪❴❪ ❇✔⑩ ❙ ✥⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ⑧ ✔❻➏❙♣♦➸P❽ ➀ ♣♦➸ ❼✑➻ ❤✛✯❋✭❅✰ ➀ ➾✻➎ ❤❡❈ ♠☛❾ ✭✭◆ ➍✠✁ ➀ ♣■✭❣➾✤➺ ➀ ❤①➾✑➸ ❼ ➺ ❧ ➸ ➻ ✭ ✁ ♦ ➸ ❧ ➸ ♠✢♠ ✭❋✰❂➾ ➶♥➀ ➺ ✭ ➀♥♠☛❾ ✭❋✰❛❤❡❈ ♠☛❾ ✭ ♠☛❾ ✰➅✭❢✭ ➀

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Page 115: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➠ P ➡ ♠✉➀♥❼❴➀ ➾✻➎P➈➠ ◆⑤➡✧➸ ♠✉➀☛❼❴➀ ➾ ➎✙❤❡❈ ➮★ ➍➅❤➇✯❋✭❋✰ ❼ ➸ ❧✛❧✠➀ ➾✻➎❳➺✐✭✲✹❣➆✻✭❣➾ ➻ ✭✌➺ ❿➄❾ ✭❋✰❡✭ ➮★ ➀ ➺❶➸➋♣ ➀ ➾ ➀ ♣♦➸ ❼❦➀ ➾✷✯✺➸✛✰ ➀ ➸①➾ ➻ ✭■✯❅✭ ➻❅♠ ❤✛✰✌➚➠❆⑧ ➡✧➸ ➠ ➮★ ➄ ➮✩ ➡❸➍ ❼ ➸ ♠✢♠✉➀✼➻ ✭ ➻ ❤✛✯❅✭❋✰ ➀ ➾ ➎✔➺✺➚ ➆ ♠✭➀ ➺ ●❝❊✌❛✜❉ ❪✼❑ ● ➸✜➾✝✁ ➠ ➮★ ➄ ➮✩ ➡ ➀ ➺✈➸❱✁■➸✔➺ ➀ ➺✙❤❡❈ ♠☛❾ ✭ ➻ ➸✜➾✷❤✜➾ ➀✸➻ ➸ ❼✌❼ ➸ ♠✢♠✉➀✼➻ ✭ ➀ ❈ ➶✰➀ ➺✁ ➀↕❧ ✭❋✰ ➀ ❤✂✁ ➀✸➻✁� ❤ ♠☛❾ ✭❅✰ ❿✢➀ ➺❞✭ ➀♥♠✓➀ ➺❶✭❿❽ ♠ ✭✺➾✝✁✛✭✵✁❨➚✖ ❊✌❯ ❑ ●✮✭➉❍■♠ ❑ ❍❱❊❢❦✤❍❝❊✌❋✑r⑤❊✺r ❪❺❑ ❍❝❍ ❬ ❈❂❊ ❈❂❇✔✇✜❊✌● ❬ ❋✤❛ ❙ ❑ ●❝❊ ❑ ❋✰❊❢❦➋❍❝❊✌❋ ❙ ❬ ❇①❋❾❇✔t➂❍❝♠✤❊♥❈❂❇✔✇✜❊✌● ❬ ❋✤❛✶❋✤❇✜❍ ❬ ❇✜❋ ❖ ⑩✭♠✤❊✌●❝❊ ❙ ❇✜❯❱❊➐ ♠✤❇ ❪ ❊ ❙❝➒ ❑✔s✤s ❊ ❑ ● ❬ ❋♥❍❝♠✤❊✚●❝❊ s ●❝❊ ❙ ❊✌❋⑤❍ ❑ ❍ ❬ ❇①❋ ④✆➎ ♠ ❬ ❙ ❬ ❙ s ❊✌●❝❍ ❬ ❋✤❊✌❋⑤❍☛t❹❇✜● ❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❬ ❈ ❬ ❙■❙ ❉✤❊ ❙ ❑ ❙ ❬ ❍ ❑❣❪❴❪ ❇✔⑩ ❙ ❍❝❇✧r⑤❊✌❍❝❊✌● ✘❯ ❬ ❋✤❊✭❍❝♠✤❊ ♣②➸ ❽ ➀ ♣②➆ ♣ ❋❨❉✤❯ ❲ ❊✌●✓❇✔t✠❇✤❈✌❈❂❉✤●❝●❝❊✌❋✑❈❂❊ ❙ ❇✔t ❑ ❛ ❬ ✇①❊✌❋ s✑❑ ❍❝❍❝❊✌●■❋ ❖ ❑➘s✑❑ ● ❑ ❯❱❊✌❍■❊✌●✢●❝❊ ❪✼❑ ❍❝❊✺r♦❍❝❇➂❍■♠✤❊➃⑩✙❇✜● ❙ ❍ ✘ ❈ ❑ ❙ ❊❈❂❇✜❯ s⑤❪ ❊❢❦ ❬ ❍ ▼ ④ ✂➔➦☎✄❷➲✉❢✷❆✺➳☎✆☎➨✠➩ ❆✞✝✑❄✠✟✳➩✺➨★➨✡✆❆➳➇ ❋✤❊ ❙ ♠✤❇✔⑩ ❙ ❍❝♠ ❑ ❍♦❍❝♠✤❊ ❙ ❉✤❯ ❇✔t ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊❷✇✜❊✺❈❂❍❝❇✜● ❙ ❬ ❙ ❑ ❋ ❬ ❋❨✇ ❑ ● ❬✼❑ ❋✑❈❂❊❩✇✜❊✺❈❂❍■❇✜● ➸ ❼ ♣■❤❻➺ ♠ ✭❅✯❋✭❋✰ ♦✔❿➄❾ ✭❋✰❡✭ ❖ ❑ ❋✑r❈■♠ ❑ ● ❑ ❈❂❍❝❊✌● ❬⑦♣ ❊ ❙ ❍❝♠ ❬ ❙ ♣ ❇✜❋✤❊✭❇❻t ❋✤❇①❋ ✘✸❬ ❋⑤✇ ❑ ● ❬✼❑ ❋✑❈❂❊ ❖ ❍■♠✤❊✙t❹●■❊✌❊ ♣ ❇✜❋✤❊ ❖ ❍❝♠ ❑ ❍➃❈❂●❝❊ ❑ ❍■❊ ❙✾➐ ❲ ❇✜●❧r⑤❊✌●✆❊❂➑✗❊✺❈❂❍ ❙■➒ ④✢➎ ♠ ❬ ❙ ❑ r✤r ❬ ❍ ❬ ✇①❊s ●❝❇ s ❊✌●❝❍ ▼❱❑❣❪❴❪ ❇✔⑩ ❙ ❍❝❇❶❉ ❙ ❊✭❛✜❊✌❋✤❊✌● ❑❣❪ ●❝❊ ❙ ❉ ❪ ❍ ❙ ❇✜❋ ❲⑤❬qs ❊✌● ❬ ❇➋r ❬ ❈➘t✉❉✤❋✑❈❂❍ ❬ ❇✜❋ ❙ ❇✜❋ ❥ ⑤ ❑ ❋✑r s ●❝❇✔✇✜❊ ❑➘❪✼❑ ❍❝❍ ❬ ❈❂❊➂r ❬ ❙ ❍❝● ❬q❲ ❉✤❍ ❬ ❇✜❋❇✔t ❑❣❪ ❯❱❇ ❙ ❍ ❑➁❪❫❪✢❬ ❋⑤✇ ❑ ● ❬❺❑ ❋✑❈❂❊❱✇✜❊✺❈❂❍❝❇✜● ❙ ④ ❅ ❇✜❍ ❬ ❈❂❊♦❍❝♠ ❬ ❙ ✇✜❊✺❈❂❍❝❇✜● ❬❺❑➁❪➹❑✔s✤s ●❝❇ ❑ ❈❝♠ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❑ ✇✜❊✌● ▼ ❙ ♠✤❇✜●❝❍ s ●❝❇❨❇❻t✆❇✔t✆❍❝♠✤❊s ●❝❊✌✇ ❬ ❇✜❉ ❙ ●❝❊ ❙ ❉ ❪ ❍ ❙ ❬ ❋ ❘ P✔❖☞☛ ❜ ④ ❏▲❑ ❋ ▼▲s ●❝❇⑤❇✔t ❙ ●❝❊ ❪q▼ ❇①❋➌❍❝♠✤❊❊❉ ❑ ❈❂❍❝❇①● ❬ ❙ ❑ ❍ ❬ ❇✜❋ ➎ ♠✤❊✌❇✜●■❊✌❯ ❘ ◗ ❜ ✥❶❊✺➅①❉ ❑ ❍ ❬ ❇✜❋ ● ❍ ✵ ❍❑●❬ ❯ s⑤❪❴❬ ❊ ❙ ❍■♠ ❑ ❍✕● ❑ ❋✑r ❍ ❑ ●❝❊ s ❇✔⑩✙❊✌● ❙ ❇✔t ❑ ❙ ❑ ❯❱❊ s ● ❬ ❯ ❬ ❍ ❬ ✇✜❊❱⑩✙❇✜●❧r ④ ❉✤❇①●➂❊❢❦ ❑ ❯ s⑤❪ ❊ ❖ ❬ ❋ ➎ ♠✤❊✌❇✜●❝❊✌❯ ◆ ❖ ❊✺➅①❉ ❑ ❍ ❬ ❇✜❋➠❆⑧ ➡☛❬ ❯ s⑤❪❴❬ ❊ ❙ ❍❝♠ ❑ ❍ ❖ t❹❇✜● ❑ ❋ ▼ ❯✢❖ ❮ ✦ ✤ ❮✗r ❬ ✇ ❬ r⑤❊ ❙ ❍ ④❷➇ ❍❝♠✤❊✌●■⑩ ❬ ❙ ❊ ❖ t✉❇✜● ❙ ❇①❯❱❊ ✺ ❖ ❇✜❋✤❊❱♠ ❑ ❙ ❍▲❯❱❇✤r♥❮✸✦ ✽ ❮➄✵ ❈✍✌✵ ✘ ④➊ ❬ ❍❝♠✧● ✵✷✦ ✽ ❘ P ❜ ✪❅✪❋✪ ✦ ✽ ❘ ❈✗❜ ❑ ❋✑r❋❍✶✵✷✦ ✽ ❘ ❈ ✳ P ❜ ✪❋✪❅✪ ✦ ✽ ❘ ❮✸✦ ✽ ❮ ❜ ❖ ✦ ✽ t ❑ ❈❂❍❝❇①● ❙ ❑ ❙ ✦ ✽ ✵✷●■❍✶✵✷❍❑●✚⑩✭♠ ❬ ❈❝♠❩❈❂❇✜❋⑤❍❝● ❑ r ❬ ❈❂❍ ❙ ❍❝♠✤❊s ● ❬ ❯ ❬ ❍ ❬ ✇ ❬ ❍ ▼ ④✏✎ ❊✌❋✑❈❂❊ ❖ ✒❶▲✼✽ ➠ ❮✸✦ ✽ ❮ ➡ r ❬ ✇ ❬ r⑤❊ ❙ ❍ ④✒✑ ❪ ❙ ❇ ❖ ➠➄⑧ ➡✙❬ ❯ s⑤❪❴❬ ❊ ❙ ❍❝♠ ❑ ❍ ✒❶▲✕✽ ➠ ❮✸✦ ✽ ❮ ➡ ➮✚ ✃ ❬ ❙ ❑❳❪✼❑ ❍❝❍ ❬ ❈❂❊❱✇①❊✺❈❂❍❝❇✜● ❖♠✤❊✌❋✑❈❂❊■❍❷➮✚ ✃ ❖ ❲⑤▼ ❍❝♠✤❊➂❯ ❬ ❋ ❬ ❯ ❑➁❪❫❬ ❍ ▼♥s ●■❇ s ❊✌●❝❍ ▼ ④✑ ❯ ❑ ✄ ❇①●✆❈❂❇✜❋ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊❶❇✔t✗❍❝♠✤❊ ❙ ❊➘⑩✙❇✜●❧r s ●■❇ s ❊✌●❝❍ ❬ ❊ ❙ ❬ ❙ ❍❝♠✤❊ s ❇ ❙❝❙ ❬q❲⑤❬❴❪❴❬ ❍ ▼ ❍■❇②❈❂❇✜❯ s ❉✤❍■❊✾❍❝♠✤❊ ❪❴❬ ❋✤❊ ❑ ●✭❛✜❊✌❋✤❊✌● ❑ ❍❝❇✜● ❖♠✤❊✌❋✑❈❂❊❩❍❝♠✤❊❳t❹❉✤❋✑r ❑ ❯❱❊✌❋❨❍ ❑❣❪✭❲✑❑ ❙ ❬ ❙ ❖ t✉●❝❇✜❯ ❑ ❋ ▼ t❹❉✤❋✑r ❑ ❯❳❊✌❋❨❍ ❑➁❪➓s✑❑ ● ❑❣❪❴❪ ❊ ❪ ❇①❛✜● ❑ ❯ ④✶➇ ❋✤❊ ❬ ❋ ❬ ❍ ❬✼❑❣❪❴❪⑦▼ ❈❂❇✜❯ s ❉✤❍❝❊ ❙ ✏ ❑ ❙✒❶▲✼✔ ➠ ➮★ ✽ ➄ ➮✩ ✽ ➡✙❑ ❋✑r ❍ ❑ ❙ ❬ ❋⑤t❅❘✗✖ ❲ ✖➂➮✚ ✃ ✱ ❍ ▼◆❋❖ ▼◗ ❩❨④ ❉➏❇✜●✭❊ ❑ ❈■♠❩❇✔t➔❍❝♠✤❊✶✏ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ❙ ➶ ✢ ❖ ✤ r⑤❊❂➈✑❋✤❊✺r ❖ ❇✜❋✤❊♦❈ ❑ ❋❩❊❢❦✤❍❝● ❑ ❈❂❍❍❝♠✤❊ ❑ ❙■❙ ❇➋❈ ❬✼❑ ❍■❊✺r s ● ❬ ❯ ❬ ❍ ❬ ✇✜❊♦⑩✙❇✜●❧r ✦ ✽ ④➓➇ ❋✤❊❶❯ ❑❣▼ ❉ ❙ ❊❶❍❝♠✤❊➂⑩✙❊ ❪❴❪ ✭⑤❋✤❇✔⑩✭❋ P ➣✩❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯✂❍❝♠ ❑ ❍ ❙ ❊ ❑ ●❧❈■♠✤❊ ❙ t❹❇①●✭❍❝♠✤❊s ● ❬ ❯ ❬ ❍ ❬ ✇✜❊ ❙ ❊✌❊✺r→❇✔t ❑ ⑩✙❇✜●❂r ➠ t✉❇✜● ❬ ❋ ❙ ❍ ❑ ❋✑❈❂❊✧❍❝♠✤❊ s ●❝❊ s ●❝❇✤❈❂❊ ❙❝❙ ❬ ❋✤❛▲❇✔t ❸ ❋❨❉✤❍❝♠ ✘✖❏ ❇✜●■● ❬ ❙ ✘✔✓ ● ❑ ❍❝❍ ➡ ④❩➎ ♠✤❊✌❋ ❖ ❇✜❋✤❊❩❈ ❑ ❋❈❂❇✜❯ s ❉✤❍■❊ ❑❣❪❴❪ ⑩ ❬ ❍❝❋✤❊ ❙■❙ ❊ ❙ ❲ ❊✌❍➄⑩➃❊✌❊✌❋❷❍➄⑩➃❇ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ❙ ✦ ✽ ❑ ❋✑r ✦ ❵✔④✙➎ ♠ ❬ ❙ r⑤❊✌❍❝❊✌●❝❯ ❬ ❋✤❊ ❙ ⑩✭♠✤❊✌❍❝♠✤❊✌●➘❍❝♠✤❊ ❙ ❊✌❍ ❬ ❙ ❈ ▼ ❈ ❪❫❬ ❈➠ ❋✤❇✜❍✢❯ ❬ ❋ ❬ ❯ ❑➁❪❹➡✆❑ ❋✑r ➠ ➮➓❊➄ ➮❏ ➡ ❙ ❍■❊ ❑ r ❬❴❪⑦▼ t❹❇ ❪❴❪ ❇✔⑩ ❙ ④✕✑ ❋ ❬ ❯ s⑤❪ ❊✌❯❱❊✌❋❨❍ ❑ ❍ ❬ ❇✜❋ ❑ ❋✑r✚❇✜❍❝♠✤❊✌● ❑❻s✤s⑤❪❫❬ ❈ ❑ ❍ ❬ ❇①❋ ❙ ❑ ●❝❊✭r⑤❊ ❙ ❈❂● ❬q❲ ❊✺r❬ ❋ ❘✎✍ ❜ ④ ✢✤✣✦✥★✧✦✣✦✩✫✪✭✬✯✮✆✰✓✱✳✲

✴ ❭ ✵❙④✗✖ ❑✿❨❬❁ ④✞❅☎❇❙✸☛❉✫❊✏✘ ✾✻❉①❳✒✼✂❉ ❁✚✙ ❅☎❇ ❅✆❚✜✛▲❏❈✼✁✢✒❊✠❑✣✖ ✾✻❉①❳✒❑✿✼✂❉✫✸☛✷✙⑩✫✾ ❨✒❑✿✼✆❊✠❑✹▼✽❑✿❀✥✤ ✸✯❉✫❊ ❑✿❀❖❳❝✸☛⑩✆⑩✆✷✿❑✹▼✻✸✯❀❖❑✿✼✂❉✓❅✧✦❘❉ ❫✩★✕✪♥❛☎✫ ✬✮✭✂❅❴❚ ⑥✏⑦❯⑦✰✯①❅❃❆❨❖✼✉▼ ✾✻✾✏❊✠❑✿❉✆■❯❳q✼✁✱❆❀✒❩✆✾ Ð ❨❲❊●❋✞✤✞✖ ⑩✫✼❯❳✒❑✿⑤✲✖ ✼✂❉●❱q❑✿❳✽▼✽❨✒✾✻❀❖✾❙④q✷✿■❯✼✂❨✒❑✿❀❖❩✲✖ ❳❍✈✴✳❂❨✒✷✹✸☛❉✫❊✠✼✫✈✆✶✶✵ ❅✴ ❻ ✵❙④✗✖ ❑✿❨●❁ ④✞❅☎❇ ✈✷✘ ✾✻❉①❳✒✼✂❉ ❁✥✙ ❅☎❇✻✈❬✸✯❉✫❊ ✶✭✸✯❨❲✸❯▼❖❩ ❁✥✸♠❅☎❇✻❅ ❚ ④❂✷❪⑩①❩✫✸✁✹✭✾✻❀P❑✿❉✫❊✠✾ ⑩✫✾✻❉✭❊✠✾✻❉✠❀P❀❘❏❈✼ ❊✉❑✺✖ ✾✻❉✆❳❖❑❪✼❯❉✫✸✯✷✻✖ ✸☛❀❲▼❖❩✆❑✿❉✆■✫❅☞✦❘❉❫✽✼✕★❬❧✷✫ ✬✮✭✂✈✠⑩✆⑩✓❅ ②✿✾ ❚✆❹✂❶✆❅☛❚ ⑥✏⑦✂⑦✿✯✆❅✞❀❂❑ ▼ ❀✒✼✂❨❖❑✹✸✆✈✲✘✕❁❬❅✴ Ð ✵❂✘❈✸✯✾❄❃✏✸❅✢❇❆▲✸✯❀✒✾ ❳♥❁❘◗❙❅☎❇✙✸✯❉✭❊❙◗❉❈✾✻■❯❉✆❑✿✾✻❨ ❁✥✸♠❅☎❇✻❅ ❚ ✶✭✸✯❳❖❀★✸✯✷✿■❯✼✂❨✒❑✿❀❖❩✲✖ ❳❊✱ ✼✂❨✳❀❘❏♥✼❬❊✠❑✣✖ ✾✻❉①❳✒❑✿✼✂❉✫✸☛✷✇✸☛❉✫❊❋✖ ⑤✆✷✿❀❖❑❪⑩①✷❪✾✳⑩✫✸✯❀❖❀✒✾✻❨❖❉❂✖●✸✯❀✽▼✒❩①❑❪❉①■✫❅❵✻✐❍●✏❢✯❤✻♦ ❥❍r❘s ❢☛✐✒■❈❤❲❢❑❏▼▲❖◆P◆✻s✹✐✠t❘◗❙▲ r r✔▲ ❤P◆✻✈✠❭✰❚✰❯✥❱❯❷ ② ✈✠❉ ➹ ❭ ✈✙⑥✏⑦✂⑦✿❲✆✈❯⑩✆⑩✩❱ ②✞❭ ❚ ② ❶❊❱❳ ❷✁❨❂✙✷❩✮❯✺❬✣❯✞❭✥❪✶❱ ❫✡❩✁❴❛❵❝❜✽❩☛❨✔❞❡❭✥❢❘❱ ❫❍❱❍❣❂✛❆❨✒⑤✲❯✣✤✷❩✁❯✿⑩✆❩❛❩✮✹❛❤❍✐✩❬✣❴❛❵✞❤✻⑩✧❤❄❴❛❵❥❤❄❴✞✐✽✐✥❦✕❚✁✢✔❵✞❬✣✖✒❤❍❴✆❳✔❬✣❚✰❴✧❩✁❯✯⑩❛❩✮✐✔✐✔❤ ❨✔❴❘✖❧❩✁✐P♠❖❩✲❬✣❴✲♥❛❱P✦✥❴❡♦✕★❬❧❆❫♣✫ ✬✁✭✿❱❍❣✦✔qrqrq ✈✫⑥❍⑦✂⑦✰✯❊❱✰❜❆❨s❚❥♠❖❤❄❤t❵✞❬✣❴✲♥❯❳✉❚✁✱✩✐✒❩❊❤ Ð✺Ð ❨▼❵❘✦✔qrq☞q✈❁✕❚✰❴❥✱❇❤✻❨✔❤❍❴❛♠P❤❋❚✰❴✒✇❊❚✂⑤✲❴✧❵✲❩✁✐s❬✺❚✿❴✆❳r❚✮✱✽❁✕❚✰✖ ⑩①⑤✲✐✔❤✻❨r①✲♠❖❬✺❤❍❴❛♠P❤✂✈✧❜✶❬✣✐✔✐✒❳s✹✆⑤✆❨s♥✂❩✓✈② ①✉④❂❱❳ ② ❨❂✵③❚✿✐✒❩❛❩✮❬✿❨✔❤❡❭✥✸④❱⑤❫❄❱❊❣ ❧♥❢☛♦⑦⑥ s✹✐✫❥✇r ❢☛❤✻s❇❏❖◆ ❢✯✐⑨⑧●❢✯❤P⑩❑◆❄❱✧❣ ④❶❵✲❵✞❬✿❳s❚✰❴✞✢✥❷④❤❄❸✔❯✣❤❄✤✠✈❆⑥✏⑦❯⑧✰❲✆✈✡❹♥✐✧❏❄❺✰❏ ❦❪❢ ♣❥▲P⑩✯s✦❥P❢✥●✤❜ ❥❍r❼❻❥▲ ♦ ❥✇r❄s❇❏❖◆ ❥✯✐❛⑩s✿r❼◆ ❛ ♣✂♣✫❦ s❇❏✽❥❍r❘s ❢✯✐❥◆ ✈✞❽✿❚✰❯✥❱ ❭ ❶❊❱❳☎❹❑❨❂❾❉❈❤❍♥✰❴✲❬✣❤❄❿✻❭✚✸④❱⑤❫✕❩✁❴❛❵➀❾✉❚✿❸✔✐▼❩✮✖✒❬✡❭✚✵☞❱ ❫❍❱✁❣♠④ ⑤✲❴✲❬➁✱❇✤✞❬✣❴✲♥✷❯✣❚✞❚✰❞✒❩✁✐✉➂✮✢➃❵❥❬✺✖➀❤❄❴✲❸s❬✺❚✿❴❛❩✁❯✠⑩✧❤❄❿✔❬✣❚✲❵✞❬➄♠P❬✣✐✔❬✣❤❄❸✗❩✮❴❛❵❡❸❖⑩❛❩✰♠❖❤❂♠P❚✁❽✰❤❍❿✔❬✣❴✲♥✰❸❑❱✞✦✥❴❧✶■ ❜✠✫ ✬✮➅✰❱✿◗❙▲P❏ r❄❣✠❤P▲✕➆❝❢✇r➃▲❖◆▲s✹✐P❧♥❢☛♦q♣✭❣✂r✔▲ ❤✕➇➈❏✻s❼▲✻✐❛❏P▲ ✈✰❽✿❚✰❯✥❱✏❹❯❸✯❷✭✈✯⑩✆⑩✩❱ ❻✞❭❍② ❣ ❻✂❻ ❶❊❱P❣❧①✠⑩❊❿✔❬✣❴✲♥✰❤❍❿✥✢✥❀r❤❄❿✔❯➄❩✮♥✫✈✆⑥❍⑦✂⑦✰❲❊❱t❜✶❿s❚✲♠P❤❄❤t❵✞❬✣❴✲♥✿❸❚✁✱✶✐✔➉✲❤❬❷✿✐✔➉☎①✞✤✞✖ ⑩✧❚✰❸s❬❪⑤❊✖➊❚✿❴☎❁✕❚✰✖❡✹✲❬✣❴❛❩✮✐✔❚✰❿s❬➄❩✁❯✲❜✶❩✁✐✔✐s❤❄❿✔❴✏✸☎❩✁✐P♠✔➉❊❬✺❴❊♥✫✈✲❜✶❩✰❵✞❚✁❽✰❩①✈✰✦✥✐P❩✁❯✣✤✞❱❳☎❶❑❨❂❾❉❈❤❍♥✰❴✲❬✣❤❄❿✻❭✚✸④❱⑤❫✉❩✮❴❛❵❉❾✉❚✰❸s✐▼❩✮✖✒❬③❭✥✵r❱⑤❫❄❱❥❣➋✸❉❬✣❴✲❬✣✖❉❩✁❯❛❵✿✢✔❵✞❬✣✖✒❤❍❴✲❸✔❬✣❚✰❴✧❩✁❯❛❩✮❴❛❵❉✸☎❩❑➌✲❬✣✖❧❩✮❯❛①✠⑩❛❩✿♠P❤✷❁✕❚✁❽✰❤❄❿s❬✺❴❊♥✰❸✏✈✙⑥❍⑦✂⑦✿➍✲❱

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Page 116: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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➎ ♠✤❊♦❈❂❇✜❋✑❈❂❊ s ❍✾❇❻t➹●❝❊✌✇①❊✌● ❙ ❬ ❋✤❛ ❑ ➈✑❋ ❬ ❍❝❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ❬ ❙ ❲ ❊ ❙ ❍ ❬ ❋⑤❍❝●❝❇✤r⑤❉✑❈❂❊✺r ❲❨▼♥❑ ❋♥❊❢❦ ❑ ❯ s⑤❪ ❊ ④ ➣ ❊❂➈✑❋✤❊ ❑ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊❇✔t✙✇✜❊✺❈❂❍❝❇✜● ❙ ③ ✃ ❲❨▼ ❍❝♠✤❊✚t✉❇✜●❝❯♦❉ ❪✼❑ ③ ✃ ✵ ▲ ✃ ➠ ③ ✃ ✩ ❫ ➡ t✉❇✜● ➱ ✵ P ➄ ✪❋✪❋✪ ➄ ➶ ✳✏P✛❲ ♠✤❊✌●❝❊ ③ ★ ❑ ❋✑r▲❍❝♠✤❊✚t❹❉✤❋✑❈❂❍ ❬ ❇①❋ ❙ ▲ ✃ ✯ ❙ ❑ ●❝❊❛ ❬ ✇✜❊✌❋ ④ ❏ ❇✜●■❊ s ●❝❊✺❈ ❬ ❙ ❊ ❪q▼ ❍■♠✤❊✭t✉❉✤❋✑❈❂❍ ❬ ❇✜❋ ❙ ▲➇❫ ➄ ✪❋✪❋✪ ➄ ▲✓✗ ❯ ❑✔s✙✘✛✚❷❬ ❋❨❍❝❇ ✘✜✚➉❑ ❋✑r♦❍❝♠✤❊ ❪❺❑ ❙ ❍✙❇✜❋✤❊ ▲✓✗ ❜ ❫ ❯ ❑❻s ❙ ✘✛✚❷❬ ❋⑤❍❝❇✘ ④ ❉✤❇①●✆❊ ❑ ❈■♠ ➱ ❖ ❍❝♠✤❊➘✇ ❑ ● ❬✼❑✔❲⑤❪ ❊ ③ ✃ ❬ ❙ ❑ t❹❉✤❋✑❈❂❍ ❬ ❇✜❋✧❇✔t ③ ★ ❖✕③ ✃ ✵ ▼ ✃ ➠ ③ ★ ➡ ④ ❏ ❇✜●❝❊✌❇✔✇✜❊✌● ❪ ❊✌❍✙❉ ❙ ❑ ❙❝❙ ❉✤❯❱❊➘❍❝♠ ❑ ❍ ❑❣❪❴❪ ❍❝♠✤❊ ❙ ❊t✉❉✤❋✑❈❂❍ ❬ ❇✜❋ ❙ ❑ ●■❊✈r ❬ ➑✗❊✌●❝❊✌❋⑤❍ ❬✼❑✔❲⑤❪ ❊ ④♦➊ ❊♦⑩ ❑ ❋❨❍➘❍❝❇❩❈❂❇✜❯ s ❉✤❍❝❊♦❍❝♠✤❊✙✢ ❑ ❈❂❇ ❲⑤❬✼❑ ❋▲❯ ❑ ❍■● ❬ ❦✤✣✖✥✍✦★✧✪✩ ➠ ③ ★ ➡ ❖ ⑩✭♠ ❬ ❈❝♠→❊❢❦ s ●❝❊ ❙■❙ ❊ ❙❍❝♠✤❊ s✑❑ ●❝❍ ❬✼❑❣❪ r⑤❊✌● ❬ ✇ ❑ ❍ ❬ ✇①❊ ❙ ❇✔t ③✖✗ ❜ ❫ ⑩ ❬ ❍❝♠❩●■❊ ❙ s ❊✺❈❂❍✙❍❝❇✚❍❝♠✤❊➷❈❂❇①❯ s ❇✜❋✤❊✌❋⑤❍ ❙ ❇✔t ③ ★ ④ �✓▼ ❍❝♠✤❊➂❈❝♠ ❑❣❬ ❋❩●❝❉ ❪ ❊ ❖ ❍❝♠ ❬ ❙ ❯ ❑ ❍❝● ❬ ❦❬ ❙ ❊❢❦ s ●❝❊ ❙❝❙ ❊✺r ❑ ❙ ❑♦s ●❝❇✤r⑤❉✑❈❂❍➘❇✔t➹❯ ❑ ❍❝● ❬ ❈❂❊ ❙ ❖✣ ✥✍✦★✧✪✩ ➠ ③ ★ ➡ ✵✫✣✖✬ ✦★✧✪✩ ➠ ③✭✗ ➡ ✛✮✣✖✬ ✦ ➠ ③✭✗ ✩ ❫ ➡ ✛✮✯✰✯✰✯❄✛✮✣✖✬ ✩ ➠ ③ ★ ➡ ✪➎ ♠✤❊✚❯ ❑ ❍❝● ❬ ❦✮✣ ✥ ✦★✧✱✩ ➠ ③ ★ ➡✓❬ ❙ ❑ ●❝❇✔⑩✏❯ ❑ ❍❝● ❬ ❦♥❇✔t✢❍ ▼⑤s ❊ P ✛ ❖ ❖ ⑩✭♠ ❬❴❪ ❊♦❍❝♠✤❊❶❯ ❑ ❍❝● ❬ ❈❂❊ ❙ ❬ ❋▲❍❝♠✤❊ s ●❝❇➋r⑤❉✑❈❂❍ ❑ ●❝❊ ❙ ➅①❉ ❑ ●❝❊❯ ❑ ❍■● ❬ ❈❂❊ ❙ ❇✔t➃❍ ▼⑤s ❊❋❖ ✛ ❖↔❊❢❦✑❈❂❊ s ❍➂❍❝♠✤❊ ❪ ❊❂t✉❍❝❯❱❇ ❙ ❍➘❇✜❋✤❊ ❖ ⑩✭♠ ❬ ❈❝♠ ❬ ❙ ❑ ●❝❇✔⑩ ❯ ❑ ❍❝● ❬ ❦ ❇✔t✙❍ ▼❨s ❊ P ✛ ❖ ④②➎ ♠✤❊❶➈✑● ❙ ❍❬ r⑤❊ ❑ ⑩☛♠ ❬ ❈■♠ ❈❂❇①❯❱❊ ❙ ❍■❇②❯ ❬ ❋✑r ❬ ❙ ❍❝♠✤❊➘t❹❇ ❪❫❪ ❇✔⑩ ❬ ❋✤❛ ④✓➊ ❊②❈❂❇①❯ s ❉✤❍❝❊✲✣✖✬ ✩ ➠ ③ ★ ➡➃❑ ❋✑r❭⑩➃❊ ❙ ❍❝❇✜●❝❊ ❬ ❍ ❲ ❋✤❊❢❦✤❍➘⑩➃❊❶❈❂❇①❯ s ❉✤❍❝❊③✣❫✌❖ ❍■♠✤❊✳✢ ❑ ❈❂❇ ❲⑤❬✼❑ ❋❩❯ ❑ ❍❝● ❬ ❦✴✣✖✬ ② ➠ ③✣❫ ➡✢❑ ❋✑r❱❍■♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍✳✣ ✥ ② ➠ ③ ★ ➡ ✵✫✣✖✬ ② ➠ ③✣❫ ➡ ✛✵✣✖✬✶✩ ➠ ③ ★ ➡ ❲ ⑩✙❊ ❙ ❍❝❇✜●❝❊✙❍❝♠ ❬ ❙ s ●❝❇✤r⑤❉✑❈❂❍ ❖⑩✙❊②❈❂❇✜❯ s ❉✤❍❝❊ ③ ⑤ ❖ ❍❝♠✤❊❶❯ ❑ ❍❝● ❬ ❦✤✣✖✬✸✷

➠ ③ ⑤ ➡ ❖ ❍❝♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍✲✣✖✬✍✷➠ ③ ⑤ ➡ ✛✮✣ ✥ ②

➠ ③ ★ ➡✭❑ ❋✑r ❙ ❇❩❇✜❋ ④❘✑ ❍➘❊ ❑ ❈■♠ ❙ ❍❝❊ s ❇✔t✆❍❝♠✤❊❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ❖ ⑩✙❊ ❙ ❍❝❇✜●❝❊ ❑ ❖ ✛ ❖ ❯ ❑ ❍❝● ❬ ❦ ④ ❄ t ❖ ❬ ❙ ❪✼❑ ●❝❛✜❊ ➠ ❑ ✇ ❑❣❪ ❉✤❊✾❇✔t ❑✔❲ ❇✜❉✤❍ P ✘✖✹ ❬ ❙ s ❇ ❙❝❙ ❬q❲⑤❪ ❊ ➡ ❖ ❍❝♠ ❬ ❙ ❯❱❊✌❍❝♠✤❇✤r❬ ❙ ❋✤❇✜❍ s ● ❑ ❈❂❍ ❬ ❈ ❑❣❪ ④➃➛ ❇ ❖ ⑩✙❊ ❑✔s✤s⑤❪q▼❾❑ ❋✤❇✜❍❝♠✤❊✌● ❙ ❍■● ❑ ❍❝❊✌❛ ▼ ④→➊ ❊✧➈✑● ❙ ❍❱❈❂❇✜❯ s ❉✤❍❝❊ ③ ✗ ❑ ❋✑r✶❍❝♠✤❊✺✢ ❑ ❈❂❇ ❲⑤❬✼❑ ❋➍❯ ❑ ❍❝● ❬ ❦✣✖✬ ✦★✧✪✩ ➠ ③✖✗ ➡ ❲ ⑩✙❊ ❙ ❍❝❇①●❝❊ ❬ ❍ ❲ ❋✤❊❢❦✤❍✾⑩✙❊❱❈❂❇✜❯ s ❉✤❍■❊ ③✖✗ ✩ ❫ ❑ ❋✑r❷❍❝♠✤❊✵✢ ❑ ❈❂❇ ❲⑤❬✼❑ ❋▲❯ ❑ ❍■● ❬ ❦✮✣✖✬ ✦ ➠ ③✭✗ ✩ ❫ ➡ ❲ ⑩✙❊②❈❂❇①❯ s ❉✤❍❝❊♦❍❝♠✤❊s ●❝❇✤r⑤❉✑❈❂❍✴✣✖✬✍✦★✧✪✩ ➠ ③✖✗ ➡ ✛✻✣✖✬✸✦ ➠ ③✖✗ ✩ ❫ ➡❶❑ ❋✑r✶⑩✙❊ ❙ ❍❝❇✜●❝❊ ❬ ❍ ❖ ❑ ❋✑r ❙ ❇▲❇✜❋ ④➉➎ ♠✤❊❩❛ ❑❣❬ ❋➍❇✔t ❙ ❍❝❇✜● ❑ ❛①❊ ❬ ❙ ❊✌✇ ❬ r⑤❊✌❋⑤❍✂✥❩❊ ❑ ❈■♠❍ ❬ ❯❱❊❱⑩✙❊ ❙ ❍❝❇①●❝❊ ❑ P ✛ ❖ ❯ ❑ ❍❝● ❬ ❦ ❬ ❋ s⑤❪✼❑ ❈❂❊❱❇✔t ❑ ❖ ✛ ❖↔❯ ❑ ❍❝● ❬ ❦ ④ � ❉✤❍✚❍❝♠✤❊✌●❝❊ ❬ ❙ ❑ ⑩ ❑ ❙ ❍❝❊✚❇✔t➃❍ ❬ ❯❳❊ ❲ ❊✺❈ ❑ ❉ ❙ ❊⑩✙❊②❈❂❇✜❯ s ❉✤❍❝❊ ❑ ❛ ❑❣❬ ❋ ❑ ❋✑r ❑ ❛ ❑❣❬ ❋♥❍❝♠✤❊✚✇ ❑❣❪ ❉✤❊ ❙ ③✣❫ ➄ ✪❅✪❋✪ ➄ ③✭✗❨④☛➇ ❲ ✇ ❬ ❇✜❉ ❙ ❪q▼ ❖ ⑩➃❊❶❈❂❇①❉ ❪ r ❙ ❍■❇✜●❝❊➂❍❝♠✤❊ ❙ ❊✚✇ ❑❣❪ ❉✤❊ ❙ ❲ ❉✤❍➘❍❝♠✤❊❑ ✇ ❑❣❬❴❪✼❑✔❲⑤❪ ❊♦❯❱❊✌❯❱❇✜● ▼ ♠ ❑ ❙ ❑➂❪❴❬ ❯ ❬ ❍❝❊✺r ❙ ❬q♣ ❊ ④➎ ♠✤❊ s ●❝❇ ❲⑤❪ ❊✌❯ ❇✔t♦●❝❊✌✇✜❊✌● ❙ ❬ ❋✤❛➍❍❝♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③ ★ ➄ ③✣❫ ➄ ✪❋✪❅✪ ➄ ③✭✗ ❯ ❑❣▼❾❲ ❊➌❋✤❇✔⑩ t❹❇✜●■❯②❉ ❪✼❑ ❍■❊✺r ④ ➊ ❊→⑩ ❑ ❋❨❍ ❑ ❋❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ ⑩✭♠ ❬ ❈■♠ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍■♠✤❊❱✇ ❑❣❪ ❉✤❊ ❙ ③✭✗ ➄ ③✖✗ ✩ ❫ ➄ ✪❋✪❅✪ ➄ ③ ❫ ❬ ❋✶❍❝♠ ❬ ❙ ❇✜●❧r⑤❊✌● ❑ ❋✑r✶❈❂❇ ❙ ❍ ❙ ❍❝♠✤❊❱❯ ❬ ❋ ❬ ❯ ❑❣❪✾❑ ❯❱❇①❉✤❋❨❍❇✔t✾❍ ❬ ❯❳❊ ❖ ✭❨❋✤❇✔⑩ ❬ ❋✤❛▲❍❝♠ ❑ ❍✚❊ ❑ ❈■♠ ❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ③ ✃ ✵ ▲ ✃ ➠ ③ ✃ ✩ ❫ ➡ ❍ ❑ ✭✜❊ ❙ ❇✜❋✤❊✧❉✤❋ ❬ ❍❱❇✔t✾❍ ❬ ❯❳❊ ❑ ❋✑r→❇✜❋ ❪q▼ ⑥ ✇ ❑➁❪ ❉✤❊ ❙❯ ❑❣▼❩❲ ❊ ❙ ❍■❇✜●❝❊✺r ❑ ❍ ❑ ❍ ❬ ❯❱❊ ④✴➛ ❉✑❈❝♠ ❑ ❋ ❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝♠✤❊♦✇ ❑➁❪ ❉✤❊ ③ ✃ ❇✜❋ ❪q▼▲❲❨▼ ❈❂❇①❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋❷t✉●❝❇✜❯ ❍❝♠✤❊s ●❝❊✌✇ ❬ ❇✜❉ ❙ ✇ ❑❣❪ ❉✤❊ ③ ✃ ✩ ❫ ❇✜● ❲❨▼ ●❝❊✌❍■● ❬ ❊✌✇ ❑❣❪ t❹●■❇✜❯✏❯❱❊✌❯❱❇①● ▼ ④✌➛ ❊✌✇✜❊✌● ❑❣❪➏❑ ❉✤❍❝♠✤❇✜● ❙ ♠ ❑ ✇✜❊ ❑ r✤r⑤●❝❊ ❙❝❙ ❊✺r✚❍❝♠ ❬ ❙ s ●❝❇ ❲⑤❪ ❊✌❯ ④ �✙❑ ❉✤●❑ ❋✑r ➛ ❍❝● ❑ ❙❝❙ ❊✌❋ ❘ ◆ ❜✳❉ ❙ ❊✺r❷❍❝♠✤❊ ❬ r⑤❊ ❑ ⑩✙❊ s ●❝❊ ❙ ❊✌❋⑤❍❝❊✺r ❑ ❙ ❑ ❋ ❬ ❋❨❍■●❝❇➋r⑤❉✑❈❂❍ ❬ ❇①❋ ❍■❇ ❙ ❍■❉✑r ▼ ❍❝♠✤❊❱❈❂❇✜❯ s⑤❪ ❊❢❦ ❬ ❍ ▼ ❇❻t s✑❑ ●❝❍ ❬✼❑❣❪r⑤❊✌● ❬ ✇ ❑ ❍ ❬ ✇✜❊ ❙ ④✉✑ ❲✤❲ ❇✜❍ ❑ ❋✑r ➬ ❑❣❪❴❪❴❬ ❛①❇ ❘ P ❜⑤❛ ❑ ✇✜❊ ❑ ❋♦❇ s ❍ ❬ ❯ ❑❣❪❴❬ ❍ ▼ ●❝❊ ❙ ❉ ❪ ❍ ❬ ❋♦❍❝♠✤❊✓t❹● ❑ ❯❱❊✌⑩✙❇✜●✮✭➂❇✔t✠r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇✜❋✑➅①❉✤❊✌●❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ ❙ ✥➘t✉❇✜● ❙ ❉✑❈❝♠ ❑ ❋ ❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❖ ❇✜❋✤❊❩❈❝♠✤❇⑤❇ ❙ ❊ ❙ ❑ ❋ ❬ ❋✑r⑤❊❢❦❀✿ ❲ ❊✌❍❆⑩✙❊✌❊✌❋ P ❑ ❋✑r❩➶ ❖ ❇✜❋✤❊✱r⑤❊ ❑❣❪ ❙ ➈✑● ❙ ❍✚⑩ ❬ ❍❝♠❍❝♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③☛❁ ➄ ✪❋✪❅✪ ➄ ③✭✗✜❖ ❑ ❋✑r ❋✤❊❢❦➋❍✚⑩ ❬ ❍❝♠➌❍❝♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③✣❫ ➄ ✪❅✪❋✪ ➄ ③☎❁ ✩ ❫❂④❩➬ ● ❬ ❯❳❯ ❖ ✓ ❇✜❍■❍ ❬ ❊✌● ❑ ❋✑r ✖ ❇ ❙ ❍ ❑❣❬ ❋✤❛✖✼➛ ❈■♠✤❯ ❬ r⑤❍ ❘❚⑧ ❜✢❈❂❇✜❋ ❙ ❬ r⑤❊✌●❝❊✺r ❑❣❪❴❪ ❍❝♠✤❊ ❑❣❪ ❛✜❇①● ❬ ❍❝♠✤❯ ❙ ❑ ❋✑r ❙ ♠✤❇✔⑩➃❊✺r❭❍❝♠ ❑ ❍ ❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❙ ❇✔t➃r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇✜❋✑➅①❉✤❊✌●❱❍ ▼⑤s ❊s ●❝❇✔✇ ❬ r⑤❊➂❍■♠✤❊➂❇ s ❍ ❬ ❯ ❑❣❪ ❍ ❬ ❯❳❊➂❇✔t➹❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ❚ ④ ❄ ❋ s ● ❑ ❈❂❍ ❬ ❈❂❊ ❖ ❬ ❍ ❬ ❙ ❋✤❊✺❈❂❊ ❙❝❙ ❑ ● ▼ ❍❝❇✈➈✑❋✑r ❑ ❍❝● ❑ r⑤❊✽✼✉❇❻➑ ❲ ❊✌❍➄⑩✙❊✌❊✌❋⑥ ❖ ❍❝♠✤❊✙❋⑤❉✤❯ ❲ ❊✌●✆❇❻t ●■❊✌❛ ❬ ❙ ❍❝❊✌● ❙ ❖ ❑ ❋✑r ❚ ❖ ❍■♠✤❊✭❋❨❉✤❯ ❲ ❊✌●✆❇✔t✗❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇①❋ ❙ ❖ ♠✤❊✌❋✑❈❂❊✭❍■♠✤❊ ❬ ❯ s ❇✜●■❍ ❑ ❋⑤❍✆➅✜❉ ❑ ❋⑤❍ ❬ ❍ ▼✚❬ ❙ ❍❝♠✤❊s ●❝❇✤r⑤❉✑❈❂❍ ⑥ ❚ ④➘➬ ● ❬ ❯❱❯ ❖ ✓ ❇✜❍❝❍ ❬ ❊✌● ❑ ❋✑r ✖ ❇ ❙ ❍ ❑❣❬ ❋✤❛✖✼ ➛ ❈■♠✤❯ ❬ r⑤❍➂❛ ❑ ✇✜❊ ❑✚❪ ❇✔⑩✙❊✌● ❲ ❇✜❉✤❋✑r❭t❹❇①●✭❍❝♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍ ➠➅⑥ ✳❀P ➡ ❚ ❖⑩✭♠ ❬ ❈■♠ ❬ ❙ ● ❑ ❍❝♠✤❊✌●✙❍ ❬ ❛✜♠⑤❍ ❑ ❋✑r ❙ ♠✤❇➁⑩ ❙ ❍■♠ ❑ ❍✭❍❝♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍ ⑥ ❚ ♠ ❑ ❙ ❇✜●❧r⑤❊✌●✆➶ ❪ ❋ ⑤ ➶ ④

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� ➛ ✓ ✁✆☎ ✵ ➠ ✘ ➄❧◆ ➄ ⑧ ➄ ☛ ➡✖ ✁✆✝ ✵ ➠ ✘ ➄❧◆ ➄ ⑧ ➡✖ ✁ ⑤ ✵ ➠ ✘ ➄❧◆➋➡✓ ✁ ❫ ✵ ➠ ✘ ➄ P ➡✞ ✟☛✡ ☞✦✍✣✏ ✒✕✔ ➎ ♠✤❊➓r ❬✼❑ ❛①● ❑ ❯ ❙ ♠✤❇✔⑩✶❍❝♠✤❊✙●❝❊✌✇✜❊✌● ❙ ❬ ❋✤❛➂❇✔t ❑ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③ ★ ➄ ✪❋✪❅✪ ➄ ③ ✹ ⑩ ❬ ❍❝♠ ⑧ ●❝❊✌❛ ❬ ❙ ❍❝❊✌● ❙ ④✂ ❇ ❪ ❉✤❯❱❋ ✺ ❈❂❇✜●❝●❝❊ ❙ s ❇✜❋✑r ❙ ❍❝❇✱❍■❊✌●❝❯ ③ ✽ t✉❇✜● ✺ ✵ P ➄ ✪❅✪❋✪ ➄ ➤ ④♦➎ ♠✤❊ ❙ ▼ ❯ ❲ ❇ ❪ � ❯❱❊ ❑ ❋ ❙ ❍❝♠ ❑ ❍➘❍❝♠✤❊✇ ❑❣❪ ❉✤❊ ❬ ❙ ❈❂❇✜❯ s ❉✤❍■❊✺r ❲ ❉✤❍➘❋✤❇✜❍ ❙ ❍❝❇✜●■❊✺r ❲ ❍❝♠✤❊ ❙ ▼ ❯ ❲ ❇ ❪ ➛ ❯❳❊ ❑ ❋ ❙ ❍■♠ ❑ ❍✾❍■♠✤❊②✇ ❑❣❪ ❉✤❊ ❬ ❙ ❈❂❇①❯ s ❉✤❍❝❊✺r❑ ❋✑r ❙ ❍■❇✜●❝❊✺r ❲ ✓ ❯❱❊ ❑ ❋ ❙ ❍❝♠✤❊❩✇ ❑➁❪ ❉✤❊ ❙ ❬ ❙ ❈ ❑❣❪ ❈❂❉ ❪✼❑ ❍❝❊✺r ❖ s ● ❬ ❋⑤❍❝❊✺r ❑ ❋✑r➍❍❝♠✤❊✌❋✰❍❝♠✤●❝❇✔⑩✭❋ ❑ ⑩ ❑❣▼ ❲ ✖❯❱❊ ❑ ❋ ❙ ❍❝♠✤❊♥✇ ❑❣❪ ❉✤❊ ❬ ❙ ●❝❊✌❍❝● ❬ ❊✌✇✜❊✺r t❹●■❇✜❯ ❯❱❊✌❯❱❇①● ▼ ❖ s ● ❬ ❋⑤❍❝❊✺r ❑ ❋✑r✶❍❝♠✤❊✌❋✰❍❝♠✤●❝❇✔⑩✭❋ ❑ ⑩ ❑❣▼ ④❾➎ ♠✤❊❪❫❬ ❙ ❍ ✁ ✽ ❛ ❬ ✇✜❊ ❙ ❍❝♠✤❊ ❬ ❋✑r ❬ ❈❂❊ ❙ ✖♥❇❻t➃❍❝♠✤❊♦✇ ❑➁❪ ❉✤❊ ❙ ③✮❵ ⑩☛♠ ❬ ❈■♠ ❑ ●❝❊ ❙ ❍❝❇①●❝❊✺r ✄ ❉ ❙ ❍ ❲ ❊❂t❹❇①●❝❊♦❍❝❊✌●❝❯ ③ ✽ ❬ ❙s ● ❬ ❋❨❍❝❊✺r ④✙➎ ♠✤❊✚❍❝❇✜❍ ❑❣❪ ❋❨❉✤❯ ❲ ❊✌●✾❇✔t ❙ ▼ ❯ ❲ ❇ ❪ ❙ � ❖✣➛ ❇①● ✓➍s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝♠✤❊➂❍ ❬ ❯❳❊❶❇✔t➹❈❂❇①❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ④❞✑➦✟✞✙❄✡✠✐❤ ❥P❆✺➲❺➨✗❢➃❆✌➨☛✠✳➲✌☞✳➲✍✠✎❄✏✎➄➭★❢✑✠✑✎❝❥✔➨❦❢✓✒➹❤✑❄✤➩❩➭✑➯✕✔✑➨★➩➁➲ ❆✞✝✳➫ ➳

➎ ♠✤❊ ❙ ❊ ❑ ●❧❈■♠▲t❹❇①● ❑ ❋➌❇ s ❍ ❬ ❯ ❑➁❪➃❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯↔❋✤❊✌❊✺r ❙ ❑ ❈ ❑ ●❝❊❂t❹❉ ❪ r⑤❊❂➈✑❋ ❬ ❍ ❬ ❇✜❋➍❇❻t➓⑩☛♠ ❑ ❍ ❬ ❙ ❑ ❋ ❑➁❪ ❛①❇✜● ❬ ❍❝♠✤❯ ❬ ❋✶❍❝♠ ❬ ❙❈❂❇✜❋⑤❍❝❊❢❦✤❍ ④✢➎ ♠✤❊➂t✉❇ ❪❴❪ ❇➁⑩ ❬ ❋✤❛❩r⑤❊❂➈✑❋ ❬ ❍ ❬ ❇✜❋ ❬ ❙ s ●❝❇ s ❇ ❙ ❊✺r ④✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜ P ✔ ✑ ●❝❊✌✇✜❊✌● ❙ ❑➁❪ ❍ ❑✔❲⑤❪ ❊♥❇✔t✾❍■♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③ ★ ➄ ✪❅✪❋✪ ➄ ③ ✗ ⑩ ❬ ❍❝♠ ⑥ ●❝❊✌❛ ❬ ❙ ❍❝❊✌● ❙ ❬ ❙ ❑ t ❑ ❯ ❬❴❪⑦▼ ➠ ✁ ✃ ❖ ✽ ➡ ❖✘ ❰ ➱ ❰ ⑥ ✽ ❖ ✘ ❰ ✺ ❰➌➶ ❖ ❙ ❉✑❈❝♠❷❍❝♠ ❑ ❍✖ ✁ ✃ ❖ ✽ ❨ ✁ ✃ ❜ ❫ ❖ ✽ t✉❇✜● ✘ ❰ ➱ ❨ ⑥ ✽ ❖ ✘ ❰ ✺ ❰➌➶ ❲✖ ✁ ★ ❖ ✽ ✵ ✘ ❑ ❋✑r ✁✆✗✙✘ ❖ ✽ ✵ ✺ t✉❇✜● ✘ ❰ ✺ ❰➌➶ ❲✖ ⑥ ✽ ❰ ⑥ t❹❇✜● ✘ ❰ ✺ ❰→➶ ④➎ ♠✤❊❶r⑤❊❂➈✑❋ ❬ ❍ ❬ ❇✜❋▲❯♦❉ ❙ ❍ ❲ ❊✚❉✤❋✑r⑤❊✌● ❙ ❍❝❇⑤❇➋r ❬ ❋❷❍❝♠✤❊➘t❹❇ ❪❫❪ ❇✔⑩ ❬ ❋✤❛✧❯ ❑ ❋✤❋✤❊✌● ④✆➎ ♠✤❊ ❪❫❬ ❙ ❍ ✁ ✽ ✵ ➠ ✁ ✃ ❖ ✽ ➡ ★ ✫ ✃ ✫ ✗ ✘ s ●❝❇✔✇ ❬ r⑤❊ ❙❍❝♠✤❊✚✇ ❑❣❪ ❉✤❊ ❙ ③✮❵ ⑩✭♠ ❬ ❈❝♠ ❑ ●❝❊ ❙ ❍❝❇✜●❝❊✺r ✄ ❉ ❙ ❍ ❲ ❊❂t❹❇①●❝❊❶❍❝♠✤❊✚✇ ❑❣❪ ❉✤❊ ③ ✽ ❬ ❙ s ● ❬ ❋⑤❍❝❊✺r ④ ❏ ❇✜●❝❊ s ●❝❊✺❈ ❬ ❙ ❊ ❪q▼ ❍❝♠✤❊ ❪❴❬ ❙ ❍❶❈❂❇✜❋⑤❍ ❑❣❬ ❋ ❙❍❝♠✤❊ ❬ ❋✑r ❬ ❈❂❊ ❙ ✖ ❑ ●■● ❑ ❋✤❛✜❊✺r ❬ ❋ ❬ ❋✑❈❂●❝❊ ❑ ❙ ❬ ❋✤❛❱❇✜●❂r⑤❊✌● ④➜➛ ❊✌❊ ❉ ❬ ❛✜❉✤●❝❊ P t✉❇✜● ❑ ❋✱❊❢❦ ❑ ❯ s⑤❪ ❊ ④ ❅ ❇✜❍ ❬ ❈❂❊➘❍❝♠ ❑ ❍✓❍❝♠✤❊✾✇ ❑❣❪ ❉✤❊ ③ ★ ❬ ❙❙ ❍❝❇①●❝❊✺r❳t❹❇①●✙t❹●■❊✌❊ ❲ ❊✺❈ ❑ ❉ ❙ ❊❶❍❝♠✤❊✚●❝❊✌❛ ❬ ❙ ❍❝❊✌●☛❉ ❙ ❊✺r ❬ ❙ ❋✤❇✜❍✭❍ ❑ ✭①❊✌❋ ❬ ❋⑤❍❝❇ ❑ ❈✌❈❂❇✜❉✤❋⑤❍ ❲ ❬ ❋❩t ❑ ❈❂❍✭❍■♠✤❊✌●❝❊ ❑ ●■❊ ⑥ ✳❀P ●❝❊✌❛ ❬ ❙ ❍■❊✌● ❙❉ ❙ ❊✺r ④➎ ❇❱❊ ❑ ❈■♠❩●❝❊✌✇✜❊✌● ❙ ❑➁❪ ❍ ❑✔❲⑤❪ ❊ ✁ ✵ ➠ ✁ ✃ ❖ ✽ ➡✐❬ ❙ ❑ ❙❝❙ ❇➋❈ ❬✼❑ ❍❝❊✺r ❬ ❍ ❙ ❍ ❬ ❯❱❊❶❇✔t✆❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋③✛✚ ✵ ✜

★ ✫ ✃ ✫ ✗ ✘★ ✫ ✽ ✫✱✗③ ✃ ❖ ✽ ➄ ⑩ ❬ ❍❝♠ ③ ✃ ❖ ✽ ✵ ✁ ✃ ❖ ✽ ❝✣✢ ✃ ❖ ✽ ➄

⑩✭♠✤❊✌●❝❊ ✢ ✃ ❖ ✽ ❬ ❙ ❍❝♠✤❊❳❯ ❑ ❦ ❬ ❯ ❑❣❪✆❬ ❋✑r⑤❊❢❦➍❇✔t ❙ ❍❝❇✜●❝❊✺r ✇ ❑❣❪ ❉✤❊ ❙ ❪ ❊ ❙❝❙ ❍❝♠ ❑ ❋ ✁ ✃ ❖ ✽ ④❩❐ ❬ ❋✤❊ ◗ ❇❻t✺❉ ❬ ❛✜❉✤●■❊ P s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝♠✤❊t✉❇ ❪❴❪ ❇✔⑩ ❬ ❋✤❛✧✇ ❑❣❪ ❉✤❊ ❙ ✥ ③ ☎ ❖ ⑤ ✵ ◆♦❲ ❊✺❈ ❑ ❉ ❙ ❊✚❍❝♠✤❊➂✇ ❑❣❪ ❉✤❊ ③ ⑤ ❯ ❑❣▼❱❲ ❊❶❇ ❲ ❍ ❑➁❬ ❋✤❊✺r ❑ ❍✭❍❝♠ ❬❙ ❍ ❬ ❯❳❊❶❇✜❋ ❪q▼ t✉●❝❇✜❯ ③ ★ ❲✤③ ☎ ❖ ✝ ✵ ✘

❲ ❊✺❈ ❑ ❉ ❙ ❊ ③ ✝✚❬ ❙ ❑ ✇ ❑❣❬❴❪✼❑✔❲⑤❪ ❊❩t✉●❝❇✜❯ ❯❳❊✌❯❱❇✜● ▼ ❖ ❑ ❋✑r ③ ☎ ❖ ☎ ✵ P ❲ ❊✺❈ ❑ ❉ ❙ ❊ ③ ☎ ❯♦❉ ❙ ❍ ❲ ❊❩❈❂❇✜❯ s ❉✤❍❝❊✺r t❹●■❇✜❯ ③ ✝ ④▲➎ ♠✤❊❛✜❇ ❑➁❪✗❬ ❙ ❍❝❇❳➈✑❋✑r ❑ ●❝❊✌✇✜❊✌● ❙ ❑➁❪ ❍ ❑✔❲⑤❪ ❊ ✁ ⑩✭♠ ❬ ❈■♠ s ●❝❇✔✇ ❬ r⑤❊ ❙ ❍❝♠✤❊♦❯ ❬ ❋ ❬ ❯ ❑❣❪ ❍ ❬ ❯❳❊②❇❻t➓❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ③✤✚➂④❶➎ ♠✤❊♦❯ ❑❣❬ ❋❍❝♠✤❊✌❇✜●■❊✌❯ ❬ ❙✾❙ ❍ ❑ ❍❝❊✺r ❑ ❙ t✉❇ ❪❴❪ ❇✔⑩ ❙ ④⑨❶⑩✎✏✻✧✌✍✣✏✕❷ P ✔ ➔ ❾ ✭❅✰❡✭❶✭✐❽ ➀ ➺ ♠ ➺❶➸✜➾✲❤ ❧✑♠✉➀ ♣♦➸ ❼ ✰❡✭❋✯❅✭❋✰■➺ ➸ ❼✦♠ ➸✻✁ ❼ ✭ ❿➄❾❨➀✸➻✐❾♥➀ ➺❶❤❡❈✕✁ ➀ ✯ ➀ ✁✛✭✐➍➄➸✜➾✆✁ ➍ ➻ ❤✜➾✆✹❣➆✻✭❅✰ ♠✢♦q❧ ✭✔➚➊ ❊ ❙ ❑❣▼ ❍❝♠ ❑ ❍ ❑ ●■❊✌✇✜❊✌● ❙ ❑❣❪ ❍ ❑✔❲⑤❪ ❊ ➠ ✁ ✃ ❖ ✽ ➡✆❬ ❙ ❇✔t➃r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇①❋✑➅✜❉✤❊✌●✚❍ ▼⑤s ❊ ❬ t➃❍❝♠✤❊✌●❝❊✚❊❢❦ ❬ ❙ ❍ ❙ ❑ ❋ ❬ ❋✑r⑤❊❢❦ ✿ ❙ ❉✑❈■♠❍❝♠ ❑ ❍ ✁ ❫ ❖ ✗ ✵ ✁ ❫ ❖ ✗ ✩ ❫ ✵ ✯✰✯✕✯P✵ ✁ ❫ ❖ ❁ ✵ ✿ ✪➎ ♠ ❬ ❙ ❯❳❊ ❑ ❋ ❙ ❍■♠ ❑ ❍➂❍❝♠✤❊ ❑❣❪ ❛✜❇✜● ❬ ❍❝♠✤❯ ❈❂❇①❯ s ❉✤❍❝❊ ❙ ❍❝♠✤❊♦✇ ❑➁❪ ❉✤❊ ③☛❁✌❖ ♠ ❑ ❋✑r ❪ ❊ ❙ ❍❝♠✤❊ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊ ③☛❁ ➄ ③☛❁ ❜ ❫ ➄ ✪❋✪❅✪ ➄ ③✖✗⑤❖ ❑ ❋✑r❋✤❊❢❦✤❍✭❍❝♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ③ ★ ➄ ✪❋✪❅✪ ➄ ③☛❁ ✩ ❫❧④

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Page 118: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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� ➛ ➛ ✓✖✖✓✞ ✟☛✡ ☞✦✍✣✏✁�✑✔ ➎ ♠✤❊➃r ❬✼❑ ❛✜● ❑ ❯ ❙ ♠✤❇✔⑩ ❙ ❑ r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇✜❋✑➅①❉✤❊✌●✙❇ s ❍ ❬ ❯ ❑❣❪ ●❝❊✌✇✜❊✌● ❙ ❬ ❋✤❛➘❇✔t ❑ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊❇✔t ❪ ❊✌❋✤❛✜❍■♠✱➶ ✵ P ✘ ❉ ❙ ❬ ❋✤❛ ⑥ ✵ ⑧ ●❝❊✌❛ ❬ ❙ ❍❝❊✌● ❙ ④✆➎ ♠✤❊❶❍ ❬ ❯❱❊➂❇✔t✆❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋ ❬ ❙ ❚ ✵ P ❲ ④

➥★➦✄✂☎✟✦❆✺➲✦➫ ➭✑➯ ❆✺➲✉➫✲❄➎ ♠✤❊ s ●❝❊✌✇ ❬ ❇✜❉ ❙ ●■❊ ❙ ❉ ❪ ❍➔●❝❊✺r⑤❉✑❈❂❊ ❙ ❍■♠✤❊ ❙ ❊ ❑ ●❂❈❝♠➽t❹❇✜● ❑ ❋❶❇ s ❍ ❬ ❯ ❑❣❪➋❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ ❍❝❇➘❍❝♠✤❊✙❈❂❇✜❋ ❙ ❬ r⑤❊✌● ❑ ❍ ❬ ❇✜❋♦❇✔t ❑❣❪ ❛✜❇✜● ❬ ❍■♠✤❯ ❙❇✔t✆r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇✜❋✑➅①❉✤❊✌●❶❍ ▼⑤s ❊ ④⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ◆✮✔ ➔ ❾ ✭ ♠✉➀ ♣❑✭✙❤❡❈❱➸✜➾ ♦ ❤ ❧✑♠✉➀ ♣②➸ ❼ ✰➅✭❅✯❋✭❅✰❝➺✌➸ ❼✦♠ ➸✻✁ ❼ ✭✙❤❡❈②➸✧➺✐✭✵✹✺➆ ✭✺➾ ➻ ✭ ③ ★ ➄ ✪❋✪❅✪ ➄ ③✭✗ ❿✢➀☛♠☛❾ ⑥ ✰❡✭❡➎ ➀ ➺ ♠ ✭❅✰❝➺ ➀ ➺➎ ➀ ✯❋✭❣➾ ✁ ♦

❚ ➠ ➶ ➄ ⑥ ➡ ✵✷✖ ➠ ➶ ✳❾P ➡ ❝ ☎ ⑥ ✳ ✖⑥ ✳❾P✝✆ ➄❿➄❾ ✭❅✰➅✭ ✖✶➀ ➺❶➸✜➾ ♦❱➀ ➾ ♠ ✭❡➎✛✭❅✰ ❿➄❾⑤➀✼➻❿❾ ➺ ➸ ♠✉➀ ➺ ✄ ✭✌➺☎ ⑥ ✳ ✖ ❝✰P⑥ ✆ ❝➍P ❰➌➶❷❰

☎ ⑥ ✳ ✖⑥ ✆ ❝✰P ✪❳ ❤➇✰➅✭❢❤✛✯❅✭❋✰➂➸➋✰➅✭❅✯❋✭❅✰❝➺✌➸ ❼✦♠ ➸✻✁ ❼ ✭■❤❉❈✕✁ ➀ ✯ ➀ ✁➇✭✐➍❆➸①➾✆✁P➍ ➻ ❤✜➾✝✹✺➆ ✭❋✰ ♠✢♦❸❧ ✭ ➀ ➺❶❤ ❧✣♠✉➀ ♣♦➸ ❼✳➀ ❈❶➸①➾✆✁➋❤✜➾ ❼✸♦❱➀ ❈ ➀♥♠ ➺ ➀ ➾✆✁➇✭✐❽ ✿ ➺✌➸ ♠✉➀ ➺ ✄ ✭➪➺☎ ⑥ ✳ ✖ ❝ ◆⑥ ✆ ❰ ✿♦❰

☎ ⑥ ✳ ✖ ❝✰P⑥ ✆ ➄ ➸✜➾✝✁ ☎ ⑥ ✳ ✖ ❝➍P⑥ ❝❾P ✆ ❝➍P ❰➌➶ ❝ ✿♦❰☎ ⑥ ✳ ✖ ❝➍P⑥ ❝➍P ✆ ❝➍P ✪

➎ ♠✤❊❳➈✑● ❙ ❍ s✑❑ ●❝❍✚❇✔t✭❍❝♠✤❊ ❑ ❙❝❙ ❊✌●❝❍ ❬ ❇①❋ ❑✔s✤s ❊ ❑ ● ❙ ❬ ❋ ❘ P ❜ ④▲➎ ♠✤❊ s ●■❇❨❇✔t➘❉ ❙ ❊ ❙ ❑ ❋ ❑ ❉ ❦ ❬❴❪❴❬✼❑ ● ▼ t❹❉✤❋✑❈❂❍ ❬ ❇✜❋✙❖ ✗ ❖ ✞ ❲ ❍❝♠ ❬ ❙t✉❉✤❋✑❈❂❍ ❬ ❇✜❋▲❛ ❬ ✇✜❊ ❙ ❍❝♠✤❊❶❯ ❑ ❦ ❬ ❯ ❑➁❪➔❪ ❊✌❋✤❛✜❍❝♠▲❇✔t ❑ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊♦⑩✭♠ ❬ ❈■♠➉❈ ❑ ❋ ❲ ❊ ❬ ❋⑤✇✜❊✌●❝❍■❊✺r♥❉ ❙ ❬ ❋✤❛❩❇①❋ ❪⑦▼ ⑥ ●❝❊✌❛ ❬ ❙ ❍■❊✌● ❙ ❑ ❋✑r❈❂❇✜❯ s ❉✤❍ ❬ ❋✤❛❳❇✜❋ ❪q▼ ✦➽❍ ❬ ❯❱❊ ❙ ❊ ❑ ❈■♠✱✇ ❑❣❪ ❉✤❊ ③✷❵ ❬ ❋❩❍■♠✤❊➂⑩➃❇①● ❙ ❍➃❈ ❑ ❙ ❊ ④✆➎ ♠✤❊ s ●❝❇⑤❇✔t➔❇❻t➔❍❝♠✤❊ ❙ ❊✺❈❂❇✜❋✑r s✑❑ ●❝❍✙●❝❊ ❪❴❬ ❊ ❙ ❇✜❋❩❍❝♠✤❊❈❂❇✜❋ ❙ ❬ r⑤❊✌● ❑ ❍ ❬ ❇✜❋♥❇✔t ▲ ➠ ✿ ➡ ✵ ✿ ✳ ❚ ➠ ✿ ❝❾P ➄ ⑥ ➡ ✳ ❚ ➠ ➶ ❝ ✿ ➄ ⑥ ❝✰P ➡ ✪➎ ♠ ❬ ❙ t✉❉✤❋✑❈❂❍ ❬ ❇✜❋♥❇❻t➔❍❝♠✤❊➂●❝❊ ❑❣❪ ✇ ❑ ● ❬✼❑✔❲⑤❪ ❊✲✿ ❑ ❈■♠ ❬ ❊✌✇✜❊ ❙ ❬ ❍ ❙ ❯ ❬ ❋ ❬ ❯♦❉✤❯ ❇✜❋❩❍❝♠✤❊ ❬ ❋❨❍❝❊✌●■✇ ❑❣❪ ❛ ❬ ✇①❊✌❋ ❬ ❋❩❍❝♠✤❊➂❍❝♠✤❊✌❇✜●■❊✌❯ ❑ ❋✑r❍❝♠ ❬ ❙ ❯ ❬ ❋ ❬ ❯♦❉✤❯ ❬ ❙ ❚ ➠ ➶ ➄ ⑥ ➡ ④➹➎ ♠ ❬ ❙ ❛ ❬ ✇✜❊ ❙ ❑ t✉❉✤❋✑❈❂❍ ❬ ❇✜❋ ❑❣❪ ❊✺➅✜❉ ❑ ❍ ❬ ❇①❋❩t✉❇✜● ❚ ➠ ➶ ➄ ⑥ ➡ ❖ ⑩☛♠ ❬ ❈■♠▲❍❝● ❑ ❋ ❙ ❪❺❑ ❍❝❊ ❙ ❊❢❦ ❑ ❈❂❍ ❪q▼ ❍❝♠✤❊r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇①❋✑➅✜❉✤❊✌● ❙ ❍❝● ❑ ❍■❊✌❛ ▼ ④❄ ❍☛❯②❉ ❙ ❍ ❲ ❊♦❋✤❇✜❍❝❊✺r✧❍■♠ ❑ ❍✙t✉❇✜● ❑ r ❬ ✇ ❬ r⑤❊✽✼ ❑ ❋✑r✾✼✖❈❂❇✜❋✑➅✜❉✤❊✌●♦❇ s ❍ ❬ ❯ ❑❣❪ ●❝❊✌✇✜❊✌● ❙ ❑❣❪ ❍ ❑✔❲⑤❪ ❊❶❍■♠✤❊❶❋⑤❉✤❯ ❲ ❊✌● ⑥ ❇✔t✢●❝❊✌❛ ❬ ❙ ❍■❊✌● ❙❬ ❙ ❊❢❦ ❑ ❈❂❍ ❪q▼ ❍■♠✤❊➂❯ ❑ ❦ ❬ ❯ ❑❣❪ ❋❨❉✤❯ ❲ ❊✌●☛❇✔t➹❍ ❬ ❯❳❊ ❙ ❑ ❍❝❊✌●❝❯ ❇✔t✢❍❝♠✤❊ ❙ ❊✺➅✜❉✤❊✌❋✑❈❂❊ ❬ ❙ ❈❂❇✜❯ s ❉✤❍■❊✺r ④✙➇ ❋✤❊❶❈ ❑ ❋❩❇ ❲ ❙ ❊✌●■✇✜❊➂❍❝♠ ❬ ❙s ♠✤❊✌❋✤❇✜❯❱❊✌❋✤❇①❋ ❬ ❋▲❍❝♠✤❊➂❊❢❦ ❑ ❯ s⑤❪ ❊❶❇✔t☛❉ ❬ ❛✜❉✤●❝❊ ◆ ❖ ⑩✭♠✤❊✌●❝❊➂❍❝♠✤❊✚❍❝❊✌●❝❯ ❙ ③✣❫ ➄ ✪❋✪❋✪ ➄ ③✣❫ ★ ❑ ●❝❊➂●❝❊ ❙ s ❊✺❈❂❍ ❬ ✇✜❊ ❪q▼ ❈❂❇✜❯ s ❉✤❍■❊✺r ⑧ ❖◆ ❖ ◆ ❖ ◆ ❖✗P✜❖★P✜❖ ◆ ❖ ◆ ❖❦P✜❖ ◆ ❖✗P ❍ ❬ ❯❱❊ ❙ ④❭✠✟✰✾

Page 119: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❁✗➦✁� ✟❦➭✑❥P❄ ✎❡❆✺➲✉➫✲❄❱❆✺➩❣➭ ✠✦❄ ✎➄➨✄✂➞ s ❍❝❇✙❋✤❇✔⑩➌❍❝♠✤❊✓❋❨❉✤❯ ❲ ❊✌● ⑥ ❇✔t ❑ ✇ ❑❣❬❴❪✼❑✔❲⑤❪ ❊➃●■❊✌❛ ❬ ❙ ❍❝❊✌● ❙ ⑩ ❑ ❙ ➈✕❦➋❊✺r ④ � ❉✤❍ ❬ ❍ ❬ ❙ ❋ ❑ ❍❝❉✤● ❑➁❪ ❍❝❇✙❯ ❑ ✭✜❊✢❍■♠✤❊➃❈❂❇✜❯ s ❉✤❍ ❑ ❍ ❬ ❇✜❋❯❱❇✜●■❊➃❊❂➟❩❈ ❬ ❊✌❋⑤❍ ❲⑤▼ ❈■♠✤❇❨❇ ❙ ❬ ❋✤❛ ⑥ ❑ ❙ ❑ t✉❉✤❋✑❈❂❍ ❬ ❇✜❋❱❇✔t✤➶ ④ ❄ ❋❱❍❝♠ ❬ ❙ ❈❂❇①❋❨❍❝❊❢❦✤❍✳❍❝♠✤❊✭➅✜❉ ❑ ❋⑤❍ ❬ ❍ ▼ ❇✔t ❬ ❋❨❍❝❊✌●■❊ ❙ ❍ ❬ ❙ ❍❝♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍⑥ ❚ ➠ ➶ ➄ ⑥ ➡ ④⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ⑧ ✔ ➔ ❾ ✭ ❧ ✰➅❤☎✁✜➆ ➻❋♠ ➠➅⑥ ✳ P ➡ ❚ ➀ ➺ ➎➇✰❡✭❧➸ ♠ ✭❅✰ ♠☛❾ ➸✜➾❩➸ ✹✺➆⑤➸✜➾ ♠✉➀☛♠✢♦❶❿➄❾❨➀✸➻✐❾✧➀ ➺✗✭✵✹✺➆ ➀ ✯✺➸ ❼ ✭✺➾ ♠✬♠ ❤ ➶ ❪ ❋ ⑤ ➶ ❪ ❋ ✩ ⑤ ☛ ➚➔ ❾ ✭❅✰❡✭■✭❿❽ ➀ ➺ ♠ ➸✛✰✐✁ ➀☛♠ ✰❆➸➇✰ ♦✙❼ ➸✛✰✢➎➇✭ ➶✆☎ ➺❶➸✜➾✝✁ ⑥ ☎ ➺➂➺ ➆ ➻✐❾ ♠☛❾ ➸ ♠❻♠☛❾ ✭ ❧ ✰❡❤☎✁✜➆ ➻❅♠ ➠➅⑥ ✳❾P ➡ ❚ ➀ ➺❀✭✲✹❣➆ ➀ ✯✺➸ ❼ ✭❣➾ ♠➜♠ ❤ ➶ ❪ ❋ ⑤ ➶ ❪ ❋ ✩ ⑤ ☛ ➚➎ ♠✤❊ ❬ r⑤❊ ❑ ❇✔t➹❍■♠✤❊ s ●❝❇❨❇❻t ❬ ❙ ❍❝❇♦●❝❊ s⑤❪✼❑ ❈❂❊♦❍❝♠✤❊➂❍❝●❝❉✤❊❶➅①❉ ❑ ❋⑤❍ ❬ ❍ ❬ ❊ ❙ ❉ ❙ ❬ ❋✤❛✧❍❝♠✤❊ ❑✔s✤s ●❝❇❅❦ ❬ ❯ ❑ ❍ ❬ ❇✜❋ ❙

➠➅⑥ ✳❀P ➡ ❚ ➠ ➶ ➄ ⑥ ➡✞✝ ➠ ➶ ✳❾P ➡ ⑥①➠ ✖ ❝❾P ➡◗➄ ☎ ⑥ ✳ ✖⑥ ✆ ✝ ➠➅⑥ ✳ ✖ ➡ ✗ ❜ ❵ ⑥ ✩ ✗✖ ✩ ❵ ✪

➎ ♠ ❬ ❙ ❛ ❬ ✇✜❊ ❙ ❑ ❋ ⑥ ⑩✭♠ ❬ ❈■♠♥❯ ❬ ❋ ❬ ❯ ❬q♣ ❊ ❙ ❍❝♠✤❊ s ●■❇➋r⑤❉✑❈❂❍ ➠❡⑥ ✳❾P ➡ ❚ ④✆➎ ♠✤❊➂●■❊ ❙ ❉ ❪ ❍ ❬ ❙ ❬❴❪❴❪ ❉ ❙ ❍❝● ❑ ❍■❊✺r ❲⑤▼ ❉ ❬ ❛①❉✤●❝❊ ⑧ ④

0

5

10

15

20

25

30

0 5 10 15 20 25 30p✞ ✟☛✡ ☞✦✍✣✏✠✟✑✔ ➎ ♠✤❊ s ●❝❇✤r⑤❉✑❈❂❍ ⑥ ❚ ➠ ➶ ➄ ⑥ ➡✓❬ ❙ ❈ ❪ ❇ ❙ ❊❱❍❝❇✾▲ ✗ ✵ ➶ ❪ ❋ ⑤ ➶ ❪ ❋ ✩ ⑤ ☛ t❹❇①●✭➶ ❪❺❑ ●❝❛✜❊ ④ ➛ ♠✤❇✔⑩✭❋♠✤❊✌●❝❊ ❑ ●■❊➂❍❝♠✤❊ ❙ ❊✺➅①❉✤❊✌❋✑❈❂❊ ❙❀⑥ ❚ ➠ ➶ ➄ ⑥ ➡☛✡ ▲ ✗ t✉❇✜● P ❰➌➶❩❰ ⑧ ✘ ❑ ❋✑r ⑥ ✵ ◆ ➄ ✪❋✪❅✪ ➄ P ✘ ④

☞✆✌✎✍✑✏✎✌✎✒✔✓✖✕✘✗✚✙✜✛✣✢❳ ❭ ❨✥✤✗✹❊✹❛❚✿✐✔✐❋❭✧✦✧❱⑤❫✉❩✁❴❛❵❉✙✷❩✮❯✺❯✣❬✣♥✰❚❘❭✎✤❂❱⑤❫❄❱✿❣✈❾✉❤❄❽✿❤❄❿✔❸s❬✣❴✲♥✒❩✆★❛❴✲❬✣✐✔❤❋❸s❤✪✩✬✫✲❤❄❴❛♠P❤✿❱✧❣➋❜ ❿✔❤☛✭✲❿s❬✣❴✴✐✯✮✔✰✻❤t♠P❤❍✖❡✹❛❤❄❿✥✱✯✲✳✲✴✱✰❱❳✶✵❑❨❂✘✕❩✘✫✲❿❡❭❼❷ ❱⑤❫✷❩✁❴✧❵④①✞✐✔❿P❩✁❸✔❸s❤❄❴✠❭❼❀❂❱⑤❫❄❱❙❣ ✛✉➉✲❤❧♠P❚✿✖✷✭✲❯✣❤P➌✲❬✣✐✥✤❉❚✁✱✸✭❛❩✮❿✔✐s❬ ❩✮❯♣❵✞❤❄❿s❬✣❽✰❩✁✐✔❬✣❽✿❤❄❸t❱✗✼✡❻✲▲✺✹✘✻▼▲✽✼✿✾❇❏✺❀✘❁❃❂❄✹❆❅✸❇✖❈✳✼✔▲❉✻❡➇➈❏❉✾❇▲❉❊❛❏P▲☛✮❴ ➹ ✵✬✵✚✮✄✱✪✲✬❋✰❲✴✮●✭✚✭✩❱ Ð✞❭✯❍ ❣ Ð ✵ ✟ ❱❳ Ð ❨❂✙❋❿s❬✺✖➀✖ ❭✧✦✧❱ ❫❉✮✲❜✡❚✰✐✔✐s❬✣❤❄❿❋❭✚✵☞❱ ❫❉✮✴❩✮❴❛❵✒❾ ❚✰❸s✐▼❩✁❬✣❴✲♥✮✢➃①❊♠✔➉❊✖✒❬➄❵✞✐✕❭❏■❝❱ ❫❍❱✁❣❑✤ ❸s➉❛❩✁❿▲✭❧❯✣❚✁❦✕❤❄❿✕✹❛❚✬✫✲❴❛❵❡❚✿❴✒✐s➉✲❤✗✐s❬✺✖➀❤P✢✥❸▼✭❛❩✿♠P❤✸✭✲❿s❚✲❵●✫❛♠P✐✱❇❚✿❿♣❿s❤❄❽✰❤❄❿s❸✔❬✣❴✲♥❉❩◆★❛❴❊❬✺✐s❤✷❸✔❤✯✩✳✫❊❤❄❴❛♠P❤✰❱❊❣✈❜✶❿✔❤❉✭✲❿✔❬✣❴✞✐✪✮✣✱✪✲✳✲✿➍✲❱❳ ❖✁❨❂✸❉❚✿❿✔♥✰❤❍❴✲❸✔✐s❤❄❿✔❴ ❭✧✦✧❱ ❫❍❱❊❣◗P✉❚✁❦⑨✐s❚❧♠P❚✿✖✷✭✚✫✲✐s❤✻✱✚❩✁❸s✐❶❩❘✱✎✫✲❴❛♠P✐s❬✺❚✿❴ ❩✁❴✧❵☎❩✁❯✣❯✩❬✣✐s❸❶❵✞❤❄❿s❬✣❽✰❩✁✐✔❬✣❽✿❤❄❸✪✮✧❩❡❽✰❩✁❿s❬➄❩✁✐✔❬✣❚✿❴❧❚✿❴☎✐✔➉❊❤✷✐✔➉✲❤❍❚✰❿✔❤❍✖❚✁✱r✘♣❩❆✫✲❿✥✢✔①✞✐s❿▼❩✁❸s❸✔❤❄❴✡❱✩➇●❘✘❙✞❚❯❂✗✼ ➆ ▲❉❱✶◆☛✮✰❴✦➹ ❭✪❲ ✮✄✱✪✲✬❋✰➍✚✮✬✭✚✭✩❱ ❲ ✟ ❣ ❲ ✵❊❱

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✎ ✵✖✹✌✷❂✷✺✹✮✭✚✵ ✌ ✟✓✯✱✰✹✗✲✶✹❄❆❅❴✖✙❄ ✑ ✼ ✖ ❇✪✳✌➅✜❉✤❊✌❋✓✳❂❇①❉✤●❝❍✢ ❑ ❋⑤❉ ❑ ● ▼ P ➤ ❖❦P✰✔✖✔✜◗❘❚❙ ❉✤❯❱❯ ❑ ● ▼❱❲⑤▼ ✓➹❬ ❊✌●❝●❝❊ ❅➓❬ ✳❂❇➋r✕✴❊✌❯❱❊✌❜

✵ ✍☞✶✸✷✯✕✘✗✺✹✻✷✛✉➉❊❤ ❜✡❚✿❯✺✤✞✖➀❤❄❿▼❩✮❸✔❤✒❁✕➉❛❩✮❬✺❴ ❾✉❤t❩✿♠P✐✔❬✣❚✿❴✜✮♣❜r❁✉❾ ✱❇❚✿❿❂❸s➉✲❚✰❿s✐✪✮✕❬✣❸⑦❩✮✹✲❯✣❤✒✐✔❚❑✭✲❿s❚❥❵ ✫❛♠P❤☎✖➀❬✺❯✣❯✣❬✣❚✰❴ ♠❖❚✳✭✲❬✣❤❄❸❡❚✮✱❩✒❸▲✭❛❤❑♠P❬ ★❛❤t❵ ✰◆■❃✤✜❸s❤❄♥✰✖➀❤❄❴✞✐t❱☎✙❋❿s❚✳✫✚✭✲❬✣❴✲♥✏❭❼✖ ✫✲❯✣✐✔❬ ✭✲❯✣❤P➌✲❬✣❴✲♥✴❫✕❴●✫✲✖➀❤❄❿✔❚✬✫✲❸❂❜r❁✉❾ ❬✣❴✈❩➀✱❇❤❄❦ ❤P➌✚✭✧❤❄❿✔❬✣✖➀❤❄❴✞✐✔❸❦♣❚✬✫✲❯➄❵✈❵✞❤t♠❖❿✔❤t❩✮❸✔❤④✐✔➉❊❤ ❜r❁✉❾ ♠P❚✿❸✔✐✔❸❉❩✁❴❛❵ ❸P❩❑❽✰❤☎✐s❬✺✖➀❤✰❱✠①✞✐P❩✁❿✔✐s❬✣❴✲♥✏✱❇❿✔❚✿✖ ❩✏✹❊❬✺❚✿❯✣❚✰♥✰❬➄♠❄❩✮❯♣✖➀❚✲❵✞❤❄❯✕✱❇❚✿❿❡✐✔➉✲❤✖ ✫✲❯✣✐✔❬ ✭✲❯✣❤P➌✲❬✣❴✲♥⑦♠❖❚✰❴❛❵✞❬✣✐s❬✺❚✿❴✲❸✪✮❙❦♣❤❡✐s❿▼❩✁❴❊❸✥✱❇❚✿❿✔✖✍✐s➉✲❤✷✭❊❿✔❚✰✹❊❯✺❤❍✖✍✐✔❚☎❩❉♠P❚✿✖❡✹✲❬✣❴❛❩✁✐s❚✰❿✔❬➄❩✮❯✩❚✰❴❊❤✳✮✩❸s➉✲❚✁❦ ✐s➉❛❩✁✐❝✐✔➉✲❤

✭✲❿✔❚✿✹✲❯✣❤❄✖✜❬✣❸✽✼✿✾❁❀✗♠P❚✰✖ ✭✲❯✣❤❄✐✔❤✳✮✿♥✰❬✣❽✿❤❶❩✁❴❉❩✘✭✚✭❊❿✔❚❑➌✲❬✣✖❧❩✁✐s❬✣❚✰❴❡❩✁❯✣♥✰❚✿❿✔❬✣✐✔➉✲✖❑✮✁❩✁❴❛❵ ❸✔➉✲❚✁❦ ❬✣✐✔❸❃✩✳✫✧❩✁❸✔❬➁✢✥❚✳✭✲✐s❬✣✖❧❩✁❯✣❬✣✐✥✤✰❱❞✫➦❱❡❣❢✮❆✺➩❣➨✓✠✐❤✗❥P❆✺➲q➨❦❢

➣ ❊✌✇ ❬ ❙ ❊✺r ❬ ❋➌❍❝♠✤❊♦❯ ❬ r✾✼ P✰✔ ❲ ✘ ❙ ❖ ❍❝♠✤❊ ✓ ❇ ❪q▼ ❯❱❊✌● ❑ ❙ ❊ ✂ ♠ ❑❣❬ ❋ ✖ ❊ ❑ ✳❂❍ ❬ ❇✜❋ ❖ ✓ ✂ ✖ t❹❇①● ❙ ♠✤❇①●❝❍ ❫ ❖ ❬ ❙ ❑❻❲⑤❪ ❊❳❍❝❇ s ●❝❇✤r⑤❉✓✳❂❊❊✌❋✤❇✜●❝❯❳❇✜❉ ❙ ❋❨❉✤❯ ❲ ❊✌● ❙ ❇✔t❂✳❂❇ s⑤❬ ❊ ❙ ❇✔t ❑ ❙ s ❊❃✳ ❬ ➈✑❊✺r ➣➂❅ ✑ ❙ ❊✺➅✜❉✤❊✌❋✓✳❂❊ ④♦➎ ♠✤❊❱❯❱❊✌❍■♠✤❇➋r ❬ ❙❶❙ ❊✌❋ ❙ ❬ ❍ ❬ ✇①❊❱❍❝❇✧✇✜❊✌● ▼ ❙ ❯ ❑❣❪❴❪❑ ❯❱❇①❉✤❋❨❍ ❙ ❇✔t ➣➂❅ ✑♦❖ ❑ ❋✑r❭♠ ❑ ❙ ❋❨❉✤❯❱❊✌●■❇✜❉ ❙ ❑❻s✤s⑤❪❫❬ ✳ ❑ ❍ ❬ ❇①❋ ❙✚➠ r ❬✼❑ ❛✜❋✤❇ ❙ ❍ ❬ ✳ ❙ ❖ ❊✌❍❄✳ ➡ ❲ ♠✤❇✔⑩✙❊✌✇✜❊✌● ❖ ❬ ❋❷❯❱❇ ❙ ❍✭❇❻t✆❍❝♠✤❊ ✓ ✂ ✖❊❢❦ s ❊✌● ❬ ❯❱❊✌❋⑤❍ ❙ s ❊✌● t❹❇✜●■❯❱❊✺r ❲⑤▼❩❲⑤❬ ❇ ❪ ❇✜❛ ❬ ❙ ❍ ❙ ❖ ❍❝♠✤❊ ❑ ❯ s⑤❪❴❬ ➈❅✳ ❑ ❍ ❬ ❇✜❋▲❇✔t✆❊ ❑ ✳■♠❩❍ ❑ ●❝❛①❊✌❍✙t❹● ❑ ❛✜❯❱❊✌❋⑤❍✭❇✔t ➣➂❅ ✑ ●■❊✺➅✜❉ ❬ ●❝❊ ❙ ❑❙ ❊ s✑❑ ● ❑ ❍❝❊ ❑ ❋✑r❆✳❂❇ ❙ ❍ ❪⑦▼✈✓ ✂ ✖ ❊❢❦ s ❊✌● ❬ ❯❱❊✌❋❨❍ ❖ ⑩ ❬ ❍❝♠♥❍❝♠✤❊❇✳❂❇✜●❝●❝❊ ❙ s ❇✜❋✑r ❬ ❋✤❛❩❯ ❑ ❋ ❬qs ❉ ❪✼❑ ❍ ❬ ❇✜❋ ❙ ❖ ❑ ❋✑r❷❍❝♠✤❊ ❬ ❯❱❯❱❇ ❲⑤❬❫❪❴❬q♣✺❑ ✼❍ ❬ ❇✜❋❩❇✔t ❑ ❋ ❑ ❉✤❍■❇✜❯ ❑ ❍ ❘ ☛ ❜ ④✓ ✂ ✖ ❊❢❦ s⑤❪ ❇ ❬ ❍ ❙ ✳❂❊✌●❝❍ ❑❣❬ ❋▲t✉❊ ❑ ❍❝❉✤●❝❊ ❙ ❇✔t ➣➂❅ ✑ ●❝❊ s⑤❪❴❬ ✳ ❑ ❍ ❬ ❇✜❋ ④➋➛ ❬ ❋✤❛ ❪ ❊✽✼ ❙ ❍❝● ❑ ❋✑r⑤❊✺r ➣➂❅ ✑ ❬ ❙ ❉ ❙ ❊✺r ❑ ❙ ❑ ❍■❊✌❯ s⑤❪✼❑ ❍❝❊t✉❇✜●❶❍❝♠✤❊ ❙ ▼ ❋⑤❍❝♠✤❊ ❙ ❬ ❙ ❇✔t ❑ ✳❂❇✜❯ s⑤❪ ❊✌❯❱❊✌❋⑤❍ ❑ ● ▼ ❋✤❊✌⑩ ❙ ❍■● ❑ ❋✑r ④✱➎ ♠✤❊ ❙ ❊ ❙ ❬ ❋✤❛ ❪ ❊ ❙ ❍❝● ❑ ❋✑r⑤❊✺r ➣➂❅ ✑ ❍❝❊✌❯ s⑤❪✼❑ ❍❝❊ ❙ ✳ ❑ ❋ ❲ ❊s ●❝❇✤r⑤❉✓✳❂❊✺r ❲❨▼ ❙ ❬ ❯ s⑤❪q▼ ♠✤❊ ❑ ❍ ❬ ❋✤❛✧r⑤❇✜❉ ❲⑤❪ ❊✽✼ ❙ ❍❝● ❑ ❋✑r⑤❊✺r ➣➂❅ ✑ ❍❝❇✚❍❝❊✌❯ s ❊✌● ❑ ❍❝❉✤●❝❊➘❋✤❊ ❑ ● ❲ ❇ ❬❫❪❴❬ ❋✤❛ ④✙➎ ♠✤❊✌❋❩⑩✙❊✭●❝❊✺➅①❉ ❬ ●❝❊ ❑❙ ❯ ❑➁❪❫❪ ❙ ❊❃✳❂❍ ❬ ❇✜❋♥❇❻t➹r⑤❇✜❉ ❲⑤❪ ❊ ❙ ❍❝● ❑ ❋✑r⑤❊✺r ➣➂❅ ✑ ❍❝❇ ❬ ❋ ❬ ❍ ❬✼❑ ❍❝❊ ➠✌➐ s ● ❬ ❯❱❊ ➒ ➡ ❙ ▼ ❋⑤❍❝♠✤❊ ❙ ❬ ❙ ④➎ ♠✤❊ ❙ ❍ ❑ ●❝❍ ❬ ❋✤❛ s ❇ ❬ ❋❨❍✚t✉❇✜● ➣➂❅ ✑ ❙ ▼ ❋⑤❍❝♠✤❊ ❙ ❬ ❙ ✳ ❑ ❋ ❲ ❊ ❙ s ❊❃✳ ❬ ➈✑❊✺r ❲⑤▼ ❙ ❉ s✤s⑤❪⑦▼①❬ ❋✤❛ ❑ ❋➌❇ ❪❫❬ ❛✜❇①❋❨❉✓✳ ❪ ❊✌❇✜❍ ❬ r⑤❊ s ● ❬ ❯❱❊✌●❍❝♠ ❑ ❍ ❑ ❋✤❋✤❊ ❑➁❪ ❙ ❍❝❇❶❍❝♠✤❊➂❍■❊✌❯ s⑤❪✼❑ ❍❝❊ ❑ ❍✓❍❝♠ ❬ ❙ s ❇ ❬ ❋⑤❍ ④ � ❇✜❍❝♠ ➣➂❅ ✑ ❙ ❍■● ❑ ❋✑r ❙ ✳ ❑ ❋ ❙ ❊✌●❝✇✜❊ ❑ ❙ ❍❝❊✌❯ s⑤❪✼❑ ❍❝❊ ❙ t❹❇✜● ❙ ▼ ❋❨❍❝♠✤❊ ❙ ❬ ❙s ●❝❇✔✇ ❬ r⑤❊✺r ❑ ❋❾❇ ❪❴❬ ❛✜❇✜❋⑤❉✓✳ ❪ ❊✌❇✜❍ ❬ r⑤❊ s ● ❬ ❯❱❊✌● ❬ ❙♥❙ ❉ s✤s⑤❪❴❬ ❊✺r❀t✉❇✜●✧❊ ❑ ✳■♠ ❙ ❍❝● ❑ ❋✑r ④ ✝ ❑ ✳❝♠❈✳ ▼ ✳ ❪ ❊➌❇✔t ✓ ✂ ✖ r⑤❉ s⑤❪❴❬ ✳ ❑ ❍❝❊ ❙❍❝♠✤❊ ❙ ❊✌❛✜❯❱❊✌❋⑤❍ ❙ ❉✤❋✑r⑤❊✌● ❑ ❯ s⑤❪❴❬ ➈❅✳ ❑ ❍ ❬ ❇✜❋ ❲ ❙ ❇ ❖ ❙ ❍ ❑ ●❝❍ ❬ ❋✤❛▲t✉●❝❇✜❯ ❇✜❋✤❊ ❙ ❊✌❛①❯❱❊✌❋❨❍ ❖ ◗❉✳ ▼ ✳ ❪ ❊ ❙ ❇✔t ✓ ✂ ✖ s ●❝❇✤r⑤❉✓✳❂❊ ◆❋❊❙ ❊✌❛✜❯❳❊✌❋❨❍ ❙ ④ ❉ ❬ ❛✜❉✤●❝❊ P ❙ ♠✤❇➁⑩ ❙ ❍❝♠✤❊ ❙ ▼ ❋⑤❍❝♠✤❊ ❙ ❬ ❙ ❬ ❋ ❬ ❍ ❬✼❑ ❍❝❊✺r ❲❨▼ ❍❝♠✤❊✚t❹❇①●❝⑩ ❑ ●❧r s ● ❬ ❯❱❊✌●❇●✧❍ ✢❏✤✗❁ ✤✗❁ ✤❘❱✣❱✺❱ ✤✗✙✷❁ ✤ ✤✉✢ Ð ❍❣❇✜❋❍❝♠✤❊ ⑧ ✯ ✼ ◗ ✯ ❙ ❍❝● ❑ ❋✑r✧❇❻t ❑ ❙ ❊✌❛✜❯❱❊✌❋⑤❍➃❇❻t ➣➂❅ ✑ ⑤ ④✓ ● ❬ ❯❳❊✌● ❙ ✳ ❑ ❋✤❋✤❇①❍ ❲ ❊✍✳■♠✤❇ ❙ ❊✌❋ ❑ ❍➂⑩ ❬❫❪❴❪✙❬ ❋ ❙ ❬ r⑤❊ ❑✧❪ ❇✪✳❂❉ ❙❱➠ ❑✧s ❇✜●❝❍ ❬ ❇①❋ ➡ ❇✔t ❑ ❛①❊✌❋✤❊✞✥➂❍❝♠✤❊ ▼ ❯♦❉ ❙ ❍➂●❝❊ ❙ s ❊❃✳❂❍■✳❂❇✜❋✒✼r ❬ ❍ ❬ ❇✜❋ ❙ s ❊✌●■❯ ❬ ❍❝❍ ❬ ❋✤❛ ❑ ✳❂❇✜●❝●■❊❃✳❂❍ ❑ ❯ s⑤❪❫❬ ➈❅✳ ❑ ❍ ❬ ❇①❋ ❲⑤▼✈✓ ✂ ✖ ❲ ❍❝♠✤❊✚❍❝❊✌❯ s ❊✌● ❑ ❍❝❉✤●❝❊✚❇✔t➹♠ ▼⑤❲ ● ❬ r ❬⑦♣✺❑ ❍ ❬ ❇✜❋ ❑ ❍✭⑩☛♠ ❬ ✳■♠▲❍❝♠✤❊s ❇ ❪⑦▼ ❯❱❊✌● ❑ ❙ ❊ ❙ ▼ ❋❨❍❝♠✤❊ ❙ ❬ ❙ ❊ ❙ ❍❝♠✤❊➂❋✤❊✌⑩ ➣➂❅ ✑ ❙ ❍❝● ❑ ❋✑r ❙ ❬ ❙ ❇✜❋✤❊➂❇✔t➔❍■♠✤❊ ❙ ❊✮✳❂❇✜❋✑r ❬ ❍ ❬ ❇✜❋ ❙ ❲ ❍❝♠ ❬ ❙ ❍■❊✌❯ s ❊✌● ❑ ❍❝❉✤●❝❊➂r⑤❊ s ❊✌❋✑r ❙❇✜❋❷❍❝♠✤❊■✳❂❇✜❯ s ❇ ❙ ❬ ❍ ❬ ❇✜❋▲❇✔t✆❍❝♠✤❊ s ● ❬ ❯❱❊✌● ❖ ❑ ❋✑r❭❯❱❇✜●❝❊ ❙ s ❊❃✳ ❬ ➈❅✳ ❑❣❪❴❪q▼ ❇✜❋▲❍❝♠✤❊✚●❝❊ ❙ s ❊❃✳❂❍ ❬ ✇✜❊ s ❊✌●❏✳❂❊✌❋❨❍ ❑ ❛✜❊❶❇✔t✆❍■♠✤❊ ❲✑❑ ❙ ❊ ❙✑ ❑ ❋✑r ➎➂❖ ✇①❊✌● ❙ ❉ ❙ ❍❝♠✤❊ ❲✑❑ ❙ ❊ ❙ ➬ ❑ ❋✑r ✂ ❲ ❑ ❯❱❇✜●❝❊ ❑ ✳✗✳❂❉✤● ❑ ❍❝❊✚❯❱❊✌❍❝♠✤❇✤r❩●❝❊ ❪✼❑ ❍■❊ ❙ ❍❝♠✤❊♦♠ ▼❨❲ ● ❬ r ❬q♣❂❬ ❋✤❛♥❍■❊✌❯ s ❊✌● ❑ ❍❝❉✤●❝❊❫ ❷④❤❋❿✔❤❖✱❇❤❄❿✗✐s❚☎❳ ● ❨③✱❇❚✰❿✗❩❘❵✞❤❄✐P❩✁❬✣❯✣❤t❵➀❬✺❴✞✐s❿✔❚✲❵●✫❛♠P✐s❬✣❚✰❴❉✐✔❚❡✐s➉✲❤❋❸▼✫✲✹❃❑P❤❑♠P✐✗❚✮✱☞❜☞❁✉❾✷❱⑤ ✛✉➉✲❤ Ð ❍ ❤❖➌❥✐s❿✔❤❄✖➀❬✣✐✥✤☎❚✁✱✗❩☎♠s➉❛❩✁❬✣❴✏❬✣❸ ■✕✢✥✐✔❤❄❿s✖✒❬✣❴❛❩✮❯▼▲❙✐✔➉✲❤ ●◆❍ ❤P➌✲✐✔❿s❤❄✖✒❬✣✐✥✤☎❬✣❸❂❁☞✢✥✛✶❤❄❿✔✖➀❬✺❴✧❩✁❯❖▲✧✐✔➉✲❤➀❴ ✫❊✖❡✹❛❤❄❿s❸ Ð ❩✁❴❛❵ ● ❿s❤P✱❇❤❄❿✐✔❚❡✐s➉✲❤✥✭✧❚✰❸s❬✺✐s❬✣❚✰❴❉❚✁✱✶✐✔➉✲❤❂♠❍❩✁❿✔✹✧❚✰❴✏♠P❚✰❴✲❴❊❤t♠P✐✔❤❑❵☎✐s❚❡✐✔➉✲❤ ■ ✢✚✐s❤❄❿✔✖➀❬✣❴❛❩✁✐s❬✺❚✿❴✒❩✁❴❛❵➀✐s❚✒✐✔➉❊❤ ❁☞✢✥✐✔❤❍❿✔✖✒❬✣❴❛❩✮✐✔❬✣❚✰❴➀❬✣❴✲❸✔❬➄❵✞❤❋✐✔➉❊❤ ● ✢✔♠❄❩✁❿s✹❛❚✿❴❸▼✫❊♥✴❩✁❿✉♠P❚✿❴✲❸✔✐s❬✺✐▲✫✲✐✔❬✣❽✿❤❶❚✮✱✩✐✔➉✲❤❋✹❛❩✮❸✔❤❄❸✉❚✮✱✑✰◆■❃✤ ❭❇❚✰✐s➉✲❤❄❿✗♠P❚✿✖✷✭✧❚✰❴✲❤❍❴✴✐s❸♣❚✮✱✽❩✷✹✧❩✁❸✔❤❋❚✮✱✑✰ ■ ✤ ❩✮❿✔❤❋❩✥✭✲➉❊❚✰❸▼✭❊➉❛❩✁✐s❤❶♥✿❿✔❚✬✫✚✭❧❩✮❴❛❵❡❚✿❴✲❤❚✳✫❊✐✉❚✁✱✩✱❼❚✳✫✲❿✉❚✿❿✔♥✴❩✮❴✲❬➄♠✉✹❛❩✮❸✔❤❄❸P❫❄❱

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Page 121: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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✚✜✛✓✢✣✛✓✚✣✤✎✛✦✥✍✚✣✧✩★✪✛✓✚✫✍✬ ✚✆✭☛✮✌✚✎✯✰✥☛✚✣✧✩★✱✛✓✚�✂✁✑☞✍✝✌☞☛✝✌☞✆☞✍✝✌✟☛✡✌✟☛✡✠✟✆✟☛✝✌☞☛✝✠✟✆☞✆✡✎✝✌☞✆☞☛✘✠✲✆✲✙✔✂✁✔✂✁☎✄✆✄✞✡✠☞☛✝✌✟☛✡✌✟✍✡✌✟✆✟☛✡✌☞✍✝✌☞☛✝✌☞✆☞✎✡✌✟☛✡✠☞✆✟✆✝✎✡✌✟✆✟✏✄✠✄✆✄✆✄✆✄✠✄✑✟✆✟✍✝✆✝✒☞✍✝✌✟✆✟☛✡✠✝✌☞☛✝✆✝✠✟✌☞☛✝✠✟✆✟☛✝✓☞✆☞☛✝✆✝✌☞✎✝✂✄✆✄✕�✖✁

✞✠✟♥✡ ☞✦✍✣✏ ✒✕✔❡❜✶❿s❬✣✖✒❤❄❿s❸r✱❇❚✿❿✸✰◆■❃✤ ✭✧❚✰❯✣✤✞✖✒❤❄❿P❩✁❸✔❤✳✵✴✷✶ ❦ s ✶✓✸✺✹✼✻✽✶✓✾✜✳❀✿✎❁❂✻✷✶✠✿☛❃❅❄✪✸❆✶✓✻✷✶✓✾✜✳✩❃❇✴ t❉❈ ✿☛❃❅✶ ✼ ❃❅✳❀✿ ✳✮✭ ✹❊✾✪❋✷✶✓✾✪✶✓✸✵❋☛● ④✻✑ ✾✣●✣❍✪✴ ⑩❏■❨⑩ ❍✪✶✓✾ ✳ ❍✪✴✜✴✜❃❑✹✼✾✪❋▲✿❏▼◆✿✌✹❊✸✕✴ t ▼✪✸❅✹❊✻✷✶✓✸✩❃ ■✳✵❍✪✶▲❍✣● ❈ ✸✺✹P❖◗✹❊❘✩✹❊✾✪❋❙✳✵✶✓✻✷▼❚✶✓✸❀✿✆✳✵❄✪✸❆✶✠❃❯✴ t ✳✵❍✪✶▲✳ ⑩ ✴✙▼✪✸✺✹✼✻✽✶✓✸❀❃✷❃❅❍✪✴☛❄✣❁❱❖ ❈ ✶✙✿ ❈ ✴☛❄✪✳✷✳✵❍✪✶✙❃✵✿✍✻✷✶ ④✠✑ ✾✪✴☛✳✵❍✪✶✓✸ ✳ ✴◗✾◆❖◗✹✼✳✺✹✼✴◗✾✸✵✶✩❁❱✿✆✳✵✶✠❃✽✳✵✴☎❍✪✴◗✻✷✴✆❁❊✴☛❋☛● ❈ ✶✓✳ ⑩ ✶✓✶✓✾❲✳✵❍✪✶▲✳ ⑩ ✴❳▼✪✸❅✹❊✻✷✶✓✸❀❃❨✿✆✾◆❖❙✳❆✴❩❃❅✶✩❁ t ✼ ❍✪✴◗✻✷✴✆❁❊✴☛❋☛● ❲ ❃❅❄ ✳ ❍❲❍✪✴◗✻✷✴✆❁❊✴☛❋☛● ⑩ ✴☛❄✣❁❱❖ ✇ ✶✓✸✵●✴ t ✳✵✶✓✾✙▼✪✸❆✶ ✇ ✶✓✾✜✳❬✿ ✳ ✴☛✸✵✸✵✶ ✳ ✳❬✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾ ■ ✳✵❍✪✶❪▼✪✸❅✹❊✻✷✶✓✸❀❃❫❍✣● ❈ ✸❅✹❱❖◗✹❊❘✩✹❊✾✪❋❳✳✵✴✷✶✠✿ ✳ ❍❳✴☛✳✵❍✪✶✓✸ ■ ✴☛✸❴✹P❖✣✶✓✾✣✳❅✹ ✳ ✿✌❁ ✳ ✴☛▼✣✹❊✶✠❃❫✴ t✿✷❃❅✶✩❁ t★✼ ❍✪✴☛✻✷✴✆❁❊✴☛❋◗✴☛❄◆❃❇▼✪✸❅✹❊✻✷✶✓✸❫❍✜● ❈ ✸❅✹❱❖◗✹❊❘✩✹❊✾✪❋✙✳✵✴☛❋◗✶✓✳✵❍✪✶✓✸ ④➛ ✶ ✇ ✶✓✸❀✿✎❁❵❃❅✴ t ✳ ⑩ ✿✆✸✵✶❛▼✪✸✵✴◗❋☛✸❀✿✆✻❜❃❉✿✍✸✵✶❝✿ ✇ ✿✌✹❭❁P✿ ❈ ❁✼✶❏✳✵✴❯▼✪✸❆✶✠❖◗✹ ✳ ✳ ⑩ ❍✣✹ ✳ ❍▲▼◆✿✌✹❊✸❇✴ t ▼✪✸✺✹✼✻✽✶✓✸❀❃❞✳✵✴ ✳ ❍✪✴✣✴✜❃❅✶❴✹❊✾◆❃❡✹❱❖✣✶❢✿❬❋✍✹ ✇ ✶✓✾❁❊✴ ✳ ❄◆❃ ④✆➎ ❍✪✶ ✳ ✴☛✾◆❖◗✹❊✳❅✹❊✴☛✾◆❃ ⑩ ❍✣✹ ✳ ❍❜❍✪✴✆❁❱❖ t ✴◗✸❣✿❬✴◗✾✪✶ ✼ ❁✼✴ ✳ ❄◆❃ ✓ ✂ ✖ ✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾✙❃❅✳❅✹❭❁❭❁✖❍◆✿ ✇ ✶❛✳✵✴❬❍✪✴✆❁❱❖ t ✴☛✸❤✻❪❄✣❁❊✳❅✹ ✼ ❁❊✴ ✳ ✹✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾ ④➛ ✳❀✿✆✸❆✳❅✹❊✾✪❋ t ✸✵✴☛✻✐✿❏❃❅✶✓✳ ❬ ✴ t ◗ ❁❊✴ ✳ ✹ ■✤⑩ ✶ ⑩ ✿✆✾✜✳❞✳✵✴ ➈ ✾◆❖✽✳✵❍✪✶❬❃❅❄ ❈ ❃❅✶✓✳ ▲ ✚❦❥ ✉ ✴ t ✻❜✿ ❦ ✹✼✻❪❄✪✻❧❃❡✹❊❘✓✶❬✴ t ❬ ■ ❃✺❄ ✳ ❍❨✳✵❍◆✿✆✳✹❊✾❩✶✠✿ ✳ ❍♠❁❊✴ ✳ ❄◆❃❏✴ t✗▲ ✚❉❥ ✉ ⑩ ✶ ✳ ✿✆✾♥❃✺✶✩❁✼✶ ✳ ✳✷✿✦▼◆✿✌✹❊✸❯✴ t ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ❁✼✶▲▼✪✸✺✹✼✻✽✶✓✸❀❃ ■ ✿✆✾◆❖♦❃❅❄ ✳ ❍♠✳✵❍◆✿✆✳❯✳❆❍✪✶❜♣ ◗ ❃✺✶✩❁✼✶ ✳ ✳❆✶✠❖▼✪✸❅✹❊✻✷✶✓✸❀❃❫✿✆✸✵✶❬✶✠✿ ✳ ❍▲✴☛✳❆❍✪✶✓✸ ✳ ✴☛✻✷▼◆✿✆✳✺✹ ❈ ❁❊✶ ④➊ ✶❫✻❜✿☛❖✣✶❬✿✆✾❨✶ ❦ ✳✵✶✓✾◆❃❑✹✼✴◗✾▲✳✵❍✪✶❬▼✪✸✵✴☛❋☛✸✩✿✆✻ ✓➜✖❇q❑r ✝ ✖ ■ ✴ t ➛✑④ ✝ ④✤❐ ✹❊✾ ✳ ✴✆❁❊✾ ■ r ④ ✢ ④ ➣ ✿✌❁❊● ■ ✿✍✾◆❖ ✝ ④✕➛✑④✤❐ ✿✍✾◆❖✣✶✓✸❯s❊t✩✉✹❊✾❲✿ r ➞✾❐⑤➎ qP✓ ✂ ✖ ▼✪✸❆✴☛❋☛✸❀✿✆✻ ④ ✓✠✖❇q❅r ✝ ✖ ✹❱❃✷✿✰✳ ⑩ ✴ ✼ ❃❅✳✵✶✓▼☎▼✪✸✵✴◗❋☛✸❀✿✆✻ ❲ ❃❅✳✵✶✓▼ ✼ t▲❃❅✶✩❁❊✶ ✳ ✳❀❃❢✈✇✴☛✸ ⑩ ✿✍✸❀❖☎✿✆✾◆❖♦✸✵✶✓①◗✶✓✸❀❃❅✶✳ ✿✆✾◆❖◗✹❱❖✪✿✆✳✵✶✠❃②▼✪✸❅✹❊✻✷✶✓✸❀❃ ❲ ❃✺✳✵✶✓▼ ✼ ♣ ✳ ❍✪✴✣✴✜❃❅✶✠❃❪✿ ❈ ✶✠❃❅✳❪▼◆✿✌✹❊✸❪✴✆✈✕✴☛✾✪✶✽✈✇✴◗✸ ⑩ ✿✆✸❀❖❳✿✆✾◆❖♠✴☛✾✪✶❜✸❆✶✓①☛✶✓✸❀❃❅✶❨▼✪✸❅✹❊✻✷✶✓✸✷✿✆✻✷✴☛✾✪❋❳✿✌❁❭❁✳✵❍✪✶✷▼❚✴✜❃✵❃❡✹ ❈ ❁❊✶❨▼◆✿✌✹❊✸❀❃❬✴✆✈ ✳ ✿✆✾◆❖◗✹❱❖✪✿✆✳✵✶✠❃ ④ r ➞✾❐⑤➎ q▼✓ ✂ ✖ ✳✩✿ ✭ ✶✠❃❬✿☛❃❴✹❊✾✪▼✪❄✪✳❪✳✵❍✪✶❪✴☛❄✪✳✵▼✪❄✪✳❏✴✆✈ ✓➜✖❇q❑r ✝ ✖ ❃❅✳✵✶✓▼ ✼ t ■ ✿✆✾◆❖✳ ❍✪✴✜✴✜❃✺✶✠❃❇✈✑✴☛✸❛✶✠✿ ✳ ❍✰❁❊✴ ✳ ❄◆❃❬✿❏✈✑✴☛✸ ⑩ ✿✆✸✩❖▲✿✆✾◆❖✙✿✽✸✵✶✓①☛✶✓✸❀❃✺✶❯▼✪✸❅✹❊✻✷✶✓✸ ✳ ✴☛✻✽▼◆✿✆✳❅✹ ❈ ❁❊✶ ⑩ ✹✼✳❆❍✙✳✵❍✪✶❪▼✪✸❅✹❊✻✷✶✓✸❀❃ ✳ ❍✪✴✜❃❅✶✓✾▲✈✑✴☛✸❫✳✵❍✪✶✴☛✳✵❍✪✶✓✸③❁✼✴ ✳ ✹ ■✑⑩ ❍✪✶✓✾✪✶✓①☛✶✓✸✕✳❆❍✣✹P❃❣✹P❃❴▼◆✴✣❃✵❃❡✹ ❈ ❁❊✶ ④➥✠➦❃❂⑤④✗➯ ❆✺➲❇✟✳➯✥❄✣⑥➔➲⑧⑦ ✔✓❆✞✝✣❄☎⑨➘➨✠➯P⑩✢➫✲❄➋➩❣➭✑➳✐❄❳❶ ✝✠➭✑➲⑧⑦ ✞✙❄⑤➭◆❷P❆✺➲❺➨✖⑦

➥✠➦✑❸✫➦✆✞✙❄✡✒✏④✗➲✼➩❅❄✫➫ ❄❚⑦✮❆✺➳①➦ ➊ ✶✷❖✣✶✓✳❀✿✌✹❭❁❉✹❊✾❳✳✵❍✣✹❱❃❬❃❅✶ ✳ ✳❅✹❊✴☛✾☎✿❨✻✷✴✪❖✣✶✩❁❦✴✍✈ ✳ ✴☛✻✷▼◆✿✆✳❅✹ ❈ ✹❭❁❭✹❊✳❑● ❈ ✶✓✳ ⑩ ✶✓✶✓✾❹▼✪✸✺✹✼✻✽✶✓✸❀❃❫✳✵❍◆✿✆✳➬ ✹❭❁❭❁❊✶✠❃ ➎ ❍✪✴☛✻❜✿◗❃ ✝ ▼✪✸✵✴☛▼❚✴✜❃❅✶✠❖✦✳✵✴❪❄◆❃❛✿✆✾◆❖▲✳❆❍✪✶ ✳ ✴☛✸✵✸✵✶✠❃❅▼❚✴☛✾◆❖◗✹❊✾✪❋❜✸❆✶ ➅ ❄✣✹❊✸✵✶✓✻✷✶✓✾✣✳❀❃✓❺➊ ✶ ⑩ ✹❻❁❭❁❂❃❅▼❚✶✠✿ ✭ ✴✆✈ ❼ ❤ ➻ ➆①➺ ✿✆✻✽▼✣❁❻✹ ➈❅✳ ✿✆✳✺✹✼✴◗✾ ⑩ ❍✪✶✓✾ ✳ ✴☛✾◆❃❡✹❱❖✣✶✓✸❅✹❊✾✪❋✷✳❆❍✪✶✕✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾▲✴✆✈❂✿❏❃❡✹❊✾✪❋✆❁❊✶❝❃❅✶✓❋◗✻✷✶✓✾✜✳ ❲ ✴☛✾✣❁❊●✴☛✾✪✶❪✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾✰✹❱❃✕✿✌❁❭❁❊✴ ⑩ ✶✠❖▲✹❊✾◆❃❡✹❱❖✣✶✷✿✽❋✆✹❊①☛✶✓✾▲❁❊✴ ✳ ❄◆❃ ❲ ✳✵✴✷✶✠✿ ✳ ❍▲❁❊✴ ✳ ❄◆❃✕✿✍✻✷▼✣❁❭✹ ➈❅✳ ✿✍✳❅✹❊✴☛✾ ✳ ✴☛✸✵✸❆✶✠❃❅▼◆✴☛✾◆❖✰✿ ❈✐❤✛✰ ❿ ➸➇✰✱✁✿✆✾◆❖▲✿ ✰❡✭❅✯❋✭❋✰■➺✐✭ ▼✪✸❅✹❊✻✷✶✓✸✌❺ ➊ ✶❯❖✣✶ ➈ ✾✪✶✷✿ ➺✌➆✕✁ ❧ ✰ ➀ ♣❑✭❅✰ ✿☛❃❴✿✷❃❅❄ ❈ ❃❅✶ ➅ ❄✪✶✓✾ ✳ ✶❪✴✆✈❼✿②▼✪✸❅✹❊✻✷✶✓✸❝✿✍✾◆❖ ⑩ ✶ ✳ ✴◗✾◆❃❡✹❱❖✣✶✓✸❫✹✼✾✰✳✵❍✪✶✈✑✴✆❁❭❁✼✴ ⑩ ✹❊✾✪❋❳✳✵❍◆✿✆✳❪✿✌❁❭❁③❃❅❄ ❈ ▼✪✸✺✹✼✻✽✶✓✸❀❃❏✴✆✈✕✿▲✻❪❄✣❁❊✳❅✹❊▼✣❁✼✶ ❦ ✹❊✾✪❋❩✶ ❦ ▼◆✶✓✸✺✹✼✻✽✶✓✾✜✳❪❍◆✿✌①☛✶✷✳✵❍✪✶❨❃✵✿✆✻✷✶❪❁❊✶✓✾✪❋☛✳❆❍♥❽❉❺ q ✾❩▼✪✸❀✿ ✳ ✳❅✹ ✳ ✿✌❁✶ ❦ ▼◆✶✓✸❅✹❊✻✷✶✓✾✣✳❀✿✆✳❅✹❊✴☛✾◆❃ ■ ❽ ⑩ ✹❭❁❻❁❤❍◆✿✌①☛✶❪①✆✿✌❁❊❄✪✶✠❃ ☛ ✴☛✸❝❾❿❺ ➊ ✶②❖✣✶ ➈ ✾✪✶❨✿✙➀ ☎ ➍✖➺✌➆✕✁ ❧ ✰ ➀ ♣❑✭❅✰ ✿◗❃❛✳✵❍✪✶✷❃❅❄ ❈ ▼✪✸✺✹✼✻✽✶✓✸❬✶✓✾◆❖◗✹✼✾✪❋❳✿▼✪✸❅✹❊✻✷✶✓✸❬✿✆✳❞✹❊✳❀❃ ⑧ ✯ ✶ ❦ ✳✵✸✵✶✓✻②✹✼✳❅● ➠ ▼✪✸❅✹❊✻✷✶✓✸❀❃ ❈ ✶✩✹❊✾✪❋✙✿✌❁ ⑩ ✿✠●✪❃❞✸✵✶✠✿☛❖✽✹❊✾❳✳✵❍✪✶❯❖◗✹❊✸✵✶ ✳ ✳❅✹❊✴☛✾❳❾ ✯➂➁ ⑧ ✯ ➡ ❺➎ ❍✪✶❬✸✵✶ ➅ ❄✣✹❊✸✵✶✓✻✷✶✓✾✣✳❀❃❫✿✆✸✵✶❬✳✵❍✪✶❫✈✑✴✆❁❭❁❊✴ ⑩ ✹✼✾✪❋ ✥➠ t ➡ ❇ ❤ ➻ ➆①➺ ✿✆✻✽▼✣❁❻✹ ➈❅✳ ✿✆✳✺✹✼✴◗✾❹✸❆✶ ➅ ❄✣✹❊✸✵✶✓✻✷✶✓✾✣✳❀❃ ✥➠ ✿ ➡ ➎ ❍✪✶❢❖◗✹❱❃❅✳❀✿✍✾ ✳ ✶ ❈ ✶✓✳ ⑩ ✶✓✶✓✾✙✳❆❍✪✶❬✈✑✴☛✸ ⑩ ✿✆✸❀❖✽▼✪✸❅✹❊✻✷✶✓✸❬✿✆✾◆❖▲✳✵❍✪✶❏✸✵✶✓①☛✶✓✸❀❃✺✶❬▼✪✸❅✹❊✻✷✶✓✸❛✹❱❃ ❈ ✶✓✳ ⑩ ✶✓✶✓✾❩t✠❾ ✘ ✿✆✾◆❖☛ ❾ ✘ ❈ ✿☛❃✺✶✠❃ ➠ ✳✵❍✪✶✠❃❅✶❏✻❪✹❊✾✣✹❊✻❢❄✪✻➃✿✆✾◆❖✦✻❜✿ ❦ ✹✼✻❪❄✪✻➄①✆✿✌❁❊❄✪✶✠❃❬✿✆✸✵✶❬❋✆✹❊①☛✶✓✾☎✿☛❃③▼◆✿✆✸❀✿✆✻✷✶✓✳❆✶✓✸❀❃❇✿✆✾◆❖ ✳ ✴☛✸❆✸✵✶✠❃ ✼▼◆✴☛✾◆❖✦✳✵✴❪✳✵❍✪✶ ➐ ▼✪✸❆✴✱❖✣❄ ✳ ✳❛✸✩✿✆✾✪❋☛✶❯❃❡✹❊❘✓✶ ➒ ✳❀✿ ✭ ✶✓✾▲✿☛❃❞✹❊✾✪▼✪❄✪✳ ❈ ●❨✳✵❍✪✶❯▼✪✸❆✴☛❋☛✸❀✿✆✻ ✓➜✖❇q❑r ✝ ✖➷➡ ❺➠ ❈ ➡ ➎ ❍✪✶❛▼✪✸❅✹❊✻✷✶✓✸❀❃❉❃❆✿✆✳❅✹❱❃❡✈✑●❢✳❆❍✪✶ ✳ ✴◗✾◆❖◗✹✼✳✺✹✼✴◗✾◆❃❤✴✍✈➅✾✪✴☛✾ ✼ ▼◆✿✌❁❭✹❊✾◆❖✣✸✵✴☛✻②✹ ✳ ✹❊✳❅● ❲ ❃❅❄ ✳ ❍❜✿❫▼◆✿✌❁❭✹❊✾◆❖✣✸✵✴☛✻❪✹ ✳ ✹❊✳❅● ⑩ ✴☛❄✣❁❱❖

✳ ✿✆❄◆❃❅✶❯❃❅✶✩❁❭✈ ✼ ❍✪✴☛✻✷✴✆❁❊✴☛❋☛●☛❺➠ ✳ ➡ ➎ ❍✪✶ ⑧ ✯ ✼ ❃✺❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❀❃❯✿✍✸✵✶❪✾✪✴☛✳❯✸✵✶✓①◗✶✓✸❀❃❅✶ ✳ ✴☛✻✷▼✣❁❊✶✓✻✷✶✓✾✣✳❀✿✆✸✵● ⑩ ✹❊✳✵❍♦✿✆✾✜●❳✴✆✈❇✳✵❍✪✶❜❃❅❄ ❈ ▼✪✸✺✹✼✻✽✶✓✸❀❃ ➠ ❃❅❄ ❈✒✼▼✪✸❅✹❊✻✷✶✓✸❀❃❛✿☛❃ ⑧ ✯ ✼ ❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸✩❃✕✿✆✸❆✶❯✿☛❃✵❃❅❄✪✻✷✶✠❖❨✳❆✴ ❈ ✶❬✴✆✈✏❁❊✶✓✾✪❋☛✳✵❍❳❽ ❈ ✿☛❃❅✶✠❃ ➡ ❺➠ ♣ ➡ ❳ ➆ ❼ ♠✉➀ ➍ ❼ ❤ ➻ ➆①➺ ✿✍✻✷▼✣❁❭✹ ➈❅✳ ✿✍✳❅✹❊✴☛✾❳✴☛✸ ✭✐❽ ❧ ✭❋✰ ➀ ♣❑✭❣➾ ♠ ✸✵✶ ➅ ❄✣✹❊✸✵✶✓✻✽✶✓✾✜✳❀❃ ✥✝ ✵✡❩✁✹✧❚✰❿▼❩✮✐✔❚✿❬✺❿s❤✷❵✞❤✷✙ ❈❤❄❴✉❈❤❄✐s❬ ✩✳✫❊❤❂❵✞❤❄❸✻✛✑✫❊✖✒❤☛✫✲❿s❸✪✮✿✦✥❴✲❸✔✐s❬✣✐▼✫✲✐❋❁ ✫✲❿✔❬✣❤✳✮✚✵ ❲ ✮✞❿▼✫❊❤❂❵ ❍ ② ❯✣✖ ✮ ❍ ● ✟✝✟ ● ❜✶❩✁❿✔❬✣❸❑❱❭✂❭ ✵

Page 122: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❜✶❿s❬✺✖➀❤❄❿ ② ❿✔❴❉❴●✫✲✖❡✹✧❤❄❿✔✂✁❢✝✌✟✆✟✆☞❩�✂✁ �✂✁✄ �✂✁ ❚✷✼✉✼ ❂ ✔✖✁ ✄ ☎✝✆✟✞

✠✡✠☛✠✡✠�✂✁ ☞✆☞✍✡✌☞✆☞☛✡✌☞✎☞✆✟ ✔✂✁

☞✆☞✍✡✌☞ ✄ ✥✌☞☞✍✡✌☞✆☞ ✄ Ð ✵ ☞✡✌☞✆☞☛✡ ✄ ❭❂Ð ✟✌☞☞✆☞☛✡✌☞ ✄ ✥✌☞☞☛✡✌☞✎☞ ✄ Ð ✵ ☞✡✌☞✆☞✆✟ ✄ ❭❂Ð✞❭✍☞

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✞ ☞ ☞✟ ❭ ✥ Ð ✵ ❲✞❭ ❭❧Ð✝✟ ❭❂Ð✞❭ ✵ ● ●

✞✠✟♥✡ ☞✦✍✣✏ �✑✔➠ ✿ ➡ ✑ ✾✣●✏✎ ✯ ✼ ❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❞✴✆✈❵✿✍✾✷✶ ❦ ▼❚✶✓✸❅✹❊✻✷✶✓✾✣✳❤✹❱❃❼✾✪✴☛✳❉✸✵✶✓①☛✶✓✸❀❃✺✶ ✳ ✴☛✻✷▼✣❁❊✶✓✻✷✶✓✾✣✳❀✿✆✸✵●✒✑❇✹❊✳✵❍❨✿✆✾✜●❪❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸ ■✹✼✾ ✳ ❁❊❄◆❖◗✹❊✾✪❋✰✹❊✳❀❃❅✶✩❁❭✈ ■ ✴✆✈❣✿✆✾✣●▲▼✪✸❅✹❊✻✷✶✓✸❫✴✆✈❤✳✵❍✪✶❏✶ ❦ ▼❚✶✓✸❅✹❊✻✷✶✓✾✜✳ ❲ ✳✵❍✣✹❱❃✓✑❣✴◗❄✣❁P❖ ✹❊✾✣✹✼✳✺✹P✿✍✳✵✶✷❍✣● ❈ ✸❅✹❱❖◗✹❊❘✠✿✆✳❅✹❊✴☛✾❳✴✆✈

✳✵❍✪✶❇▼✪✸❅✹❊✻✷✶✓✸❀❃❉✳❆❍✪✶✓✻❜❃❅✶✩❁❊①☛✶✠❃✓❺ ✑ ✾✷✶ ❦ ✿✍✻✷▼✣❁❊✶❤✈✑✴☛✸❉✳✵❍✣✹❱❃ ✳ ✴☛✾◆❖◗✹❊✳❅✹❊✴☛✾❪✹❱❃❉❋✆✹❊①☛✶✓✾❏✹❊✾❜❃❅❄ ❈ ❃✺✶ ✳ ✳❅✹❊✴☛✾❜♣✪❺ ♣❿❺✕✔❴✴☛✳✵✶✳✵❍◆✿✆✳❤❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸✩❃ ➠ ✹✼✾ ✳ ❁❊❄◆❖◗✹❊✾✪❋❨✳✵❍✪✶✖✎ ✯ ✼ ❃✺❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❀❃ ➡ ✻❜✿✌● ❈ ✶❛✹❱❖✣✶✓✾✣✳❅✹ ✳ ✿✌❁ ❈ ✶✓✳✗✑❇✶✓✶✓✾ ❖◗✹ ➑ ✶✓✸✵✶✓✾✣✳❉❁❊✴ ✳ ✹ ■✴☛✸❇✹❊✾◆❃❡✹❱❖✣✶✷✿❬❁❊✴ ✳ ❄◆❃✓❺➠ ❈ ➡ ➎ ❍✪✶❳✳✵✶✓✻✷▼◆✶✓✸✩✿✆✳✵❄✪✸✵✶✠❃✽✴✆✈②❖✣✶✓✾◆✿✍✳✵❄✪✸❀✿✆✳❅✹❊✴☛✾ ■ ✴☛✸❨✳✵❍✪✶ ➬ ✂✙✘ ✑✆➎ ▼◆✶✓✸ ✳ ✶✓✾✜✳❀✿✍❋☛✶✰✹✼✾ ✳✵❍✪✶❳▼✪✸❅✹❊✻✷✶✓✸✩❃❨✴✆✈❢✿✻❢❄✣❁❊✳❅✹ ✼ ❁❊✴ ✳ ❄◆❃ ✓ ✂ ✖ ✿✆✻✷▼✣❁❭✹ ➈❅✳ ✿✆✳❅✹❊✴☛✾❨❍◆✿✌①☛✶❤✳❆✴ ❈ ✶✩❁❊✴☛✾✪❋❯✳❆✴❝✿❴❁❭✹❊✻❪✹❊✳✵✶✠❖✽✸❀✿✆✾✪❋☛✶❇✴✆✈◆①✆✿✌❁❊❄✪✶✠❃ ➠ ❈ ●❬✹❊✾◆❃❅✳❀✿✍✾ ✳ ✶☛ ❲✛✚ ❝ ❾☛♣ ✚❱➡ ❺➠ ✳ ➡ ✝ ❁❊✶ ✳ ✳✵✸✵✴☛▼✪❍✪✴◗✸✵✶✠❃❡✹❱❃ ☎ ❖◗✹P❃✺✳❀✿✆✾ ✳ ✶ ✥ ✳✵❍✪✶❯❖◗✹ ➑ ✶✓✸❆✶✓✾ ✳ ✶❯✴✆✈✏❁❊✶✓✾✪❋☛✳✵❍◆❃ ❈ ✶✓✳✗✑❇✶✓✶✓✾✙✿✆✾✜●❨✳✗✑❇✴❢❃❅✶✓❋☛✻✽✶✓✾✜✳❀❃❴✿✆✻✷▼✣❁❭✹ ✼➈ ✶✠❖❫✹❊✾❪✳✵❍✪✶❣❃✵✿✍✻✷✶❉✻❪❄✣❁✼✳✺✹ ✼ ❁❊✴ ✳ ❄◆❃ ✓ ✂ ✖ ✿✍✻✷▼✣❁❭✹ ➈❅✳ ✿✍✳❅✹❊✴☛✾❏✹P❃✂❋☛✸✵✶✠✿✍✳✵✶✓✸✖✳✵❍◆✿✆✾ ✏❞❈ ✿☛❃❅✶✠❃ ❲ ✳✵❍✣✹❱❃❵✹❱❃✏✾✪✶ ✳ ✶✠❃✵❃✵✿✆✸✵●✳✵✴❢✿✌❁❭❁❊✴✜✑ ✿ ✳ ✴☛✸✵✸✵✶ ✳ ✳❇❖◗✹ ➑ ✶✓✸❆✶✓✾✜✳❅✹❱✿✆✳✺✹✼✴◗✾✙✴✆✈✖✳✵❍✪✶❯✿✆✻✽▼✣❁❻✹ ➈ ✶✠❖✰❃❅✶✓❋☛✻✷✶✓✾✣✳❀❃❤✿✎✈✇✳✵✶✓✸❇✶✩❁❊✶ ✳ ✳✵✸✵✴◗▼✪❍✪✴☛✸✵✶✠❃❡✹❱❃✓❺ ➎ ❍✣✹P❃❖◗✹P❃✺✳❀✿✆✾ ✳ ✶✙❃❅❄✪▼✪▼❚✴✜❃❅✶✠❃❪✳✵❍◆✿✍✳❢✳❆❍✪✶✷❁❊✴ ✳ ✹❝✿✆✸✵✶❨✾✪✴☛✳❪▼◆✴✆❁❊●✣✻✷✴☛✸✵▼✪❍✣✹ ✳✆■ ✹❊✾✢✑❛❍✣✹ ✳ ❍ ✳ ✿☛❃❅✶▲✳✵❍✪✶❨▼✪✸✵✴ ❈ ❁❊✶✓✻ ✴✆✈❖◗✹❻✈ ✈✑✶✓✸✵✶✓✾✜✳✺✹P✿✍✳❅✹❊✾✪❋❜✳✵❍✪✶❯✿✍✻✷▼✣❁❭✹ ➈ ✶✠❖❳❃❅✶✓❋◗✻✷✶✓✾✜✳✩❃❇❍◆✿☛❃❇✳✵✴ ❈ ✶❯❍◆✿✍✾◆❖◗❁✼✶✠❖ ✹❊✾❹✿✷❖◗✹ ➑ ✶✓✸✵✶✓✾✣✳✖✑❛✿✌●☛❺

➥✠➦✸➥★➦✏✣✰⑦ ④✗➩☛⑦❀➫▲➨✑✠✦❄✤➯❻❆✌➨❾➳✌➨★➯✌☞✣❄❱❆✞✝✣❄ ✟✳➩❣➨✥✤✳➯✥❄✫➫ ➨✩✆❯❷✔➨❦➫ ✟❦➭✕❆✺➲✦✤✳➲✸➯✼➲ ❆❀⑩✧✤➄❄ ❆✩★❑❄ ❄◆⑦ ✟✳➩➁➲✦➫✲❄➋➩✔➳✜➦ ➊ ✶❪❋✆✹❊①☛✶❍✪✶✓✸✵✶❪✿ ✳ ✴◗✾◆❃❅✳✵✸✵❄ ✳ ✳❅✹❊①☛✶❏✶ ❦ ✿✍✻✷▼✣❁❊✶❯✴✆✈❉✴☛❄✪✸✕✿✌❁❊❋☛✴◗✸❅✹❊✳✵❍✪✻✙❺

✪ ➞ ❃❡✹❊✾✪❋❫✳✵❍✪✶❤✻❨✿✆▼✪▼✣✹❊✾✪❋ ➠ ✑ ➁✘■ ✂ ➁ t ■ ➬ ➁ ♣ ■ ➎ ➁ ✎ ➡ ■ ➊ ✶❤✳✵✸❀✿✍✾◆❃❡✈✇✴◗✸✵✻ ✶✠✿ ✳ ❍❢❃❅❄ ❈ ▼✪✸✺✹✼✻✽✶✓✸❉✴✆✈✜❁❊✶✓✾✪❋☛✳❆❍❽ ✵ ☛ ✹❊✾☎✿❪✾✣❄✪✻ ❈ ✶✓✸❫✹❊✾ ❈ ✿☛❃❅✶ ☛ ❈ ✶✓✳✗✑❣✶✓✶✓✾

✘ ✿✍✾◆❖ ☛ ☎ ✵ ♣☛❾ ➤ ■ ✿✍✾◆❖▲✶✠✿ ✳ ❍☎❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❫✴✆✈❉❁❊✶✓✾✪❋☛✳✵❍☎❽ ✵ ❾✹✼✾❙✿▲✾✣❄✪✻ ❈ ✶✓✸ ❈ ✶✓✳✗✑❇✶✓✶✓✾

✘ ✿✆✾◆❖ ☛ ✂ ✵ t ✘ ♣ ☛✮❲ ✳❆❍✪✶❜✸✵✶✠❃✺❄✣❁✼✳✺✹✼✾✪❋❳✾✣❄✪✻ ❈ ✶✓✸❀❃❪✿✆✸✵✶ ✳ ✴☛✾✜①◗✶✓✸✵✳✵✶✠❖✰✹❊✾ ❈ ✿☛❃❅✶❳t ✘ ➠➎✭➎r✑ ➁ ✎✫✎ ✘ ☎ ➁ ➤ ✘ ❫ ★ ➡ ❺

✪ ➊ ✶❯✳✵❍✪✶✓✾ ✳ ✴☛✾◆❃❡✹❱❖✣✶✓✸❯✿✽✻✷✴✱❖✣✶✩❁❉✴✆✈❤♣☛❾ ➤ ❄✪✸❆✾◆❃ ■ ✑❴❍✪✶✓✾ ❽ ✵ ☛ ■ ✴☛✸❬✿✽✻✷✴✱❖✣✶✩❁❉✴✆✈❛t✘ ♣ ☛ ❄✪✸✵✾◆❃ ■ ✑❛❍✪✶✓✾☎❽ ✵ ❾✪❺

❉ ✴☛✸❛✶✠✿ ✳ ❍❳❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸ ■ ✑❇✶ ✳ ✴☛✻✷▼✪❄✪✳❆✶❯✳✵❍✪✶❪✿☛❃✵❃❅✴ ✳ ✹❱✿✆✳✵✶✠❖▲✾✣❄✪✻ ❈ ✶✓✸❯✿☛❃❴❖✣✶✠❃ ✳ ✸❅✹ ❈ ✶✠❖☎✿ ❈ ✴✆①☛✶ ■ ✿✆✾◆❖✬✑❇✶❯✳✵❍✪✸✵✴✜✑✿ ❈ ✿✎❁❻❁✏✹❊✾✙✳✵❍✪✶ ✳ ✴◗✸✵✸✵✶✠❃❅▼❚✴☛✾◆❖◗✹❊✾✪❋❜❄✪✸✵✾✖❺➎ ❍✪✶ ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ✹❻❁❭✹❊✳❅● ✳ ✴☛✾◆❃❅✳✵✸❀✿✎✹✼✾✣✳ ➠ ✸✵✶☛✭◗❄✣✹✼✸❆✶✓✻✷✶✓✾✜✳❯♣ ➠ ✿ ➡ ✴✆✈✓✮❀♣✪❺❊t ➡ ✹P❃❫✳❆❍✪✶✓✾❹✳❆✸❀✿✆✾◆❃❡✈✑✴☛✸✵✻✷✶✠❖✰✿☛❃❫❃❅❍✪✴✜✑❛✾✰✹✼✾ ❉ ✹❊❋◆❺➂♣➠ ✑❛❍✪✶✓✾❙❽ ✵ ☛ ➡ ❺ ➎ ❍✪✶ ✳ ✴☛✻✽▼✣❁✼✶✓✻✽✶✓✾✜✳❀✿✍✸✵●❳✴✆✈❛✳✵❍✪✶✯✎ ✯ ✼ ❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❏✹❱❃❏✳❀✿ ✭ ✶✓✾ ➠ ✂ ➎✭➎☞✑ ✹❊✾ ❉ ✹❊❋◆❺❂♣ ➡ ✿✍✾◆❖☎✸✵✶✓①◗✶✓✸❀❃❅✶✠❖

☎ q✶❯✣❤t♠❖✐✔❿✔❚✬✭✲➉✲❚✿❿✔❤❄❸s❬✺❸❘❬✣❸✷❩❡✖✒❬✣♥✿❿▼❩✁✐s❬✣❚✰❴✒✖➀❤❄✐✔➉❊❚❥❵ ❦✉➉✲❬➄♠✔➉④❩✁❯✣❯✣❚✁❦✉❸✉❸✔➉❊❚✰❿✔✐❝❸✔❤❄♥✿✖✒❤❄❴✞✐✔❸❋✐s❚✒✖✒❚✁❽✿❤✻✱✚❩✁❸s✐✔❤❄❿✷✐s➉❛❩✁❴✏✐✔➉❊❤❂❯✣❚✰❴❊♥✒❚✰❴❊❤❄❸❄▲✐✔➉❊❬✺❸✉✖➀❤❄✐✔➉❊❚❥❵➀❩✁❯✣❯✣❚✁❦✉❸♣✐s➉✲❤✷❵✞❬✱✰➈❤❍❿✔❤❄❴✞✐✔❬➄❩✮✐✔❬✣❚✰❴❉❚✁✱✶❸✔❤❄♥✿✖✒❤❄❴✞✐s❸✉❚✁✱ ❵❥❬✲✰③❤❄❿s❤❄❴✞✐✗❯✣❤❄❴✲♥✿✐✔➉✲❸✯✮✿✱❇❿✔❚✿✖ ❩❝✖✒❬➁➌✲✐▼✫✲❿s❤✗❚✮✱✽✐✔➉❊❤❄✖ ✮✞✹✚✫❊✐✉❬✺✐✕➉❛❩✮❸✗❩❯✣❬✣✖✒❬✣✐✔❤t❵❯✭❊❿✔❤t♠P❬✣❸s❬✺❚✿❴☎♠P❚✰❿s❿✔❤❄❸▲✭❛❚✿❴❛❵✞❬✣❴✲♥✒✐s❚❡❚✳✫✲❿ ✭❛❩✮❿▼❩✁✖➀❤❄✐✔❤❍❿✴✳✞❱❭✂❭❧Ð

Page 123: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

➠ ✑✆➎✭➎ ✂ ✹❊✾ ❉ ✹❊❋◆❺❇♣ ➡ ■ ✑❇✹❊✳✵❍✁�✄✂ ❈ ✶✩✹✼✾✪❋❙✳❆❍✪✶✙▼◆✿✌❁❭✹❊✾◆❖✣✸✵✴☛✻❪✹ ✳ ✴◗▼◆✶✓✸❀✿✆✳✺✹✼✴◗✾❲✴☛✾ ✿ ✳ ❍◆✿✌✹❊✾ ➡ ❺✆☎❛✸❀❖◗✹❊✾◆✿✆✸✵● ❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❀❃❋☛✶✓✾✪✶✓✸❀✿✍✳✵✶ ❈ ❁❱✿ ✳✮✭▲❈ ✿✎❁❻❁❱❃ ■ ✑❛❍✣✹❭❁❊✶❯✸✵✶✓①◗✶✓✸❀❃❅✶✠❖ ✳ ✴◗✻✷▼✣❁❊✶✓✻✷✶✓✾✜✳✩✿✆✸✵● ✎ ✯ ✼ ❃❅❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸✩❃❇❋☛✶✓✾✪✶✓✸❀✿✆✳❆✶ ✑❛❍✣✹❊✳✵✶ ❈ ✿✌❁❭❁❱❃✓❺➎ ❍✪✶ ✳ ✴☛✻✷▼◆✿✆✳✺✹ ❈ ✹❭❁❭✹❊✳❅●❙✸✵❄✣❁❊✶✷✹❊✻✷▼✣❁❭✹❊✶✠❃❨✳✵❍◆✿✆✳❪✿✆✾❩❄✪✸❆✾ ✳ ✿✆✾♦✾✪✶✓①☛✶✓✸ ✳ ✴☛✾✣✳❀✿✌✹❊✾❙❃❡✹❊✻❢❄✣❁❊✳❀✿✍✾✪✶✓✴☛❄◆❃❡❁❊● ❈ ❁❱✿ ✳✮✭ ✿✆✾◆❖ ✑❴❍✣✹✼✳❆✶❈ ✿✌❁❭❁❱❃✓❺➥✠➦✥❁❦➦✏✣✰⑦➍➭✑➯✌✔✫➨✠➩✔➲✥❆✞✝✳➫ ✠✎❄➋➩✔➲✕☞➔➲⑧⑦ ✔⑨✆➄➩✺➨❦➫ ❆✞✝✣❄❙④✗➩☛⑦❀➫▲➨✑✠✦❄✤➯✖➦ ➊ ✶❯▼✪✸✵✴◗▼◆✴✜❃❅✶❫✹❊✾❳✳✵❍✣✹❱❃❫❃❅✶ ✳ ✳❅✹❊✴☛✾☎✿✆✾❹✿✍▼✪▼✪✸✵✴ ❦ ✹ ✼✻❜✿✆✳❆✶✕✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻ ✑❇✹❊✳✵❍▲❍✣✹❊❋☛❍❨✶ ➟ ✳ ✹❊✶✓✾ ✳ ●❨✹❊✾▲▼✪✸❀✿ ✳ ✳❅✹ ✳ ✿✌❁ ✳ ✴☛✻✷▼✪❄✪✳❀✿✍✳❅✹❊✴☛✾◆❃ ❲ ✳✵❍✣✹❱❃❇✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻⑤✹❱❃❞❁❭✹ ✭ ✶✩❁❊●▲✳✵✴ ❈ ✶❝✿✌❁❊✻✷✴✣❃❅✳✴☛▼✪✳❅✹❊✻❜✿✎❁⑧❺☎❛❄✪✸▲✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻ ✹❱❃❜✿☛❃❢✈✇✴✆❁❭❁❊✴✜✑✕❃ ✥ ✑❇✶✙❃❅✴☛✸✵✳✷✴◗❄✪✸❜❃❅✶✓✳❨✴✆✈✕❁❊✴ ✳ ✹✕✹❊✾ ✹❊✾ ✳ ✸✵✶✠✿☛❃❡✹❊✾✪❋❙✴☛✸✩❖✣✶✓✸❜✿✌❁❊✴☛✾✪❋♦✳✵❍✪✶▲✾✜❄✪✻ ❈ ✶✓✸❜✴✆✈

✳ ✿✆✾◆❖◗✹❱❖✪✿✆✳✵✶✠❃❴▼◆✿✌✹❊✸❀❃❞✴✆✈❉▼✪✸❅✹❊✻✷✶✓✸❀❃ ❲ ✑❣✶❫▼✪✸✵✴ ✳ ✶✠❃✵❃❇✴☛❄✪✸❫❃❅✶✓✳❇✴✆✈❂✴☛✸❀❖✣✶✓✸❆✶✠❖✽❁✼✴ ✳ ✹ ■ ❁❊✴ ✳ ❄◆❃✕✿✎✈✇✳✵✶✓✸❞❁❊✴ ✳ ❄◆❃ ❲ ✈✑✴☛✸❇✶✠✿ ✳ ❍❨❁❊✴ ✳ ❄◆❃ ■ ✑❇✶✳✵✸✵●✰✶✠✿ ✳ ❍❹▼❚✴✜❃✵❃❡✹ ❈ ❁❊✶▲▼◆✿✌✹❊✸❯✴✍✈❣▼✪✸❅✹❊✻✷✶✓✸❀❃✓✑③✹✼✳❆❍☎✸✵✶✠❃❅▼❚✶ ✳ ✳❯✳✵✴▲✳✵❍✪✶ ✳ ✴☛✾◆❖◗✹❊✳❅✹❊✴☛✾◆❃ ■ ✹❊✾ ✳ ❁✼❄◆❖◗✹❊✾✪❋☎✳❆❍✪✶②❖◗✹❱❃❅✳✩✿✆✾ ✳ ✶ ✳ ✴◗✾◆❖◗✹✼✳✺✹✼✴◗✾➠ ✸✵✶☛✭◗❄✣✹❊✸✵✶✓✻✷✶✓✾✣✳❯t ➠ ✿ ➡❝➡ ❺❉ ✴◗✸✕✶✠✿ ✳ ❍☎▼◆✿✌✹❊✸ ■ ✑❇✶ ➐ ✳✵❍✪✸❆✴ ✑ ✑❛❍✣✹❊✳✵✶❜✿✍✾◆❖ ❈ ❁❱✿ ✳✮✭✰❈ ✿✌❁❭❁❱❃❬✹❊✾☎❄✪✸❆✾◆❃ ➒ ■ ✿✌❁❊✴☛✾✪❋▲✳✵❍✪✶❪✻✷✴✪❖✣✶✩❁③❖✣✶✠❃ ✳ ✸❅✹ ❈ ✶✠❖♦✿ ❈ ✴✆①☛✶ ❲ ✑❇✶✶✩❁❭✹❊✻❪✹❊✾◆✿✆✳✵✶❫✳✵❍✪✶❇▼◆✿✌✹❊✸❀❃ ✑❛❍✣✹ ✳ ❍ ✳ ✿✆❄◆❃❅✶ ➐ ❈ ❁❱✿ ✳ ✭ ✿✍✾◆❖✒✑❛❍✣✹❊✳✵✶ ➒ ✳ ✴✆❁❭❁❭✹❱❃❡✹❊✴☛✾◆❃ ❲ ✿✆✻✽✴☛✾✪❋✕✳❆❍✪✶✕✿ ✳✗✳ ✶✓▼✪✳❀✿ ❈ ❁❊✶❛▼◆✿✎✹✼✸✩❃✏✴✆✈➅▼✪✸❅✹❊✻✷✶✓✸✩❃ ■✑❇✶❯❃❅✶✩❁❊✶ ✳ ✳✕✳❆❍✪✶❬▼◆✿✌✹❊✸✕✴✆✈❉▼✪✸❅✹❊✻✷✶✓✸❀❃ ✑❛❍✣✹ ✳ ❍✰✻❪✹❊✾✣✹✼✻②✹✼❘✓✶✠❃ ■ ✹✼✾✰✳✵❍✪✶❬✈✑✴✆❁❭❁❊✴✜✑❇✹❊✾✪❋✷✴☛✸❀❖✣✶✓✸ ✥➠ t ➡ ✳✵❍✪✶❬✾✜❄✪✻ ❈ ✶✓✸❛✴✆✈❉❄✪✸✵✾◆❃ ✳ ✴☛✾✣✳❀✿✌✹❊✾✣✹❊✾✪❋ ✑❴❍✣✹✼✳❆✶ ❈ ✿✌❁❭❁❱❃ ❲➠ ♣ ➡ ✳✵❍✪✶❇✾✜❄✪✻ ❈ ✶✓✸❞✴✆✈✖❄✪✸✵✾◆❃ ✳ ✴◗✾✜✳❀✿✎✹✼✾✣✹❊✾✪❋ ❈ ❁P✿ ✳✮✭✷❈ ✿✎❁❻❁❱❃ ■ ✑❛❍✪✶✓✾✪✶✓①◗✶✓✸❤✳✵❍✪✶❛✾✣❄✪✻ ❈ ✶✓✸❞✴✆✈ ➐ ✑❴❍✣✹✼✳❆✶❛❄✪✸✵✾◆❃ ➒ ✹P❃❦✹❱❖✣✶✓✾✜✳❅✹ ✳ ✿✌❁✈✇✴☛✸❇✳✗✑❇✴❪▼◆✿✌✹❊✸❀❃✓❺

➎ ❍✪✶ ➐ ✑❴❍✣✹✼✳❆✶❢✿✆✾◆❖ ❈ ❁❱✿ ✳ ✭▲❈ ✿✌❁❭❁❱❃ ➒ ✳ ✴◗✸✵✸✵✶✠❃❅▼❚✴☛✾◆❖◗✹❊✾✪❋❜✳✵✴❪▼◆✿✌✹❊✸❀❃❴✴✆✈❉▼✪✸❅✹❊✻✷✶✓✸❀❃❛✿✎❁✼✸❆✶✠✿☛❖✣●✙❃❅✶✩❁❊✶ ✳ ✳✵✶✠❖▲✸❆✶✓✻❜✿✌✹❊✾▲✹❊✾✙✳❆❍✪✶❬❄✪✸✵✾◆❃✑❛❍✪✶✓✾✰▼✪✸✵✴ ✳ ✶✠❃❆❃❡✹❊✾✪❋ ✿❪✾✪✶ ✑ ❁✼✴ ✳ ❄◆❃✓❺➎ ❍✪✶❏❁❊✴ ✳ ✹❤▼✪✸❆✴✎①◗✹❱❖◗✹❊✾✪❋✙✾✪✴ ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ❁✼✶✽▼◆✿✌✹❊✸ ✑❇✹❊✳✵❍❳✳✵❍✪✶❪▼◆✿✌✹❊✸❀❃❫✴✆✈❣✳❆❍✪✶❬❁❊✴ ✳ ✹❛✿✌❁❊✸✵✶✠✿☛❖✣● ✳ ❍✪✴✜❃✺✶✓✾✙✈✑✴☛✸❫✳✵❍✪✶ ✳ ❄✪✸✵✸✵✶✓✾✣✳✶ ❦ ▼◆✶✓✸❅✹❊✻✷✶✓✾✣✳❝✿✍✸✵✶❫❁❊✶✩✈✇✳❬✿✆▼◆✿✆✸✵✳❛✿✆✾◆❖❨▼✪✸❆✴ ✳ ✶✠❃✵❃✺✶✠❖❨✹❊✾❹✿❪✾✪✶ ❦ ✳❛✶ ❦ ▼◆✶✓✸❅✹❊✻✷✶✓✾✣✳✠❺✝➄❦ ▼◆✶✓✸✺✹✼✻✽✶✓✾✜✳❀✿✎❁❂✸✵✶✠❃❅❄✣❁❊✳❬❃❅❍✪✴✜✑✕❃❇✳✵❍◆✿✆✳ ■ ✑❴❍✪✶✓✾✙▼✪✸✵✴ ✳ ✶✠❃✵❃❡✹❊✾✪❋▲♣ ☛ ❲ ❁❊✴ ✳ ✹❉✴✆✈ ➬ ✶✓✾ ❈ ✿✆✾ ✭➅■ ✹✼✳ ✑❣✴◗❄✣❁P❖ ❈ ✶❏✳✵❍✪✶✓✴☛✸✵✶✓✳❅✹ ✳ ✿✌❁❭❁❊●▼◆✴✣❃✵❃❡✹ ❈ ❁❊✶✕✳✵✴❯✿✍✻✷▼✣❁❭✹❻✈✑●✷❃❡✹❊✻❪❄✣❁✼✳✩✿✆✾✪✶✓✴☛❄◆❃❡❁❊●❜♣ ☛ ❾❴❁✼✴ ✳ ✹ ■ ✑❇✹❊✳✵❍✷❽ ✵ ❾ ❲ ✳❆❍✪✶✕✿✌①☛✶✓✸❀✿✆❋☛✶❇❃❡✹❊❘✓✶❛✴✆✈➂✳✵❍✪✶❇❁❊✴ ✳ ✹❚✹❱❃ ☛ ✘✞✘❄✘ ❈ ▼✖❺ ■ ✑❇✹❊✳✵❍✿✆✾❳✿✠①◗✶✓✸❀✿✆❋☛✶❬✾✣❄✪✻ ❈ ✶✓✸❫✴✆✈❣♣✘■✘❄✘✞✘ ✿☛❖✣✻❪✹❱❃✵❃❡✹ ❈ ❁❊✶✷▼◆✿✌✹❊✸❀❃❴✴✆✈❤▼✪✸❅✹❊✻✷✶✓✸❀❃✒❺ ✎ ✴ ✑❇✶✓①☛✶✓✸ ■ ✹❊✳❫✹❱❃ ❈ ✹✼✴✍❁✼✴◗❋✆✹ ✳ ✿✌❁❭❁✼●♠❄✪✾✪✸✵✶✠✿✌❁❭✹❱❃❅✳❅✹ ✳ ✳✵✴✳✵❍✣✹❊✾ ✭ ✳✵✴❜✿✍✻✷▼✣❁❭✹❻✈✑●✙❃❡✹❊✻❪❄✣❁❊✳❀✿✆✾✪✶✓✴☛❄◆❃❡❁❊●▲✻❪❄ ✳ ❍▲✻✷✴☛✸✵✶❬✳✵❍◆✿✍✾▲✳✵✶✓✾▲❁❊✴ ✳ ✹⑧❺❁❦➦✞✝➋❄ ❆✐❄➋➩①➫➌➲✑⑦✗➲⑧⑦ ✔t❆✞✝✑❄✠✟❦➭✑➲✼➩✔➳♦➨✡✆⑦✟✳➩✔➲✉➫✲❄✤➩➁➳ ★④✝✗➲ ❷✲✝❀➫▲➭✪⑥➔➲✦➫ ➲✠✟✛❄✾❆✞✝✣❄♦⑦✖④✳➫ ✤➄❄➋➩✈➨✩✆➂➯q➨✖❷✜➲✭➲⑧⑦➍➭➉➳✺➲⑧⑦ ✔✠➯ ❄❄✣⑥♣✟➄❄✤➩✔➲✉➫✲❄◆⑦✷❆✈➲✸➳❳➭☛✡ ❒ ✎✵❷✔➨❦➫ ✟✳➯✥❄ ❆✐❄ ✟✳➩❣➨✥✤✳➯✥❄✫➫

➊ ✶❪✻✷✴✪❖✣✶✩❁❤✴☛❄✪✸❬▼✪✸✵✴ ❈ ❁❊✶✓✻ ✿☛❃❬✿▲❃✺✶✓✳✕✴✆✈ ❈ ✹❊▼◆✿✆✸✵✳❅✹❊✳✵✶❜❃✺❄ ❈ ❋☛✸❀✿✆▼✪❍◆❃✓✑❇✹❊✳✵❍☎✿☛❖✪❖◗✹❊✳❅✹❊✴☛✾◆✿✎❁❣✶✠❖✣❋☛✶✠❃ ➠ ❉ ✹❊❋☛❄✪✸❆✶ ✎ ➠ ✿ ➡❝➡ ❲ ✹❊✾✳✵❍✣✹❱❃❴❋☛✸❀✿✆▼✪❍ ■ ✶✠✿ ✳ ❍✰▼✪✸❅✹❊✻✷✶✓✸❛✹❱❃❴✸✵✶✓▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖ ❈ ●✙✿❪①◗✶✓✸✵✳✵✶ ❦ ❲ ✳✵❍✪✶❢❃✺✶✓✳❛✴✆✈❉①☛✶✓✸✵✳❅✹ ✳ ✶✠❃③✹P❃❫▼◆✿✍✸✵✳❅✹❊✳❅✹❊✴☛✾✪✶✠❖ ❈ ●❨❁❊✴ ✳ ❄◆❃ ■ ✶✠✿ ✳ ❍❁❊✴ ✳ ❄◆❃ ✳ ✴◗✸✵✸✵✶✠❃❅▼❚✴☛✾◆❖◗✹❊✾✪❋▲✳✵✴❜✿ ❈ ✹❊▼◆✿✆✸✵✳✺✹✼✳❆✶②❃✺❄ ❈ ❋☛✸❀✿✆▼✪❍ ❲ ✹❊✾❹✴◗❄✪✸❛✶ ❦ ✿✍✻✷▼✣❁❊✶ ■ ①☛✶✓✸✵✳❅✹ ✳ ✶✠❃ ❈ ✶✩❁❊✴☛✾✪❋✆✹❊✾✪❋▲✳✵✴❨✳✵❍✪✶❯❃✵✿✆✻✽✶❬❁❊✴ ✳ ❄◆❃✿✆✸✵✶▲✸❆✶✓▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖ ❈ ●♦✳✵❍✪✶✙❃✵✿✍✻✷✶ ✳ ❍◆✿✍✸❀✿ ✳ ✳✵✶✓✸ ➠✌☞ ✈✑✴☛✸❪❁❊✴ ✳ ❄◆❃✦t ■✎✍ ✈✇✴☛✸❏❁❊✴ ✳ ❄◆❃❜♣ ■✑✏ ✈✇✴◗✸❯❁❊✴ ✳ ❄◆❃ ✎ ➡ ■ ✳✵❍✪✶❨✈✑✴☛✸ ✑❛✿✆✸❀❖▼✪✸❅✹❊✻✷✶✓✸❀❃ ❈ ✶✩✹✼✾✪❋❪✸✵✶✓▼✪✸❆✶✠❃❅✶✓✾✜✳❆✶✠❖✷✴☛✾✽✳✵❍✪✶❛❁❊✶✩✈✑✳❤▼◆✿✆✸❆✳❤✴✆✈✖✳✵❍✪✶✓✒◆❋◗❄✪✸✵✶ ➠ ❉ ✹✼❋◗❄✪✸✵✶✖✎ ➠ ✿ ➡❝➡ ■ ✑❛❍✣✹❭❁❊✶❬✳✵❍✪✶❛✸❆✶✓①☛✶✓✸❀❃❅✶❫▼✪✸❅✹❊✻✷✶✓✸❀❃❞✿✆✸✵✶✸✵✶✓▼✪✸✵✶✠❃✺✶✓✾✜✳✵✶✠❖✦✴☛✾▲✳✵❍✪✶❬✸❅✹❊❋☛❍✣✳❛▼◆✿✆✸❆✳✠❺ ➎ ❍✪✶✓✸✵✶❢✿✍✸✵✶❬✳✗✑❣✴ ✭ ✹❊✾◆❖▲✴✆✈❉✶✠❖✣❋☛✶✠❃ ✥✪ ✿ ✳✗✳ ✶✓▼✪✳❀✿✆✾ ✳ ✶▲✶✠❖✣❋☛✶✠❃ ■ ✹❊✾◆❃❡✹❱❖✣✶❳✳✵❍✪✶ ❈ ✹❊▼◆✿✆✸✵✳❅✹❊✳✵✶❳❃❅❄ ❈ ❋☛✸❀✿✍▼✪❍❙✸✵✶✠❃❅✳✵✸❅✹ ✳ ✳✵✶✠❖ ✳✵✴☎✿☎❃❡✹❊✾✪❋✆❁❊✶▲❁❊✴ ✳ ❄◆❃ ❲ ❃✺❄ ✳ ❍ ✿❳✾✪✴☛✾ ✼✿✆✸✵✸✵✴✜✑❇✶✠❖❳✶✠❖✣❋☛✶✦✹✼✾◆❖◗✹ ✳ ✿✆✳❆✶✠❃✷✳✵❍◆✿✍✳✷✳✵❍✪✶❨✈✑✴☛✸ ✑❛✿✆✸❀❖♦✿✆✾◆❖♦✳✵❍✪✶▲✸✵✶✓①◗✶✓✸❀❃❅✶▲▼✪✸❅✹❊✻✷✶✓✸❀❃ ✄ ✴✆✹❊✾✪✶✠❖ ❈ ●❩✳✵❍✪✶▲✶✠❖✣❋◗✶✙✿✆✸✵✶

✳ ✴☛✻✷▼◆✿✆✳❅✹ ❈ ❁❊✶ ❲✪ ✹✼✾ ✳ ✴◗✻✷▼◆✿✆✳❅✹ ❈ ✹❭❁❭✹✼✳❅●❨✶✠❖✣❋☛✶✠❃ ■ ✄ ✴✆✹❊✾✣✹✼✾✪❋✷✿ ①☛✶✓✸✵✳✵✶ ❦ ✴✆✈❂✿❫❁❊✴ ✳ ❄◆❃❞✳✵✴❢✿ ①☛✶✓✸✵✳✵✶ ❦ ✴✆✈❂✿❯❖◗✹ ➑ ✶✓✸✵✶✓✾✜✳❞❁❊✴ ✳ ❄◆❃ ❲ ✳✵❍✪✶✠❃❅✶❫✶✠❖✣❋☛✶✠❃✑❇✹❊✳✵❍✙✿✆✸✵✸✵✴✜✑❇✶✠❖✽✶ ❦ ✳✵✸❆✶✓✻❪✹❊✳❅✹❊✶✠❃❇✹❊✾◆❖◗✹ ✳ ✿✆✳✵✶❪✳✵❍◆✿✆✳❇✳✵❍✪✶❬▼✪✸✺✹✼✻✽✶✓✸❀❃❛✳❆❍✪✶✓● ✄ ✴✆✹❊✾❹✿✆✸❆✶❬✾✪✴☛✳ ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ❁✼✶☛❺☎❛❄✪✸ ➐ ❨ ❤✛♣ ❧ ➸ ♠✕✔ ✁ ❼ ✭✼� ✰ ✔ ♣❑✭❅✰❝➺ �❻✰➅❤ ✁ ❼ ✭❋♣ ➒ ■ ✹❊✾❹❃❅❍✪✴◗✸✵✳ ✂ ✓✻✓ ■ ❍◆✿☛❃③✳✵❍✪✶❬✈✑✴✆❁❭❁❊✴ ✑③✹✼✾✪❋❨❖✣✶✠❃ ✳ ✸❅✹❊▼✪✳❅✹❊✴☛✾ ✥✖ ⑦✗➳✐❆✌➭➂⑦✖❷P❄➌➨✩✆❀❆✞✝✣❄⑨✟➔➩❣➨✥✤✳➯ ❄✑➫✘✗ ✿✷❋☛✸✩✿✆▼✪❍ ✳ ✴☛✻✽▼◆✴✜❃❅✶✠❖✰✴✆✈❣✿❨❃❅✶✓✳❬✴✆✈ ❈ ✹❊▼◆✿✆✸❆✳❅✹❊✳✵✶❪❋☛✸❀✿✆▼✪❍◆❃ r ❫ ➄ r ⑤ ➄ ✪❋✪❋✪ ➄ r✚✙ ❲ ✳✵❍✪✶✶✠❖✣❋☛✶✠❃❴✴✆✈❤✳✵❍✪✶✠❃❅✶❏❋☛✸❀✿✆▼✪❍◆❃ ✳ ✴☛✾◆❃❅✳✺✹✼✳❆❄✪✳✵✶✷✿✷❃❅✶✓✳❫✴✆✈❣✿ ✳✗✳ ✶✓▼✪✳❀✿✆✾ ✳ ✶❪✶✠❖✣❋☛✶✠❃ ➴ ❲ ✿❨❃❅✶✓✳❫✴✆✈❉✹❊✾ ✳ ✴☛✻✷▼◆✿✆✳❅✹ ❈ ✹❭❁❭✹❊✳❑●❳✶✠❖✣❋☛✶✠❃ ■ ✳✵❍✪✶✠❃❅✶✶✠❖✣❋☛✶✠❃ ✄ ✴✆✹❊✾✣✹❊✾✪❋▲▼◆✿✌✹❊✸❀❃❇✴✆✈❉①☛✶✓✸✵✳✺✹ ✳ ✶✠❃ ✑❛❍✣✹ ✳ ❍☎❖✣✴✷✾✪✴☛✳ ❈ ✶✩❁✼✴◗✾✪❋▲✳✵✴❪✳✵❍✪✶❢❃✵✿✍✻✷✶ ❈ ✹❊▼◆✿✆✸❆✳❅✹❊✳✵✶❢❃❅❄ ❈ ❋◗✸❀✿✆▼✪❍◆❃ ❲ ✿✍✾❨✹✼✾✣✳✵✶✓❋☛✶✓✸✜✛♦❺

✢ ④✑❄✤➳✐❆✺➲❺➨✖⑦✣✗ ✹❱❃❞✹❊✳❣▼❚✴✜❃✵❃❡✹ ❈ ❁❊✶❯✳❆✴ ✳ ❍✪✴✣✴✜❃❅✶❬✿❢❃✺❄ ❈ ❃❅✶✓✳❛✴✆✈❦✿ ✳✗✳ ✶✓▼✪✳❀✿✆✾ ✳ ✶❬✶✠❖✣❋☛✶✠❃ ➴✥✤✑➁❾➴ ✑❇✹❊✳✵❍ ❮ ➴✥✤✦❮ ✫ ✛ ❃❅❄ ✳ ❍▲✳✵❍◆✿✆✳➴ ✤ ✳ ✴◗✾✜✳❀✿✎✹✼✾◆❃❫✿✆✳❇✻✷✴✜❃✺✳❛✴☛✾✪✶❬✶✠❖✣❋☛✶ ✈✇✸✵✴◗✻➄✶✠✿ ✳ ❍ r ✃ ■ t ❰ ➱ ❰ ✣❦■ ✿✆✾◆❖✙❃❅❄ ✳ ❍✙✳❆❍◆✿✆✳❇✾✪✴❜✳✗✑❇✴❪①☛✶✓✸✵✳❅✹ ✳ ✶✠❃ ❈ ✶✩❁❊✴☛✾✪❋✆✹❊✾✪❋▲✳✵✴✳✵❍✪✶✠❃❅✶❬✶✠❖✣❋◗✶✠❃✕✿✆✸❆✶❬✶ ❦ ✳✵✸❆✶✓✻❪✹❊✳❅✹❊✶✠❃❛✴✆✈❉✿✆✾▲✹❊✾ ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ✹❻❁❭✹❊✳❅●✙✶✠❖✣❋☛✶☛❺❭✂❭ ❖

Page 124: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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➓ ✝➠ ✿ ➡ ✑ ✸❆✶✓▼✪✸✵✶✠❃❅✶✓✾✣✳❀✿✆✳❅✹❊✴☛✾✰✴✆✈❂✳✵❍✪✶✳ ✴☛✻✷▼◆✿✆✳✺✹ ❈ ❁❊✶❏▼✪✸❅✹❊✻✷✶✓✸✕▼✪✸❆✴ ❈ ❁❊✶✓✻

➠ ❈ ➡ ✑ ✳✵✸❀✿✆✾◆❃❑✈✇✴☛✸❆✻✐✴✍✈❂✳✵❍✪✶❯✻❪❄✣❁❊✳❅✹❊▼✣❁❊✶✳ ❍✪✴✆✹ ✳ ✶❯✻❜✿✍✳ ✳ ❍✣✹❊✾✪❋✷▼✪✸❆✴ ❈ ❁❊✶✓✻

✞ ✟☛✡ ☞✦✍✣✏ ✟✑✔ ➎ ✸❀✿✆✾◆❃❑✈✇✴☛✸❆✻❜✿✆✳❅✹❊✴☛✾✰✴✆✈❣✿✆✾✣●✙❋☛✸❀✿✍▼✪❍✙✳✵✴▲✿❜❃✺✶✓✳❬✴✆✈ ❈ ✹❊▼◆✿✆✸✵✳❅✹❊✳✵✶❜❃✺❄ ❈ ❋☛✸❀✿✆▼✪❍◆❃❴✻✷✴✪❖✣✶✩❁❻❁❭✹❊✾✪❋✳✵❍✪✶ ✳ ✴☛✻✽▼◆✿✆✳❅✹ ❈ ❁❊✶❯▼✪✸❅✹❊✻✷✶✓✸❀❃❴▼✪✸✵✴ ❈ ❁❊✶✓✻✑ ✳❅●✣▼✣✹ ✳ ✿✌❁❯❋☛✸❀✿✆▼✪❍ ✴✆✈ ✂ ✓✗✓ ✹❱❃✙❃❅❍✪✴✜✑❛✾ ✹✼✾ ❉ ✹✼❋◗❄✪✸✵✶ ✎ ➠ ✿ ➡ ❲ ✿✆✾✣●❲✶✠❖✣❋◗✶❹✴✍✈❢✿✕✔ ❳✗✖ ❼✸♠✕✔❹❧✑❼ ✭ ❨ ❾ ❤ ✔✸➻ ✭ ❳▲➸ ♠✉➻✐❾ ✔ ➾ ➎� ✰❡❤✻✁ ❼ ✭❋♣✙✘ ➠ ✹❊✾ ❃❅❍✪✴☛✸❆✳ r ✂ r ✓✙➡ ❋☛✸❀✿✍▼✪❍❲✹❱❃❨✳✵✸✩✿✆✾◆❃❡✈✑✴☛✸✵✻✷✶✠❖ ✹❊✾ ✿♠①☛✶✓✸✵✳✵✶ ❦ ✴✆✈②✿ ✂ ✓✻✓ ❋☛✸❀✿✆▼✪❍ ❲ ❖✣❄✪✻✽✻❢● ✾✪✴✱❖✣✶✠❃➠ ✒◆❋☛❄✪✸❆✶✠❖ ❈ ● ✏ ➡ ✿✆✸✵✶✷✿☛❖✪❖✣✶✠❖ ■ ✴☛✾✪✶❏✈✑✴☛✸❫✶✠✿ ✳ ❍❳❃❅❄ ❈ ❃❅✶✓✳❬✴✆✈❤①◗✶✓✸✵✳❅✹ ✳ ✶✠❃❫✴✆✈ r ✂ r ✓ ❺ ❉ ✹❊❋☛❄✪✸✵✶✏✎ ➠ ❈ ➡ ✸✵✶✓▼✪✸❆✶✠❃❅✶✓✾✜✳✩❃✕❃❅❄ ✳ ❍☎✿✳✵✸❀✿✍✾◆❃❡✈✇✴◗✸✵✻❧✴✆✈❦✿ r ✂ r ✓ ❋☛✸❀✿✍▼✪❍ ➠ ✾✪✴◗✳❛✸✵✶✓▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖✽✹❊✾✙✳❆❍✪✶✚✒◆❋☛❄✪✸✵✶ ➡ ✳✵✴✷✿ ✂ ✓✗✓ ✴☛✾✪✶☛❺ ➎ ❍✣✹P❃❴✳✵✸❀✿✍✾◆❃❡✈✇✴◗✸✵✻❜✿✆✳❅✹❊✴☛✾②✹P❃❖✣✶✓✳❀✿✌✹❭❁❊✶✠❖❏✹❊✾✙s ♣ ■ ✎✆✉✞❺ ➎ ❍✪✶✓✸✵✶✩✈✑✴☛✸✵✶ ■ ❃❅✴✆❁❊①◗✹❊✾✪❋ ✂ ✓✻✓ ✹❊✾✷▼❚✴✆❁❊●✜✾✪✴◗✻❪✹❱✿✌❁◆✳❅✹❊✻✷✶ ✑❇✴☛❄✣❁❱❖❢✿✎❁P❃✺✴❯❃❅✴✆❁❊①☛✶ r ✂ r ✓ ✹❊✾❪▼◆✴✍❁✼●✣✾✪✴☛✻❪✹❱✿✌❁

✳❅✹❊✻✷✶ ■ ✑❛❍✣✹ ✳ ❍ ✳ ✴☛✾✣✳✵✸❀✿☛❖◗✹ ✳ ✳❀❃❫✳✵❍✪✶ ✡ ❒ ✼★✳ ✴◗✻✷▼✣❁❊✶✓✳✵✶✓✾✪✶✠❃✵❃❏✴✆✈ r ✂ r ✓ ❺ ➊ ✶✷❍✪✶✓✾ ✳ ✶❨▼✪✸✵✴✆①☛✶✠❖ ✡ ❒ ❝ ✳ ✴☛✻✷▼✣❁❊✶✓✳✵✶✓✾✪✶✠❃✵❃❏✴✆✈✂ ✓✻✓ ❺✂✳➦✛✚ ☞✤➭✑➯✑④★➭✕❆✺➲✑⑦ ✔➌❆✞✝✣❄ ➯✸➲✦➫ ➲ ❆ ✟✳➩❣➨✥✤❦➭ ✤➔➲✸➯✸➲✥❆✩⑩❀➨✩✆✾➩❅❄✢✜✐❄✪❷P❆✺➲q➨✂⑦❾➨✩✆☛➭➉➯q➨✖❷✣④✗➳

➎ ❍✪✶❛✶ ❦ ▼◆✶✓✸✺✹✼✻✽✶✓✾✜✳❀✿✎❁➅✸✵✶✠❃❅❄✣❁❊✳❀❃❼✴ ❈ ✳❀✿✌✹❊✾✪✶✠❖✒✑③✹✼✳❆❍ ♣ ☛ ❲ ❁❊✴ ✳ ✹✂❃✺❍✪✴ ✑❙✳❆❍◆✿✆✳❤✿ ❈ ✴◗❄✪✳❤❾✘ ❁❊✴ ✳ ✹❂✿✆✸✵✶❇✶✓✾✪✴☛❄✪❋◗❍✷✳✵✴✚✒✪❁❭❁❵✿✌❁❊✻✷✴✣❃❅✳

✳ ✴☛✻✷▼✣❁❊✶✓✳✵✶✩❁❊●✰✳✵❍✪✶❯❃❅●✪❃❅✳✵✶✓✻➄✴✆✈❉❄✪✸✵✾◆❃✓❺✤✣☎✶ ✑③✿✍✾✜✳❇✳✵✴✷✶✓①✆✿✌❁❊❄◆✿✆✳✵✶❏✳✵❍✪✶❯▼✪✸✵✴ ❈ ✿ ❈ ✹❭❁❻✹❊✳❅●✙✴✍✈❦✸✵✶ ✄ ✶ ✳ ✳❅✹❊✴☛✾✰✴✆✈❼✿❢❁✼✴ ✳ ❄◆❃③✹✼✾☎❃❅❄ ✳ ❍✿✷❃✵✿✍✳✵❄✪✸❀✿✆✳✵✶✠❖❨❃❅●✪❃❅✳✵✶✓✻➄✴✍✈❦❄✪✸✵✾◆❃✒❺✹❭✈ ✦ ✹❱❃❫✳✵❍✪✶❪✾✜❄✪✻ ❈ ✶✓✸✕✴✆✈❣❃✺❄ ❈ ▼✪✸❅✹❊✻✷✶✓✸❀❃❬✴✍✈❣✿✷▼✪✸❅✹❊✻✷✶✓✸ ➠ ▼✪✸❀✿ ✳ ✳❅✹ ✳ ✿✌❁❭❁✼● ■ ✹❭✈③❽ ✵ ☛ ■✰✦❑✵ t ✍ ✈✇✴◗✸❛▼✪✸❅✹❊✻✷✶✓✸❀❃❫✴✆✈❉❁❊✶✓✾✪❋☛✳❆❍

♣ ✘ ➡ ■ ✑❇✹❊✳✵❍✗✥ ❫ ❖ ✦⑦❖ ❊ ✳❆❍✪✶❬▼✪✸✵✴ ❈ ✿ ❈ ✹❭❁❭✹❊✳❑●✰✴✆✈❣✿ ✳✗✳ ✶✓▼✪✳❀✿✍✳❅✹❊✴☛✾✙✴✆✈❤✿❪▼✪✸❅✹❊✻✷✶✓✸ ❈ ●▲✿❜❃❅●✪❃❅✳✵✶✓✻ ✴✆✈★✧ ❄✪✸✵✾◆❃ ✳ ✴☛✾✣✳❀✿✌✹❊✾✣✹❊✾✪❋❜✶✩✹❊✳✵❍✪✶✓✸✑❛❍✣✹❊✳✵✶ ■ ✴◗✸ ❈ ❁❱✿ ✳✮✭▲❈ ✿✎❁❻❁❱❃ ■ ✑❇✶❬❍◆✿✌①☛✶✥ ❫ ❖ ✦⑦❖ ❊ ✵ ❍✧ ✩ t ❝ ❍✧✫✪ ✞ ✿✆✾◆❖ ✥ ❫ ❖ ✝ ★ ❖ ⑤➅⑤ ✹ ✵ ✘ ✪ ✘ t ☛ ✪➠ t ➡✬ ❍✪✶❇▼✪✸✵✴ ❈ ✿ ❈ ✹❻❁❭✹❊✳❅●✭✥ ❫❡❫ ✴✆✈ ✳ ✴☛✻✷▼◆✿✍✳❅✹ ❈ ✹❻❁❭✹❊✳❅●✷✴✆✈◆✳✗✑❇✴✕▼✪✸✺✹✼✻✽✶✓✸❀❃ ❈ ✶✓✳✗✑❇✶✓✶✓✾❪✳✵❍✪✶✓✻❜❃❅✶✩❁❊①☛✶✠❃ ■ ✑❛❍✪✶✓✾ ✳ ✴☛✾◆❃❡✹❱❖✣✶✓✸❅✹❊✾✪❋✷✿✆✾❯✶✓✻✽▼✪✳❑●❃❅●✪❃❅✳✵✶✓✻➄✴✍✈❦❄✪✸✵✾◆❃ ■ ✹❱❃ ✥ ❫❡❫ ✵

t✧ ✩ t ❝ t✧✭✪ ⑤ ✞ ✳ ✩ t ❝ t✧✭✪ ✩ t ❝ ♣✧✭✪ ⑤ ✞✵ ✘ ✪ ✍➁➤✜➤ ✪➠ ♣ ➡

❭✂❭ ●

Page 125: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✬ ❍✪✶ r ➞✾❐ ✬❇q▼✓ ✂ ✖ ✿✌❁❊❋☛✴◗✸❅✹❊✳✵❍✪✻ ✳ ✴☛✾◆❃❡✹❱❖✣✶✓✸❀❃✷✿✰✾✣❄✪✻ ❈ ✶✓✸✁� ✴✆✈❛✈✑✴☛✸ ✑❛✿✆✸✩❖❳▼✪✸❅✹❊✻✷✶✓✸❀❃ ✈✑✴☛✸✷✿▲❁❊✴ ✳ ❄◆❃ ■ ✿✆✾◆❖ ■ ✈✇✴☛✸❪✶✠✿ ✳ ❍✈✑✴☛✸ ✑❛✿✆✸❀❖❨▼✪✸❅✹❊✻✷✶✓✸ ■ ✿✷✾✣❄✪✻ ❈ ✶✓✸✄✂ ✴✍✈❤✸✵✶✓①☛✶✓✸❀❃❅✶❏▼✪✸❅✹❊✻✷✶✓✸❀❃❬✿✆✳❬✿✆✾❳✿ ✳✗✳ ✶✓▼✪✳❀✿ ❈ ❁❊✶❜❖◗✹❱❃❅✳❀✿✍✾ ✳ ✶❢✴✍✈❤✳✵❍✣✹❱❃❫▼✪✸❅✹❊✻✷✶✓✸ ➠ ❈ ✶✓✳✗✑❇✶✓✶✓✾t✠❾ ✘ ✿✆✾◆❖ ☛ ❾ ✘ ❈ ▼ ➡ ❲ ❖✣✶✓▼◆✶✓✾◆❖◗✹❊✾✪❋✙✴✆✈❉✳✵❍✪✶ ❁✼✴ ✳ ❄◆❃❴❁❊✶✓✾✪❋☛✳✵❍ ■ � ✹P❃ ❈ ✶✓✳✗✑❣✶✓✶✓✾♦t ✘✞✘ ✿✍✾◆❖✙❾ ✘✞✘ ■ ✑❴❍✣✹❻❁❊✶✁✂ ✸❆✶✓✻❜✿✌✹❊✾◆❃ ✳ ❁❊✴✜❃✺✶✳✵✴❜❾ ✘ ❺✬ ❍✪✶❛❃❅✻❜✿✎❁❻❁✪①✎✿✎❁✼❄✪✶❴✴✆✈ ✥ ❫ ❖ ✝ ★ ❖ ⑤➅⑤ ✹ ✿✎❁❻❁❊✴✜✑✕❃✂❄◆❃✏✳✵✴❬✿✆▼✪▼✣❁❊●❢✳❆❍✪✶ ✓ ✴✆✹❱❃✵❃❅✴◗✾②✿✍▼✪▼✪✸✵✴ ❦ ✹❊✻❜✿✆✳✺✹✼✴◗✾❯✳✵✴❫✳✵❍✪✶ ❈ ✹❊✾✪✴☛✻❪✹❱✿✌❁➅❖◗✹❱❃❅✳✵✸❅✹ ❈ ❄ ✼✳❅✹❊✴☛✾✷✴✍✈➅✳✵❍✪✶❇✾✣❄✪✻ ❈ ✶✓✸❤✴✆✈✖✿ ✳✗✳ ✶✓▼✪✳✵✶✠❖②✈✇✴◗✸ ✑❛✿✆✸❀❖❯✿✍✾◆❖❪✸✵✶✓①☛✶✓✸❀❃✺✶❣▼✪✸✺✹✼✻✽✶✓✸❀❃ ■ ✑③✹✼✳❆❍✷✸✵✶✠❃❅▼❚✶ ✳ ✳❅✹❊①☛✶❛▼◆✿✆✸❀✿✍✻✷✶✓✳✵✶✓✸❀❃✆☎ ✵ � ✥ ❫ ❖ ✦⑦❖ ❊✿✆✾◆❖✞✝ ✵ ✂ ✥ ❫❡❫ ✥ ❫ ❖ ✦⑦❖ ❊ ❺✬ ❍✪✶❬▼✪✸✵✴ ❈ ✿ ❈ ✹❭❁❻✹❊✳❅●✠✟ ✴✆✈❉✸✵✶ ✄ ✶ ✳ ✳❅✹❊✴☛✾▲✴✆✈❤✿❏❁❊✴ ✳ ❄◆❃③✹❱❃❛✳✵❍✪✶✓✾✟ ➠ ☎ ➠ � ➡❾➄ ✝ ➠ ✂ ➡❝➡ ✵

✡✜ ✃☛ ★➠ ✓ ✸ ❘ ✩ ✵ ➱ ❩ ✛ ➠ ✓ ✸ ❘ ⑥ ✵ ✘ ❩ ➡ ✃ ➡ ✵ ✚ ✩✌☞ ❜ ☞✎✍✑✏✓✒✞➄➠ ✎ ➡

▼✪✸✵✴ ❈ ✿ ❈ ✹❻❁❭✹❊✳❅● ✑❛❍✪✴✜❃❅✶❪❃❅✴☛✻✷✶❫①✎✿✎❁✼❄✪✶✠❃❴✈✑✴☛✸✔✂ ✵ ❾ ✘ ✿✍✸✵✶✕ ♣☛❾ ✘ ✎ ✘✞✘ ✎☛❾ ✘ ☛ ✘✞✘ ☛ ❾ ✘

✟ ➠ ☎ ➠ � ➡❾➄ ✝ ➠ ❾ ✘ ➡❝➡ ✘ ❺ ♣ ✎ ✘ ✘ ❺❊t ✍ t ✘ ❺❊t✌♣ ❲ ✘ ❺ ✘ ✔ ❾ ✘ ❺ ✘ ✍ t✂ ✴☛✾◆❃❑✹P❖✣✶✓✸✺✹✼✾✪❋❨✴☛❄✪✸❛✶ ❦ ▼◆✶✓✸✺✹✼✻✽✶✓✾✜✳❀✿✎❁❦✸✵✶✠❃✺❄✣❁✼✳✩❃❇✴☛✾❹♣ ☛ ❲ ❁✼✴ ✳ ✹ ■ ✳❆❍✣✹P❃❫❃❅❍✪✴✜✑✕❃❞✳✵❍◆✿✆✳❴✴☛❄✪✸✕✿✌❁❊❋☛✴☛✸✺✹✼✳❆❍✪✻❧✹❱❃✖✭◗❄◆✿☛❃❡✹ ✼ ✴☛▼✪✳❅✹❊✻❜✿✎❁⑧❺

☞✆✌✎✍✑✏✎✌✎✒✔✓✖✕✘✗✚✙✜✛✣✢❳ ❭ ❨❂✵③❬✣❴❛♠❖❚✰❯✣❴☎❭✥①③❱❛q✉❱⑤❫❉✮✔✰❋❩✁❯✣✤☎❭✥✸④❱✚✦✧❱⑤❫☛✮❛❩✮❴❛❵❉✵✩❩✮❴❛❵✞❤❄❿❝❭✚q✉❱✧①③❱⑤❫❄❱✞❣ ■✗✖❄❘✙✘❉❹✗✖✛✚ ❚ ❂❄✹❆❅✸❇✖❈✬✼➃▲❉✻❋■❄✻✺✹✙✜✘✻ ❀❆❅ ●✪✹❆✻✸❚◆❈✬✼ ✹❆❅ ❀ ✼❏✾❼❏ ❀❆❁ ❁ ❺➇➈▲❉❁✺▲P❏✽✼❏✾ ❊✢✜✒■✸❂✣✖✜■ ✻☛✾ ❅❡▲☛✻P◆❄❱❊❣ ✸❉✦✥✛✜❁✕❤❄❴✞✐✔❤❄❿❝✱❇❚✿❿ ✙ ❤❄❴✲❚✰✖➀❤⑦❾ ❤❄❸✔❤❑❩✁❿▼♠s➉ ❩✁❴❛❵ ❷✠➉✲❬✣✐✔❤❍➉✲❤t❩✰❵✏✦✥❴❊❸✔✐✔❬✣✐▲✫✲✐✔❤ ✱❇❚✰❿✷✘☞❬✺❚✿✖✒❤t❵❥❬ ♠❍❩✁❯❾✉❤❍❸✔❤t❩✮❿▼♠s➉✜✮❛❁✉❩✮✖❡✹✲❿✔❬➄❵✞♥✿❤✳✮✞✸☎❩✁❸s❸▼❩✰♠s➉●✫✲❸s❤❄✐✔✐s❸✪✮ ✱✪✲✬✲✚✱✰❱❳✶✵❑❨ ■✉❬➄♠P❚✲❵✥✤❤❍✖✒❤ ❭✚❜✶❱⑤❫❄❱❘❣ ❚ ❏✺✹✘❅ ❇✔❈✬✼✔▲☛✻ ◆☛❈✯❇✳❇✚✹✘✻✽✼❧●✪✹❆✻✦✜✮▲❉❊✔✹✯✼✥❺✺❇✔✾ ❊✧✜ ⑥❄❺ ❅❯❈ ❁ ✼❏✾ ❇✔❁✺▲✑★ ■ ❂✣✖✗❱❘❣ ✛✶❤t♠s➉✲❴❊❬ ♠❍❩✁❯④❾✉❤☛✭✧❚✰❿s✐❴ ➹ ✵❙✦✪✩✬✫✰❾✻❾✛✫ ✾✺Ð ✫ ✟✰✾ ✮✰✵③✦✪✩❯✮ ❈qr♠P❚✿❯✣❤ ✭✧❚✰❯✣✤✞✐✔❤❑♠✔➉❊❴✲❬ ✩✳✫❊❤✳✮❛✇❊❿▼❩✮❴❛♠P❤✳✮✣✱✪✲✳✲✿❲✲❱❳ Ð ❨ ■✉❬➄♠P❚✲❵✥✤❤❍✖✒❤✷❭✥❜✶❱⑤❫❄❱✮❣ ② ❴❧❸▲✫✚✭✚✭✧❚✰❿s✐✉❬✺❴❥✱❇❚✰❿s✖❧❩✁✐s❬ ✩✳✫❊❤❄✭✧❚✳✫✲❿✉❯✣❤❋✖ ✫✲❯✣✐✔❬ ✭✲❯✣❤P➌❛❩✮♥✰❤✉❵✞❤❋❯ ❩❘❜r❁✉❾❝❱r✼➈▲P❏❖❻ ❊✚✾✮✭☛❈✲▲❘▲✺✼r➇③❏☛✾❇▲❉❊❛❏P▲ ❘☛❊❄●✪✹❆✻✙✯

❅ ❀✯✼✿✾✰✭☛❈✲▲❉✮✄✱✪✲✬✲✰➍✲❱✮❣ ■❃✫❊✖✠❈❤❄❿s❚❂❸▲✭❛❤t♠❖❬ ❩✮❯✩✹✲❬✣❚✿❬✺❴❥✱❇❚✰❿s✖❧❩✁✐s❬ ✩✘✫✲❤✳✮✱✤❩❯✭❛❩✁❿P❩✎✲✳✣✐✔❿s❤✰❱❳ ❖✁❨❂✳✻❯✣❸▼♠s➉✞❦ ❩✮❴✲♥✏❭✚①③❱⑤❫☛✮ ✰✻❤❄❯➄❩✁❬✣✐✔❿s❤❉❭✚✳❘❱⑤❫☛✮✶✸❉❤❄❯✣❚✰✐ ❭❇✛✷❱⑤❫☛✮✶❜✡❤❄✐✔❤❄❿➀❭✚✸➋❱ ❫❉✮✽①❊♠✔➉❊✖✒❬✣✐✔✐❘❭✧✤❘❱⑤❫☛✮✶✇✲❿s❤❄❯➄❩✁✐❡❭✥✙❡❱⑤❫☛✮✩❩✮❴❛❵✏✛✉➉✲❚✰✖❉❩✁❸❝❭✚✙❡❱⑤❫❄❱➈❣✰✻❤❄❸▼♠❖❿✔❬ ✭✲✐✔❬✣❚✿❴✈❩✁❴❛❵ ✫✲❸✔❤➀❚✁✱✗❩❉❸✔❬✣✖ ✭✲❯✣❤✷❯➄❩✁✹✧❚✰❿▼❩✮✐✔❚✿❿✔✤✿✢✚✖❉❩✰❵✞❤❘❩✘✫✲✐s❚✰✖❧❩✮✐✉✱❇❚✿❿✵✴✷✶✹✸✺✴✪✻✽✼✿✾ ✰ ■ ✤✜❩✁✖✷✭❊❯✺❬ ★➈♠❍❩✁✐✔❬✣❚✿❴✩❱✥✘ ▲✽✼❇❻✚✹t⑩❅◆✷✾ ❊✘ ✹✘❁✣▲▼❏❉❈●❁ ❀❆✻ ❀❆❊❛⑩ ❂♣▲☛❁ ❁ ❈●❁ ❀❆✻✆❀❃✾✧✹✘❁ ✹✙✜✁❺✘✮✲❽✿❚✰❯✥❱ ❭ ✮✞❴✿➹ Ð ✮✲✸☎❩❑✤❁✫✘✦✬✫✲❴✲❤ ✱✪✲✬❋✳✲✚✮●✭✴✭✩❱ ❭ ✵ ❭ ❣ ❭ ✵ ❍ ❱❳ ● ❨✷❷✈❩✁✐s❸✔❚✿❴❂❭✎✦❛❱✘✰❘❱⑤❫☛✮❄❷ ❬✺✐s❞✰❚✁❦✉❸s❞✴❬❊❭✧✦✧❱ ❫❉✮✁✙❋❬✣❯✺✖❉❩✁❴❋❭✥✸④❱⑤❫☛✮✁❩✁❴❛❵❝❪✧❚✰❯✣❯✣❤❄❿r❭✥✸④❱⑤❫❄❱P❣❂✖ ▲P❏ ✹❆❅⑦⑥❉✾ ❊✔❀❆❊●✼✩✪✻➆ ❚❝❱P❣⑦①✲♠❖❬✺❤❍❴✴✐s❬ ★➈♠✞✤✻✖✒❤❄❿s❬➄♠❄❩✁❴✘☞❚✴❚✿❞✞❸✪✮✄✱✪✲✬✲✰✯✴✮✚✵✁❴❛❵ ❤t❵✞❬✣✐✔❬✣❚✰❴✣✮ ❍✰✾ ❣ ✾✦✥ ✭✩❱

❭✂❭✪❲

Page 126: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✏ ✞✡✒✙✁☞✄✬✚✁�✄✂✽✞☛✄✝✆✔✞✓✒☎�✪✞✝✆✂✁☞✄✬✘☎✞❅✠◆✚✠✟❋✁☞✒

✎☛✡✌☞✎✍✑✏ ✎☛✍✒☞✒✓✕✔✖✍✑✗✂ ✴☛✻✷▼✪❄✪✳✵✶✓✸ ➛ ✳ ✹✼✶✓✾ ✳ ✶✙✘❫✶✓▼◆✿✆✸❆✳✵✻✷✶✓✾✣✳✬ ❍✪✶ ✓ ✶✓✾✪✾◆❃❅●◗❁❊①✎✿✆✾✪✾✣✹❱✿ ➛ ✳✩✿✆✳✵✶✛✚❛✾✣✹❊①☛✶✓✸❀❃❑✹✼✳❅●✚❛✾✣✹❊①☛✶✓✸✩❃❡✹❊✳❑● ✓ ✿✍✸ ✭➅■ ✓ ✑ t✢✜ ❲ ✘ ♣

✢ ❄✪✾✪✶✷♣✒✜ ■ t ✔✖✔ ❾s ❃✺❄✪✻✷✻❜✿✆✸✵● ❈ ● r ✹✼✸❆✶✩✹❻❁❭❁❊✶ ✖✤✣✶✓❋☛✾✣✹❊✶✓✸✵✉

❸✦✥ ✖ ⑦✮❆✢✧✩★✓✠❼④✖❷P❆✺➲✪★✂⑦➛ ✶☛✭◗❄✪✶✓✾ ✳ ✶ ✳ ✴☛✻✷▼◆✿✆✸❅✹❱❃❅✴◗✾☎✹❱❃❏✳✵✸❀✿☛❖◗✹❊✳❅✹❊✴☛✾◆✿✎❁❻❁❊● ❈ ✿☛❃❅✶✠❖♠✴☛✾♦❋☛✶✓✾✪✶ ✳ ✴◗✻✷▼◆✿✆✸❅✹❱❃❅✴☛✾ ❈ ✿☛❃❅✶✠❖♠✴☛✾❳❁❊✴ ✳ ✿✌❁❛✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾◆❃✬✫✑✹❊✾ ✼❃❅✶✓✸✵✳✺✹✼✴◗✾◆❃ ■ ❖✣✶✩❁❊✶✓✳❅✹❊✴☛✾◆❃❨✴◗✸②❃✺❄ ❈ ❃❅✳❅✹❊✳✵❄✪✳❅✹❊✴☛✾◆❃✽✴✆✈❬✾✜❄ ✳ ❁❊✶✓✴☛✳❅✹❱❖✣✶✠❃✮✭✩❺ ➛ ❄ ✳ ❍ ✳ ✴☛✻✷▼◆✿✆✸✺✹P❃✺✴☛✾◆❃✷❖✣✴☎✾✪✴☛✳✽●☛✹❊✶✩❁❱❖ ✶✓①☛✴✆❁❊❄✪✳❅✹❊✴☛✾◆✿✆✸✵●

✹❊✾✣✈✇✴◗✸✵✻❜✿✆✳❅✹❊✴☛✾✖❺ q ✳❛✿✆▼✪▼◆✶✠✿✍✸❀❃❇✳✵❍◆✿✆✳❇✶✓①☛✴✍❁✼❄✪✳✺✹✼✴◗✾❨✹P❃③✻❜✿✆✾✣✹❭✈✇✶✠❃✺✳✵✶✠❖▲✿☛❃❇✳✵❍✪✶❬❖◗✹❊①☛✶✓✸✵❋☛✶✓✾ ✳ ✶ ✹❊✾▲❋☛✶✓✾✪✶❬✴☛✸❀❖✣✶✓✸✠❺ ❉ ✴☛✸❞✶ ❦ ✿✆✻✽▼✣❁✼✶ ■✳✵❍✪✶❨❁❱✿✆✸✵❋◗✶▲✾✜❄✪✻ ❈ ✶✓✸❨✴✆✈ ✳ ✴◗✾◆❃❅✶✓✸✵①☛✶✠❖❙❃❅✶✓❋◗✻✷✶✓✾✜✳✩❃❏✹❊✾❲✳✵❍✪✶▲✻❜✿✍▼◆❃❪✴✆✈✕✻❜✿✍✾❲✿✆✾◆❖♦✻✷✴☛❄◆❃❅✶✙❃✺❄✪❋☛❋☛✶✠❃❅✳❀❃②✳✵❍◆✿✆✳❪✻❪❄✣❁✼✳✺✹✼▼✣❁❊✶✳ ❍✪✸✵✴☛✻✷✴✜❃✺✴☛✻✷✶❬✸✵✶✠✿✆✸❆✸❀✿✆✾✪❋☛✶✓✻✷✶✓✾✣✳❀❃❇❍◆✿✌①☛✶❏✴ ✳✗✳ ❄✪✸❆✸✵✶✠❖❳❃❡✹❊✾ ✳ ✶❢✳❆❍✪✶❢❖◗✹❊①☛✶✓✸✵❋☛✶✓✾ ✳ ✶❪✴✆✈❉❁❭✹❊✾✪✶✠✿✆❋☛✶✠❃❝❁❊✶✠✿☛❖◗✹❊✾✪❋▲✳✵✴❜❍✣❄✪✻❜✿✆✾❳✿✆✾◆❖✻❪✹ ✳ ✶☛❺ ✬ ❍✪✶✷✾✣❄✪✻ ❈ ✶✓✸❬✴✆✈③❃✺❄ ✳ ❍❳✸✵✶✠✿✆✸❆✸❀✿✆✾✪❋☛✶✓✻✷✶✓✾✣✳❀❃❴❍◆✿☛❃ ❈ ✶✓✶✓✾♠✸✵✶ ✳ ✶✓✾✜✳✺❁✼●❳✶✠❃❅✳✺✹✼✻❨✿✆✳✵✶✠❖✰✳✵✴ ❈ ✶❜✿✆▼✪▼✪✸❆✴ ❦ ✹❊✻❜✿✆✳✵✶✩❁❊●♦t ❲ ✘ ❺✬ ❍✣✹❱❃③❁✼✶✠✿◗❖✪❃❫✳✵✴❜✿❪✻❜✿ ✄ ✴◗✸③❃✺❍✣✹❻✈✑✳❫✴✆✈❣❃❅✶☛✭◗❄✪✶✓✾ ✳ ✶ ✳ ✴◗✻✷▼◆✿✆✸❅✹❱❃❅✴☛✾▲✳❆✴ ✑❛✿✆✸✩❖✷✳✵❍✪✶❪✿✆✾◆✿✌❁❊●✪❃❡✹❱❃❫✴✆✈❼❃✺❄ ✳ ❍✰✸✵✶✠✿✆✸✵✸❀✿✍✾✪❋☛✶✓✻✷✶✓✾✣✳❀❃❛✿✆✳✳✵❍✪✶ ➎✛✭❣➾✮❤✛♣❑✭ ❼ ✭❋✯❋✭ ❼ ❺ ✔❛✶✓①◗✶✓✸✵✳✵❍✪✶✩❁❊✶✠❃✵❃ ■ ✳✵❍✪✶✓✸✵✶✷✿✆✸✵✶✷✿✌❁❊✻✷✴✜❃✺✳❬✾✪✴ ✳ ✴☛✻✷▼✪❄✪✳✵✶✓✸❯❃ ✳ ✹❊✶✓✾ ✳ ✶❨✸✵✶✠❃❅❄✣❁❊✳❀❃❬✿✌❁❭❁❊✴✜✑❇✹❊✾✪❋❹✿ ❈ ✹❊✴✆❁❊✴☛❋✆✹❱❃❅✳✳✵✴❜✿✍✾◆✿✌❁❊●✜❘✓✶❬❋☛✶✓✾✪✶❏✸✵✶✠✿✆✸✵✸✩✿✆✾✪❋☛✶✓✻✷✶✓✾✣✳❀❃✓❺✬ ❍✣✹❱❃❉✳✩✿✌❁ ✭ ✿◗❖✪❖✣✸✵✶✠❃✵❃❅✶✠❃❼✳ ✑❇✴❬▼✪✸✵✴ ❈ ❁✼✶✓✻❨❃ ✥ ❖✣✶ ✒◆✾✪✶❯✿✆✾◆❖❪✶✠❃❅✳❅✹❊✻❜✿✍✳✵✶❇✳✵❍✪✶❝❖◗✹❱❃❅✳✩✿✆✾ ✳ ✶ ❈ ✶✓✳✗✑❇✶✓✶✓✾❨✳ ✑❇✴❬❖◗✹✰✯❵✶✓✸❆✶✓✾✜✳❇❃❅▼◆✶ ✳ ✹❊✶✠❃✈✑✴☛✸✕✿❪❃✵✿✆✻✷✶❬❋◗✶✓✾✪✶❢✿✆✾◆❖❨✸✵✶ ✳ ✴◗✾◆❃❅✳✵✸✵❄ ✳ ✳❛✳❆❍✪✶❬✸✵✶✠✿✆✸✵✸❀✿✍✾✪❋☛✶✓✻✷✶✓✾✣✳✕❃ ✳ ✶✓✾◆✿✆✸❅✹❊✴◆❺ ✑ ▼◆✿✆▼❚✶✓✸✕①◗✶✓✸❀❃❡✹❊✴☛✾ ✳ ✿✆✾ ❈ ✶❫✈✑✴☛❄✪✾◆❖❨✹❊✾❩sPt❀✉❡❺

✱✲✥❑�✑❆✑✳✕❆✐❄✴★✡✆❛❆✞✝✣❄ ✣✵✧❅❆➛ ✴☛✻✷✶❳❋☛✶✓✾✪✴◗✻✷✶✠❃❨✶✓①☛✴✆❁❊①☛✶☎❃❅✴❙✸❀✿✍▼✣✹P❖◗❁❊● ✳✵❍◆✿✆✳❨✳✵❍✪✶☎❃❡✹❊✻❪✹❭❁❱✿✆✸❅✹❊✳❅● ❈ ✶✓✳✗✑❇✶✓✶✓✾ ✻❜✿✆✾✣●❲❋☛✶✓✾✪✶✠❃✽✹❱❃✦①☛✶✓✸✵●♦❁❊✴✜✑ ✿✆✾◆❖ ✹P❃

✹❊✾◆❖◗✹❱❃❅✳❅✹❊✾✪❋☛❄✣✹❱❃❅❍◆✿ ❈ ❁❱✶②✈✇✸✵✴◗✻➄✳✵❍✪✶ ❈ ✿ ✳✮✭ ❋☛✸✵✴☛❄✪✾◆❖❨✾✪✴✍✹P❃✺✶☛❺✙✔❛✶✓①☛✶✓✸❆✳✵❍✪✶✩❁❊✶✠❃✵❃ ■ ✿ ✳✗✳ ✴☛✸❀❖◗✹❊✾✪❋❨✳✵✴ ☎❛❍✪✾✪✴ ✯ ❃③❁❱✿✡✑ ■ ❋☛✶✓✾✪✶ ✳ ✴☛✾✜✳❆✶✓✾✜✳✴✆✈ ✆ ✳ ❍✪✸❆✴☛✻✷✴✜❃❅✴◗✻✷✶✠❃❞✹❱❃✕✿◗❃✵❃❅❄✪✻✷✶✠❖✦✳✵✴✷❍◆✿✌①☛✶❯✸❆✶✓✻❜✿✌✹❊✾✪✶✠❖▲✳✵❍✪✶❪❃✵✿✆✻✷✶❏✳✵❍✪✸✵✴☛❄✪❋◗❍✪✴☛❄✪✳❛✻❜✿✆✻✽✻❜✿✌❁❭✹❱✿✆✾❹❖✣✶✓①☛✶✩❁❊✴☛▼✪✻✽✶✓✾✜✳❴✹❊✾✳✵❍✪✶❨❁❱✿☛❃❅✳✰t✠♣☛❾❳✻❪✹❭❁❭❁❭✹❊✴☛✾ ●☛✶✠✿✆✸❀❃✓❺ ✎ ✴✜✑❣✶✓①◗✶✓✸ ■ ✳✵❍✪✶▲✴☛✸✩❖✣✶✓✸✷✴✆✈❬❋☛✶✓✾✪✶✠❃❪✴☛✾ ✆ ✳ ❍✪✸❆✴☛✻✷✴✜❃❅✴◗✻✷✶✠❃❪❍◆✿☛❃ ❈ ✶✓✶✓✾ ❖◗✹❱❃❅✸✵❄✪▼✪✳❆✶✠❖❃❅✶✓①☛✶✓✸✩✿✌❁✖✳❅✹❊✻✷✶✠❃ ■ ✶✓①☛✶✓✾✰✳✵❍✪✴☛❄✪❋☛❍✙❃✺●✜✾✣✳✵✶✓✾✣●❜❍◆✿☛❃ ❈ ✶✓✶✓✾❹✿✎❁✼✻✽✴✜❃❅✳ ✳ ✴☛✻✽▼✣❁✼✶✓✳❆✶✩❁✼● ✳ ✴☛✾◆❃❅✶✓✸✵①◗✶✠❖➂❺✬ ❍✪✶❪✴☛✸❀❖✣✶✓✸❫✴✆✈❤❋☛✶✓✾✪✶✠❃❴✹❊✾☎✳✗✑❇✴✷✴☛✸❆❋✜✿✆✾✣✹❱❃❅✻❜❃③✹❱❃❫✸✵✶✓▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖ ❈ ●✰▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾◆❃ ✥ ✵ ✫ ✥ ❫ ✥ ⑤ ✪❋✪❋✪ ✥ ❊ ✭❛✿✆✾◆❖❳❽ ✵✫❑❽ ❫ ❽ ⑤ ✪❋✪❋✪ ❽ ❊ ✭❀❺✘✙✏✕✚✛✟✢✜✣✟✥✤✦✟☛✧✌✜ t ✔ ✑ ✰➅✭❅✯❋✭❅✰✷✶✑✸ ❼ ✝✷✴✆✈❤✿✆✾❨✹❊✾✜✳❆✶✓✸✵①✎✿✌❁❇s ➱ ➄ ✺ ✉❿✹❱❃✕✿❪▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾

✝ ✵ s❊t ➄ ♣ ➄ ✪❅✪✐✪ ➄ ➱ ❝ t ➄ ✺ ➄ ✺ ❝ t ➄ ✪❋✪❋✪ ➄ ➱ ✳ t ➄ ➱ ➄ ✺ ✳ t ➄ ✪❋✪❋✪ ➄ ◗ ✉✥ ✪ ✝✽❍◆✿☛❃❇✳✵❍✪✶❬✶✮✯✖✶ ✳ ✳❛✴✆✈❉✸✵✶✓①☛✶✓✸✩❃❡✹❊✾✪❋✷❋☛✶✓✾✪✶✠❃ ✥ ❫ ➄ ✥ ✃✥❜ ❫ ➄ ✪❅✪❋✪ ➄ ✥ ✽ ❺✬ ❍✪✶ ✰❡✭❋✯❅✭❋✰✹✶✺✸ ❼ ✁ ✔ ✶ ♠ ✸✜➾✦✻ ✭ ❧ ✰❡❤✻✁ ❼ ✭❋♣ ✹❱❃✖✳✵✴✑✒◆✾◆❖❯✿❛❃❅✶✓✸✺✹✼✶✠❃✂✴✆✈✪✸✵✶✓①☛✶✓✸❀❃❆✿✌❁❱❃✣✝ ❫ ➄ ✝ ⑤ ➄ ✪❅✪❋✪ ✝✌✼◆❃✺❄ ✳ ❍❬✳✵❍◆✿✍✳ ✥ ✯ ✝ ❫ ✯ ✝ ⑤ ✯✕✯✰✯ ✝✌✼ ✵ ❽✿✆✾◆❖✾✽❇✹❱❃❫✻❪✹❊✾✣✹❊✻❪❄✪✻✿✫ ❉ ✹❊❋◆❺✏t✠✿✎✭❀❺ ✬ ❍✪✶❪✾✣❄✪✻ ❈ ✶✓✸✛✽❇✹❱❃ ✳ ✿✌❁❭❁❊✶✠❖❳✳✵❍✪✶ ✰❡✭❋✯❅✭❋✰✹✶✺✸ ❼ ✁ ✔ ✶ ♠ ✸①➾❀✻❢✭ ❺✛❁ ❤✛✰ ♠✕✔ ➾ ➎ ✁ ♦ ✰❡✭❋✯❅✭❋✰✹✶✺✸ ❼ ✶ ✹P❃✳✵❍✪✶❬▼✪✸✵✴ ❈ ❁✼✶✓✻ ✴✆✈ ✒◆✾◆❖◗✹❊✾✪❋❜✸✵✶✓①◗✶✓✸❀❃✵✿✌❁❦❖◗✹❱❃❅✳✩✿✆✾ ✳ ✶❃❂❄✫ ✥✖✭ ❈ ✶✓✳✗✑❇✶✓✶✓✾✗✥☎✿✆✾◆❖✽✹❱❖✣✶✓✾✣✳❅✹❊✳❅● ➱ ❺✖ ✶✓①☛✶✓✸✩❃✵✿✌❁❱❃❫❋☛✶✓✾✪✶✓✸❀✿✆✳❆✶❯✳✵❍✪✶❪❃❅●✜✻✽✻✷✶✓✳✵✸❅✹ ✳ ❋◗✸✵✴☛❄✪▼ ❬ ❊ ❺ ➬ ✹✼①◗✶✓✾ ✿✽❃❅✶✓✳✕✴✍✈❤❋☛✶✓✾✪✶✓✸❀✿✆✳✵✴◗✸❀❃❛✴✍✈❼✿✽▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾❳❋☛✸✵✴☛❄✪▼ ■❖✣✶✓✳✵✶✓✸✵✻②✹✼✾✣✹❊✾✪❋ ✳✵❍✪✶☎❃❅❍✪✴☛✸❆✳✵✶✠❃❅✳❨▼✪✸✵✴✱❖✣❄ ✳ ✳✰✴✆✈❯❋☛✶✓✾✪✶✓✸❀✿✍✳✵✴☛✸❀❃❨✳✵❍◆✿✍✳❜✶☛✭◗❄◆✿✌❁❱❃ ✥ ✹❱❃ ✔ ✓ ✼ ❍◆✿✆✸❀❖ s ♣✌✉✞❺ ✬ ❍✪✶☎▼✪✸❆✴ ❈ ❁❊✶✓✻ ✹P❃✓ ➛ ✓ ✑ ✂ ✝✝✼★✳ ✴☛✻✷▼✣❁❊✶✓✳✵✶✰s ☛ ✉✞❺ ✑ ✾◆❖✰✹❊✾❲s ❾✠✉✂✹❊✳❫✹❱❃ ✳ ✴☛✾ ✄ ✶ ✳ ✳✵❄✪✸✵✶✠❖✰✳✵❍◆✿✆✳❬❃❅✴☛✸❆✳❅✹❊✾✪❋ ❈ ●✰✸✵✶✓①☛✶✓✸❀❃✵✿✎❁P❃③✹❱❃ ✔ ✓ ✼★✳ ✴☛✻✽▼✣❁✼✶✓✳❆✶✷✶✓①☛✶✓✾

❭✂❭✪❍

Page 127: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✑❛❍✪✶✓✾❳✳✵❍✪✶❏❋☛✶✓✾✪✶✓✸❀✿✆✳✵✴◗✸✕❃❅✶✓✳❴✹P❃✥✒ ❦ ✶✠❖➂❺ � ✴☛❄✪✾◆❖✪❃❴✈✇✴◗✸❛✳✵❍✪✶❯✸❆✶✩❁P✿✍✳✵✶✠❖✰▼✪✸✵✴ ❈ ❁❊✶✓✻➃✴✆✈❣❃❅✴☛✸❆✳❅✹❊✾✪❋ ❈ ●▲▼✪✸✵✶ ✒ ❦ ✸❆✶✓①☛✶✓✸❀❃✵✿✌❁❱❃ ✳ ✿✆✾❈ ✶❨✈✑✴☛❄✪✾◆❖♠✹❊✾ s✲✎✌✉✞❺ ➬ ✴✆❁❭❁P✿✍✾ ✳ ✴☛✾ ✄ ✶ ✳ ✳❆❄✪✸✵✶✠❖☎✳❆❍◆✿✆✳❪✳✵❍✪✶❜✸❆✶✓①☛✶✓✸❀❃✵✿✌❁✕❖◗✹❱✿✆✻✷✶✓✳❆✶✓✸❢✴✍✈ ❬ ❊ ■ ✹✞❺ ✶☛❺☎✳❆❍✪✶❜✻❜✿ ❦ ✹❊✻❜✿✌❁❛✸✵✶✓①◗✶✓✸❀❃✵✿✌❁❖◗✹❱❃❅✳❀✿✆✾ ✳ ✶ ❈ ✶✓✳ ✑❇✶✓✶✓✾❳✳✗✑❇✴✷▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾◆❃ ■ ✹❱❃✛❂ ✫ ◗ ✭ ✵ ◗ ❝ t ■ ✿ ❈ ✴◗❄✪✾◆❖❹✿ ✳ ❍✣✹❊✶✓①☛✶✠❖✰✈✑✴☛✸❛✴◗✾✣❁✼●❳✴☛✾✪✶❏▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾✖❺❐ ✴✜✑❇✶✓✸ ❈ ✴◗❄✪✾◆❖✙✿✆✾◆❖❨①☛✶✓✸✺✹ ✒ ✳ ✿✍✳❅✹❊✴☛✾▲✈✑✴☛✸ ◗ ❨ ♣ ✘✞✘ ✿✆✸✵✶❬▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖✽✹❊✾❩s ❾✆✉✞❺

❁ ✥ ✁ ✧❋❄✎✳✄✂r✟✖★✆☎✑⑦✮❆ ✔ ✧✩✳✩✟✉✝✬ ❍✪✶ ✭ ✶✓●✽✹❱❖✣✶✠✿✷✳❆✴❜❃❅✴☛✸✵✳ ❈ ●❜✸❆✶✓①☛✶✓✸❀❃✵✿✌❁❱❃❞✹❱❃❴✳✵❍✪✶❯❖✣✶ ✒◆✾✣✹❊✳❅✹❊✴☛✾❳✴✆✈❉✳✵❍✪✶ ✁✐✰❡✭✮✸P☎ ❧ ❤ ✔✞✝✷♠ ➎➇✰ ✸ ❧✮❾ ✫❑❃❅✶✓✶ ❉ ✹❊❋◆❺➂t✕✭❀❺❐ ✶✓✳✭✥ ✵ ✫ ✥ ❫ ✪❋✪❅✪ ✥ ❊ ✭ ❈ ✶▲✿✰▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾❩✴✍✈③✳❆❍✪✶❜✶✩❁❊✶✓✻✷✶✓✾✣✳❀❃ ❘ t ➄ ✪❋✪❋✪ ➄ ◗ ❩ ❺ ✘❫✶✓✾✪✴☛✳✵✶ ➱✠✟ ✺ ✹❭✈ ❮ ➱ ❝ ✺ ❮➄✵ t☛❺✝➄❦ ✳✵✶✓✾◆❖❙✿❳▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ✥ ✵ ✫ ✥ ❫ ✪❅✪❋✪ ✥ ❊ ✭ ❈ ●♥✿◗❖✪❖◗✹✼✾✪❋ ✥ ★ ✵ ✘ ✿✆✾◆❖ ✥ ❊ ❜ ❫ ✵ ◗ ✳ t☛❺ ✣☎✶ ✳ ✿✌❁❭❁❝✿❳▼◆✿✌✹❊✸✷✴✆✈✳ ✴☛✾◆❃❅✶ ✳ ❄✪✳✺✹✼①◗✶❬✶✩❁✼✶✓✻✽✶✓✾✜✳❀❃ ✥ ✃ ✿✆✾◆❖ ✥ ✃✥❜ ❫ ■ ✘ ❰ ➱ ❰✙◗✏■ ✴✆✈ ✥❳✿ ✁✐✰❡✭✮✸P☎ ❧ ❤ ✔✞✝✷♠ ✹❭✈ ✥ ✃

✌✟ ✥ ✃✥❜ ❫ ❺ ✬ ❍✪✶ ✁✐✰❡✭✮✸P☎ ❧ ❤ ✔✞✝✷♠ ➎✛✰ ✸ ❧✮❾ ✴✆✈✥❨✹❱❃❇✿✆✾❨✶✠❖✣❋☛✶ ✼★✳ ✴✆❁❊✴☛❄✪✸✵✶✠❖❨❋◗✸❀✿✆▼✪❍ ✒ ✫ ✥✖✭ ✑❇✹❊✳✵❍ ◗ ✳ ♣❏①☛✶✓✸✵✳✺✹ ✳ ✶✠❃ ❘ ✥ ★ ➄ ✥ ❫ ➄ ✪❅✪❋✪ ➄ ✥ ❊ ➄ ✥ ❊ ❜ ❫❸❩ ❺ ✣♠✶ ✄ ✴✍✹✼✾❨①☛✶✓✸✵✳✺✹ ✳ ✶✠❃ ✥ ✃ ✿✆✾◆❖✥ ✽ ❈ ●✷✿ ✁ ❼ ✸ ✻✐☎ ✶✠❖✣❋☛✶❴✹❭✈ ➱✡✟ ✺ ✿✆✾◆❖ ❈ ●✷✿❬❋☛✸✩✿✠●❏✶✠❖✣❋☛✶❇✹❭✈ ✥ ✃ ✟ ✥ ✽ ❺☎✫ ➛ ✶✓✶ ❉ ✹❊❋◆❺✪t ❈ ✭❀❺ ❐ ✿✍✳✵✶✓✸✴✑❇✶❛✿✌❁❱❃❅✴❯❄◆❃✺✶✕✳✵❍✪✶❴✾✪✴☛✳❅✹❊✴☛✾✴✆✈ ❈ ✸✵✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❫❋☛✸❀✿✆▼✪❍ ✒ ✫ ✥ ➄☞☛ ✭✖✈✑✴☛✸ ♠✍✌ ❤ ▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾◆❃ ✥♦✿✆✾◆❖ ☛ ✑❴❍✣✹ ✳ ❍✰✹❱❃❬❖✣✶ ✒◆✾✪✶✠❖❹✿◗❃ ✒ ✫ ✥ ➄☞☛ ✭✏✎ ✒ ✫ ✥ ☛ ✩ ❫ ✭❖✣✶✠❃ ✳ ✸❅✹ ❈ ✶✠❖♦✶✠✿✆✸❅❁❭✹❊✶✓✸✠❺ ✑ ✻ ♦ ✻ ❼ ✭ ✹❊✾❙✿✆✾❩✶✠❖✣❋◗✶ ✼★✳ ✴✆❁❊✴☛❄✪✸✵✶✠❖♠❋☛✸❀✿✆▼✪❍ ✒ ✹❱❃ ✸ ❼✸♠ ✭❋✰

✝✸ ♠✕✔✑✝ ➎ ✹❭✈✕✳✵❍✪✶ ✳ ✴✆❁❊✴☛❄✪✸✩❃❯✴✍✈③✶✓①◗✶✓✸✵●❳✳ ✑❇✴

✳ ✴☛✾◆❃❅✶ ✳ ❄✪✳✺✹✼①◗✶✕✶✠❖✣❋☛✶✠❃❞✴✆✈✖✳✵❍✣✹❱❃ ✳ ● ✳ ❁✼✶❯✿✍✸✵✶✕❖◗✹❱❃❅✳❅✹❊✾ ✳ ✳✠❺ q ✾❨✳✵❍✪✶❴✈✇✴✆❁❭❁❊✴✜✑❇✹❊✾✪❋ ■✣❈ ● ✳ ● ✳ ❁❊✶✠❃ ✑❇✶❛✻✷✶✠✿✆✾▲✿✌❁❊✳✵✶✓✸✵✾◆✿✆✳✺✹✼✾✪❋ ✳ ● ✳ ❁❊✶✠❃✓❺❐ ✶✓✳ ➮✥ ❈ ✶❬✿ ✶ ✔ ➎ ✝ ✭✲✁ ▼◆✶✓✸✵✻❪❄✪✳❀✿✆✳✺✹✼✴◗✾❜✴✆✈ ❘ t ➄ ✪❋✪❅✪ ➄ ◗ ❩ ■ ✹✞❺ ✶☛❺❞✿❯▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ✑❇✹❊✳✵❍✓✒ ✳✕✔ ✴☛✸✖✒ ❝✗✔ ❃❑✹✼❋◗✾✙✿☛❃✵❃❅✴ ✳ ✹❱✿✆✳✵✶✠❖✑❇✹❊✳✵❍❳✶✠✿ ✳ ❍☎✶✩❁❊✶✓✻✷✶✓✾✣✳ ✫ ❉ ✹❊❋◆❺❉t ✳ ✭❀❺ q ✾❳✳✵❍✪✶❜❃❡✹❊❋☛✾✪✶✠❖ ✳ ✿◗❃❅✶ ■ ✶✓①☛✶✓✸✵●✰✸✵✶✓①☛✶✓✸❀❃✵✿✎❁❦✴✆✈❉✈✑✸❀✿✆❋◗✻✷✶✓✾✜✳❪s ➱ ➄ ✺ ✉ ✳ ❍◆✿✆✾✪❋☛✶✠❃ ✁q❤ ♠☛❾ ✳✵❍✪✶✴☛✸❀❖✣✶✓✸▲✿✆✾◆❖ ✳✵❍✪✶❳❃❡✹❊❋☛✾◆❃❨✴✆✈❯✳✵❍✪✶✰✶✩❁✼✶✓✻✽✶✓✾✜✳❀❃ ✑③✹✼✳❆❍✣✹✼✾ ✳✵❍◆✿✆✳✽✈✇✸❀✿✍❋☛✻✷✶✓✾✣✳✠❺ ✣☎✶❹✿✍✸✵✶▲✹❊✾✣✳✵✶✓✸✵✶✠❃❅✳✵✶✠❖ ✹❊✾ ✳✵❍✪✶❳✻❪✹❊✾✣✹❊✻❢❄✪✻✾✣❄✪✻ ❈ ✶✓✸✷✴✆✈✕✸❆✶✓①☛✶✓✸❀❃✵✿✌❁❱❃ ❂❄✫ ➮✥ ✭❯✸✵✶☛✭◗❄✣✹✼✸❆✶✠❖♦✳✵✴❳✳✵✸❀✿✆✾◆❃❡✈✑✴☛✸✵✻ ✿❳❃❡✹❊❋☛✾✪✶✠❖❙▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ➮✥ ✹❊✾✜✳❆✴❹✳❆❍✪✶❨✹P❖✣✶✓✾✣✳❅✹❊✳❅●♥❃❑✹✼❋◗✾✪✶✠❖▼◆✶✓✸❆✻❢❄✪✳✩✿✆✳❅✹❊✴☛✾ ✫ ✳ t ✳ ♣ ✯✰✯✕✯ ✳ ◗ ✭❀❺✴✘❫✶ ✒◆✾✪✶✙✿✰✳✵✸❀✿✆✾◆❃❑✈✇✴☛✸❆✻❜✿✆✳❅✹❊✴☛✾❳✈✑✸✵✴☛✻ ✿❳❃❡✹❊❋☛✾✪✶✠❖♦▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ➮✥ ✴✆✈✕✴☛✸❀❖✣✶✓✸ ◗✳✵✴☎✿✆✾ ✫✞❄✪✾◆❃❑✹✼❋◗✾✪✶✠❖✦✭❢▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ✥ ✴✆✈ ❘ t ➄ ✪❋✪❋✪ ➄ ♣ ◗ ❩ ✿◗❃❬✈✑✴✆❁❭❁❊✴✜✑✕❃✓❺ ✬ ✴♠✻✷✴✱❖✣✶✩❁❛✳✵❍✪✶✙❃❑✹✼❋◗✾◆❃✷✴✆✈❫✶✩❁✼✶✓✻✽✶✓✾✜✳❀❃②✹❊✾ ➮✥✸✵✶✓▼✣❁❱✿ ✳ ✶✷✳❆❍✪✶❯▼◆✴✣❃❡✹❊✳❅✹❊①☛✶✷✶✩❁❊✶✓✻✷✶✓✾✣✳❀❃ ✳✗③ ❈ ●❹♣ ③➋❝ t ➄ ♣ ③ ✿✆✾◆❖✰✾✪✶✓❋✜✿✆✳✺✹✼①◗✶❯✶✩❁❊✶✓✻✷✶✓✾✣✳❀❃ ❝❛③ ❈ ●✙♣ ③ ➄ ♣ ③ ❝ t✤✫ ❉ ✹❊❋◆❺✏t ✳ ✭❀❺✣☎✶ ✳ ✿✌❁❭❁❣✳✵❍✪✶❨❄✪✾◆❃❡✹❊❋☛✾✪✶✠❖♦▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ✥ ■ ✳❆❍✪✶ ✔ ♣ ✸❋➎➇✭ ✴✆✈❛✳✵❍✪✶▲❃❡✹❊❋☛✾✪✶✠❖☎▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ➮✥✏❺ q ✾♦✳✵❍✪✶ ❈ ✸❆✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❋☛✸❀✿✍▼✪❍ ✒ ✫ ✥✖✭ ■ ✶✩❁✼✶✓✻✽✶✓✾✜✳❀❃❬♣ ③❃❝ t❪✿✆✾◆❖❳♣ ③ ✿✆✸✵✶ ✄ ✴✆✹❊✾✪✶✠❖ ❈ ● ❈ ✴☛✳✵❍ ❈ ❁❱✿ ✳ ✭ ✿✆✾◆❖✰❋☛✸❀✿✌●▲✶✠❖✣❋☛✶✠❃❴✈✑✴☛✸❪t ❰ ③ ❰ ◗ ❺ ✣☎✶❖✣✶ ✒◆✾✪✶❨✳✵❍✪✶ ❈ ✸✵✶✠✿ ✭ ▼◆✴✍✹✼✾✣✳❪❋☛✸❀✿✆▼✪❍ ✒ ✫ ➮✥ ✭❛✴✆✈✕✿✙❃❑✹✼❋◗✾✪✶✠❖☎▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ➮✥ ✿☛❃❫✳✵❍✪✶ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳❯❋☛✸✩✿✆▼✪❍ ✒ ✫ ✥✖✭✙✑❇✹❊✳✵❍✳✵❍✪✶✠❃❅✶✷♣ ◗ ✶✠❖✣❋☛✶✠❃❫✶ ❦✓✳ ❁❊❄◆❖✣✶✠❖➂❺ ☎ ❈ ❃❅✶✓✸✵①◗✶❢✳❆❍◆✿✆✳❛✹❊✾ ✒ ✫ ➮✥ ✭❛✶✓①☛✶✓✸✵●✰①☛✶✓✸✵✳✵✶ ❦ ❍◆✿☛❃❬❖✣✶✓❋◗✸✵✶✓✶❜♣ ✫ ❉ ✹❊❋◆❺❂t ✳ ✭✕✿✆✾◆❖✰✳✵❍✪✶✓✸✵✶✩✈✑✴☛✸✵✶✳✵❍✪✶ ❈ ✸✵✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❛❋◗✸❀✿✆▼✪❍❨✴✆✈❼✿❪❃❡✹❊❋☛✾✪✶✠❖✦▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾❨✹❱❃❛✿ ✳ ✴✆❁❭❁✼✶ ✳ ✳✺✹✼✴◗✾❹✴✍✈❦❖◗✹❱❃ ✄ ✴✍✹✼✾✣✳ ✳ ● ✳ ❁❊✶✠❃✓❺ ✘❫✶✓✾✪✴◗✳✵✶❬✳✵❍✪✶❬✾✣❄✪✻ ❈ ✶✓✸✴✆✈✕❃❅❄ ✳ ❍ ✳ ● ✳ ❁❊✶✠❃❪✿☛❃ ❏ ✫ ➮✥ ✭❀❺ ✣☎✶✽✴ ❈ ❃❅✶✓✸✵①☛✶✽✳✵❍◆✿✆✳❯✳❆❍✪✶❪✹❱❖✣✶✓✾✜✳❅✹❊✳❅●❩❃❡✹❊❋☛✾✪✶✠❖♠▼◆✶✓✸❆✻❢❄✪✳✩✿✆✳❅✹❊✴☛✾♦✴✆✈❛✴☛✸❀❖✣✶✓✸ ◗ ✻❨✿✆▼◆❃❬✳✵✴✰✳✵❍✪✶✹❱❖✣✶✓✾✜✳✺✹✼✳❅●✵✫❡❄✪✾◆❃❡✹❊❋☛✾✪✶✠❖✦✭❉▼◆✶✓✸✵✻❪❄✪✳❀✿✆✳✺✹✼✴◗✾✷✴✆✈✖✴☛✸❀❖✣✶✓✸❇♣ ◗✏■ ✿✆✾◆❖✽✳✵❍✪✶❛✶✮✯✖✶ ✳ ✳❤✴✍✈✂✿ ✸✵✶✓①☛✶✓✸❀❃❆✿✌❁◆✴☛✾ ➮✥ ✳ ✿✆✾ ❈ ✶❫✻❪✹❊✻❪✹ ✳ ✭ ✶✠❖ ❈ ●✷✿✸✵✶✓①☛✶✓✸✩❃✵✿✌❁✖✴☛✾ ✥✰✳✵❍✣❄◆❃❞✹❊✻✷▼✣❁❊●☛✹❊✾✪❋ ❂❄✫ ➮✥✲✭ ✫ ❂ ✫ ✥✖✭❀❺ q ✾▲✳✵❍✪✶❫✈✑✴✆❁❭❁✼✴✜✑❇✹❊✾✪❋ ■❚❈ ● ❃❅✴◗✸✵✳❅✹❊✾✪❋❪✳✵❍✪✶❫✹❊✻❜✿✆❋☛✶ ✥ ✵ ✥ ❫ ✥ ⑤ ✪❅✪❋✪ ✥ ⑤ ❊ ✴✆✈✿❨❃❡✹❊❋☛✾✪✶✠❖✰▼◆✶✓✸✵✻❪❄✪✳❀✿✆✳✺✹✼✴◗✾ ➮✥ ✵ ➮✥ ❫ ➮✥ ⑤ ✪❋✪❅✪ ➮✥ ❊ ■ ✑❇✶❯✻✷✶✠✿✍✾❹❃❅✴☛✸❆✳❅✹❊✾✪❋❜✴✆✈ ✥ ❈ ●▲✸✵✶✓①◗✶✓✸❀❃✵✿✌❁❱❃ ✝❀✫❑♣ ➱ ✳ t ➄ ♣ ✺ ✭ ✑❴❍✣✹ ✳ ❍✘✒ ✳ ❄✪✳ ✔❤✝✷❼ ♦ ✸❡❈ ♠ ✭❅✰❀✭❋✯❅✭

✝ ❧ ❤✕✶ ✔☛♠✕✔ ❤ ✝ ✶ ✹❊✾✗✥❉❺ q ✾▲✳✵❍✪✶❏✸✵✶✠❃❅✳❇✴✆✈❉✳✵❍✣✹❱❃✕❃❅✶ ✳ ✳✺✹✼✴◗✾ ■ ✥✰✹❱❃✕✿✍✾❨✹✼✻❨✿✆❋☛✶❬✴✆✈❤✿✷❃❡✹❊❋☛✾✪✶✠❖✦▼◆✶✓✸✵✻❪❄✪✳❀✿✆✳✺✹✼✴◗✾✖❺✂ ● ✳ ❁❊✶✙❖✣✶ ✳ ✴☛✻✷▼◆✴✣❃❡✹❊✳❅✹❊✴☛✾◆❃❪▼✣❁❱✿✌●♥✿✆✾♠✹❊✻✷▼◆✴◗✸✵✳❀✿✆✾✣✳❪✸✵✴✆❁❊✶❨✹❊✾❙✶✠❃❅✳❅✹❊✻❜✿✆✳❅✹❊✾✪❋☎✳❆❍✪✶❜✸✵✶✓①◗✶✓✸❀❃✵✿✌❁❛❖◗✹P❃✺✳❀✿✆✾ ✳ ✶☛❺ ✑ ▼✪▼✣❁❊●☛✹❊✾✪❋❙✿✸✵✶✓①☛✶✓✸✩❃✵✿✌❁❉✳✵✴✙✿✷▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾❳✻❜✿✌● ✳ ❍◆✿✆✾✪❋◗✶❢✳❆❍✪✶❢✾✣❄✪✻ ❈ ✶✓✸❏✴✆✈ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳❀❃ ■ ❍ ✫ ✥✖✭ ■ ✿◗❃✓✑❣✶✩❁❭❁❣✿☛❃❫✳❆❍✪✶❢✾✣❄✪✻ ❈ ✶✓✸❬✴✆✈✳ ● ✳ ❁✼✶✠❃❼✹❊✾▲✿❬✻❜✿ ❦ ✹❊✻❪❄✪✻✐❖✣✶ ✳ ✴☛✻✷▼❚✴✜❃❡✹❊✳❅✹❊✴☛✾ ■✪❏ ✫ ✥✖✭✩❺ ✬ ❍✪✶ ✭ ✶✓●❯✹❱❖✣✶✠✿ ✹❊✾❜✳❆❍✪✶✕✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻⑤✴✆✈❦sPt✓✉✣✹❱❃❤✳❆✴❬✳❀✿ ✭ ✶✕✿◗❖✣①✎✿✆✾✣✳❀✿✆❋☛✶✴✆✈❉✳✵❍✣✹❱❃❛❃❅✳✵✸❆✴☛✾✪❋ ✳ ✴☛✸✵✸❆✶✩❁P✿✍✳❅✹❊✴☛✾✖❺✓☎❛✾✪✶❯▼✪✸❆✴✎①◗✶✠❃ ✥⑨❶⑩✎✏✻✧✌✍✣✏✕❷ t ✔✶❺✦❤✛✰❴✭❋✯❋✭❅✰ ♦ ❧ ✭❅✰ ♣ ✖ ♠ ✸ ♠✕✔ ❤ ✝ ✥ ✸

✝✁ ✰❡✭❋✯❋✭❅✰✷✶✑✸ ❼ ✝ ➈✠❤

✝✭ ❾ ✸✕✶ ➀

✙ ❍ ✫ ✥ ➄ ✝✦✭ ✳ ✙ ❏ ✫ ✥ ➄ ✝✦✭ ❰ t ✪✚✗✍✕✧✬✧ ✚↔✔ ✫❑❃ ✭ ✶✓✳ ✳ ❍✲✭ ✥ ✶✓①☛✶✓✸✵●❲✸❆✶✓①☛✶✓✸❀❃✵✿✌❁❫✸✵✶✓✻✷✴✆①☛✶✠❃ ✘ ✿◗❖✪❖✪❃✷✿✆✳❨✻✷✴✜❃❅✳✷✳✗✑❇✴ ❈ ✸✵✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❀❃✒❺ ☎❛✾✪✶ ✳ ✴☛✾◆❃❡✹❱❖✣✶✓✸❀❃▲✿✌❁❭❁❯❾▼◆✴◗✳✵✶✓✾✜✳✺✹P✿✎❁❂①✎✿✌❁❊❄✪✶✠❃❴✴✆✈ ✙ ❍ ✹❊✾❹✿ ✳ ✿☛❃❅✶ ✼✑❈ ● ✼★✳ ✿◗❃❅✶❬✈✞✿☛❃❅❍✣✹❊✴☛✾✖❺✬ ❍✣✹❱❃③✹✼✻✽✻✷✶✠❖◗✹❱✿✆✳✵✶✩❁❊●▲❋✆✹❊①☛✶✠❃❫✿❪✾✪✶ ✑ ❁❊✴✜✑❣✶✓✸ ❈ ✴☛❄✪✾◆❖ ✈✇✴☛✸❴✳✵❍✪✶❬✸✵✶✓①☛✶✓✸❀❃❆✿✌❁❂❖◗✹P❃✺✳❀✿✆✾ ✳ ✶ ✥⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ♣ ✔✶❺✦❤✛✰❴✭❋✯❋✭❅✰ ♦ ❧ ✭❅✰ ♣ ✖ ♠ ✸ ♠✕✔ ❤ ✝ ✥ ➈ ❂ ✫ ✥✖✭ ✫ ❍ ✫ ✥✖✭ ❝ ❏ ✫ ✥✖✭✜✛❉ ✴◗✸✕✿✌❁❭❁ ❈ ✹❊✴✆❁❊✴☛❋✆✹ ✳ ✿✌❁❉✶ ❦ ✿✍✻✷▼✣❁❊✶✠❃ ■ ✴◗✾✪✶❬❍◆✿☛❃ ❂❄✫ ✥✖✭ ✵✷❍ ✫ ✥ ✭ ❝ ❏ ✫ ✥✖✭❀❺ ✎ ✶✓✾ ✳ ✶ ■ ✳✵❍✪✶❬❄◆❃❅✶❏✴✆✈❉✳✵❍✪✶ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳✕❋◗✸❀✿✆▼✪❍✸✵✶✠❖✣❄ ✳ ✶✠❃❴✳✵❍✪✶❬✸✵✶✓①☛✶✓✸✩❃✵✿✌❁❂❖◗✹❱❃❅✳❀✿✆✾ ✳ ✶❏▼✪✸✵✴ ❈ ❁❊✶✓✻ ✳❆✴✷✻❜✿ ❦ ✹❊✻❜✿✌❁ ✳ ● ✳ ❁❊✶❢❖✣✶ ✳ ✴☛✻✷▼❚✴✜❃❡✹❊✳❅✹❊✴☛✾✰▼✪✸✵✴ ❈ ❁❊✶✓✻✙❺✥☎❛✾✪✶❢❃❅❍✪✴✜✑✕❃ ✥

❭✂❭ ✥

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+3 -5 +8 -6 +4 -7 +9 +2 +1 +10 -11

oriented cyclenon-oriented cycle

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✞ ✟☛✡ ☞✦✍✣✏ ✒✕✔ ✫❑✿✎✭✓☎❛▼✪✳❅✹❊✻❜✿✌❁❦❃✺✴☛✸✵✳❅✹❊✾✪❋❪✴✆✈❦✿❪▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾▲❽ ✵ ✫ ✎❪❾ ❲ ✜ ☛ ✍ ✔ ♣❨t❪t ✘ t☛t✕✭ ❈ ● ❾✸✵✶✓①☛✶✓✸❀❃✵✿✎❁P❃✒❺✛✫ ❈ ✭ � ✸✵✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❫❋☛✸❀✿✆▼✪❍ ✒ ✫❑❽ ✭❀❺ ✫ ✳ ✭ ✬ ✸✩✿✆✾◆❃❡✈✑✴☛✸✵✻❜✿✆✳✺✹✼✴◗✾▲✴✆✈❣✿❜❃❑✹✼❋◗✾✪✶✠❖▲▼◆✶✓✸❆✻❢❄✪✳✩✿✆✳❅✹❊✴☛✾✹✼✾✣✳✵✴▲✿✆✾✙❄✪✾◆❃❑✹✼❋◗✾✪✶✠❖❳▼◆✶✓✸✵✻❪❄✪✳❀✿✍✳❅✹❊✴☛✾✗✥☎✿✍✾◆❖▲✳✵❍✪✶ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳❬❋☛✸❀✿✆▼✪❍ ✒ ✫ ✥✖✭✩❺ ➬ ✸❀✿✌●❨✶✠❖✣❋☛✶✠❃ ✫ ❲❪➄ ✔ ✭✿✆✾◆❖✾✫❑♣☛♣ ➄ ♣✫✎✎✭❉✿✆✸✵✶❫✴☛✸❅✹❊✶✓✾✜✳❆✶✠❖ ✑❛❍✣✹❭❁✼✶❏❋☛✸❀✿✌●✷✶✠❖✣❋☛✶✠❃ ✫ ☛ ➄ ❾ ✭❦✿✆✾◆❖✾✫❀t ❲❪➄ t ✔ ✭❂✿✆✸✵✶❫❄✪✾✪✴☛✸❅✹❊✶✓✾✜✳❆✶✠❖➂❺ ✂ ● ✳ ❁❊✶✠❃▲ ✿✆✾◆❖ ❏ ✿✆✸✵✶❬✴☛✸❅✹❊✶✓✾✣✳✵✶✠❖ ✑❴❍✣✹❻❁❊✶ ✳ ● ✳ ❁❊✶✠❃ ➴ ➄ r❉➄ ✔ ✿✆✾◆❖ ➓ ✿✆✸✵✶❬❄✪✾✪✴☛✸❅✹❊✶✓✾✣✳✵✶✠❖➂❺ ➬ ✸❀✿✌●✷✶✠❖✣❋☛✶✠❃ ✫ ✜ ➄ ✍ ✭✿✆✾◆❖✄✫❀t✠♣ ➄ t☛✎✎✭❦✿✍✸✵✶❬✹❊✾✣✳✵✶✓✸❅❁❊✶✠✿✌①☛✹❊✾✪❋ ✑❛❍✣✹❭❁❊✶❪❋☛✸❀✿✌●❜✶✠❖✣❋◗✶✠❃ ✫ ✜ ➄ ✍ ✭❼✿✍✾◆❖ ✫ ☛ ➄ ❾✎✭❤✿✆✸✵✶❬✾✪✴☛✾ ✼ ✹❊✾✣✳✵✶✓✸❅❁❊✶✠✿✌①☛✹❊✾✪❋◆❺✫❑❖✦✭ q ✾✣✳✵✶✓✸❅❁❊✶✠✿✌①◗✹✼✾✪❋❨❋☛✸❀✿✍▼✪❍✁�✄✂✒✑❇✹❊✳✵❍▲✳✗✑❇✴❪✴☛✸❅✹❊✶✓✾✜✳❆✶✠❖✙✿✆✾◆❖❨✴☛✾✪✶❬❄✪✾✪✴◗✸❅✹❊✶✓✾✜✳✵✶✠❖ ✳ ✴☛✻✽▼◆✴☛✾✪✶✓✾✣✳✠❺

❭✂❭t✾

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⑨❶⑩✎✏✻✧✌✍✣✏✕❷ ✎✵✫✁� ✤➄✍●✧ ✜✑✡✄✂❑✧✆☎✝☎✟✞✌✜✡✠✣✧✌✜☞☛ ✏✌✠✷✤➄☞✦✍✣✏ ✭ ✔❴❺✦❤✛✰❀✭❅✯❋✭❅✰ ♦✕◗ ➈ ♠☛❾ ✭❑❤✝✷❼✸♦❴❧ ✭❅✰ ♣ ✖ ♠ ✸ ♠✕✔ ❤ ✝ ✶ ♠☛❾ ✸ ♠ ✰❡✭✵✹ ✖ ✔ ✰❡✭◗ ❝ t ✰❡✭❋✯❋✭❅✰✷✶✑✸ ❼ ✶ ♠ ❤➂✁q✭ ✶❞❤✛✰ ♠ ✭✵✁ ✸✛✰❡✭ ☛ ❊ ✸

✝✁ ✔☛♠ ✶ ✔✑✝ ✯❋✭❅✰✷✶✐✭✗☛ ✩ ❫❊ ➀

☛ ❊ ✵✍ ✫❀t ➄ ✎ ➄ ❾ ➄ ✍ ➄ ✪✐✪✐✪ ➄ ◗ ❝ t ➄ ◗ ➄ ✪❅✪❋✪ ➄✵❲❪➄ ✜ ➄ ☛ ➄ ♣✎✭ ➄ ◗ ✭❋✯❅✭

✝❙�✫❀t ➄ ✎ ➄ ❾ ➄ ✍ ➄ ◗ ➄ ◗ ❝ t ➄ ✪❋✪❅✪ ➄✲❲❪➄ ✜ ➄ ☛ ➄ ♣✒✭ ➄ ◗ ❤✂✁❄✁ ✛✚✗✍✕✧✬✧ ✚↔✔ ✫❑❃ ✭ ✶✓✳ ✳ ❍✲✭❀❺ ❐ ✶✓✳ ❒ ❊ ❈ ✶❢✳❆❍✪✶❢❃❅✶✓✳❛✴✍✈ ◗☎✼ ▼◆✶✓✸❆✻❢❄✪✳✩✿✆✳❅✹❊✴☛✾◆❃❴✳✵❍◆✿✆✳✕❃✵✿✍✳❅✹❱❃❡✈✇● ❂❄✫ ✥✖✭ ✵ ◗ ❺ q ✳ ✳ ✴◗✾✜✳❀✿✎✹✼✾◆❃ ☛ ❊ ✿✆✾◆❖☛ ✩ ❫❊ ❺ ☎❛✾✪✶ ✹✼✾◆❖✣❄ ✳ ✳✺✹✼①◗✶✩❁✼●❳▼✪✸✵✴✆①☛✶✠❃③✳✵❍◆✿✆✳❇✳✵❍✪✶✓✸✵✶❯✿✆✸❆✶❬✾✪✴✷✴☛✳✵❍✪✶✓✸❛✶✩❁❊✶✓✻✷✶✓✾✣✳❀❃✓❺❉ ✹❊✾◆✿✌❁❭❁❊● ■ ✴☛✾✪✶❜▼✪✸❆✴✎①◗✶✠❃❯✳❆❍◆✿✆✳❪✳✵❍✪✶❜✶ ❦ ▼◆✶ ✳ ✳❆✶✠❖❙✸✵✶✓①☛✶✓✸✩❃✵✿✌❁③❖◗✹❱❃❅✳✩✿✆✾ ✳ ✶❨✹❱❃❪①☛✶✓✸✵● ✳ ❁❊✴✜❃✺✶▲✳✵✴❳✳✵❍✪✶▲✸✵✶✓①☛✶✓✸❀❃❆✿✌❁③❖◗✹❱✿✆✻✷✶✓✳❆✶✓✸✠❺✬ ❍✪✶ ✭ ✶✓●▲✹❱❖✣✶✠✿❨✹❱❃❬✳❆❍◆✿✆✳❝✿❨✳❅●✣▼✣✹ ✳ ✿✌❁ ✳ ● ✳ ❁❊✶✽✹❱❃❫❁❊✴☛✾✪❋ ■ ❍✪✶✓✾ ✳ ✶❨✳✵❍✪✶❪✾✜❄✪✻ ❈ ✶✓✸❯✴✆✈ ✳ ● ✳ ❁❊✶✠❃❫✹❱❃❏❃❅✻❜✿✌❁❭❁✞❺ r ✴☛✸✵✶❪▼✪✸✵✶ ✳ ✹❱❃❅✶✩❁❊● ✥➓ ✫ ❂❄✭ ✫ ✫✩t ❝ ☎✎ ✏✒✑ ❊ ✭ ◗ ✂ ✥✏✣✔✓✕✔❀★ ✧ ☎ ❆✞✝✖✕✘✗✂ ✥✑❸✦✥✏✣ ✔✲✧❅❄✻❄✡✠✖⑩ ✳✙✓✌✔✦★ ✧ ☎ ❆✞✝✖✕ ✥ ✘❫✶ ✒◆✾✪✶❳✿ ✶ ♠ ✰ ✔❹❧ ✴✆✈ ✥ ✿◗❃❜✿✆✾ ✹❊✾✜✳✵✶✓✸❆①✎✿✌❁✷s ➱ ➄ ✺ ✉❣❃❅❄ ✳ ❍ ✳✵❍◆✿✆✳✵✫ ➱ ❝ t ➄ ➱ ✭❯✿✆✾◆❖

✫ ✺ ➄ ✺ ✳ t✕✭❯✿✆✸✵✶ ❈ ✸✵✶✠✿ ✭ ▼◆✴✍✹✼✾✣✳❀❃ ■ ✿✆✾◆❖♦✾✪✴ ❈ ✸❆✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳✽❁❭✹❊✶✠❃ ❈ ✶✓✳ ✑❇✶✓✶✓✾❙✳✵❍✪✶✓✻✰❺ ✑ ❃❅✳✵✸❅✹❊▼❙✹❱❃ ✔✑✝ ✻❅✰❡✭ ✸✕✶ ✔✑✝ ➎ ✹❭✈ ✥ ✃ ➄ ✥ ✽ ■✴☛✳✵❍✪✶✓✸ ✑❇✹❱❃❅✶❏✹✼✳ ✹❱❃ ✁✛✭ ✻❅✰❡✭ ✸✕✶ ✔✑✝ ➎ ❺ ✑ ✸✵✶✓①☛✶✓✸❀❃✵✿✎❁ ✳ ✿✆✾❳✸✵✶✓✻✽✴✎①◗✶❢✿✆✳❬✻✷✴✣❃❅✳✕✳✗✑❇✴ ❈ ✸✵✶✠✿ ✭ ▼❚✴✆✹❊✾✜✳❀❃ ❲ ✳✵❍✪✶✓✸✵✶✩✈✑✴☛✸✵✶✙❂❄✫ ✥✖✭ ✫ ✦ ✡ ✂ ☞⑤❺

q ✾☎s ❾✠✉✖✿❏❋☛✸✵✶✓✶✠❖✣●✽▼✪✸✵✴ ✳ ✶✠❖✣❄✪✸❆✶❫✹P❃③❋✆✹❊①☛✶✓✾ ■ ✑❛❍✪✶✓✸✵✶❬✴☛✾✪✶ ✳ ❍✪✴✣✴✜❃❅✶✠❃❇✿❏✸✵✶✓①☛✶✓✸✩❃✵✿✌❁➅✳❆❍◆✿✆✳❇✸✵✶✓✻✷✴✆①☛✶✠❃❉✳❆❍✪✶✕✻✷✴✣❃❅✳ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳❀❃✴✆✈ ✥ ■ ✸❆✶✠❃❅✴✆❁❊①☛✹❊✾✪❋☎✳✺✹✼✶✠❃ ✹❊✾♦✈✞✿✠①◗✴☛❄✪✸❯✴✆✈❫✸✵✶✓①☛✶✓✸❀❃✵✿✎❁P❃❏✳✵❍◆✿✍✳❬❁❊✶✠✿✌①☛✶✙✿✙❖✣✶ ✳ ✸✵✶✠✿◗❃❡✹❊✾✪❋❩❃❅✳✵✸❅✹❊▼✖❺ ✑ ✾❙❄✪▼✪▼◆✶✓✸ ❈ ✴☛❄✪✾◆❖♦✴☛✾♦✳✵❍✪✶✾✣❄✪✻ ❈ ✶✓✸✕✴◗✾ ❂ ✫ ✥ ✭❂✳✵❍◆✿✆✳❴▼✪✸✵✴✆①☛✹❱❖✣✶✠❃❫✿❯▼❚✶✓✸❅✈✑✴☛✸✵✻❜✿✆✾ ✳ ✶❏❋☛❄◆✿✆✸❀✿✍✾✜✳✵✶✓✶❫✴✆✈❤♣ ■ ✈✇✴✍❁❻❁❊✴✜✑✕❃③✈✇✸❆✴☛✻❧✳✵❍✪✶❫❁❊✶✓✻✷✻❜✿ ✥✚✠✏✕❷❴❷✛✞ t ✔✶➆✥❈ ✥ ✔ ✶ ✸ ✁✛✭ ✻❅✰❡✭ ✸✕✶ ✔✑✝ ➎ ❧ ✭❋✰❢♣ ✖ ♠ ✸ ♠✕✔ ❤ ✝ ✌✣✔☛♠☛❾ ✸ ✁✛✭✮✻❋✰❡✭✮✸✕✶ ✔✑✝ ➎ ✶ ♠ ✰ ✔↕❧ ➈ ♠☛❾ ✭

✝ ✥ ✸ ❼☛❼ ❤ ✌ ✶ ✸ t ❤✛✰ ♣ ➍✰❡✭❋✯❅✭❋✰✹✶✺✸ ❼ ✛ ➏✑✁✞✁ ✔☛♠✕✔ ❤ ✝ ✸ ❼☛❼ ♦ ➈❻➆✥❈✙✭❋✯❅✭❋✰ ♦ ✰❡✭❋✯❋✭❅✰✷✶✑✸ ❼➄♠☛❾ ✸ ♠ ✰❡✭❋♣❑❤✛✯❋✭ ✶❃✸❱✁✐✰❡✭✮✸P☎ ❧ ❤ ✔✑✝✮♠ ❤❡❈ ✥ ❼ ✭✮✸✛✯❋✭ ✶❃✸ ❧ ✭❋✰❢♣ ✖ ♠ ✸ ♠✕✔ ❤ ✝ ✌✣✔☛♠☛❾✝

❤ ✁✛✭✮✻❋✰❡✭✮✸✕✶ ✔✑✝ ➎✬✶ ♠ ✰ ✔↕❧ ✶ ➈ ♠☛❾ ✭✝ ✥ ❾ ✸✕✶ ✸ ♣ ➍➅✰❡✭❋✯❅✭❋✰✹✶✺✸ ❼ ✛✂ ✥ ✱✲✥✏✣✰⑦✵✳✩✟♣✟✖✧✩★✪⑥ ☎✜✕ ✳✕❆ ☎ ★✖⑦✵✳✙✓✌✔✦★ ✧ ☎ ❆✞✝✖✕ ✆✁★ ✧✢✗ ☎✌✔✂⑦✑❄✡✠ ✟➄❄ ✧✝✕☎④✣❆✑✳✕❆ ☎✪★✂⑦✣✗ ✥ ✣ ❍✣✹❭❁✼✶❇✳✵❍✪✶❇▼✪✸✵✴ ❈ ❁✼✶✓✻ ✴✆✈➅❃❅✴◗✸✵✳❅✹❊✾✪❋

❃❡✹❊❋☛✾✪✶✠❖❨▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾◆❃❼✹❱❃❇✶✠✿☛❃❡✹❊✶✓✸❇✳✵✴❪❍◆✿✆✾◆❖◗❁❊✶ ■ ✹❊✳❇✹❱❃❇✿✌❁❱❃❅✴❪✻✷✴☛✸✵✶❫✸✵✶✩❁❊✶✓①✎✿✍✾✜✳❛✳❆✴②✿ ❈ ✹❊✴✆❁❊✴☛❋✆✹ ✳ ✿✌❁❂▼❚✴✆✹❊✾✜✳❛✴✍✈❂①☛✹❊✶ ✑ ✥ ❋☛✶✓✾✪✶✠❃✿✆✸✵✶❨❖◗✹✼✸❆✶ ✳ ✳✵✶✠❖♠✈✇✸✩✿✆❋☛✻✷✶✓✾✣✳❀❃❬✴✍✈☛✘ ✔ ✑ ❃❅✶☛✭◗❄✪✶✓✾ ✳ ✶✠❃✓❺ ❉ ✴☛✸❆✳✵❄✪✾◆✿✆✳✵✶✩❁❊● ■ ✳✵❍✪✶ ✳ ✴☛✾ ✳ ✶✓▼✪✳❪✴✆✈ ❈ ✸✵✶✠✿ ✭ ▼◆✴✆✹❊✾✣✳❢❋◗✸❀✿✆▼✪❍❙✿☛❃ ✑❇✶✩❁❭❁✿☛❃❫❃❅✳✵✸❅✹❊▼◆❃❫✶ ❦ ✳✵✶✓✾◆❖✪❃❴✾◆✿✆✳✵❄✪✸❀✿✌❁❭❁❊●✙✳❆✴ ❃❡✹❊❋☛✾✪✶✠❖✰▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾◆❃ ✫❑❃✺✶✓✶❢✿ ❈ ✴✎①◗✶✕✭❀❺ ✬ ❍✪✶❪✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻ ➛ ✹❊❋☛✾✪✶✠❖ ➛ ✴◗✸✵✳❯❃❅✴☛✸✵✳✩❃❛✿❃❡✹❊❋☛✾✪✶✠❖♦▼❚✶✓✸✵✻❪❄✪✳❀✿✆✳❅✹❊✴☛✾ ✥♥✹❊✾❲✿✆✳❯✻✷✴✣❃❅✳ ❍ ✫ ✥✖✭ ❝ ❫

⑤ ❏☎ ✫ ✥✖✭❛✸❆✶✓①☛✶✓✸❀❃✵✿✌❁❱❃ ■ ✑❛❍✪✶✓✸❆✶ ❏ ☎ ✹❱❃❏✳✵❍✪✶❜✾✣❄✪✻ ❈ ✶✓✸❪✴✆✈ ☛ ✼★✳ ● ✳ ❁❊✶✠❃✓❺ q ✳▼✪✸✵✴✆①◗✹P❖✣✶✠❃❫✿✆✾✙✿✆▼✪▼✪✸❆✴ ❦ ✹❊✻❜✿✆✳❅✹❊✴☛✾▲✸✩✿✆✳❅✹❊✴✷✴✆✈ ✝

⑤❺

✂ ✥✥❁ ✥✏✣✰⑦✴✳✩✟♣✟✖✧✩★✪⑥ ☎✤✕ ✳✕❆ ☎ ★✖⑦ ✳✙✓✕✔❀★ ✧ ☎ ❆✞✝✖✕ ✆✁★ ✧✥✗ ★ ✧❅❆ ☎✑⑦ ✔ ✤➂⑩ ✧❅❄✏☞✣❄ ✧✦✗✑✳✙✓✧✗✒✥ ✑ ❃❣♣ ✼ ✸✵✶✓①☛✶✓✸❀❃✵✿✎❁P❃ ✳ ✴☛✸✵✸✵✶✠❃❅▼❚✴☛✾◆❖❨✳✵✴✶✩❁❭✹❊✻❪✹❊✾◆✿✆✳❅✹❊✴☛✾☎✴✆✈ ☛ ✼★✳ ● ✳ ❁❊✶✠❃ ■ ✴☛✾✪✶ ✳ ✴☛✾ ✳ ✶✓✾✣✳✵✸❀✿✍✳✵✶✠❃❛✴◗✾ ✒◆✾◆❖◗✹❊✾✪❋❹✿ ✳ ● ✳ ❁❊✶✷❖✣✶ ✳ ✴☛✻✷▼❚✴✜❃❡✹❊✳❅✹❊✴☛✾ ✑③✹✼✳❆❍❹✿②❁P✿✍✸✵❋☛✶❪✾✜❄✪✻ ❈ ✶✓✸✕✴✆✈☛ ✼★✳ ● ✳ ❁❊✶✠❃✓❺ ✬ ❍✪✶❯✿✌❁❊❋☛✴☛✸❅✹❊✳✵❍✪✻✩★ ✭❋✯❅✭❋✰✹✶✺✸ ❼ ❁ ❤✛✰ ♠ ✿ ✳ ❍✣✹❊✶✓①☛✶✠❃✕✿✍✾✙✿✆▼✪▼✪✸✵✴ ❦ ✹❊✻❜✿✍✳❅✹❊✴☛✾▲✸❀✿✆✳❅✹❊✴✷✴✍✈✫✪ ✂ ❺✬ ✴ ✳ ✴☛✾ ✳ ❁❊❄◆❖✣✶ ■ ❁✼✶✓✳❫❄◆❃ ✳ ✹❊✳✵✶❢✿✍✻✷✴☛✾✪❋❨✳✵❍✪✶❯✸✵✶✓✻❨✿✌✹❊✾✣✹✼✾✪❋✰✴☛▼◆✶✓✾✰▼✪✸✵✴ ❈ ❁❊✶✓✻❜❃❫✳✵❍✪✶✷✿✆✾◆✿✎❁✼●✪❃❡✹❱❃❫✴✆✈❉❋☛✶✓✾✪✴☛✻✷✶❪✸✵✶✠✿✍✸✵✸❀✿✆✾✪❋☛✶ ✼✻✷✶✓✾✣✳❀❃❞✹❊✾ ♣ ✖ ❼✸♠✕✔❹❧✑❼ ✭ ❋☛✶✓✾✪✴☛✻✷✶✠❃✒❺☞✆✌✎✍✑✏✎✌✎✒✔✓✖✕✘✗✚✙✜✛✣✢

❳ ❭ ❨❂✘✕❩❑✱❇❴❛❩❝❭❼❀❂❱⑤❫r❩✁❴✧❵❂❜✡❤❄❽✞❃❄❴✲❤❍❿❋❭✚❜✶❱⑤❫❄❱❑❣☎①✞❚✰❿s✐✔❬✣❴✲♥❋✹✞✤❂❿s❤❄❽✰❤❍❿✔❸▼❩✮❯✣❸✭✬✶❿✔❤❑❩✁❿✔❿P❩✁❴✲♥✿❤❄✖✒❤❍❴✴✐s❸r❬✣❴ ✭❊❯ ❩✮❴✞✐r❚✰❿s♥✴❩✁❴❊❤❄❯✣❯✺❤❍❸ ❩✮❴❛❵❘❤❄❽✿❚✰❯ ✫✲✐✔❬✣❚✿❴❛❩✁❿s✤➉✲❬✣❸✔✐s❚✰❿s✤❡❚✁✱r✖❧❩✮✖✒✖❡❩✁❯✣❬✺❩✮❴⑦♠s➉✲❿s❚✰✖✒❚✿❸✔❚✿✖✒❤✰❱✧✘ ✹❆❁✺▲P❏☛❈●❁ ❀✘✻✵❀❃✾✧✹✘❁ ✹✙✜✁❺✷❀✘❊✧⑩❘❹✖✮✘✹✘❁ ❈✳✼✿✾✧✹❆❊✚✮✲❽✿❚✰❯✥❱ ❭ ✵✚✮✄✱✯✲✳✲✰✯✖✮●✭✚✭✩❱✚✵ Ð✰✾ ❣✚✵✘❖ ❲ ❱❳✶✵❑❨❂q✶❽✿❤❄❴④❭✚①❙❱ ❫✉❩✮❴❛❵☎✙❋❚✿❯➄❵✞❿✔❤❄❬➄♠s➉✏❭✚✳❘❱⑤❫❄❱❊❣ ✛✉➉❊❤❂✖➀❬✺❴❊❬✺✖❯✫✲✖❝✢✚❯✣❤❄❴❊♥✰✐✔➉❡♥✿❤❄❴✲❤❄❿P❩✁✐s❚✰❿✗❸s❤✪✩✬✫✲❤❄❴❛♠❖❤ ✭✲❿✔❚✿✹✲❯✣❤❄✖ ❬✣❸✸■✗❜✡✢✥➉❛❩✁❿P❵③❱✲✱●✹✘❈●✻☛❊✔❀❆❁✹✥●❃❚◆❁ ✜❆✹❆✻☛✾ ✼❼❻ ❅❝◆✽✮✞❽✿❚✰❯✥❱●✵✚✮✄✱✪✲✬❋✚✱✬✮●✭✚✭✩❱ Ð✞❭☎❭ ❣ Ð✞❭❧Ð ❱❳ Ð ❨❂✙✷❩✮✐✔❤❄❸✻❭✚❢❘❱✲❷ ❱ ❫☞❩✁❴❛❵❉❜✶❩✘✭❛❩✿❵✞❬✣✖✒❬✣✐✔❿s❬✣❚✳✫❡❭✥❁✕➉✩❱⑤❫❄❱✿❣✈✘r❚✬✫✲❴❛❵✞❸✕✱❇❚✿❿♣❸s❚✰❿s✐✔❬✣❴✲♥❘✹✴✤ ✭❊❿✔❤✺★✲➌☎❿s❤❄❽✰❤❄❿s❸▼❩✮❯✺❸❑❱③✪◆✾✣◆t❏☛✻P▲✺✼✔▲ ✘ ❀✯✼❼❻❥▲❉❅ ❀ ✼❏✾❼❏P◆❚◆❁ ✜✳✹✘✻❉✾ ✼❇❻●❅✷◆☛✮✿❽✰❚✿❯✚❱●✵ ❍ ✮✄✱✪✲✴✳✳✲✚✮✬✭✚✭✩❱✴❖ ❍ ❣ ● ❍ ❱❳ ❖✁❨✥✦✰❤❍❿✔❿▼✫❊✖ ❭✚✸➋❱ ❫❍❱❊❣ ✛✉➉✲❤⑦♠❖❚✰✖✷✭❊❯✺❤❖➌❥❬✣✐✥✤➀❚✁✱✞★❛❴✧❵✞❬✣❴✲♥✒✖➀❬✺❴❊❬✺✖❯✫✲✖❘✢✥❯ ❤❄❴❊♥✰✐✔➉➀♥✰❤❄❴❊❤❄❿▼❩✮✐✔❚✰❿❝❸✔❤✪✩✬✫✲❤❄❴✧♠P❤❄❸t❱✷✼✡❻✲▲✺✹✘✻▼▲✽✼✿✾❇❏✺❀✘❁✞❂❄✹❆❅✸❇✖❈✬✼➃▲❉✻➇➈❏❉✾❇▲❉❊❛❏P▲☛✮❊❽✰❚✰❯✥❱ Ð✳❲ ✮✄✱✪✲✳❋✿➍✚✮✬✭✚✭✩❱✖✵ ❲ ● ❣ ✵ ✥✰✾ ❱❳ ● ❨❂❢✻❤t♠P❤t♠❖❬✺❚✿♥✰❯ ✫➀❭✧✦❛❱⑤❫✶❩✁❴✧❵✷①✲❩✁❴❊❞✰❚ ✰☎❭✿✰❘❱ ❫❍❱P❣✒q✡➌❛❩✰♠P✐r❩✮❴❛❵❂❩❆✭✚✭✲❿s❚❑➌❥❬✣✖❉❩✁✐✔❬✣❚✿❴❶❩✁❯✣♥✿❚✰❿✔❬✣✐s➉✲✖✒❸❊✱❇❚✰❿✡✐✔➉✲❤✉❿s❤❄❽✰❤❍❿✔❸▼❩✮❯❛❵✞❬✣❸✔✐P❩✁❴❛♠❖❤✉✹❛❤❄✐✥❦✕❤❄❤❄❴✐✥❦✕❚ ✭✧❤❄❿✔✖ ✫❊✐▼❩✁✐s❬✣❚✰❴✲❸❑❱✚❚◆❁ ✜✳✹✘✻☛✾ ✼❼❻ ❅❯✾❇❏✺❀✘✮✖✱✪✲✬✲✰➍❊❱✁❣④✛✶❚⑦❩❆✭✚✭❛❤❑❩✁❿t❱

❭ ✵ ✟

Page 130: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✫ ✞✕✠❋✆✁�

✣ ✚✠✟✕�✪✞✓✥✛✥✠✞✕✒☞✖

Page 131: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 132: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

� ✒☎✆✧✠✧✁✂✁ ✆☎� ✆✧✚★✁☞✒ ✆✧✁ ✆✂✁☎✄✬✘✙✥✛✞✪✩✬✣ ✆✙✥✦✆✧✚★✘✙✥✛✚✠� ✞✡✆✧✚★✁☞✒

✄ ✗✩✡ ✔✆☎✌ ✟✞✝✠✟☛✡✂✟ ✗✢✡ ✝ ✔❐ q⑦✆ ■ ✣✝✙✳ ✴✍❁✼✶❏▼◆✴✆❁❊●✣✳✵✶ ✳ ❍✪✾✣✹ ✭◗❄✪✶

✑ ▼✪✸❅✹❭❁❛t ✘ ■ t ✔✖✔ ❾s ❃❅❄✪✻✷✻❜✿✍✸✵● ❈ ● ✝ ✹✼✳❆❍✪✾✪✶ r ❄✪✸✵✸❀✿✌●✣✉

✵ ✍☞✶✸✷✯✕✘✗✺✹✻✷✛✉➉❊❤ ♠❖❚✰❴❛♠P❤❉✭✲✐✒❚✮✱ ♠P❚✿✖✷✭✲❯✣❤P➌✈✖ ✫✲❯✣✐s❬ ✭❊❯✺❬➄♠❄❩✮✐✔❬✣❚✁❴✏❬✺❸✒❵❥❤✺★❛❴✲❤t❵ ✮✗❩❑✱❇✐s❤❄❿❡❸✔❚✿✖✒❤➀✹❛❩✰♠s❞✞♥✰❿s❚✳✫✲❴❛❵ ❬✣❸❘♥✰❬✣❽✰❤❄❴ ❚✿❴❤❄❯✣❯✺❬ ✭✲✐s❬➄♠☞✱✧✫✲❴❛♠P✐s❬✣❚✰❴✲❸♣❩✮❴❛❵✷✩✬✫❛❩✿❵✞❿▼❩✮✐✔❬➄♠✕✱❼❚✰❿✔✖➀❸t❱✄✤ ✭✚✭✲❯✣❬➄♠❄❩✁✐s❬✣❚✰❴✲❸r✐s❚❂✐s➉✲❤✷♠P❯➄❩✁❸s❸♣❴●✫✲✖❡✹✧❤❄❿✞✭✲❿s❚✰✹✲❯✣❤❄✖❑✮✘✭✲❿s❬✺✖❉❩✁❯✣❬✣✐✥✤

✭✲❿✔❚✁❽✞❬✣❴✲♥❡❩✁❴❛❵➀❾✗❩✁✖❉❩✁❴●✫❄❑❄❩✮❴ ❍ ❸✡✱❇❚✰❿s✖ ✫✲❯➄❩✁❸✶✱❇❚✿❿ ❭✌☞✎✍ ❩✁❿s❤ ✭❊❿✔❤❄❸s❤❄❴✞✐✔❤t❵③❱❸✦✥ ✖ ⑦✮❆✢✧✩★✓✠❼④✖❷P❆ ☎✪★✂⑦✬ ❍✣✹❱❃❼✹❱❃❣✿✍✾✷✹❊✾✣✳✵✸✵✴✪❖✣❄ ✳ ✳❅✹❊✴☛✾❜✳❆✴❯✳✵❍✪✶❴✹❱❖✣✶✠✿☛❃❞✴✆✈ ✳ ✴☛✻✷▼✣❁❊✶ ❦ ✻❪❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾✙✴✍✈➅❁❱✿✆✳❆✳❅✹ ✳ ✶✠❃❣✿✍✾◆❖✷✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳✮✳ ❄✪✸✵①☛✶✠❃✒❺ ✬ ❍✪✶✳✵❍✪✶✓✴☛✸❆●✷▼✣❁❱✿✠●✪❃❛✿✆✾❨✹❊✻✷▼❚✴☛✸✵✳❀✿✍✾✜✳❇✸✵✴✆❁❊✶❫✹❊✾ ✳ ❁❱✿☛❃✵❃ ✒◆✶✩❁❱❖✦✳✵❍✪✶✓✴☛✸✵● ■ ✿✆✾◆❖❨❍◆✿☛❃❞❍◆✿☛❖❨✸❆✶ ✳ ✶✓✾✜✳✕✿✍▼✪▼✣❁❻✹ ✳ ✿✆✳✺✹✼✴◗✾◆❃❇✹❊✾✙✿✌❁❊❋☛✴☛✸✺✹✼✳❆❍✪✻❪✹ ✳✾✣❄✪✻ ❈ ✶✓✸❇✳✵❍✪✶✓✴☛✸✵● ■ ✶✠❃❅▼❚✶ ✳ ✹P✿✎❁❻❁❊●✦✹✼✾❨✶✩❁❭❁❭✹✼▼✪✳✺✹ ✳❇✳ ❄✪✸✵①◗✶✕▼✪✸❅✹❊✻❜✿✎❁❻✹❊✳❅●❨▼✪✸✵✴✆①☛✹❊✾✪❋◆❺ ✬ ❍✣✹P❃❞▼✪✸✵✶✠❃✺✶✓✾✜✳❀✿✍✳❅✹❊✴☛✾✷✹❱❃❛✿ ✒◆✸❀❃✺✳❤❋✆❁❭✹❊✻✷▼◆❃❅✶❬✴✆✈

✿❪①☛✶✓✸❆●❜✸❅✹ ✳ ❍❹✿✆✾◆❖▲❖✣✶✓✶✓▼✰✳✵❍✪✶✓✴☛✸✵●▲❖✣✶✓①☛✶✩❁❊✴☛▼❚✶✠❖ ❈ ●✑✏❫✸✵✴☛✾✪✶ ✳ ✭ ✶✓✸ ■ ✣☎✶ ❈ ✶✓✸ ■ ✎ ✹❭❁ ❈ ✶✓✸✵✳ ■ ➛ ❍✣✹❊✻❢❄✪✸✩✿ ■ ✘❫✶✩❁❭✹❊❋☛✾✪✶ ■ ✶✓✳ ✳ s✲✎✌✉✞❺ ✑❋☛✴✣✴✱❖✽✹❊✾✣✳✵✸✵✴✪❖✣❄ ✳ ✳❅✹❊✴☛✾✙✳❆✴✷✳✵❍✪✶❫✹❱❖✣✶✠✿☛❃❴▼✪✸✵✶✠❃❅✶✓✾✣✳✵✶✠❖▲❍✪✶✓✸✵✶❫✹❱❃❏s ✜✌✉✞❺❉ ✹❊✸❀❃❅✳ ■ ❃✺✴☛✻✷✶ ❈ ✿ ✳ ✭ ❋◗✸✵✴☛❄✪✾◆❖❙✻❨✿✆✳✵✶✓✸❅✹❱✿✌❁❬✴☛✾❲✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳ ✈✑❄✪✾ ✳ ✳❅✹❊✴☛✾◆❃▲✿✆✾◆❖ ✭☛❄◆✿◗❖✣✸❀✿✆✳❅✹ ✳ ✾✣❄✪✻ ❈ ✶✓✸❀❃✽✹❱❃✽❋✆✹❊①☛✶✓✾✖❺ ✬ ❍✣✹P❃❈ ✿ ✳ ✭ ❋◗✸✵✴☛❄✪✾◆❖❪✳✵❍✪✶✓✾▲✿✌❁❭❁❊✴✜✑✕❃❉❄◆❃❞✳✵✴❪❖✣✶ ✒◆✾✪✶ ✳ ✴☛✻✽▼✣❁✼✶ ❦ ✻❢❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾✖❺ ➛ ✴☛✻✽✶❛✳✵❍✪✶✓✴☛✸✵✶✓✻❨❃❉✳✵❍◆✿✆✳❇❖✣✶✓✻✷✴☛✾◆❃❅✳❆✸❀✿✆✳✵✶❇❍✪✴✜✑✳✵❍✪✶✠❃❅✶❏✳✵❍✪✸✵✶✓✶❯✿✆✸❆✶✠✿☛❃❛✿✆✸✵✶❫✹❊✾✣✳✵✶✓✸ ✳ ✴☛✾✪✾✪✶ ✳ ✳❆✶✠❖❹✿✍✾◆❖▲❃❅✴☛✻✷✶❯✿✆▼✪▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾◆❃❝✹❊✾✙▼✪✸❅✹❊✻❜✿✌❁❭✹❊✳❅●▲▼✪✸✵✴✆①☛✹❊✾✪❋ ■ ✳✵❍✪✶ ✳ ❁❱✿☛❃✵❃❴✾✣❄✪✻ ❈ ✶✓✸▼✪✸✵✴ ❈ ❁❊✶✓✻➃✿✆✾◆❖ ✖ ✿✆✻❨✿✆✾✜❄ ✄ ✿✆✾ ✯ ❃ t ✡ ✥✦✈✇✴◗✸✵✻❪❄✣❁P✿◗❃❛✿✆✸✵✶❬▼✪✸✵✶✠❃✺✶✓✾✜✳✵✶✠❖➂❺

✱ ✥ ✚ ✓✧✓✑☎❇✟✎❆ ☎❱❷✓✒❉④✏⑦❵❷ ❆ ☎✪★✂⑦✣✗✑ ❼ ✸ ♠✢♠✕✔ ✻❢✭ ✹❱❃❣✿✍✾ ✿☛❖✪❖◗✹❊✳❅✹❊①☛✶❬❃❅❄ ❈ ❋☛✸❆✴☛❄✪▼ ❍ ✴✆✈✕✔❙❋◗✶✓✾✪✶✓✸❀✿✆✳✵✶✠❖ ❈ ●❪✳✗✑❣✴ ✳ ✴◗✻✷▼✣❁❊✶ ❦ ✾✣❄✪✻ ❈ ✶✓✸❀❃✗✖ ❫ ✿✆✾◆❖✘✖ ⑤ ✑❴❍✣✹ ✳ ❍▲✿✆✸✵✶❁❭✹❊✾✪✶✠✿✆✸❅❁❊●❳✹❊✾◆❖✣✶✓▼◆✶✓✾◆❖✣✶✓✾✣✳❪✴✎①◗✶✓✸ ✘ ❺ ✣☎✶✒✑❛✸❅✹❊✳✵✶ ❍❳✵ s ✖ ❫ ➄ ✖ ⑤ ✉✞❺ ✑ ✾ ✭ ❼☛❼ ✔↕❧✑♠✕✔ ✻❻❈✢✖ ✝

✻ ♠✕✔ ❤ ✝ ✈✑✴☛✸ ❍ ✹❱❃❯✿✽✈✑❄✪✾ ✳ ✳❅✹❊✴☛✾ ▲ ✫✚✙✎✭✻✷✶✓✸✵✴◗✻✷✴☛✸✵▼✪❍✣✹ ✳ ✴◗✾✛✔ ✳✵❍◆✿✆✳❞✹❱❃✕❖✣✴◗❄ ❈ ❁✼●▲▼❚✶✓✸❅✹❊✴✱❖◗✹ ✳ ✥ ▲ ✫✜✙ ✳ ✖✕✢✁✭ ✵ ▲ ✫✜✙✎✭❉✈✑✴☛✸✤✣ ✵ t✦✥❀♣✪❺☎❛✾✪✶❪✴✆✈❤✳✵❍✪✶❏✻✷✴✜❃❅✳❴✹❊✻✷▼◆✴☛✸❆✳❀✿✆✾✣✳❛✶✩❁❭❁❻✹❊▼✪✳❅✹ ✳ ✈✑❄✪✾ ✳ ✳❅✹❊✴☛✾◆❃❴✹❱❃❛✳❆❍✪✶ ✣♠✶✩✹✼✶✓✸✩❃❅✳✵✸❀✿☛❃❆❃★✧ ✼ ✈✇❄✪✾ ✳ ✳✺✹✼✴◗✾ ■ ❖✣✶ ✒◆✾✪✶✠❖✰✈✇✴◗✸✕✿❪❁❱✿✆✳❆✳❅✹ ✳ ✶❍ ✿◗❃

✧ ✫✜✙ ✭ ✵t✙ ⑤ ✳ ✜

✩●✇✐①✕❖ ✩✫✪☛ ★✩ t✫✜✙ ❝ ✖ ✭ ⑤ ❝

t✖ ⑤ ✪✛✬✭ ✶✓✳ ✒ ❵ ■✆✖✑✮ ♣ ■✜❈ ✶❯✳✵❍✪✶✰✯ ✔ ✶✲✱ ✝ ✶ ♠ ✱ ✔✑✝ ✶✲✱✴✳ ✔ ✱✑✶ ✈✑✴☛✸✤✵ ✥

✒ ❵ ✫✜✵ ✭✂✶ ✜✩✕✇✐①✸✷ ✩✫✪☛ ★

t✖ ❵ ✬

✬ ❍✪✶✓✾✰✶ ❦ ▼◆✿✆✾◆❖◗✹❊✾✪❋✹✧ ✫✚✙✎✭❣✿✆✾◆❖✹✧ ✤ ✫✜✙✎✭❉✾✪✶✠✿✆✸❛✳✵❍✪✶❏✴☛✸❅✹❊❋✆✹❊✾ ■ ✑❇✶❬❋☛✶✓✳✧ ✫✜✙✎✭✂✶ t ✡ ✙ ⑤✻✺ ✎✦✙✦✼ ✒ ☎ ✺ ❾✽✙ ☎ ✒ ✹ ✺ ✯✰✯✕✯ ✥✧ ✤ ✫✜✙✎✭✂✶✿✾❛♣ ✡ ✙ ✝ ✺ ✜✦✙ ✒ ☎ ✺ ♣ ✘ ✙ ✝ ✒ ✹ ✺ ✯✰✯✕✯ ✬

❭ ✵✎❀

Page 133: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✘❫✶ ✒◆✾✪✶ ▼ ✼ ✶ ✜ ✘ ✒ ☎ ✿✆✾◆❖ ▼ ✝ ✶ t ☛ ✘ ✒ ✹ ❺ ✬ ❍✪✶✓✾ ✧❳❃✵✿✆✳❅✹❱❃✄✒◆✶✠❃❴✳✵❍✪✶❯❖◗✹✰✯✖✶✓✸✵✶✓✾✜✳✺✹P✿✎❁❂✶☛✭☛❄◆✿✍✳❅✹❊✴☛✾✧ ✤ ✫✚✙✎✭✜✼✆✶ ☛ ✧ ✫✚✙✎✭ ✝ ✾ ▼ ✼ ✧ ✫✜✙ ✭ ✾ ▼ ✝ ✬

q ✾❲✿◗❖✪❖◗✹✼✳✺✹✼✴◗✾ ■ ✧❲✿✆✾◆❖ ✧ ✤ ✿✆✸✵✶❨❋☛✶✓✾✪✶✓✸❀✿✍✳✵✴☛✸❀❃ ✈✑✴☛✸❪✳✵❍✪✶ ✒◆✶✩❁❱❖ ✴✆✈✕✶✩❁❭❁❭✹✼▼✪✳✺✹ ✳ ✈✇❄✪✾ ✳ ✳❅✹❊✴☛✾◆❃②✴✎①◗✶✓✸ ✵❴❺ ☎❛✾✪✶✙✴✆✈❫✳✵❍✪✶▲✻❜✿✌✹❊✾✳✵❍✪✶✓✴☛✸❆✶✓✻❜❃❞✴✆✈ ✳ ✴◗✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✍✳❅✹❊✴☛✾☎❃❅✳❀✿✆✳✵✶✠❃ ✑❛❍✪✶✓✾ ✑❇✶ ✳ ✿✆✾ ✑❴✸❅✹❊✳✵✶ ✧ ✫ ❈ ✙✎✭❤✿☛❃❇✿❪✸✩✿✆✳❅✹❊✴☛✾◆✿✌❁➂✈✑❄✪✾ ✳ ✳❅✹❊✴☛✾❨✹❊✾ ✧ ✫✜✙✎✭❀❺q ✾▲✴◗✸❀❖✣✶✓✸❇✳✵✴❪✶✠✿☛❃❡✹❭❁❊● ❖✣✶✓✳✵✶ ✳ ✳❇✳✵❍✪✶❯❖◗✹✰✯✖✶✓✸✵✶✓✾ ✳ ✶ ❈ ✶✓✳ ✑❇✶✓✶✓✾❨❁❱✿✆✳✵✳✺✹ ✳ ✶✠❃③✳✵❍◆✿✆✳❛✿✆✸✵✶ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❢❄✣❁❊✳❅✹❊▼✣❁❊✶✠❃❴✴✆✈❂✶✠✿ ✳ ❍❜✴◗✳✵❍✪✶✓✸✿✆✾◆❖✽❁❱✿✆✳✵✳✺✹ ✳ ✶✠❃❴✳✵❍◆✿✆✳❫✿✆✸✵✶❬✳✵✸✵❄✣❁❊●▲❖◗✹✰✯❵✶✓✸❆✶✓✾✜✳ ■ ✑❣✶❫✹❊✾✣✳✵✸✵✴✪❖✣❄ ✳ ✶❯✳✵❍✪✶ ✳ ✴◗✾ ✳ ✶✓▼✪✳✕✴✆✈✄✂ ✼ ✹❊✾✜①✆✿✆✸❅✹❱✿✆✾✣✳❛✴✆✈❤✿❏❁❱✿✆✳✵✳❅✹ ✳ ✶☛❺❉ ✴◗✸✕✿❪❁❱✿✆✳❆✳❅✹ ✳ ✶ ✵ ✶ s ✖✆☎ ✥✚✖ ✼ ✉ ■ ❖✣✶ ✒◆✾✪✶✞✝ ✶ ✖ ✼ ✡ ✖✆☎❀❺ ✬ ❍✪✶✓✾▲❁❊✶✓✳ ✙ ✫✟✝✦✭ ✶ ▼ ✝

✼ ✫✠✝✦✭✕✾♦♣ ✍ ▼ ✼✝ ✫✟✝✦✭❀❺ ✬ ❍✪✶✡✂☞☛ ✔✑✝✍✌ ✸✽✳ ✔ ✸ ✝✍✎✴✆✈ ✵♦✹❱❃❴✳✵❍✪✶ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✾✣❄✪✻ ❈ ✶✓✸ ✂✦✫✠✝✦✭✂✶ t✑✏✆♣ ❲ ▼ ✝✼ ✫✟✝✦✭ ✡ ✙ ✫✠✝✦✭ ✬q ✳❴✳✵❄✪✸✵✾◆❃❇✴☛❄✪✳❴✳✵❍◆✿✆✳❛✳✗✑❇✴❬❁❱✿✆✳✵✳✺✹ ✳ ✶✠❃❫✿✆✸✵✶❫✹❱❃❅✴◗✻✷✴☛✸✵▼✪❍✣✹ ✳ ✹❭✈❣✿✆✾◆❖❨✴◗✾✣❁✼●❨✹❭✈❤✳✵❍✪✶✓●❨❍◆✿✌①☛✶❬✳✵❍✪✶❯❃✵✿✍✻✷✶✒✂ ✼ ✹✼✾✣①✎✿✍✸❅✹❱✿✆✾✜✳✌❺✬ ❍✪✶✓✂ ✼ ✹✼✾✣①✎✿✍✸❅✹❱✿✆✾✜✳ ✳ ✿✆✾♥✿✎❁P❃✺✴ ❈ ✶▲❄◆❃❅✶✠❖♦✳❆✴ ✳ ❁❱✿☛❃✵❃❡✹❭✈✑●❩✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳✑✳ ❄✪✸✵①☛✶✠❃❨s ❲ ✉✞❺✕✔❞✴☛✾◆❃❡✹❱❖✣✶✓✸✷✳✵❍✪✶▲✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳ ✳ ❄✪✸❆①☛✶✗✖ ■✑❛❍✣✹ ✳ ❍▲✹❱❃✕✿✍✾▲✶☛✭☛❄◆✿✆✳✺✹✼✴◗✾✙✴✆✈❉✳✵❍✪✶❫✈✑✴☛✸✵✻✙✘ ✼ ✶ ☛✛✚ ✝ ✾ ▼ ✼ ✚ ✾ ▼ ✝ ❺ ❉ ✸❆✴☛✻➄✳✵❍✪✶❬✳✵❍✪✶✓✴◗✸✵●❜✴✍✈❦✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳■✳ ❄✪✸✵①☛✶✠❃ ■ ✑❣✶ ✭ ✾✪✴✜✑✳✵❍✪✶✓✸✵✶❞✹❱❃❤✿❫❄✪✾✣✹✦✭◗❄✪✶❛❁❱✿✆✳❆✳❅✹ ✳ ✶ ✵✢✜✙❃❅❄ ✳ ❍✷✳✵❍◆✿✍✳ ▼ ✼ ✶ ▼ ✼ ✫✜✵✣✜ ✭❂✿✍✾◆❖ ▼ ✝ ✶ ▼ ✝ ✫✜✵✣✜✖✭❀❺☎✫ ✬ ❍✪✶❞✹❊✾✜①☛✶✓✸✩❃❅✶❇✹❱❃❤✿✌❁❱❃❅✴❬✳❆✸✵❄✪✶ ✼ ❋✍✹✼①◗✶✓✾✿❏❁❱✿✆✳✵✳✺✹ ✳ ✶ ✵ ✴✎①◗✶✓✸ ✔ ■ ✳✵❍✪✶✓✸❆✶❫✹P❃❬✿②❄✪✾✣✹ ✭◗❄✪✶ ✳ ✴☛✸✵✸✵✶✠❃✺▼◆✴☛✾◆❖◗✹❊✾✪❋❨✶✩❁❻❁❭✹❊▼✪✳❅✹ ✳ ✳ ❄✪✸✵①☛✶✤✖✦✥✦✭❀❺ ✣♠✶❬✶ ✁ ✳✵✶✓✾◆❖✦✳✵❍✪✶❢❖✣✶ ✒◆✾✣✹❊✳❅✹❊✴☛✾❳✴✆✈✂❨✳✵✴❪✶✩❁❭❁❻✹❊▼✪✳❅✹ ✳■✳ ❄✪✸❆①☛✶✠❃ ❈ ●▲❃✵✿✌●☛✹❊✾✪❋✷✳✵❍◆✿✍✳✆✂✦✫✠✖ ✭ ✶✧✂✦✫✜✵ ✜ ✭❀❺ ✬ ❍✪✶✓✾✙✳✗✑❇✴❪✶✩❁❻❁❭✹❊▼✪✳❅✹ ✳■✳ ❄✪✸✵①◗✶✠❃✒✖ ☎ ✥★✖ ✼ ✿✆✸✵✶❫✹❱❃❅✴☛✻✽✴☛✸✵▼✪❍✣✹ ✳ ✹❭✈✿✆✾◆❖❨✴☛✾✣❁❊●❨✹❭✈✩✂✦✫✠✖✪☎ ✭✂✶✕✂❀✫✟✖ ✼ ✭❀❺

✫ ✥ ✢ ④✲✳ ✠ ✧✩✳✭✬ ☎ ❷ ✒ ★ ✧✝✕✘✗☎❛✾✪✶✙✿✆▼✪▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ✴✆✈ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁✼✳✺✹✼▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ✹❱❃❏✹❊✾❲❃❅✴✆❁❊①☛✹❊✾✪❋☎✳❆❍✪✶ ✳ ❁P✿◗❃✵❃❏✾✜❄✪✻ ❈ ✶✓✸✽▼✪✸✵✴ ❈ ❁❊✶✓✻ ■ ✑❛❍✣✹ ✳ ❍❙✹❱❃❪✿▼✪✸✵✴ ❈ ❁❊✶✓✻ ✸✵✶✩❁❱✿✆✳✵✶✠❖♠✳✵✴ ✭☛❄◆✿☛❖✣✸✩✿✆✳❅✹ ✳ ✈✑✴☛✸✵✻❜❃✓❺✯✮☛✴☛✻✽✶ ❈ ✿ ✳✱✰ ❋☛✸✵✴☛❄✪✾◆❖❳✴◗✾ ✭☛❄◆✿◗❖✣✸❀✿✆✳❅✹ ✳ ✈✇✴☛✸❆✻❜❃❴✹❱❃❯✾✪✶✓✶✠❖✣✶✠❖♠✹❊✾♦✴☛✸❀❖✣✶✓✸❪✳✵✴❃❅✳❀✿✍✳✵✶❇✳✵❍✣✹❱❃❤▼✪✸❆✴ ❈ ❁❊✶✓✻✙❺ ✑✳✲ ✖✎✸✵✴✦✳ ✸ ✎✕✔ ✻✢✶✸✷✦✳✺✹ ✹❱❃❤✿❝✈✇❄✪✾ ✳ ✳✺✹✼✴◗✾✗✻ ✫ ✚ ✥★✘❄✭✕✶✽✼ ✚ ✼ ✺✿✾ ✚ ✘ ✺✗❀ ✘ ✼ ✑❇✹❊✳✵❍❁✼ ✥ ✾ ✥ ❀❃❂✯❄ ■ ✿✍✾◆❖❏✹❊✳❀❃✴ ✔ ✶✺✻✴✳ ✔ ✹ ✔✞✝ ✸ ✝✍✎ ✹❱❃ ✾✒❅ ✶ ✾ ✼ ✾❇❆✛✼ ❀ ❺✢❈✪✴☛✸❼✈✇❄✪✳❆❄✪✸✵✶❛✸✵✶✩✈✑✶✓✸✵✶✓✾ ✳ ✶ ■ ❖✣✶ ✒◆✾✪✶❬✳✵❍✪✶ ✴ ✔ ✶✑✻✎✳ ✔ ✹ ✔✑✝ ✸ ✝☞✎ ✷✟✶✛✸ ✲ ✖✌✸✵✴✽✳ ✸ ✎✕✔ ✻ ✝

✖❉✹✞❊ ✱✎✳✝✽✳✵✴ ❈ ✶✕✳✵❍✪✶❬❖◗✹❱❃ ✳ ✸❅✹❊✻❪✹❊✾◆✿✆✾✣✳❛✴✆✈✖✳✵❍✪✶❫❄✪✾✣✹✦✭☛❄✪✶ ✭◗❄◆✿☛❖✣✸❀✿✆✳✺✹ ✳ ✈✑✴☛✸✵✻ ✫✟✼✫✥ ✾ ✥ ❀ ✭ ■ ✼ �●❋ ■ ✫✠✼ ✥ ✾ ✥ ❀ ✭ ✶ t✕❃✺❄ ✳ ❍❨✳✵❍◆✿✆✳❃✝❪✹❱❃❞✳✵❍✪✶✸✵✴✣✴☛✳❇✴✆✈✆✼ ✚ ✼ ✺✧✾ ✚ ✺✧❀ ✶ ❋ ❺✘❫✶ ✒◆✾✪✶■❍ ✫ ✾✒❅ ✭❪✳✵✴ ❈ ✶❳✳✵❍✪✶☎❃❅✶✓✳❜✴✍✈❢✿✌❁❭❁ ✭☛❄◆✿☛❖✣✸✩✿✆✳❅✹ ✳ ✈✇✴☛✸❆✻❜❃✒✑❇✹❊✳✵❍ ❖◗✹❱❃ ✳ ✸❅✹❊✻❪✹❊✾◆✿✆✾✣✳ ✾✒❅ ✿✆✾◆❖ ✫✠✼✫✥ ✾ ✥ ❀ ✭ ✶ t☛❺❏ ❃✵❃❅✴ ✳ ✹P✿✍✳✵✶ ✑❇✹❊✳✵❍❑✻☎✿✽✻❜✿✆✳✵✸❅✹ ✁▼▲ ✶❖◆ ❥ ✦◗P ✼✦◗P ✼❙❘❯❚ ❺ ✬ ❍✪✶✓✾❹✳✗✑❇✴✏✭☛❄◆✿◗❖✣✸❀✿✆✳❅✹ ✳ ✈✑✴☛✸✵✻❨❃✒✻✫✥✺✻❲❱❂✿✆✸❆✶ ✱ ✲ ✖ ✔❳✌ ✸✵❨ ✱ ✝✍✎ ✹❭✈❤✳✵❍✪✶✓✸✵✶ ✹P❃✿❪✻❜✿✍✳✵✸❅✹ ✁❬❩ ❂❑❭ ✵ ✼ ✫ ❄ ✭❂❃❅❄ ✳ ❍▲✳❆❍◆✿✆✳ ▲ ✤ ✶ ❩❫❪ ☎ ▲❴❩ ❺✘❫✶ ✒◆✾✪✶ �✄✫ ✾✒❅✵✭ ✶❵❍✬✫ ✾✒❅ ✭ ✡ ✟ ■ ✑❛❍✪✶✓✸✵✶ ✟ ✹❱❃❨✳✵❍✪✶❳✶☛✭☛❄✣✹❊①✆✿✌❁❊✶✓✾ ✳ ✶❙✸✵✶✩❁❱✿✆✳❅✹❊✴☛✾ ❖✣✶ ✒◆✾✪✶✠❖ ✿ ❈ ✴✎①◗✶☛❺ ✬ ❍✪✶✓✾ ✿✆✾

✹❊✻✷▼◆✴◗✸✵✳❀✿✆✾✣✳❬✳✵❍✪✶✓✴☛✸✵✶✓✻➃❃❅✳❀✿✍✳✵✶✠❃❫✳✵❍◆✿✆✳✡❛✲✫ ✾✒❅ ✭ ✶❝❜ �✄✫ ✾✒❅ ✭❞❜◗✹❱❃✚✒◆✾✣✹❊✳✵✶☛❺✓❡❤✿ ✳ ❍ ✳ ❁❱✿☛❃✵❃ ✳ ✴☛✾✜✳✩✿✌✹❊✾◆❃❫✶ ✁ ✿ ✳ ✳✺❁✼●✰✴☛✾✪✶❪✈✑✴☛✸✵✻✑❛❍✣✹ ✳ ❍❳✹❱❃ ✳✜✱✺✴ ✖✎✻ ✱✺✴ ✫❞❜ ✾ ❜✭❢❣✼▼❢ ❀ ■ ✿✍✾◆❖ ✾ ✮ ❋ ✹❭✈❤❜ ✾ ❜ ✶✐✼▲✴☛✸✡✼ ✶ ❀ ✭ ■ ✿✆✾◆❖ ✑❣✶❏✹❱❖✣✶✓✾✣✳❅✹❭✈✇●❳✶✠✿ ✳ ❍ ✳ ❁❱✿☛❃✵❃✓✑③✹✼✳❆❍☎✳✵❍✣✹❱❃✈✑✴☛✸✵✻▼❥✄�✄✫ ✾✒❅ ✭★✶❧❦♠❍✓☎✌✥★❍ ✼ ✥ ✬✎✬✴✬ ✥★❍♦♥✑♣✜❺ ✬ ❍✪✶✓✾ ■ ✳✵❍✪✶✓✸❆✶✷✹❱❃❪✿✄✫✑✈⑧✿✎✹✼✸✺❁✼● ✳ ✴☛✻✷▼✣❁❭✹ ✳ ✿✆✳✵✶✠❖✦✭ ✑❛✿✌●❳✴✆✈ ✻★✷✵✹✦q✭✷✕✶ ✔✑✝✛r ✳ ✑❇✴✈✑✴☛✸✵✻❜❃ ■ ✿✆✾◆❖✰✳✵❍✣✹❱❃❫✴☛▼◆✶✓✸❀✿✍✳❅✹❊✴☛✾✙✻❜✿ ✰ ✶✠❃ �✄✫ ✾✒❅ ✭❉✹❊✾✣✳✵✴✙✿✆✾❹✿ ❈ ✶✩❁❭✹❱✿✆✾☎❋☛✸✵✴◗❄✪▼✖❺ �✄✫ ✾✒❅ ✭❉✹❱❃ ✳ ✿✌❁❭❁✼✶✠❖ ✳✵❍✪✶ ✻s❨✰✸✕✶✮✶ r ✳✟✷ ✖tq ■✿✆✾◆❖❇❛✲✫ ✾✒❅ ✭✖✹❱❃❇✳❆❍✪✶ ✻✉❨ ✸ ✶ ✶ ✝✖❉✹✈❊ ✱✴✳ ❺ ✬ ❍✪✶✕▼✪✸❆✴ ❈ ❁❊✶✓✻ ✹❱❃❞✳✵✴ ✒◆✾◆❖▲✿✌❁❭❁ ✾✒❅✐✈✇✴☛✸ ✑❛❍✣✹ ✳ ❍✿❛✲✫✌✾✒❅✵✭✏✹❱❃ ✒ ✁ ✶✠❖ ■ ✶✠❃❅▼❚✶ ✳ ✹P✿✎❁❻❁❊●✈✑✴☛✸✇❛✲✫✌✾✒❅✵✭✂✶ t◗❺❃✮☛✶✓✶✷s①✏✠✉✞❺

② ✥▲❶ ★✲✕■③✖✓⑤④✜⑥●⑥⑤④✲✓⑤✬ ☎❳③ ✓✞☎ ❷✕✳✭✬ ☎ ★✂⑦❈✪✴◗✸❛✳✗✑❣✴❏❁❱✿✆✳✵✳✺✹ ✳ ✶✠❃ ✵❲✿✍✾◆❖ ❩ ■ ✑❇✶❯❃✵✿✌●✷✳✵❍◆✿✆✳ ✵ ✟ ❩ ✹❭✈❣✿✆✾◆❖❨✴☛✾✣❁❊●❨✹❭✈✒⑦✛⑧ ❂ ✔ ❃❅❄ ✳ ❍✰✳✵❍◆✿✆✳✒⑧✻✵ ✶ ❩ ❺☎✘❫✶ ✒◆✾✪✶

❭ ✫✚✵ ✭✻✶⑨❦♠⑧ ❂ ✔✆✥★⑧✻✵⑨⑩ ✵❃♣✜❺❈✂✹❊✾◆✿✌❁❭❁❊● ■ ✑❇✶ ✳ ✿✆✾✰❋✆✹❊①☛✶❬✴☛❄✪✸✕❖✣✶ ✒◆✾✣✹❊✳❅✹❊✴☛✾❳✴✆✈ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❻✹ ✳ ✿✆✳✺✹✼✴◗✾✖❺❶✈❷✭❸✵❹◗❺❲❹❼❻✄❹❾❽✢❺ t✛❿ q ✈ ❭ ✫✜✵ ✭ ✳ ✴◗✾✜✳❀✿✎✹✼✾◆❃❫✻✽✴☛✸✵✶❯✳❆❍◆✿✆✾ ❄ ■ ✵ ✹❱❃❯❃✵✿✌✹❱❖✰✳✵✴❨❍◆✿✌①☛✶ ✻★✷✵✹✦q➀❨ ✱t➁✗✹ ✖❉❨ ✎✕✔ q➀❨ ✔ ✻ ✸ ✎✕✔ ✷ ✝ ❺ q ✈➂⑧♥✹P❃✹❊✾ ❭ ✫✜✵ ✭ ✾ ❄ ■ ✵ ❍◆✿☛❃ ✻✺✷✵✹✦q➀❨ ✱✸➁✈✹ ✖❉❨ ✎✕✔ q➀❨ ✔ ✻ ✸ ✎✕✔ ✷ ✝ ❊✸➃ ⑧❤❺❭ ✫✚✵ ✭❉❍◆✿☛❃❛❃❅✴◗✻✷✶❯❃❅▼◆✶ ✳ ✹❱✿✌❁❉▼✪✸✵✴☛▼❚✶✓✸✵✳❅✹❊✶✠❃✓❺➄❤➅➆❷✛❽✢➇❲❷✭➈ t✛❿✦➉ ✱ ✎ ✵ ✶ s ✖➊☎✲✥ ✖ ✼ ✉ ✛✞➋✄➌ ✱ ✝ ⑧ ❂➍❭ ✫✜✵ ✭ ✥★⑧ ❂ ✔ ✾ ❄ ✔ ✶✛✸ ✝ ✴❯✷ ✝ ❨①➃ ✔ ✶ ⑧ ✔ ✶✛✸ ✲ ✖✎✸✵✴✦✳ ✸ ✎✕✔ ✻ ✔✞✝☞✎ ✱ r ✱✎✳ ✛

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Page 134: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✣☎✸❅✹❊✳❅✹❊✾✪❋■✝ ✶ ✖ ✼ ✡ ✖✆☎ ■ ✳✵❍✪✶✓✾❙⑧✿✶❝✼❉✝ ✺✽✾ ■ ✝✁�❂✄✂ ■ ❃❅✴✆☎✙✫✟⑧ ✭ ✶✝☎ ✫✠✝✦✭☛✶✞☎✙✫✠✟ ✾✒❅✾✭ ■ ✑❛❍✪✶✓✸✵✶✹✾✒❅ ✹❱❃❏✳✵❍✪✶❖◗✹❱❃ ✳ ✸❅✹❊✻❪✹❊✾◆✿✆✾✣✳❬✴✆✈❉✳✵❍✪✶ ✭☛❄◆✿◗❖✣✸❀✿✆✳❅✹ ✳ ✾✣❄✪✻ ❈ ✶✓✸ ✝➂❺☎✘❫✶✓✾✪✴☛✳✵✶❬✳✵❍✣✹❱❃ ✒◆✶✩❁❱❖ ❈ ● ✛♦❺

✡ ❄◆✿☛❖✣✸❀✿✍✳❅✹ ✳ ✒◆✶✩❁❱❖▲✳✵❍✪✶✓✴◗✸✵●❜✳❆✶✩❁❻❁❱❃❴❄◆❃❛✳❆❍◆✿✆✳❇✳✵❍✪✶❯✸❅✹❊✾✪❋✷✴✍✈❂✹❊✾✣✳✵✶✓❋☛✶✓✸❀❃❇✴✍✈ ✛ ✹❱❃☞☛✍✌ ✶ ❄ s✰✫✌✾✒❅ ✺ ✟ ✾✒❅✾✭ ✡ ♣✆✉✞❺ ✬ ❍✪✶✓✾❭ ✫✚✵ ✭✏✹❱❃✕✿✷❃✺❄ ❈ ✸❅✹❊✾✪❋▲✴✆✈✎☛✍✌❬❺ ✬ ❍✣❄◆❃ ■ ✹❭✈ ✵ ❍◆✿☛❃ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❢❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ❈ ●▲✿✷❃❡✹❊✾✪❋✆❁❊✶❪✶✩❁✼✶✓✻✽✶✓✾✜✳✡⑧ ■ ✳✵❍✪✶✓✾❨✹❊✳❫❍◆✿☛❃✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ❈ ●✷✶✠✿ ✳ ❍✷✻✷✶✓✻ ❈ ✶✓✸❣✴✍✈✂✿ ✸❅✹❊✾✪❋❪✴✆✈✖✶✩❁✼✶✓✻✽✶✓✾✜✳❀❃❼✹❊✾✙✿✆✾❪✹❊✻❜✿✍❋✆✹❊✾◆✿✆✸✵● ✭◗❄◆✿☛❖✣✸❀✿✆✳✺✹ ✳ ✒◆✶✩❁❱❖➂❺✴✔❴✴☛✳✵✶✳✵❍◆✿✆✳❏✳✵❍✪✶❨✾✪✴☛✾✑✏ ✹❊✾✜✳✵✶✓❋◗✶✓✸❢✶✩❁❊✶✓✻✷✶✓✾✣✳❀❃❪✴✍✈ ❭ ✫✜✵ ✭❬✿✆✸✵✶✷❋◗✶✓✾✜❄✣✹❊✾✪✶✩❁❊● ✳ ✴☛✻✷▼✣❁❊✶ ✁ ■ ✑❛❍✣✹ ✳ ❍❙✶ ✁ ▼✣❁❱✿✌✹❊✾◆❃❪✳✵❍✪✶❨✾◆✿✆✻✷✶ ✳ ✴☛✻✷▼✣❁❊✶ ✁✻❪❄✣❁❊✳❅✹❊▼✣❁❻✹ ✳ ✿✆✳✺✹✼✴◗✾✖❺

✒✔✓✲✞✢➈✍✕ ☎✵❷ ❿ ✭ ✶✓✳✿❍ ✶✿✫✠✼ ✥ ✾ ✥ ❀ ✭ ❂ �✴✫✌✾✒❅✵✭ ■ ✿✍✾◆❖ ❃✺✶✓✳✗✝✗✖ ✶✿✫ ✾ ✾ ✺ ✟ ✾✒❅ ✭ ✡ ✫❑♣ ✼ ✭❀❺ ✬ ❍✪✶✓✾ ✳✵❍✪✶▲❁❱✿✆✳❆✳❅✹ ✳ ✶✵✘✖ ✶ s❊t✦✥✺✝✗✖✪✉✖❍◆✿◗❃ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❻✹ ✳ ✿✆✳✺✹✼✴◗✾ ❈ ●▲✿✌❁❭❁❂✴✆✈✔☛ ✶ ❄ s ✫ ✾✒❅ ✺ ✟ ✾✒❅✾✭ ✡ ♣✆✉✞❺☎❛✾✪✶❯✸❆✶✓✻❜✿✆✸ ✰ ✿ ❈ ❁❊✶❯✈✞✿ ✳ ✳❇✹❱❃❴✳✵❍✪✶❯✸❆✶✩❁P✿✍✳❅✹❊✴☛✾◆❃❅❍✣✹❊▼ ❈ ✶✓✳✗✑❇✶✓✶✓✾▲❁❱✿✆✳❆✳❅✹ ✳ ✶✠❃✙✑❇✹❊✳✵❍ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾❩✿✆✾◆❖✦✳✵❍✪✶ ✧

✈✑❄✪✾ ✳ ✳❅✹❊✴☛✾✖❺➄❤➅➆❷✛❽✢➇❲❷✭➈ ♣✍❿✦➉ ✱ ✎ ✵ ❊ ✱ ✸✡❨✰✸ ✎◗✎✕✔ ✻ ✱✚✙ ✸ ✝ ✴ ✧ ❊ ✱ ✎ ➌ ✱ ✧➆☛ ✶✢✖ ✝ ✻ ✎✕✔ ✷ ✝ ✶✸✷✦✳ ✵ ✛✓➋✄➌ ✱ ✝ ✵✕➌ ✸✕✶ ✻★✷ ✹✒q❲❨ ✱t➁✒✹ ✖❉❨ ✎✕✔ q❲❨ ✔ ✻✮✸ ✎✕✔ ✷ ✝❊✸➃ ⑧ ❂ ✔ ✾ ❄ ✔ ✶ ✸ ✝ ✴❁✷ ✝ ❨①➃ ✔ ✶ ✧ ✫✟⑧✕✙✎✭✂✶✁✛ ✫ ✧ ✫✚✙✎✭✷✭ ✡✢✜ ✫ ✧ ✫✜✙✎✭✷✭

✌✣✔❾✎ ➌✣✛✆✥ ✜ ✳✚✱✉❨ ✸ ✎✕✔❳✌ ✱s❨①➃❴q ✳ ✔ ✹✘✱❴q✭✷✵❨①➃ ✝ ✷✵✹ ✔ ✸✵❨ ✶✤✙ ✸ ✝ ✴ ❖✣✶✓❋✦✫✥✛ ✭ ✶❲❖✣✶✓❋✦✫ ✜ ✭ ✺ t ✶ ✡ ✫✟⑧ ✭✜✛❏ ❁✼❋◗✴☛✸❅✹❊✳✵❍✪✻❜❃❇✶ ✁ ✹❱❃❅✳❫✳✵✴ ✒◆✾◆❖✦✛ ✿✍✾◆❖ ✜ s ✜✆✉❡❺✔❤✴☛✻✽▼✣❁✼✶ ✁ ✻❪❄✣❁❊✳❅✹❊▼✣❁❻✹ ✳ ✿✆✳✺✹✼✴◗✾ ✳ ✿✆✾✙✿✌❁❱❃❅✴ ❈ ✶❪❖✣✶ ✒◆✾✪✶✠❖▲✴☛✾▲✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳■✳ ❄✪✸✵①☛✶✠❃ ■ ✹✼✾✰✳✵❍✪✶❬✴ ❈ ①☛✹❊✴☛❄◆❃ ✑❛✿✌●☛❺❶✈❷✭❸✵❹◗❺❲❹❼❻✄❹❾❽✢❺ ♣✍❿ ❏ ✾❢✶✩❁❭❁❭✹❊▼✪✳❅✹ ✳ ✳ ❄✪✸✵①☛✶✒✖ ❍◆✿☛❃ ✻✺✷✵✹✦q➀❨ ✱✸➁✡✹ ✖❉❨ ✎✕✔ q❲❨ ✔ ✻✮✸ ✎✕✔ ✷ ✝ ✹❭✈❂✿✆✾◆❖❏✴☛✾✣❁❊●❬✹❭✈➅✳✵❍✪✶❛✿☛❃❆❃❅✴ ✳ ✹❱✿✆✳❆✶✠❖❬❁❱✿✆✳❆✳❅✹ ✳ ✶✵❙❍◆✿◗❃✓❺✬ ❍✪✶❫✈✑✴✆❁❭❁❊✴ ✑③✹✼✾✪❋❨✳✵❍✪✶✓✴☛✸❆✶✓✻ ❃❅❍✪✴✜✑✕❃ ✑❛❍✣✹ ✳ ❍ ✖✍✖❳❍◆✿✌①☛✶ ✳ ✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁✼✳✺✹✼▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ■ ✿✆✾◆❖ ❈ ● ✑❛❍◆✿✍✳❛✸❅✹❊✾✪❋◆❺➄❤➅➆❷✛❽✢➇❲❷✭➈ ✎✍❿✔✧ ❨❾❨ ✱s❨❾❨ ✔ q ✎✕✔ ✻ ✻ ✖ ✳ ✌ ✱✑✶ ✖★✖ ✶ ✔ ✡ ✵✘✖ ✙

✌ ➌ ✱✴✳✜✱ ✵✘✖ ✔ ✶✆✴✦✱✪✩ ✝✱✺✴ ✸✕✶ ✔✞✝✓✎ ➌ ✱ ✱✸➁ ✸ ✹✒q❲❨ ✱✚✙ ➌ ✸ ✌ ✱☛✻★✷✵✹✦q➀❨ ✱t➁✹ ✖✛❨ ✎✕✔ q➀❨ ✔ ✻✮✸ ✎✕✔ ✷ ✝ ❊✸➃ ✎ ➌ ✱❴✶ ✖❉❨❾❨✕✳ ✔✞✝❉r ✷ ✶ ✔✑✝✍✎ ✱ r ✱✴✳✷✶ ☛ ✛ ➋✄➌ ✱✑✶ ✱✙✸✦✳✚✱ ✎ ➌ ✱❇✷ ✝ ❨①➃❇✷ ✝ ✱ ✶ ✌✣✔❾✎ ➌ ✻✺✷✵✹✦q➀❨ ✱✸➁❇✹ ✖❉❨ ✎✕✔ q❲❨ ✔ ✻✮✸ ✎✕✔ ✷ ✝❊✸➃ ☛ ✙ ✖✸q ✎ ✷ ✔ ✶❞✷✵✹✓✷✦✳ q ➌ ✔ ✶✸✹ ✛

✬ ❍✪✶❫✈✑✴✆❁❭❁❊✴ ✑③✹✼✾✪❋❨✳✵❍✪✶✓✴☛✸❆✶✓✻➄✸✵✶✩❁❱✿✆✳✵✶✠❃ ✳ ✴◗✻✷▼✣❁❊✶ ✁ ✻❢❄✣❁❊✳❅✹❊▼✣❁❭✹ ✳ ✿✆✳❅✹❊✴☛✾ ✑③✹✼✳❆❍✙✳✵❍✪✶✒✂✫✏ ✹❊✾✜①✆✿✆✸❅✹❱✿✆✾✣✳✠❺➄❤➅➆❷✛❽✢➇❲❷✭➈ ❆➀❿✦➉ ✱ ✎ ✖ ❊ ✱✛✸

✝✱s❨❾❨ ✔ q ✎✕✔ ✻✛✻ ✖ ✳ ✌ ✱ ✌✣✔❳✎ ➌ ✻✺✷✵✹✦q➀❨ ✱✸➁✓✹ ✖✛❨ ✎✕✔ q➀❨ ✔ ✻✮✸ ✎✕✔ ✷ ✝ ✙ ✵ ✔❳✎ ✶✛✸✕✶✮✶❞✷✩✻ ✔ ✸ ✎ ✱✺✴✤❨✰✸ ✎◗✎✕✔ ✻✌✱✗✙ ✸ ✝ ✴❅ ✎ ➌ ✱✙✸ ✶ ✶✸✷✢✻ ✔ ✸ ✎ ✱✺✴✈✴ ✔ ✶✑✻✎✳ ✔ ✹ ✔✑✝ ✸ ✝☞✎ ✛✓➋✄➌ ✱ ✝ ✂✦✫✠✖ ✭ ✔ ✶ ✸ ✝ ✸✵❨ r ✱✑❊ ✳ ✸ ✔ ✻ ✔✞✝☞✎ ✱ r ✱✎✳❴✷✟✶❤✴✦✱ r ✳✚✱ ✱ ❛ ✫ ✾✒❅✵✭ ✛

➄❤➅➆❷✛❽✢➇❲❷✭➈ ❾✍❿❯➋✄➌ ✱♦✹ ✔✞✝ ✔ ✹ ✸✵❨❉q✭✷✵❨①➃ ✝ ✷✵✹ ✔ ✸✵❨✄✷✟✶ ✂❀✫✟✝✗✖ ✭ ✙✭✬✝✷✌✡✝

✸✕✶ ✎ ➌ ✱ ✳ ❁P✿◗❃✵❃❇✶☛✭◗❄◆✿✆✳❅✹❊✴☛✾ ✙ ✔ ✶� ❪✯✮ ✫✱✰ ✭✻✶ ✲✖✴✳✶✵✭✷ ❪✫✮✹✸

✫✱✰ ✾✿✂✦✫✠✝✗✖✖✭✷✭✺❼✶ ✛ ✔ ✶✛✸ ✝ ✔ ✹ ✸ r ✔✞✝ ✸✦✳★➃ ✲ ✖✎✸✵✴✦✳ ✸ ✎✕✔ ✻✔✩✆✱s❨①✴✻✙ ✎ ➌ ✱ ✝ ✛ ✵ ✶ ✛✄✫❳✂✦✫✠✝ ✖ ✭✷✭ ✔ ✶✽✼ ✸✵❨①✷ ✔ ✶ ✸ ✝ ✴ ✔ ✶ ✻✮✸✵❨❾❨ ✱★✴ ✎ ➌ ✱☞✾ ✹❭❁ ❈ ✶✓✸❆✳❀✿❆❁P✿◗❃✵❃✒◆✶✩❁❱❖▲✴✆✈ ✛ ✛

❁ ✥✏✣✿③ ③✖✓✑☎❱❷ ✳✭✬ ☎✪★✂⑦✣✗❁ ✥✑❸✦✥✭✚❬❶❪⑨❯⑨✙✥ ❡❦❁❻❁❭✹❊▼✪✳❅✹❂✿✕✔❤❄✪✸❆①☛✶❄❃❼✸❅✹❊✻❜✿✌❁❭✹❊✳❑●❅❃❼✸✵✴✆①☛✹❊✾✪❋☎✻❨✿ ✰ ✶✠❃❪❄◆❃❅✶✰✴✆✈❯✳✵❍✪✶✦✿❆❁❱✿☛❃✵❃✽✶☛✭◗❄◆✿✆✳❅✹❊✴☛✾ ✳✵✴ ✒◆✾◆❖♥❁P✿✍✸✵❋☛✶

▼✪✸❅✹❊✻✷✶❏✾✜❄✪✻ ❈ ✶✓✸✩❃✓❺❆❃❉✿✆✸✵✳❇✴✆✈❤✳✵❍✪✶❬✻✽✶✓✳✵❍✪✴✱❖ ✹❱❃❫✳✵✴❜❖✣✶✓✳✵✶✓✸✵✻②✹✼✾✪✶ ✹❭✈ ■ ✈✇✴◗✸✕✿✷▼✪✸✺✹✼✻✽✶★❇ ■ ✫❈❇✲✭❣❃❅▼✣❁❭✹❊✳❀❃☞✿✩✴☛✻✷▼✣❁❊✶✓✳✵✶✩❁❊●✦✹✼✾ ✛❉✵ ■✴☛✸❫✶☛✭☛❄✣✹❊①✆✿✌❁❊✶✓✾✜✳❅❁❊● ■ � ❪✯✮ ✫❊✰✝✭❤❍◆✿◗❃✇❛✰✸✵✴✣✴☛✳❀❃❫✻✷✴✪❖✫❇✖❺ ✬ ❍✜❄◆❃❴✴☛✾✪✶❯✴✍✈❤✳✵❍✪✶❪▼✪✸✵✴ ❈ ❁❊✶✓✻❜❃③✹P❃❫✳❆✴ ✿❋✿✩✳❆❄◆✿✌❁❭❁✼●●✿✩✴☛✻✷▼✪❄✪✳✵✶❏✳✵❍✪✶✿❆❁❱✿☛❃✵❃❴✶☛✭☛❄◆✿✍✳❅✹❊✴☛✾✖❺✓☎❛✾✪✶❢✿✎❁✼❋◗✴☛✸❅✹❊✳✵❍✪✻➄✳✵✴❨❖✣✴✷✳✵❍✣✹❱❃❞✹❊✾✜①◗✴✆❁❊①☛✶✠❃❛✳❆❍✪✶❬✳✵❍✪✶✓✴☛✸✵●❨✴✆✈✘✿✩✴☛✻✷▼✣❁❊✶ ✁ ✻❪❄✣❁✼✳✺✹✼▼✣❁❭✹❂✿✓✿✆✳❅✹❊✴☛✾ s ♣✌✉✞❺

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Page 135: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

❁ ✥ ✱✲✥❨❶ ✓ ✳✙✗✟✗✁� ④✖✕ ✤ ④ ✧❏⑨ ✧✩★✥✤ ✓❼④ ✕ ✥ ✣♠✶✙✑❇✴☛❄✣❁❱❖❏❁❭✹ ✰ ✶✕✳✵✴ ❈ ✶❝✿ ❈ ❁✼✶❫✳✵✴❀✿✓✿✌❁❂✿✩❄✣❁❱✿✆✳✵✶❫✳✵❍✪✶❛✾✣❄✪✻ ❈ ✶✓✸❞✴✆✈ ✾✒❅✄✂ ❃❼✳✵❍◆✿✆✳❍◆✿✌①☛✶★✿❆❁❱✿☛❃✵❃❞✾✣❄✪✻ ❈ ✶✓✸ ❛ ■ ✿☛❃ ✑❇✶✩❁❭❁❵✿☛❃❞❖✣✶✓✳✵✶✓✸✵✻❪✹❊✾✪✶✓✑❛❍◆✿✆✳❞✳✵❍✪✴✜❃❅✶★✾✒❅☎✂ ❃❞✿✆✸✵✶☛❺ ✣☎✴☛✸ ✰ ❖✣✴☛✾✪✶❴✈✇✸✵✴◗✻ t✝✆✫✎ ❆❬✴☛✾ ✑❛✿✆✸✩❖✪❃✏❍◆✿☛❃❃❅✴✆❁❊①☛✶✠❖✦✳✵❍✪✶❬▼✪✸✵✴ ❈ ❁❊✶✓✻ ✈✇✴◗✸➂❛ ✶ t✦✥✩♣✸✥✩✎ ✥ ❆❯✿✆✾◆❖▲❾❯❢●❛✿❢❲♣✫✎❢✈✇✴☛✸❴❛▲✴✪❖✪❖☎s①✏ ■ t✩✉✞❺☎❛✾✪✶▲✻✷✶✓✳✵❍✪✴✪❖♠✹❱❃❪✳✵✴✆✿✩✴☛✾◆❃❡✹❱❖✣✶✓✸✷✳❆❍✪✶▲✻❪✹❊✾✣✹✼✻❨✿✌❁✕▼◆✴✍❁✼●✣✾✪✴☛✻❪✹❱✿✌❁❫✴✆✈ ✂✦✫✠✝✦✭✖✑❴❍✣✹ ✿❆❍❲❍◆✿◗❃❢❖✣✶✓❋◗✸✵✶✓✶▼❛ ✶✙❛ ✫ ✾✒❅✵✭✩❺ q ✈✑❇✶✣✿✓✿✆✾ ✒◆✾◆❖☎✳❆❍✪✶❜✻❪✹❊✾✣✹❊✻❜✿✌❁❛▼❚✴✆❁❊●✜✾✪✴☛✻②✹P✿✎❁ ■ ✳✵❍✪✶✓✾♠✹❊✳❀❃❯❖✣✶✓❋☛✸❆✶✓✶ ✑❇✹❭❁❭❁✕✳✵✶✩❁❭❁❇❄◆❃❯✳❆❍✪✶ ✿❆❁❱✿☛❃✵❃❏✾✣❄✪✻ ❈ ✶✓✸✤❛♠✈✑✴☛✸❏✳✵❍✪✶ ✾✒❅✿☛❃✵❃✺✴ ✿❆✹❱✿✆✳✵✶✠❖ ✑③✹✼✳❆❍ ✝➂❺ ✬ ❍✪✶❫✈✑✴✆❁❭❁❊✴✜✑❇✹❊✾✪❋❜✳✵❍✪✶✓✴◗✸✵✶✓✻ ❃❅❄✪▼✪▼✣❁❭✹❊✶✠❃❫✴☛✾✪✶❢✿✍▼✪▼✪✸✵✴✜✿❋✿❆❍❜✳❆✴✷✳✵❍✪✶❬▼✪✸✵✴ ❈ ❁❊✶✓✻✙❺➄❤➅➆❷✛❽✢➇❲❷✭➈ ✜✍❿✦➉ ✱ ✎ ☛ ✼ ✫✜✙✎✭✂✶✟✞✠ ✂✦✫✜✙✎✭ ✶ ✱ ✝ ✴ ✔✞✝❉r ✣ ✂ ✎ ✷ ✂ ✛ ✺❼✶ ✎ � ❜ ❅ ✎ ➌ ✱ ✝ ☎ ✫ ☛ ✼ ✫✠✝✦✭✷✭✂✶✁☎✙✫❾✂❀✫✟✝✦✭ ✭ ✛✬ ❍✣❄◆❃ ■ ✒◆✾◆❖◗✹❊✾✪❋❜✳✵❍✪✶❯❖✣✶✓❋◗✸✵✶✓✶❬✴✆✈❂✳✵❍✪✶❬✻②✹✼✾✣✹❊✻❜✿✎❁❦▼❚✴✆❁❊●✜✾✪✴☛✻②✹P✿✎❁❂✴✆✈ ☛ ✼ ✑❇✹❭❁❭❁❦❋✍✹✼①◗✶❬✳✵❍✪✶❝❖✣✶✓❋◗✸✵✶✓✶❬✴✆✈✄✂❀✫✚✙✎✭ ■ ✿✍✾◆❖❨❍✪✶✓✾ ✿✩✶❛✲✫✌✾✒❅✵✭❀❺ ✬ ❍✣✹❱❃❴✹P❃❏✿✆✾❳✶✠✿☛❃❡✹❊✶✓✸❬✳❀✿☛❃ ✰ ✳✵❍◆✿✆✾ ✑❇✴☛✸ ✰ ✹✼✾✪❋ ✑③✹✼✳❆❍✗✂✦✫✜✙ ✭③❖◗✹❊✸✵✶■✿✩✳❅❁❊●☛❺ ✕ ✿✆✸❅✹❊✴☛❄◆❃ ✴☛✳✵❍✪✶✓✸❫✸❀✿✆✳✵❍✪✶✓✸❀✿✩✴☛✻✽▼✣❁❻✹❂✿✓✿✆✳❆✶✠❖✈✑❄✪✾ ✿✩✳❅✹❊✴☛✾◆❃✤✫ ✣☎✶ ❈ ✶✓✸❏✈✇❄✪✾ ✿✩✳❅✹❊✴☛✾◆❃✦s✡✆✆✉ ✭❬✿✆✸✵✶❨❄◆❃❅✶✠❖♠✹❊✾❙✳✵❍✪✶ ❖✣✶✓①◗✶✩❁✼✴◗▼✪✻✷✶✓✾✜✳✽✴✆✈✕✳✵❍✣✹❱❃❏▼✪✸✵✴ ❈ ❁❊✶✓✻✙❺ q ✾♦▼◆✿✆✸✵✳❅✹❂✿✩❄✣❁❱✿✆✸ ■ ✳✵❍✪✶✣☎✶ ❈ ✶✓✸❛✈✑❄✪✾ ✿✩✳❅✹❊✴☛✾◆❃❫✿✌❁❭❁✼✴✜✑ ❄◆❃❴✳✵✴ ✒◆✾◆❖✙✿✎❁❻❁✂✹✼✻❨✿✆❋✆✹❊✾◆✿✆✸✵● ✭◗❄◆✿☛❖✣✸❀✿✆✳✺✹ ✿✥✒◆✶✩❁❱❖✪❃❴✴✆✈✘✿❆❁P✿◗❃✵❃❛✾✣❄✪✻ ❈ ✶✓✸❯t◗❺➄❤➅➆❷✛❽✢➇❲❷✭➈ ✏ ❿❃❛✲✫✌✾✒❅✵✭✂✶ t ✔ ✶ ✸ ✝ ✴❇✷ ✝ ❨①➃ ✔ ✶ ❂✘✶ ✎✸✥ ❆✫✥t✏ ✥☞☛ ✥✓t☛t✦✥✓t✝✆ ✥✟❆ ✎✸✥✷✜ ✏ ✥✓t✢✜✜✎✄✛❁ ✥✍✌ ✥✏✎✙✳ ✕ ✳➂⑦✖④ ✜✑✳➂⑦ ✥✁✑✓✒ ✿✕✔✗✖✘✖✘✙✍✚✜✛✣✢✥✤ ✒ ❡✦✙★✧ ✒ ✚✩✧✪✢ ✒ ✙✍✚✫✧ ✒✕✬ ✙ ✒ ✧✕✭✩✮ ✒ ✒✩✚ ✒ ✖✰✯✲✱✴✳ ✜ ✯ ✶✶✵✸✷✎✫✺✹✦✭✠✖✻✯✝✭✼✔✽✚✩✮✏✢✾✤ ✒ ✚✄✮ ✒❀✿ ✚ ✒

❁ ✼ ✶ ✩ ✖ ✼ ✫✠✝✦✭ ✾ ❂✥✦❃☛✫✠✝✦✭ ✪ ✖✲❄✩✫✠✝✦✭✖✻❅ ✫✠✝✦✭ ✬✬ ✤ ✒ ✚ ✑ ✔✽❆❇✔✽✚❉❈✽❊✥✔✽✚✣❋ ✬✥●✽❍■✒ ✮

➄❤➅➆❷✛❽✢➇❲❷✭➈ ☛✍❿ ✺❼✶ ✝ ❂✄❏ ✙ ✎ ➌ ✱ ✝ ❁ ✼ ❂✄❏ ✵ ✛❑ ✤ ✒ ✚❄✿ ● ❆▲✱❉✙✍✚ ✒ ✮✫▼✓✙✍✢✥✤✫✔✽✚✣✙★✮ ✒ ✚❉✢✪✙✍✢✪✳✣◆ ✬✥● ❆ ❈ ✬ ✙❂✿ ✰ ✒ ✔✽✚✩✮ ✔❖✖★✔✽❈✩✧ ✒ ✚✄✙✍✚ ❍■● ✖ ❍ ✙P✚✜✛ ❁ ✼ ✭❲❅◗✔✽✚✩✮❇✂✦✫✠✝✦✭☞✭✜✧ ● ❆ ✒✁❍■✒✕✬ ✳

✿ ● ❆✏❋❉✖✘✙❂✿✕✔✽✢ ✒ ✮❘✙★✮ ✒ ✚❉✢✪✙✍✢✪✙ ✒ ✧✓✙✍✚ ❍■● ✖ ❍ ✙✍✚✜✛✄❙❚✔ ✬✥✒ ❋ ✬✥● ✮❉❈ ✿ ✒ ✮❯✭❉✙✍✚ ✿✾✖P❈✩✮✸✙✍✚✼✛✣✢✥✤ ✒ ◆ ● ✖✘✖ ● ▼❱✙P✚✜✛❲▼❳✤ ✒ ✚▼❅ ✶❩❨✢✜ ❂ ❥✡❬

❊✽❭✜❪✪❫ ❀ ☎ ✺❵❴❜❛ ❫✺❝ ❴❜❛☞❞❫ ❂ ❴❜❛☞❞❡❴❢❞❤❣ ❫ ✾✐❨ ❛ ❊

❝ ❆ ❋ ❂ ✵ ❋ ❣ ❊ ✶ ❫✺❝ ❆ ❋ ❂ ✵ ❋ ❛ ❣ P ✼❨ ❝ ❂✐❥ ☛ ❥ ✵❉✏ ❥ ❨■❨ ❥ ❨✝✆ ❥ ❨✝✵❉✏❨❙

▼❳✤ ✒✕✬✥✒ ❀ ☎✂✶❩❨ ❂■❦ ✆✜❨✸❆ ❋ ✆❉❧ ❫ ❨ ❝ ❂❯❥ ✵ ❥ ✆ ❥ ✏ ❥ ❨■❨ ❥ ❨✝✆ ❥ ❨✝✵❉✏ ❛❀♠✩♥ ✤❉✙★✧❖✧ ✒✕✬ ✙ ✒ ✧✦✛✽✙ ❍■✒ ✧✦✔ ❍✸✒✕✬ ✳✻◆♦✔✸✧✪✢ ✏❊✿ ● ✚ ❍■✒✕✬ ✛✽✙✍✚✜✛✐✔✽❋✜❋ ✬✥● ✁ ✙P❆❲✔✽✢✪✙ ● ✚◆ ●■✬ ❨✽❧♣❙ ♠❖q ✢✥✤ ✒✕✬✻❍ ✔✗✖✍❈ ✒ ✧ ● ◆✆❅r❋ ✬✥● ✮❉❈ ✿ ✒ ✧✺✙P❆s✙t✖★✔ ✬ ◆ ●■✬ ❆▲❈❉✖★✔■✧ ♠ ✮ ✒✕✒❲✉ ❆✽✈❢✔✽✚✩✮ ✉ ❦ ✈✼◆ ●■✬ ❆ ●✸✬✥✒ ✮ ✒ ✢☞✔✗✙✘✖★✧ ♠✇✲①③②⑤④③①③⑥✴⑦❉⑧✕⑨■⑩✩❶✼❷❸ ➎✪❹❳❺❼❻❾❽■❿✣➀➂➁✜➃➅➄✥➆❯➇❖❿✝➈✸➉t❽✸➊➋❿✝❽☎➀➍➌❘➃⑤➎❜➃ ➄✾➆⑤➏➐❽✴➑❲➒❚➓■➔✾➔✥→✘➔✥❻✁➀➂➣✦➃⑤➁✜➃➅➄✾➃✜↔❩↕➂➙▲➏✕➛✗➉t❽❉➏✕❻➋➜✏➝✗➞✴➏✗➑✽❻✺➏➐➟➋➉✍➠✲➡✴➔✥→✍➑✽➊✻➢❖➉✘➟➋➓✣➊➋➙▲➏✕→✘→✩❿■➑■➑☎➠✪→✍➏✕➊❾➊❽✽➞■➙✐➈❉➔✥❻☞➃➐↔❘➤➥➔☞➠➦➔✥➙✐➈✴➔✾❻✰➧☞➨✗➨✝➩✸➃♣➫❯❻❾➔✥➭■❻❾➉t❽✽➟❀➃❸ ➏❀❹❳❺❖➟➋➯✽➉✘❽❲➀★❺✻➃✴➲✻➃✴➎❜➃ ➄❖➏➐❽✴➑▲➌▲❿✝❻✪➏✕➉✘❽❲➀➍➣✸❻✺➏➐❽⑤➳➠✪❿✝➉✘➊✪➄✥➃✽↔❚➵❯→✘→✘➉t➭✸➟➋➉✍➠✓➠✪➞■❻➋➸✗➔✥➊➺➏➐❽✴➑▲➭■❻❾➉✘➙➻➏✕→✘➉✘➟➂➜❳➭■❻❾❿✕➸✽➉t❽✸➛✴➃❉➼❇➽❀➾③➚➶➪✾➹➘➽➴➾➍➷③➬✪➮➘➱♦✃✐❐❢➱✕➹✲❒❮✴❰ ➾➋➽❀➾➂➷★➱✕Ï✸➆■➸✝❿✗→➂➃♣Ð ➎✝➆✽❽■Ñ✑➏✝Ò✝Ó✸➆✝Ô✗➞■→✘➜❇➧❀➨✝➨✝➩✸➆✝➭✸➭✩➃✛➏✗Õ❀↔➶Ð✗Ö■➃❸ Ó❀❹✰×❜❿✝❻➋➔✾→❢➀③❺✰➃➅➄✥➆✜Ø✦➓■❿✕➢❖→✍➏Ù➀➍➁✜➃➅➄✾➆ÛÚÜ➔✥❻➋ÝÞ➀➍Ø✓➃✜➁✜➃➅➄✾➆■↕➂➢❖➏✕➊✺➏❀➢❖➏Þ➀➍ß✻➃➅➄✥➆✜➏➐❽✴➑✏➁✽➔✥❻❾❻➋➔Þ➀★Ô❉➃ à➋➫❯➃➅➄✥➃➶↔âáÛ➪✾➹✰➷✍Ï❉➽✕ã✐➱✕Ï✣➬✺➱➐➹ ❮❉ä ➪➦å✁➹ ❰✽ä ➾➍➷ ❮❉ä ➷✘❒➬✪➽❀➾➂➷★➱✕Ï✸➃✗↔❘➁✽➭✸❻➋➉✘❽■➛✝➔✾❻☞➆✩➧❀➨✝æ✗æ■➆❉ç✩➪✺➬➦➾ ❰ ã✪➪➥è❱➱➴➾♦➪➦➮❳➷✍Ï▲➼❇➽❀➾③➚➶➪✾➹✐➽❀➾➂➷★➬✪➮✥➃❸ é ❹✰×❜❿✝❻➋➢✦➔✥➉✘❽✫➀★Ô✗❿✝❽✴➏➐➟➋➓✴➏➐❽✄➌✣➃➅➄❳➏✕❽❉➑✣×ê❿✗❻➋➢✦➔✥➉✘❽❚➀➍➫✼➔✥➟❾➔✥❻✁×➥➃ ➄✾➃✜↔ë➌▲❿✗❻➋➔➻➇➥➏✕➙▲➏✕❽✽➞☞ì✥➏➐❽✽à➍➟➂➜✗➭✴➔✲➊➋➔✥❻❾➉t➔✾➊✻í★❿✝❻❤➎❀î✝ï❯➃✜↕➂❽☎❺❼❽✴➑➶❻➋➔✥➢❖➊➀➍ðÙ➃♣➵❖➃➅➄✾➆✽❺❼➊➋➯✗➔✥➜✏➀➂➇❳➃✽❺✻➃ ➄✾➆♣×❜➔✥❻❾❽✴➑✽➟❳➀➂×❼➃❉Ø✓➃➅➄✥➆✽➇❼➏✕➙▲➏✕❽✴➏➐➟➋➓✴➏➐❽✁➀➂ß✻➃■ð✐➃➅➄✥➆■➏✕❽❉➑✁➇❼➏➐❽■➯✽➉✘❽▲➀➍➇❳➃✽❺✻➃➅➄❖➀③➔☞➑✽➉✘➟➋❿✗❻➋➊✺➄✾➆✜ñò➽➐➹➘➽➐Ï ❰✪ó ➽✕Ïã✺➪✾ô❀➷✘➮✥➷✘➾♦➪✪õ➐➃✝➭■➭✼➃■Ó■❍✝Õ➴↔➶Ó✗ö é ➃➐↔✣❺➺➠✥➏✗➑✽➔✥➙✁➉✍➠➥➫❯❻➋➔✥➊❾➊☞➆ê➧❀➨✝÷✗÷■➃❸ ❍❀❹✰Ø✦➓✽➞✴➑✽❽■❿✕➸✽➊❾➯♣➜▲➀➂➤✻➃■ø✰➃➅➄✦➏✕❽✴➑▲Ø✦➓✽➞✴➑✽❽✸❿✕➸♣➊❾➯✽➜✏➀➍ðÙ➃✽ø✰➃➅➄✥➃➶↔ù❺➥➭■➭■❻➋❿❀ú■➉✘➙➻➏➐➟➋➉✘❿✝❽✸➊❢➏✕❽✴➑▲➠✪❿✗➙✁➭■→✘➔✪ú✐➙✐➞■→✘➟➋➉✘➭■→✘➉✍➠✥➏➐➟➋➉✘❿✝❽✐➏✝➠✥➠➦❿✝❻✺➑➶➉t❽✸➛➟➋❿▲➇❼➏➐➙➻➏✕❽✽➞☞ì✾➏✕❽✩➃✗↕➂❽❇❺➥❽✴➑✽❻❾➔✥➢❖➊✐➀➍ðÙ➃Û➵Ü➃ ➄✾➆❉❺❼➊➋➯✗➔✥➜☎➀➍➇❳➃❉❺✻➃ ➄✾➆✜×ê➔✥❻❾❽✴➑✽➟✐➀➂×❼➃✼Ø✓➃ ➄✾➆✜➇❼➏✕➙▲➏✕❽✴➏➐➟➋➓✴➏➐❽✏➀➂ß✰➃✼ð✐➃➅➄✥➆✜➏✕❽✴➑û➇❼➏✕❽✸➯♣➉✘❽➀➍➇✲➃✽❺✰➃➅➄Ü➀★➔☞➑✽➉✘➟❾❿✝❻➋➊✪➄✥➆✼ñò➽➐➹➘➽➐Ï ❰✪ó ➽✕Ï❲ã✺➪✾ô☞➷P➮➦➷P➾♦➪✪õ✕➃✗➭■➭✩➃❉Ó✝ö ❍❀↔ é ös➏✸➃❀↔ù❺✓➠✥➏✝➑➶➔✥➙✁➉✍➠✓➫❯❻➋➔✾➊➋➊☞➆❯➧❀➨✝÷✝÷✸➃❸ Ð❀❹✰Ø✦❿❀ú✁➀➂➤➺➏❀➸✽➉✍➑✲❺✰➃➅➄✥➃➐↔❇ü❢ã✾➷✍➹➘➪➦➮➺➱➂✃Ü➾★➚■➪❯✃☞➱➐ã✥➹þý✴ÿ✁�✄✂✆☎✝ÿ✞✝✠✟❢➪✥ã✥➹✐➽❀➾☛✡ ➬ ä ➽➴➮✪➮✌☞❢➪ ä õ✓➾③➚➶➪✪➱➐ã✎✍✏✡❢➽✕Ï✴õ✐➬✪➱✕➹ ❮✴ä ➪✪å❳➹ ❰✽ä ➾➂➷ ❮✴ä ➷★➬✪➽❀➾➂➷★➱✕Ï■➃➴↔Ô✝❿✗➓■❽▲➒❚➉✘→✘➔✥➜✒✑â➁✽❿✗❽■➊☞➆✔✓Ü➔✥➢✖✕❢❿✗❻➋➯✜➆✜➧☞➨✗÷✝➨■➃❸ ö❀❹✰ð✓❿✗→P➑♣í★➔✥→✍➑✓➀➂➤❼❿✗❻➋➉✍➏✕❽❉➄✥➃❾↔➘ð❳➏➐➞■➊➋➊✏✗☞➠✪→✍➏➐➊➋➊✩❽✽➞■➙✐➈❉➔✥❻✜➭■❻❾❿✝➈■→✘➔✥➙ í★❿✗❻✩➉✘➙➻➏➐➛✝➉✘❽✴➏✕❻❾➜❢➝✗➞✴➏✝➑➶❻✺➏✕➟❾➉✍➠✼➡✴➔✥→✍➑✽➊❀➃✙✘ ❰✽ä✍ä ➪➦➾➂➷✍Ï✰➱➂✃❜➾③➚➶➪✛✚✓➹✐➪✥ã✥➷③➬✺➽➐Ï➼❇➽❀➾③➚➶➪✾➹➘➽➴➾➍➷③➬✺➽ ä áÛ➱❀➬✥➷★➪➦➾✜✍✕➆■➸✝❿✗→➂➃✭➎☞Ó■➆✗❽ Ñ ➎✝➆✽Ô✝➞✸→t➜❲➧☞➨✗÷✙✢■➆✗➭■➭✩➃❉➏✝Ó➴↔➶Ó✝ö✸➃❸ Ö❀❹✰➁✽➉✘→✘➸✝➔✥❻❾➙➻➏➐❽✄➀③Ô✴➃êÚ❳➃➅➄✾➃✜↔✣✚✓õ✕ô✕➽✕Ï✴➬✪➪✪õ✥✤✜➱ ❮ ➷★➬➦➮✁➷✍Ï☎➾★➚■➪✦✚✓ã✥➷✘➾③➚♣➹✐➪✪➾➂➷★➬Þ➱➂✃★✧ ä✍ä ➷ ❮ ➾➂➷★➬û❐ ❰ ã✥ô➴➪➦➮✥➃✜↔ ➁✽➭✸❻➋➉✘❽■➛✝➔✾❻➂à➂øê➔✥❻➋→✍➏➐➛✴➆❖➧☞➨✗➨✪✩❉➆✫ ã✺➽✗õ ❰ ➽❀➾➋➪✒✤✜➪➦å☞➾③➮➺➷ Ï▲➼❇➽❀➾③➚➶➪✾➹➘➽➴➾➍➷★➬➦➮✥➆■➸✗❿✝→➂➃✛➎ ❍✵➎✗➃❸ Õ❀❹❳➒✣➔✥➈❉➔✥❻✓➀➍Ú✲➃➅➄✥➃✗↔✫ç ➪➦➚♣ã✭✬ ❰ ➬✪➚❇õ✗➪✥ã✮✚ ä✰✯ ➪✏✬✾ã✺➽✕➃✗↔✄Ø✦➓■➔✥→✘➊❾➔☞➏✁➫❯➞✸➈■→✘➉t➊❾➓■➉✘❽■➛✐Ø✦❿✝➙✁➭❉➏✕❽✽➜♣➆✞✓❖➔✥➢✱✕❢❿✝❻❾➯✜➆✜➧☞➨✙✲✞✳■➆✗➸✝❿✗→➍➃✽↕✥➆✽↕❾↕✥➆■↕❾↕➋↕✥➃

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Page 136: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

�✂✁☎✄✝✆✟✞✡✠☞☛☞✌✍✄✏✎✑✞✒✁✓✄✏✞✕✔✖✎✘✗✙☛☞✚✑✛✜✄✏✢✣✠✓✤✥✁☞✁☞✢✣✛✦✚✘✎✘✁★✧✩✛✦✁☞✠✫✪✬✞✒✚✭✄✏✮✯✗✓✛✦✁★✁✱✰✳✲✵✴✶✛✦✌✏✷☞✎✑✁☞✢

✸✙✹✻✺✂✼✾✽❀✿❂❁✯❃❅❄✒❆✟✽❈❇❊❉✍❋✏●✱❇❍❃✣✽

■❑❏ ✑ ■ ❏ ✏ ✑✓● ✿▼▲■❈ ✒ ✚ ✿ ● ❈ ✬ ✢◆ ✔✽✚❉❈✩✔ ✬ ✳✫❨ ❝ ✭❜❨✝✆■✆ ❦❖✐②✒P❍◗❀⑧✕⑨❙❘❚◗➁➶➉t➙✐➞✸→P➏➐➟➋➔☞➑▲➏➐❽■❽■➔☞➏➐→t➉✘❽■➛✐➉✘➊❳➏Þ➟➋➔☞➠❾➓■❽✸➉P➝✗➞■➔✻➟➋❿Þ➡✴❽❉➑❇➏➐➭■➭■❻➋❿❀ú■➉✘➙➻➏➐➟➋➔✓➊➋❿✗→✘➞■➟➋➉✘❿✝❽✸➊❼➟➋❿▲❽✽➞■➙Þ➔✥❻➋❿✗➞■➊➺➑✽➉❱❯➻➠✪➞✸→t➟❿✝➭■➟❾➉t➙Þ➉✘Ý☞➏✕➟❾➉t❿✗❽✁➭■❻❾❿✝➈■→✘➔✥➙Þ➊❖➊➋➞✴➠❾➓✄➏➐➊ ✓➥➫✼à➋➠✪❿✝➙Þ➭■→✘➔✥➟➋➔❳➭✸❻➋❿✝➈✸→t➔✾➙✁➊☞➃❳❲❖➓✸➔✰➙Þ➔✥➟➋➓■❿■➑▲➉✘➊✓➑✽➉❱❯➻➠✪➞■→✘➟❼➟❾❿➻➞✸➊➋➔✁➏✕❽❉➑➠✥➏✕❽✻➈✴➔❖➏✕➭✸➭■→✘➉t➔❀➑✓➟➋❿✓➭■❻❾❿✝➈■→✘➔✥➙Þ➊✩➢❖➓■❿✗➊➋➔✦➭■❻➋❿✗➭✴➔✥❻❾➟➋➉✘➔✥➊❖➏✕❻❾➔❢➓✴➏➐❻✺➑✽→✘➜✓➞■❽✴➑➶➔✥❻➋➊❾➟➋❿✽❿■➑✜➃❢×❜❿✝→✘➟➋Ý✾➙➻➏✕❽✸❽✌✗ ➊✜➙➻➏✝➠❾➓■➉✘❽■➔❜➉t➊➏❖➊➋➭❉➔☞➠✪➉✍➏➐→■❿✝➭■➟❾➉✘➙✁➉✘Ý☞➏✕➟❾➉✘❿✝❽➺➏➐→✘➛✝❿✝❻❾➉✘➟➋➓■➙â➑✽➔✾➊➋➉✘➛✝❽■➔❀➑✰➏✗➠✥➠✪❿✝❻✪➑✽➉✘❽■➛✓➟➋❿✓➟➋➓✸➔❢➭■❻❾➉✘❽✴➠✪➉✘➭■→✘➔✥➊ê❿➐í✴➊➋➉✘➙✐➞■→✍➏✕➟❾➔☞➑✓➏✕❽■❽✸➔☞➏✕→✘➉✘❽■➛✴➃

❲❖➓✸➉t➊❯➟✪➏✕→✘➯✓➭■❻➋➔✥➊❾➔✥❽✽➟➋➊✦➊➋➉✘➙✐➞■→✍➏✕➟❾➔☞➑❳➏➐❽■❽■➔☞➏➐→t➉✘❽■➛➥➢❖➉✘➟➋➓✻➔✥➙✁➭■➓❉➏✕➊➋➉✘➊✼❿✝❽✻➟➋➓■➔❖➭■❻✪➏✝➠✪➟❾➉✍➠✥➏✕→■➞✸➊➋➔✦❿✕í✜➟➋➓■➔❖➙Þ➔✥➟➋➓■❿■➑✜➃❲❖➓■➔✓➭■❻➋➔✥➊❾➔✥❽✽➟✺➏➐➟➋➉✘❿✝❽✏❿➐í❢×ê❿✗→t➟❾Ý✥➙➻➏➐❽■❽✌✗ ➊ê➙▲➏✝➠❾➓■➉✘❽■➔❼➉✘➊❖➉✘❽✽➟➋➔✥❻❾➟➂➢❖➉✘❽■➔☞➑Þ➢❖➉✘➟➋➓✏➏✐➠✪❻➋➉✘➟❾➉P➠✾➏✕→⑤➏➐❽✴➏✕→✘➜✽➊➋➉✘➊✦❿✕íê❻➋➔✾➊➋➔☞➏➐❻✺➠❾➓❿✝❽✁➟❾➓■➉✘➊❢➟❾❿✝➭■➉✍➠✕➃❯↕➂❽▲➭✴➏➐❻➋➟❾➉P➠➦➞■→✍➏✕❻☞➆✗➢✦➔❱➑➶➉t➊✪➠✪➞■➊❾➊❼➢✦❿✝❻➋➯✽➊❖➏✕➈❉❿✝➞■➟❖➭✸❻✺➏✝➠➦➟➋➉✍➠✥➏✕→✩➏➐➭■➭■→✘➉✍➠✥➏✕➟❾➉✘❿✝❽■➊✦❿✕í✩➟❾➓■➔✰➏✕→✘➛✗❿✝❻➋➉✘➟❾➓■➙❇➆➏✕➊✦➢❢➔✥→✘→❯➏✕➊❖➉✘➟➋➊❖➞■➊❾➔✓❿✝❽Þí➍➏✕➊❾➟❖➊➋➭❉➔☞➠✪➉✍➏✕→✘➉✘Ý✥➔☞➑Þ➓✴➏➐❻✺➑✽➢❖➏✕❻❾➔✝➃❺✫➑✽➔✥➙Þ❿✝❽■➊❾➟➋❻✺➏➐➟➋➉✘❿✝❽✓➉✘➊✜➛✝➉✘➸✗➔✥❽❳❿✕í■➟❾➓■➔❢➢✦❿✝❻❾➯✽➉t❽✸➛❖❿✕í✴×ê❿✗→✘➟➋Ý✥➙▲➏✕❽■❽✌✗ ➊✜➙▲➏✝➠❾➓■➉✘❽■➔✩❿✗❽❳➊➋➭❉➔☞➠✪➉✍➏➐→t➉✘Ý✥➔❀➑❳➓✴➏➐❻✺➑✽➢❖➏✕❻❾➔✝➃❲❖➓■❻➋➔✥➔✲❿✝➭■➟❾➉t➙Þ➉✘➊✺➏✕➟❾➉✘❿✝❽✻➭■❻➋❿✗➈■→✘➔✥➙✁➊✦➉✘→t→✘➞■➊❾➟➋❻✪➏✕➟➋➔✓➟❾➓■➔❳➟✺➏➐→✘➯❩❨❯➛✗❻✺➏➐➭■➓▲➭✴➏✕❻❾➟➋➉✘➟➋➉✘❿✝❽✸➉t❽✸➛✁➀③➟➋➓■➔✰➠➦→P➏➐➊➋➊❾➉P➠✾➏✕→⑤➠➦❿✝➙✁➭✸➞■➟➋➔✥❻➊✺➠✪➉✘➔✥❽✴➠➦➔❱➌s↕ ✓ Ø✡❬❭❲❚➭■❻➋❿✗➈■→✘➔✥➙➻➄✾➆✝➊❾➜✽❽✴➠❾➓■❻➋❿✗❽■➉✘Ý✥➉✘❽■➛✰➈✸➉t❽❉➏✕❻➋➜✻➊➋➔❀➝✝➞✸➔✥❽✴➠✪➔✥➊✻➀➂➏✕❽✁❿✗➭✴➔✾❽✁➭■❻❾❿✝➈■→✘➔✥➙ í③❻➋❿✝➙ ➠✪❿■➑✽➉✘❽■➛➟➋➓■➔✥❿✗❻➋➜■➄❖➏✕❽❉➑➻➏➐➉✘❻➋→✘➉✘❽■➔❼➟❾❻✺➏✾❯➻➠➥➭■→✍➏➐❽■❽■➉✘❽■➛✴➃

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Page 137: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination
Page 138: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✤✥✁✫✤ ✚✑✧✒✢ ✁ ✆✏✛✦✎✘✌✥✤✄✂☎✂★✆✏✞✒✛✦✌✏✷ ✄✏✞✝✆✥✢✜✲✻✎✘✠★☛☞✢✣✲✬✎✘✁ ✔✖✢✟✞ ✢✜✆✏✛✦✚✡✠ ✛✦✆✏✎✑✛ ✁ ✚✘✢✣✲

☛ ❋▼✺✾✿ ✹✂✺✌☞ ✸✎✍✯❄❙✺✾✺ ✹✂✽❀✿

■❑❏ ✑ ■ ❏ ✏✑✏ ● ❋✜✤❉✙★✔✻✏ ❏ ✚❉✢✪✙✍❋ ● ✖t✙➂✧✒ ✔ ✬ ✿✥✤ ❝ ✭ê❨✗✆■✆ ❦❖✐②✒P❍◗❀⑧✕⑨❙❘❚◗➒✣➔✻➭■❻❾➔✥➊➋➔✥❽✽➟✰➏➐→✘➛✝➔✥➈■❻✪➏✕➉✍➠✲➙✁➔✥➟❾➓■❿■➑✽➊✻➀★➙➻➏➐➉✘❽■→✘➜✻í★❻➋❿✗➙ë→✘➉✘❽■➔☞➏✕❻✓➏✕→✘➛✝➔✾➈■❻✺➏✗➄❼➟❾❿✏➠✪❿✝➙Þ➭■➞■➟➋➔✻→✘❿■➠✥➏✕→❯❿✝❻✓➛✗→t❿✗➈✴➏✕→❻➋➔✥➊❾➉P➑➶➞■➔✥➊✁❿➐í❳➙✐➞■→✘➟➋➉✘➸✝➏✕❻❾➉P➏➐➟➋➔✐➭❉❿✝→✘➜✽❽■❿✝➙Þ➉✍➏✕→✡➊❀➃ ❲❖➓✸➔✥➊➋➔✏➙Þ➔✥➟➋➓✸❿➶➑➶➊✁➏✕❻➋➔û➈✴➏✕➊❾➔☞➑✫❿✝❽❚➠✪❿✗➙✁➭■➞✸➟✺➏✕➟❾➉✘❿✝❽■➊✻❿✕í✰×❜➔✪àÝ✥❿✝➞■➟❾➉✍➏✕❽■➊❀➆ê❿✕í❼➢❖➓✸➉P➠❾➓☎➢❢➔▲❻➋➔❀➠✥➏✕→✘→❖➟➋➓✸➔➻➭✸❻➋❿✝➭❉➔✥❻❾➟➋➉✘➔✥➊☞➃✫➒✣➔Þ➊➋➓■❿✕➢ ➓■❿✕➢ ➟➋➓✸➔✥➜✄➙▲➏✕➯✝➔✐➉✘➟✻➭✴❿✗➊➋➊❾➉t➈✸→t➔Þ➟➋❿û➡✴❽✴➑➟➋➓■➔✐➊❾➟➋❻➋➞❉➠✪➟➋➞■❻❾➔✏❿✕í❼➟❾➓■➔➻➝✗➞■❿✗➟➋➉✘➔✥❽✽➟❳➉✘❽✣➟➋➓✸➔➻➠✥➏➐➊➋➔✁❿➐í➺➏✏➠✪❿✗➙✁➭■→✘➔✥➟❾➔✐➉t❽✽➟❾➔✥❻➋➊❾➔☞➠✪➟➋➉✘❿✗❽ ➏✕❽❉➑❲❿✕í❼➔✥➉✘➛✝➔✾❽■➊➋➭✴➏✗➠✪➔✥➊✐❿➐í➟➋➓■➔✻➙✐➞■→✘➟➋➉✘➭■→✘➉✍➠✥➏✕➟❾➉✘❿✕❽✁➙➻➏➐➟➋❻❾➉P➠➦➔✥➊✓➉t❽û➟➋➓■➉✘➊❳➝✗➞■❿✝➟❾➉t➔✾❽♣➟❀➃✱❲❖➓■➔✻❻➋➔✾→P➏➐➟➋➉✘❿✝❽û➢❖➉t➟❾➓✔✓✪➠✪→✍➏✕➊❾➊➋➉✍➠✥➏✕→✖✕Þ❻➋➔✥➊❾➉P➑➶➞■➔✥➊❳➢❖➉✘→✘→❯➈✴➔➙✁➔✥❽✽➟➋➉✘❿✗❽■➔☞➑✜➃

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Page 139: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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Page 140: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

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✁✄✂✆☎✞✝✠✟✡☞☛✍✌✏✎✒✑✔✓✕✂✖✝✗☛✘☎✙✑✛✚✢✜

✣ ✚❉✙✘◆ ●✸✬ ❆ ✑ ✔✽✚✩✮ ● ❆✥✤ ✒ ✚ ✒✕✬ ✔✽✢✪✙ ● ✚❲◆ ●■✬ ✢✥✤ ✒ ❃ ● ▼ ✒✕✬ ✧ ✒ ✢✄✦ ● ✚✩✧✪✢ ✬ ❈ ✿❀✢✪✙ ● ✚ ♠★✧✪✩✖✫✞✬✮✭✆✯✱✰✲✰✴✳✶✵✷✰✠✩✹✸✖✸ ✌✺ ✚✼✻✾✽ ✿✾✙ ✒ ✚❉✢☞❃❖✔ ✬ ✧ ✒✕✬ ❑ ✒ ✖✘✖ ✏■❈❉✙P✢ ✒ ✮✣✢ ●❇✑ ❏ ✺❀✿ ● ✖★✮✸✙P✚✜✛ ♠❂❁❃✩❅❄✙✵❆✯❈❇❉✳❋❊✾✳✶●✔✳✹❄■❍✙✵❉✳ ❁❃❖✔✸✧ ✿✕✔✗✖➋✂✡✧ ♥ ✬ ✙★✔✽✚✜✛✽✖ ✒ ✭ ✺ ❈✜✢ ● ❆❇✔➶✢☞✔✜✭✜✔✽✚✩✮ ✒ ❈✩✧❾✙❂✿ ♠❑❏■✳✗✩✹✸▼▲✛✧✪✩❅✫✞✬✒◆❖✬P✬❘◗❅✫❙❇❯❚▼✳ ❱✑ ✙ ●✸✬ ✮✜✔✽✚ ✺ ✬✥✬ ✔✗✳✜✧✓✔✽✚✩✮✣✢✥✤ ✒ ✙ ✬ ✺ ❋✜❋❉✖✘✙❂✿✕✔✽✢✪✙ ● ✚✩✧ ♠☞❲❑◗✙✸▼✩❨❳❆✳✷✬P✬❘✩❬❩❭✳✶✵❆✬P✯✱✸❙✯ ✟ ✌

✏■✢ ✬ ❈ ✿❀✢✥❈ ✬✥✒ ✮ ❏ ❈✜❆▲✱ ✒✕✬ ✧ ♠✴❪✾✯✱✸✕❇❉✳✶✸✆❳❴❫✪✬✛◗✙✸✕❵❙✳✷✬ ✟ ❱✁✄✂✆☎✞✝❜❛❝✘❞❡✌✏✎✾☛✘❢❘✑✛✚❣✡☞☛❤✌❥✐❡❦✘✝✗✂✖✝❧✑♠☛❤✓

✻ ❍ ✔✗✖✍❈✩✔✽✢➦✙P✚✜✛ ✏✽✙✍✛■✚✩✧ ● ◆❡♥ ✒ ✢ ✒✕✬ ❆▲✙✍✚✩✔✽✚❉✢☞✧ ♠✄❏■✳✗✩✹✸▼▲✛❲❑✩✙✸❙✯✛✳✷✬✮❫❖◗❧✯✱♦✷♦❉◗✹✸✖✸▼✩❙❳ ❛ ❁❃ ● ✖P✳❉✚ ● ❆▲✙★✔✗✖ ✏ ● ✖✍❈✜✢✪✙ ● ✚✩✧ ● ◆❡♣✼✙✍✚ ✒ ✔ ✬ q ❋ ✒✕✬ ✔✽✢ ●■✬ ✻★▲■❈✩✔➶✢✪✙ ● ✚✩✧ ♠❋❩❭✩✹✵rq❙◗☞✧✪✳❧❳sq❙◗■❍✾t♦❉✳✶q ✌ ✟

✏■✳❉❆▲✱ ● ✖✘✙❂✿▲✔✽✚✩✮ ❏ ❈✜❆ ✒✕✬ ✙❂✿✕✔✗✖ ✒ ✔➶✚❉✙P❋✜❈❉✖★✔✽✢➦✙ ● ✚✩✧ ● ◆✉♥✲✙ ❍■✒✕✬ ✛ ✒ ✚❉✢★❃ ● ▼ ✒✕✬ ✏ ✒✕✬ ✙ ✒ ✧ ♠✈❏■✳✗✩✙✸①✇✒❚▼◗✹✰✠✩✹✸✖✸ ✌✴❁✾ ● ✖ ● ✚ ● ❆s✙ ✿ ✏■✳Û✧➦✢ ✒ ❆❇✧❳✔✽✚✩✮ ✺ ❈✜✢ ● ❆❲✔✽✢✪✙❂✿☞❃ ✬✥●❉● ◆➋✧ ● ◆ ■ ✮ ✒ ✚❉✢✪✙✍✢✪✙ ✒ ✧ ♠✈❁✆✵✍②✳❧❵★②✳✶✵❆✯❈❇✈③✮❚⑤④❅⑥✙✩✹q ✌ ❱

✏■✤ ●✸✬ ✢✰✔✽✚✩✮⑦✻➥✔■✧✪✳⑧✦ ● ❆✏❋✜❈✜✢ ✒✕✬ ❃ ✬✥●❉● ◆➋✧ ● ◆ ❃❖✔ ✬ ✢✪✙✍✢✪✙ ● ✚✄✔✽✚✩✮⑦⑨ ✏ ■ ✮ ✒ ✚❉✢✪✙✍✢✪✙ ✒ ✧ ♠☞✧✪✳❧❳❆✳✶✵❴✧✪✩❅✫✞✬❘✳ ⑩ ✌✻❷❶ ✒ ✿❀✢✪✙ ❍■✒ ■ ✮ ✒ ✚❉✢✪✙✍✢✪✳ ♥ ✒ ✧✪✢➦✙P✚✜✛s✙P✚❥✻❷❸Û✢ ✒ ✚✩✧✺✙ ● ✚✩✧ ● ◆✉♥✲✙❹❶ ✒✕✬✥✒ ✚❉✢✪✙★✔✗✖ ✿ ✙ ✒ ✖★✮✜✧ ♠✈◆✄✵❆✯❘✩✹✸▼✳❂✧⑧②✳✷✬❘✩❨❵❙✩✹✸▼▲❯❺❂✳✶✵✷✰✴✩ ⑩✍❻✺ ❈✜✢ ● ❆❲✔✽✢✪✙❂✿ ✺ ✧➦✳✴❆✏❋✜✢ ● ✢✪✙❂✿✕✧ ♠✈❏✢◗✹✵❆✯✱♦✈❍✗✩✙✸❥❵❙✳✶✵★❼❽◗❨✳❧❍⑤✳✶✸ ❁ ✟❏ ●■✬ ❆❲✔✗✖✒❾➺✔✸✧ ✒ ✧❳✔✽✚✩✮⑧✦➺✔➶✚ ● ✚❉✙❂✿✕✔✗✖ ✑ ✔✽✢✪✙ ● ✚✩✔✗✖ ✿ ●■✬ ❆ ❫ q ❍■✒✕✬ ✿ ✙P✚❉✙✍✢ ✒ ✿ ✙ ✒ ✖ ✮✜✧ ❛☞♠✈❲❑✩✹✸❙✯❘✳✷✬✒◆❿✫➁➀▼◗❨❳ ❁✜✌✿ ✔❋✿❀✢ ●■✬ ✙P✚✜✛ ❃ ● ✖✍✳✴✚ ● ❆s✙ ✔♣✖ ✧ q ❍■✒✕✬ ✿ ✙✍✚❉✙✍✢ ✒ ✿ ✙ ✒ ✖★✮✜✧ ♠✈❲❑✩✹✸❙✯❘✳✷✬✮✧✪✩✹✸▼✩✹✵❆✯❘◗ ❁ ❻♥ ✤ ✒ ■ ✚❉✢ ✒ ✛ ✬ ✔✗✖✮❾➺✔✸✧❾✙★✧ ● ◆❼✔✽✚ ✺ ✖✍✛ ✒ ✱ ✬ ✔✗✙❂✿ ✿ ❈✜✚ ✿❀✢✪✙ ● ✚ ✿ ✙ ✒ ✖★✮ ♠✈❩❭✩✹✵✷q⑦❍➁✩✹✸✼❼❽◗❨✳✷✯ ➂ ➃ ✟

✏■✳❉❆▲✱ ● ✖✘✙❂✿➄✦ ● ❆✏❋✜❈✜✢❀✔✽✢✪✙ ● ✚ ● ◆ ✾ ✳❉❋ ✒✕✬✥✒ ✖✘✖✘✙✍❋✜✢✪✙❂✿ ■ ✚✴✢ ✒ ✛ ✬ ✔✗✖★✧ ♠❋❊❷✩❅✫✙✵❉✳✶✸▼❳✉❫❖✳✶✵✗❳s✵❉✩✹✸✕❵ ➃ ✌✁✄✂✆☎✞✝ ✌➅⑦✜➁❞✮✌❣✐✍✝✗☛✆✝❧✑❘✚⑦➅⑧✓✕✂✆❢✱❞✒✜✞✑✛✜

✺ ✧✪✳❉❆✏❋✜✢ ● ✢➦✙ ✿✕✧ ● ◆ ✒ ✔✽✤❉✖ ✒✕✬✰✑❱✒ ✿❀❈ ✬✥✬✥✒ ✚ ✿ ✒ ✧ ♠☞✧✪❚❙✯P✬❹✯➇➆✖➆✾✳❿❲✲✫✙✰✴✩✹♦ ➃▼❱q ✧ ✿✾✙t✖✘✖★✔✽✢✪✙✍✚✜✛ ✑ ✙ ❍■✒✕✬ ✧ ♠✈❁✆✵❉✩✹✸✕❇❆q✴❩✼✯❈❇❆❚▼✳✷✬ ❻ ✌

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Page 141: Inria · HAL Id: inria-00074021  Submitted on 24 May 2006 HAL is a multi-disciplinary open access archive for the deposit and dissemination

✺ ✚✩✔✗✖✍✳❉✢✪✙❂✿✕✔✗✖ ✺ ❋✜❋ ✬✥● ✔❋✿✾✤✏✢ ● ✏ ● ❆ ✒ ❃ ✬✥● ✱❉✖ ✒ ❆❇✧ ■ ✚ ❍■● ✖ ❍ ✙P✚✜✛ q ✬ ✮ ✒✕✬ ✏■✢☞✔✽✢✪✙★✧✪✢➦✙ ✿✕✧ ♠✁�⑦◗ ➂✞❇❆✯❘✳❧❇❯❚✄✂■⑥❉➆❤✩✙✸✖q❙◗✆☎✉♦✷q✢✯ ❻▼❻♥ ✤ ✒ ✏ ● ✖✍❈✜✢✪✙ ● ✚✫✢ ● ✔✴✦ ● ✚✽❊ ✒ ✿❀✢✥❈ ✬✥✒✐● ◆ ✾ ✔ ✬ ✮❉✳ ♠✈❏■◗✹❚✖✸✝✂❨❚▼✩❙❇❯q❙✳✷✬P✬ ✞ ✟✁✄✂✆☎✞✝ ⑩➅⑧✓✕✂✆❢✱❞✒✜✞✑✛✜❬☛✠✟✈➅⑦❢☛✡▼☛✘☎✙✑✱✝✌☞✾✌❥✜ ✂✕✓✎✍✑✏✴✂✖✝✗✂ ❝✘✝❧☎✢❦❤✚✙✝✙❦❤☎✓✒✖✜

♥ ✤ ✒ ✤➘✔✽❈✩✧✥✧ ✑✓✒ ✮❉❈ ✿❀✢✪✙ ● ✚ ✺ ✖✍✛ ●✸✬ ✙✍✢✥✤✜❆ ♠❋❫❴✵❆✯➇➀❨✯❈❳✷❳ ✳❜❪✕✩❧✬P✬■②✳✗✳ ✞❃❻✺ ❍■✒✕✬ ✔➶✛ ✒ ✦➺✔■✧ ✒ ✺ ✚✩✔✗✖✍✳Û✧❾✙★✧ ● ◆ ♥ ✬✥✒✕✒▲✑✓✒ ▼ ✬ ✙✍✢✪✙✍✚✜✛ ✏■✳Û✧➦✢ ✒ ❆❇✧ ♠ ③✍④ ✵ ✯❹✬❴③✮❚▼✩❅❄✢✩❅✫❙❵ ❱ ✟■ ✚✴✢ ✒✕✬✥❍ ✔✗✖ ✺ ✖✍✛ ●■✬ ✙P✢✾✤✜❆r◆ ●■✬❳✑ ✔✽✚✩✮ ● ❆ ❏ ❈✜❆➻✱ ✒✕✬ ✤ ✒ ✚ ✒✕✬ ✔✽✢✪✙ ● ✚ ♠❋❩❭✩✹✰✠◗✹✵❧✫❑❼✈◗✹♦r❚❙✯ ❱ ❁✺ ✖✍✛ ●■✬ ✙✍✢✥✤✜❆s✙ ✿ ❃ ✬✥● ✱❉✖ ✒ ❆❲✧✓✙✍✚ ❏ ● ✚✕✔❆✦➺✔➶✱❉✖ ✒ ✮ ❏ ✒ ✢✪▼ ●■✬✗✖ ✧ ♠★✧✪❚❙✯❹✬P✯➇➆✖➆✒✳➄❏■✩❨❇✙✘✖✫✢✳❧❳ ❱▼❱✒ ✙✍✚❉✙✍❆❇✔✗✖ò✵✚✔➋✮✸✙P❆ ✒ ✚✩✧❾✙ ● ✚✩✔✗✖✎❃ ✒✕✬ ✙ ● ✮✸✙ ✿✾✙✍✢✪✙ ✒ ✧✐✔✽✚✩✮ ✒ ✔✞❸✴✙✍❆❇✔♣✖ ✏■❋✩✔ ✿ ✒ ✦ ●✽❍■✒✕✬ ✙✍✚✜✛✴✧ ♠★❩✼✯✱✵❉✳✷✯P✬P✬❘✳✜✛❭②✳❆➀❅✸❙✯❘✳✶✵ ✟✣✢ ✌✑❱✒✕❍■✒✕✬ ✧❾✙✍✚✜✛✣✔ ✿ ✙✍✚❉✙P✢ ✒ ✏ ✒ ▲✸❈ ✒ ✚ ✿ ✒ ♠❂❊❷◗✣✤✥ ❇❂✧✪◗❙❳✷❳❈✯❘✳✶✵ ✟✣✢ ❻✺ ✦ ● ❆û❋✜❈✜✢ ✒✕✬ ✏■❈✜❋✜❋ ●✸✬ ✢❳◆ ●■✬ ✤ ✒ ✚ ● ✢✺✳❉❋❉✙✍✚✜✛✏✱❉✳ ✒ ❈❉✖✍✢✪✙✍❋❉✖ ✒ ❸ ❃ ✦ ✑ ♠❤✧❡✯✛✳✶✵r✵❉✳✧✦❖✯❈❇❉◗❅❵✩★✳✶✰✴✳ ✟✆✟▼✟✤ ✒ ✚ ● ❆▲✙❂✿ ✏ ✒ ▲✸❈ ✒ ✚ ✿ ✒ ✦ ● ❆✏❋✩✔ ✬ ✙★✧ ● ✚ ♠❋✧✪✩■❍✙✳✷✬❤✧✪✳❧❍❧⑥❧✸▼✳✶✵ ✟✆✟ ❻✁✄✂✆☎✞✝ ❁

✪ ✑✛✜✞✚✌✒❅❢❘❢♠✂✕✓✆❞■ ✚✴✢ ✬✥● ✮❉❈ ✿❀✢➦✙ ● ✚✄✢ ● ✦ ● ❆û❋❉✖ ✒ ❸ ✒ ❈❉✖✍✢✪✙✍❋❉✖✘✙❂✿✕✔✽✢✪✙ ● ✚ ♠ ❁✆✵❉✩✹✸✬✫ ❇❉◗✞✯ ♦❖❩❥◗✙✵❉✩❧✯✱✸ ✟✖❛ ✌■ ✚✴✢ ✬✥● ✮❉❈ ✿❀✢➦✙ ● ✚✄✢ ● ✏✽✙✍❆▲❈❉✖ ✔➶✢ ✒ ✮ ✺ ✚✜✚ ✒ ✔✗✖✘✙✍✚✜✛✄✔✽✚✩✮⑦❾ ● ✖✍✢✗✭✕❆❇✔➶✚✜✚ê✂✡✧ ✒ ✔❋✿✾✤❉✙P✚ ✒ ♠✈❩❭✩✹✵✗❇❆✯✱✸✝✂❨q✕✫✖❄✞✯✱♦❆⑥✙✳✓☎✉♦✷q✢✯ ✟✖❛ ❻✺ ✚ ✺ ✖P✛ ✒ ✱ ✬ ✔✗✙❂✿ ✺ ❋✜❋ ✬✥● ✔❋✿✥✤✣✢ ●❇✑✓✒ ✧❾✙★✮❉❈ ✒ ✧✲✙✍✚ ✏ ✒✕❍■✒✕✬ ✔✗✖✯✮❼✔ ✬ ✙★✔✽✱❉✖ ✒ ✧ ♠✈❫❖✳✶✵✷✸▼✩✹✵✗❵✴❩❥◗✖✫✙✵✷✵❉✩❧✯✱✸ ✟✖❛ ❱

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