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.