CB
SE
, © P
rof.
Uw
e A
ßman
n 1
12. F
indi
ng C
ompo
nent
s in
C
ompo
nent
Rep
osito
ries
Pro
f. D
r. U
we
Aßm
ann
Tech
nisc
he U
nive
rsitä
t Dre
sden
In
stitu
t für
Sof
twar
e- u
nd
Mul
timed
iate
chni
k ht
tp://
st.in
f.tu-
dres
den.
de
Ver
sion
14-
0.1,
12.
04.1
4
1.
Com
pone
nt S
earc
h w
ith
Met
adat
a 2.
Sea
rchi
ng a
nd B
row
sing
w
ith F
acet
ed C
lass
icat
ion
3.
Face
ted
Com
pone
nt S
tore
s 4.
Sea
rchi
ng b
y C
onfo
rman
ce
to P
roto
cols
Pro
f. U
. Aßm
ann,
CB
SE
2
Obl
igat
ory
Lite
ratu
re
►
R. P
rieto
-Dia
z. Im
plem
entin
g Fa
cete
d C
lass
ifica
tion
for S
oftw
are
Reu
se. C
AC
M M
ay 1
991,
vol
34(
5). I
n th
e A
CM
dig
ital l
ibra
ry.
►
U. A
ßman
n. R
euse
in S
eman
tic A
pplic
atio
ns. R
EW
ER
SE
sum
mer
sc
hool
200
5, L
a V
alet
ta, M
alta
. Lec
ture
Not
es In
Com
pute
r Sci
ence
(L
NC
S) 3
564.
■
http
://w
ww
.spr
inge
rlink
.com
/con
tent
/blx
9yfth
kq5x
jtjg/
Pro
f. U
. Aßm
ann,
CB
SE
3
Ref
eren
ces
• ht
tp://
sim
ile.m
it.ed
u/w
iki/L
ongw
ell
• ht
tp://
sim
ile.m
it.ed
u/ex
hibi
t •
http
://fla
men
co.b
erke
ley.
edu
• ht
tp://
sear
ch.e
xpre
ss.e
bay.
com
•
http
://ba
se.g
oogl
e.co
m
►
Face
tMap
: Gre
g S
mith
, Mar
y C
zerw
insk
i, B
rian
Mey
ers,
Dan
iel
Rob
bins
, Geo
rge
Rob
erts
on, D
esne
y S
. Tan
. Fac
etM
ap: A
Sca
labl
e S
earc
h an
d B
row
se V
isua
lizat
ion.
IEE
E T
rans
actio
ns o
n vi
sual
izat
ion
and
com
pute
r gra
phic
s, v
ol.1
2 , N
o. 5
, sep
tem
ber/
octo
ber 2
006.
►
Thor
sten
Tes
chke
. Sem
antis
che
Kom
pone
nten
such
e au
f Bas
is v
on
Ges
chäf
tspr
ozes
smod
elle
n. D
isse
rtatio
n. U
nive
rsitä
t Old
enbu
rg,
2003
. ►
Face
t-bas
ed s
earc
h of
com
pute
r sci
ence
lite
ratu
re in
DB
LP
repo
sito
ry
►
http
://db
lp.l3
s.de
/?q=
&ne
wQ
uery
=yes
&re
sTab
leN
ame=
quer
y_re
sultO
sC5m
C
►
CB
SE
, © P
rof.
Uw
e A
ßman
n 4
12.1
. Com
pone
nt S
earc
h
in C
ompo
nent
Rep
osito
ries
It sh
ould
be
as e
asy
to fi
nd g
ood
qual
ity re
usab
le
softw
are
asse
ts a
s it
is to
find
a b
ook
on th
e in
tern
et
ht
tp://
softw
arer
euse
.nas
a.go
v/
Pro
f. U
. Aßm
ann,
CB
SE
5
Com
pone
nt R
epos
itorie
s
§ C
ompo
nent
s m
ust b
e st
ored
in c
ompo
nent
repo
sito
ries
with
m
etad
ata
(mar
kup,
attr
ibut
es) t
o fin
d th
em a
gain
§
Des
crip
tions
(Met
adat
a)
• A
ttrib
utes
: Key
wor
ds, A
utho
r dat
a •
Usa
ge p
roto
cols
(beh
avio
ral s
peci
ficat
ions
) S
tate
mac
hine
s S
eque
nce
diag
ram
s C
ontra
cts
(pre
/pos
t/inv
aria
nts)
§ E
xam
ples
of C
ompo
nent
Rep
osito
ries
• C
OR
BA
im
plem
enta
tion
regi
stry
in
terfa
ce re
gist
ry
• C
OM
+ re
gist
ry
• C
omm
erci
al C
ompo
nent
Sto
res
ww
w.c
ompo
nent
sour
ce.c
om
• D
ebia
n Li
nux
Com
pone
nt S
yste
m (a
pt, d
pkg)
•
CTA
N T
eX A
rchi
ve
Pro
f. U
. Aßm
ann,
CB
SE
6
Why
Sea
rchi
ng C
ompo
nent
s?
§ A
pub
lic c
ompo
nent
repo
sito
ry is
cal
led
a m
arke
t, m
anag
ed b
y a
trad
er (b
roke
r)
• D
istri
butin
g or
sel
ling
com
pone
nts
• C
ompa
nies
can
regi
ster
com
pone
nts
at th
e th
e tra
der
• C
usto
mer
s ca
n se
arch
com
pone
nts
in th
e m
arke
ts a
nd b
uy o
r ren
t the
m
§ S
earc
hing
for f
unct
iona
lity
(inte
rface
, con
tract
, pro
toco
l) •
Reu
se in
stea
d of
bui
ld
• S
earc
hing
for c
ompo
nent
s to
repl
ace
own
ones
•
Sem
antic
sub
stitu
abili
ty (C
M-S
) sho
uld
be e
nsur
ed
§ S
earc
hing
for q
ualit
y fe
atur
es
• P
erfo
rman
ce, e
nerg
y co
nsum
ptio
n, re
liabi
lity
CB
SE
, © P
rof.
Uw
e A
ßman
n 7
12.2
Sea
rchi
ng a
nd B
row
sing
with
Fa
cete
d C
lass
ifica
tions
(tha
nks
to J
an P
olow
insk
i)
Pro
f. U
. Aßm
ann,
CB
SE
8
Face
ted
Cla
ssifi
catio
n fo
r Bet
ter M
atch
mak
ing
►
Face
ts a
re d
imen
sion
s of
a c
lass
ifica
tion
■ Fa
cets
sim
plify
sea
rch:
Fac
et c
lass
ifica
tion
has
been
inve
nted
in li
brar
y sc
ienc
e to
si
mpl
ify th
e de
scrip
tion
and
sear
ch fo
r boo
ks [R
anga
nath
an].
■
A c
ompo
nent
(or s
ervi
ce) i
s de
scrib
ed in
sev
eral
face
ts, d
imen
sion
s, w
hich
are
or
thog
onal
to e
ach
othe
r
►
Mat
chm
akin
g en
gine
s ca
n lo
ok u
p a
serv
ice
by s
tatin
g th
e de
sire
d pr
oper
ties
for a
ll fa
cets
. ►
Cla
ssifi
catio
ns c
an b
e ar
rang
ed in
face
ts if
sev
eral
par
titio
ns o
f a
grou
p of
obj
ects
exi
st th
at a
re o
rthog
onal
■
In d
omai
n m
odel
ling,
this
is o
ften
the
case
■
With
out f
acet
s, m
ultip
le in
herit
ance
hie
rarc
hies
hav
e to
be
spec
ified
, whi
ch a
re
ofte
n cl
umsy
and
err
or-p
rone
►
Idea
: use
face
ts fo
r bet
ter m
atch
mak
ing
Pro
f. U
. Aßm
ann,
CB
SE
9
Com
paris
on
Stan
dard
Cla
ssifi
catio
n ►
V Vö
gel
■ V
1 A
tmun
g de
r Vög
el
■ V
2 Fo
rtpfla
nzun
g de
r Vög
el
►
F Fi
sche
■
F1 A
tmun
g de
r Fis
che
■ F2
For
tpfla
nzun
g de
r Fis
che
►
S Sä
uget
iere
■
S1
Atm
ung
der S
äuge
tiere
■
S2
Fortp
flanz
ung
der S
äuge
tiere
►
I Ins
ekte
n
■ I1
Atm
ung
der I
nsek
ten
■ I2
For
tpfla
nzun
g de
r Ins
ekte
n •
Kie
men
: F1
Exa
mpl
e: W
ikip
edia
Face
ted
Cla
ssifi
catio
n ►
Proz
eßfa
cette
■
P P
hysi
olog
ie
. P
A A
tmun
g .
PF
Fortp
flanz
ung
►
Tier
face
tte
■ 1
Vög
el
■ 2
Fisc
he
■ 3
Säu
getie
re
■ 4
Inse
kten
•
Kie
men
: PA
2 P
rof.
U. A
ßman
n, C
BS
E
10
Face
tted
Bro
wsi
ng
►
Her
e Fa
cet m
eans
: an
inte
rest
ing
prop
erty
of a
n ob
ject
orth
ogon
al
to o
ther
pro
perti
es
►
Incr
emen
tal r
efin
emen
t of a
set
of r
esul
ts b
y re
stric
ting
valu
es o
f the
da
ta's
face
ts
►
Em
pty
resu
lt vi
ews
impo
ssib
le
►
Man
y ap
plic
atio
n do
mai
ns
Pro
f. U
. Aßm
ann,
CB
SE
11
Pro
f. U
. Aßm
ann,
CB
SE
12
Face
t
Face
t
Face
t
Face
t
Pro
f. U
. Aßm
ann,
CB
SE
13
Wid
get f
or R
estri
ctio
n of
Fac
et V
alue
s
Pro
f. U
. Aßm
ann,
CB
SE
14
Sor
ting
and
Gro
upin
g M
echa
nism
s
Pro
f. U
. Aßm
ann,
CB
SE
15
Res
ult S
et
Pro
f. U
. Aßm
ann,
CB
SE
16
Mor
e Ex
ampl
es o
f Fac
ette
d B
row
sers
►
Flam
enco
■
FLex
ible
info
rmat
ion
Acc
ess
usin
g M
Eta
data
in
Nov
el C
Om
bina
tions
■
Uni
vers
ity o
f Cal
iforn
ia,
Ber
kele
y ■
Bro
wse
s D
B
►
Long
wel
l ■
SIM
ILE
-Pro
ject
■
Bro
wse
s R
DF
►
Exh
ibit
■ S
IMIL
E-P
roje
ct
►
mS
pace
■
Uni
vers
ity o
f Sou
tham
pton
►
Face
tMap
■
Mic
roso
ft R
esea
rch
Pro
f. U
. Aßm
ann,
CB
SE
17
Face
tted
Bro
wsi
ng in
e-C
omm
erce
Pro
f. U
. Aßm
ann,
CB
SE
18
Pro
f. U
. Aßm
ann,
CB
SE
19
Pro
f. U
. Aßm
ann,
CB
SE
20
Pro
f. U
. Aßm
ann,
CB
SE
21
CB
SE
, © P
rof.
Uw
e A
ßman
n 22
12.3
Fac
eted
Com
pone
nt
Rep
osito
ries
and
Stor
es
Pro
f. U
. Aßm
ann,
CB
SE
23
Exam
ple:
Ser
vice
Fac
ets
in a
UN
IX S
yste
m
►
To d
escr
ibe
the
serv
ices
of a
UN
IX s
yste
m, [
Prie
to-D
iaz]
em
ploy
ed a
4-
face
ted
sche
me
■
func
tion
■ lo
gica
l obj
ect
■ im
plem
enta
tion
obje
ct
■ to
ol
►
UN
IX s
ervi
ces
can
be d
escr
ibed
with
app
ropr
iate
face
t val
ues
and
look
ed u
p in
a re
posi
tory
►
Exa
mpl
e: “a
ppen
d a
line
to a
file
with
a te
xt e
dito
r”
■ (fu
nctio
n =
appe
nd,
■ lo
gica
l cla
ss =
line
, ■
impl
emen
tatio
n cl
ass
= fil
e,
■ to
ol =
text
edi
tor)
:
Pro
f. U
. Aßm
ann,
CB
SE
24
Exam
ple:
Ser
vice
s in
a U
NIX
Sys
tem
►
[Prie
to-D
iaz]
alre
ady
sugg
este
d to
use
con
trolle
d vo
cabu
lary
(dom
ain
onto
logi
es) t
o im
prov
e th
e ef
fect
iven
ess
of th
e se
arch
: ■
If ev
ery
face
t is
desc
ribed
by
an o
ntol
ogy,
the
serv
ice
desc
riptio
ns a
re
stan
dard
ized
for a
use
r gro
up a
nd im
prov
e un
ders
tand
ing
of s
ervi
ce s
eman
tics.
►
Face
ts s
impl
ified
the
desc
riptio
n of
the
com
pone
nts,
impr
oved
the
unde
rsta
ndin
g of
thei
r dom
ain,
and
faci
litat
ed th
e se
arch
in
com
pone
nt li
brar
ies.
Pro
f. U
. Aßm
ann,
CB
SE
25
And
for C
ompo
nent
s?
Pro
f. U
. Aßm
ann,
CB
SE
26
And
for C
ompo
nent
s?
Pro
f. U
. Aßm
ann,
CB
SE
27
Oth
er A
dvan
tage
s
►
The
face
t cla
ssifi
catio
n is
rath
er im
mun
e to
ext
ensi
ons
■ E
xten
ding
one
face
t lea
ves
all o
ther
s in
varia
nt
■ E
xam
ple:
If E
urop
e is
ext
ende
d w
ith a
new
mem
ber s
tate
, the
mat
chm
akin
g al
gorit
hm c
an d
eliv
er n
ew c
ours
es fr
om th
e ne
w m
embe
r sta
te, w
ithou
t affe
ctin
g th
e re
st o
f the
sem
antic
spe
cific
atio
ns a
t all
►
The
accu
racy
can
be
impr
oved
by
syno
nym
list
s (th
esau
ri)
■ S
ynon
yms
incr
ease
the
chan
ces
for a
mat
ch
■ Th
ey p
erm
it to
sea
rch
not o
nly
for k
eyw
ords
, but
als
o fo
r the
ir sy
nony
ms
(ass
embl
ed in
a th
esau
rus)
■
Bey
ond
syno
nym
s ot
her r
efin
emen
t rel
atio
ns o
f con
cept
s ca
n be
use
d to
impr
ove
the
sear
ch
■ E
xam
ple:
Gre
at B
ritai
n is
use
d as
a s
ynon
ym fo
r Eng
land
, Sco
tland
, and
Wal
es.
Syn
onym
s al
low
s fo
r mat
chm
akin
g on
any
of t
he k
eyw
ords
, so
that
stu
dent
s lo
okin
g fo
r a c
ours
e ne
ed n
ot b
othe
r abo
ut g
eogr
aphi
c an
d po
litic
al d
etai
ls.
Pro
f. U
. Aßm
ann,
CB
SE
28
The
Use
of O
ntol
ogie
s in
Fac
eted
Mat
chm
akin
g
►
Ont
olog
ies
sim
plify
mat
chm
akin
g by
sta
ndar
diza
tion
■ S
ince
they
pro
vide
sta
ndar
dize
d te
rmin
olog
y an
d st
anda
rdiz
ed
onto
logi
cal r
elat
ions
bet
wee
n th
e te
rms,
que
ries
can
spec
ify
. ke
ywor
ds w
ith a
pre
cise
, sha
red,
and
sta
ndar
dize
d m
eani
ng (s
eman
tic
sear
ch),
.
cont
extu
al in
form
atio
n fo
r sea
rch
in c
onte
xt, w
here
the
cont
ext i
s de
fined
by
the
onto
logi
cal r
elat
ions
of t
he te
rms.
►
Exa
mpl
e:
■ A
web
cou
rse
on IT
bas
ics
can
be q
uerie
d by
the
stan
dard
ized
wor
d IT
-ba
sics
(bei
ng s
eman
tic s
earc
h)
■ al
so in
con
text
, by
rela
ting
it to
cou
rses
suc
h as
IT-a
dvan
ced
or IT
-pr
epar
ator
y (c
onte
xtua
l sea
rch)
.
“find
me
an IT
bas
ics
cour
se, w
hich
has
a p
rece
ding
pre
para
tory
IT c
ours
e an
d ha
s a
follo
w-u
p ad
vanc
ed IT
cou
rse“
Pro
f. U
. Aßm
ann,
CB
SE
29
Exam
ple:
Fin
ding
Cou
rses
in E
urop
e ba
sed
on
Ont
olog
ies
►
A c
ours
e in
the
unifi
ed B
olog
na w
orld
of E
urop
ean
educ
atio
n ca
n be
de
scrib
ed b
y se
vera
l fac
ets:
■
topi
c ar
ea (c
ompu
ter s
cien
ce, m
usic
, lite
ratu
re, e
tc.),
■
leve
l of a
dvan
cem
ent (
unde
rgra
duat
e, g
radu
ate)
, ■
cost
(fre
e, n
on-fr
ee),
■ co
untry
(Ger
man
y, It
aly,
Wes
tern
Eur
ope,
Eas
tern
Eur
ope,
etc
.)
►
Eve
ry fa
cet c
an b
e de
scrib
ed b
y an
ont
olog
y, in
this
cas
e on
■
topi
c ar
ea
■ le
vel
■ co
st
■ co
untry
►
A s
eman
tic d
escr
iptio
n of
a c
ours
e se
lect
s on
e va
lue
for e
ach
face
t an
d fo
rms
a tu
ple
■ A
free
und
ergr
adua
te m
usic
cou
rse
coul
d be
des
crib
ed b
y th
e tu
ple
(topi
c ar
ea =
m
usic
, adv
ance
men
t = u
nder
grad
uate
, cos
t = fr
ee, c
ount
ry =
Wes
tern
Eur
ope)
.
Pro
f. U
. Aßm
ann,
CB
SE
30
Ex. F
indi
ng C
ours
es in
Eur
ope
►
Sea
rchi
ng a
cou
rse
thro
ugho
ut th
e co
urse
dat
abas
es in
Eur
ope
cons
ists
of c
ompa
ring
the
tupl
e po
int-w
ise
to d
atab
ase
entri
es.
►
The
valu
es n
eed
not m
atch
exa
ctly
, ■
Sub
sum
ptio
n (in
herit
ance
) in
the
face
t ont
olog
ies
can
be u
sed
to d
eliv
er
refin
emen
t of m
atch
ings
. ■
Exa
mpl
e: if
free
-cou
rse
is s
ubsu
med
by
non-
free-
cour
se, t
he m
atch
er c
an y
ield
a
free
cour
se, e
ven
if th
e cl
ient
des
ired
a no
n-fre
e on
e.
■ E
xam
ple:
a m
atch
mak
er c
an re
turn
a (m
usic
, und
ergr
adua
te, n
on-fr
ee, G
erm
any)
-co
urse
whi
ch s
houl
d fit
the
clie
nt's
des
ires.
Pro
f. U
. Aßm
ann,
CB
SE
31
Putti
ng u
p a
Com
pone
nt R
epos
itory
for
Your
Com
pany
►
Def
ine
face
ts fo
r com
pone
nt m
etad
ata
■ If
poss
ible
, reu
se a
n on
tolo
gy fo
r a fa
cet
■ Fo
rm a
thes
auru
s fo
r syn
onym
s ■
Sto
re th
e m
etad
ata
as a
tupl
e in
the
data
base
►
Rea
lize
a se
arch
alg
orith
m th
at u
ses
face
ts to
geth
er w
ith th
esau
ri
CB
SE
, © P
rof.
Uw
e A
ßman
n 32
12.4
Sea
rchi
ng b
y
Prot
ocol
Con
form
ance
Pro
toco
l Con
form
ance
mea
ns s
eman
tic s
ubst
ituab
ility
Pro
f. U
. Aßm
ann,
CB
SE
33
Com
pone
nt C
ontr
acts
with
UM
L C
ompo
nent
s
• A
UM
L co
mpo
nent
is a
hie
rarc
hica
l cla
ss (c
lass
ifier
, typ
e) w
ith
prov
ided
and
requ
ired
inte
rface
s (r
oles
) •
Pro
vide
d in
terfa
ces
(rol
es) a
re u
sing
„Lol
lipop
“ not
atio
n •
Req
uire
d in
terfa
ces
(rol
es) u
se „p
lug“
not
atio
n
• S
ome
com
pone
nts
are
requ
ired
to u
se s
peci
fic o
ther
inte
rface
s
<<co
mp
spec
>>
Com
pany
Mgr
IC
ompa
nyM
gt
<<co
mp
spec
>>
Com
pany
Mgr
IC
ompa
nyM
gt
IAdd
ress
Mgt
<<co
mp
spec
>>
Adr
essM
gr
Pro
f. U
. Aßm
ann,
CB
SE
34
Lolli
pops
and
Plu
gs (B
alls
and
Soc
kets
)
►
For a
UM
L cl
ass,
pro
vide
d an
d re
quire
d in
terfa
ces
can
be
dist
ingu
ised
n
A re
quire
d in
terfa
ce s
peci
fies
wha
t the
cur
rent
cla
ss n
eeds
to e
xecu
te.
<<pr
ovid
ed>>
A
ddre
sses
<<re
quire
d>>
Text
A
ddre
ssM
anag
er
listA
dres
ses(
) lis
tAdr
esse
s()
sort(
)
Adr
esse
s
Text
Pro
f. U
. Aßm
ann,
CB
SE
35
Port
s
►
Por
ts c
onsi
st o
f por
t cla
sses
with
inte
rface
s an
d be
havi
or in
form
of
inte
rfac
e au
tom
ata
n
prov
ided
: nor
mal
, offe
red
inte
rface
n
requ
ired:
use
d, n
eces
sary
inte
rface
Com
pone
nt
<<pr
ovid
ed>>
P
ort c
lass
<<
requ
ired>
> P
ort c
lass
Com
pone
nt
Por
t
Inte
rface
au
tom
aton
Inte
rface
au
tom
aton
Pro
f. U
. Aßm
ann,
CB
SE
36
Com
pone
nt P
roto
cols
with
Ope
ratio
nal C
ontr
acts
§ C
ompo
nent
s ha
ve a
pro
toco
l in
whi
ch th
eir p
orts
, ser
vice
s, p
roce
dure
s sh
ould
be
calle
d, in
voke
d, o
r sig
nalle
d •
The
prov
ided
pro
toco
l spe
cifie
s in
whi
ch o
rder
the
serv
ices
can
be
invo
ked
(giv
en b
y a
prov
ided
inte
rface
aut
omat
on)
• Th
e re
quire
d pr
otoc
ol s
peci
fies
in w
hich
ord
er th
e se
rvic
es c
an b
e in
voke
d (g
iven
by
a re
qurie
d in
terfa
ce a
utom
aton
)
§ Th
e or
der o
f com
pone
nt in
voca
tion
can
be s
peci
fied
by a
lang
uage
ove
r the
al
phab
et o
f the
por
ts, s
ervi
ces,
pro
cedu
res
(sta
te-b
ased
pro
toco
l co
ntra
ct, o
pera
tiona
l con
trac
t) •
Fini
te s
tate
aut
omat
on (r
egul
ar la
ngua
ge)
UM
L st
ate
char
t (H
iera
rchi
cal f
inite
sta
te m
achi
ne, p
roco
col m
achi
nes)
D
ata
flow
dia
gram
•
Sta
ck m
achi
ne (c
onte
xt-fr
ee la
ngua
ge)
• P
etri
net (
regu
lar d
iale
cts,
con
text
-free
and
con
text
-sen
sitiv
e di
alec
ts)
§ Th
e co
ntra
ct p
rovi
des
an a
bstra
ctio
n of
the
impl
emen
tatio
n of
the
com
pone
nt
• Im
plem
enta
tions
mus
t be
prov
en to
be
conf
orm
ant t
o th
e pr
ocot
ol
§ Th
e co
nfor
man
ce c
heck
ing
is d
ecid
able
if th
e pr
otoc
ol la
ngua
ge is
de
cida
ble
Pro
f. U
. Aßm
ann,
CB
SE
37
Sear
chin
g by
Pro
toco
l
§ A
com
pone
nt p
roto
col P
(C1)
can
sub
sum
e a
com
pone
nt p
roto
col
P(C
2)
•
P(C
1) <
= P
(C2)
•
For f
inite
aut
omat
a: P
(C1)
P(C
2)
§ Th
en, C
1 is
con
form
ant t
o C
2 an
d C
1 ca
n su
bstit
ute
C2
§ Su
bsum
ptio
n ch
ecki
ng a
nd th
us, c
onfo
rman
ce c
heck
ing,
sho
uld
be d
ecid
able
(pro
toco
l lan
guag
e sh
ould
be
deci
dabl
e)
§ A
com
pone
nt C
can
be
foun
d in
a re
posi
tory
, if a
que
ry p
roto
col Q
is
giv
en w
ith Q
<=
P(C
) §
Sea
rch
cons
ists
of s
ubsu
mpt
ion
chec
king
with
all
com
pone
nt
prot
ocol
s in
the
repo
sito
ry !
Pro
f. U
. Aßm
ann,
CB
SE
38
Dec
lara
tive
Prot
ocol
s
§ A
pro
toco
l can
als
o be
spe
cifie
d as
pre
dica
tes
over
the
stat
es o
f a
com
pone
nt (d
ecla
rativ
e co
ntra
ct)
• P
reco
nditi
ons
(ass
umpt
ions
) •
Pos
tcon
ditio
ns (g
uara
ntee
s)
• In
varia
nts
§ Th
en, t
he p
roto
col c
onsi
sts
of lo
gic
expr
essi
ons
§ Th
e lo
gic
shou
ld b
e de
cida
ble
• O
CL
• D
escr
iptio
n lo
gic
• D
atal
og
• Te
mpo
ral l
ogic
(pro
posi
tiona
l log
ic w
ith te
mpo
ral q
uant
ifier
s)
§ S
ubsu
mpt
ion
chec
king
of p
roto
cols
and
con
form
ance
can
be
done
by
reas
onin
g •
E.g
., by
sub
sum
ptio
n ch
ecki
ng o
f an
OW
L cl
ass
hier
arch
y
Pro
f. U
. Aßm
ann,
CB
SE
39
The
End
- Ack
now
ledg
emen
ts
§ Fa
cete
d br
owsi
ng s
lides
are
cou
rtesy
to J
an P
olow
insk
i.
