Agent-oriented programming : from prolog to guarded definite clauses

394 Pages·1999·4.2 MB·English

by  Huntbach, Matthew M

L e c t u r e N o t e s i n A r t i f i c i a l I n t e l l i g e n c e 1 6 3 0
S u b s e r i e s o f L e c t u r e N o t e s i n C o m p u t e r S c i e n c e
E d i t e d b y J . G . C a r b o n e l l a n d J . S i e k m a n n
L e c t u r e N o t e s i n C o m p u t e r S c i e n c e
E d i t e d b y G . G o o s , J . H a r t m a n i s a n d J . v a n L e e u w e n
3
B e r lin
H e id e lb e r g
N e w Y o r k
B a r c e lo n a
H o n g K o n g
L o n d o n
M ila n
P a r is
S in g a p o r e
T o k y o
M a t t h e w M . H u n t b a c h G r a e m A . R i n g w o o d
A g e n t - O r i e n t e d
P r o g r a m m i n g
F r o m P r o l o g t o G u a r d e d D e fi n i t e C l a u s e s
1 3
S e r ie s E d ito r s
J a im e G . C a r b o n e ll, C a r n e g ie M e llo n U n iv e r s ity , P itts b u r g h , P A , U S A
J o¨ rg S ie k m a n n , U n iv e r s ity o f S a a r la n d , S a a r b r u¨ c k e n , G e r m a n y
A u th o r s
M a tth e w M . H u n tb a c h
G r a e m A . R in g w o o d
D e p a r tm e n t o f C o m p u te r S c ie n c e , Q u e e n M a r y a n d W e s tfi e ld C o lle g e
M ile E n d R o a d , L o n d o n E 1 4 N S , U K
E - m a il: {m m h /g a r }@ d c s .q m w .a c .u k
C a ta lo g in g - in - P u b lic a tio n d a ta a p p lie d f o r
D ie D e u ts c h e B ib lio th e k - C I P - E in h e its a u f n a h m e
H u n t b a c h , M a t t h e w M .:
A g e n t- o r ie n te d p r o g r a m m in g : f r o m p r o lo g to g u a r d e d d e fi n ite
c la u s e s / M a tth e w M . H u n tb a c h ; G r a e m A . R in g w o o d . - B e r lin ;
H e id e lb e rg ; N e w Y o r k ; B a r c e lo n a ; H o n g K o n g ; L o n d o n ; M ila n ;
P a r is ; S in g a p o r e ; T o k y o : S p r in g e r, 1 9 9 9
( L e c tu r e n o te s in c o m p u te r s c ie n c e ; V o l. 1 6 3 0 : L e c tu r e n o te s in
a r tifi c ia l in te llig e n c e )
I S B N 3 - 5 4 0 - 6 6 6 8 3 - 4
C R S u b je c t C la s s ifi c a tio n ( 1 9 9 8 ) : I .2 , D .1 .6 , D .1 .3 , D .3 , C .2 .4
I S B N 3 - 5 4 0 - 6 6 6 8 3 - 4 S p r in g e r- V e r la g B e r lin H e id e lb e r g N e w Y o r k
T h is w o rk is su b je c t to c o p y rig h t. A ll rig h ts a re re se rv e d , w h e th e r th e w h o le o r p a rt o f th e m a te ria l is
c o n c e rn e d , sp e c ifi c a lly th e rig h ts o f tra n sla tio n , re p rin tin g , re -u se o f illu stra tio n s, re c ita tio n , b ro a d c a stin g ,
re p ro d u c tio n o n m ic ro fi lm s o r in a n y o th e r w a y , a n d sto ra g e in d a ta b a n k s. D u p lic a tio n o f th is p u b lic a tio n
o r p a rts th e re o f is p e rm itte d o n ly u n d e r th e p ro v isio n s o f th e G e rm a n C o p y rig h t L a w o f S e p te m b e r 9 , 1 9 6 5 ,
in its c u rre n t v e rsio n , a n d p e rm issio n fo r u se m u st a lw a y s b e o b ta in e d fro m S p rin g e r-V e rla g . V io la tio n s a re
lia b le fo r p ro se c u tio n u n d e r th e G e rm a n C o p y rig h t L a w .
(cid:2)c S p rin g e r-V e rla g B e rlin H e id e lb e rg 1 9 9 9
P rin te d in G e rm a n y
T y p e se ttin g : C a m e ra -re a d y b y a u th o r
S P IN 1 0 7 0 3 3 5 9 0 6 /3 1 4 2 – 5 4 3 2 1 0 P rin te d o n a c id -fre e p a p e r
P r e f a c e
A b o o k th a t fu r n is h e s n o q u o ta tio n s is , m e ju d ic e , n o b o o k – it is a
p la y th in g .
T L P e a c o c k : C r o c h e t C a s tle
T h e p a r a d ig m p r e s e n te d in th is b o o k is p r o p o s e d a s a n a g e n t p r o g r a m m in g la n g u a g e .
T h e b o o k c h a r ts th e e v o lu tio n o f th e la n g u a g e f r o m P r o lo g to in te llig e n t a g e n ts . T o a
la r g e e x te n t, in te llig e n t a g e n ts r o s e to p r o m in e n c e in th e m id - 1 9 9 0 s b e c a u s e o f th e
W o r ld W id e W e b a n d a n ill- s tr u c tu r e d n e tw o r k o f m u ltim e d ia in f o r m a tio n . A g e n t-
o r ie n te d p r o g r a m m in g w a s a n a tu r a l p r o g r e s s io n f r o m o b je c t- o r ie n te d p r o g r a m m in g
w h ic h C + + a n d m o r e r e c e n tly J a v a p o p u la r iz e d . A n o th e r s tr a n d o f in f lu e n c e c a m e
f r o m a r e v iv a l o f in te r e s t in r o b o tic s [ B r o o k s , 1 9 9 1 a ; 1 9 9 1 b ] .
T h e q u in te s s e n c e o f a n a g e n t is a n in te llig e n t, w illin g s la v e . S p e c u la tio n in th e a r e a o f
a r tif ic ia l s la v e s is f a r m o r e a n c ie n t th a n tw e n tie th c e n tu r y s c ie n c e f ic tio n . O n e
d o c u m e n te d e x a m p le is f o u n d in A r is to tle ’ s P o litic s w r itte n in th e f o u r th c e n tu r y B C .
A r is to tle c la s s if ie s th e s la v e a s “ a n a n im a te a r tic le o f p r o p e r ty ” . H e s u g g e s ts th a t
s la v e s o r s u b o r d in a te s m ig h t n o t b e n e c e s s a r y if “ e a c h in s tr u m e n t c o u ld d o its o w n
w o r k a t c o m m a n d o r b y a n tic ip a tio n lik e th e s ta tu e s o f D a e d a lu s a n d th e tr ip o d s o f
H e p h a e s tu s ” . R e f e r e n c e to th e le g e n d a r y r o b o ts d e v is e d b y th e s e m y th o lo g ic a l
te c h n o c r a ts , th e f o r m e r a n a r tif ic e r w h o m a d e w in g s f o r I c a r u s a n d th e la tte r a
b la c k s m ith g o d , te s tif y th a t th e c o n c e p t o f r o b o t, if n o t th e n a m e , w a s a n c ie n t e v e n in
A r is to tle ’ s tim e . A r is to tle c o n c lu d e d th a t e v e n if s u c h m a c h in e s e x is te d , h u m a n
s la v e s w o u ld s till b e n e c e s s a r y to r e n d e r th e little p e r s o n a l s e r v ic e s w ith o u t w h ic h lif e
w o u ld b e in to le r a b le .
T h e n a m e r o b o t c o m e s f r o m th e C z e c h w o r d s f o r s e r f a n d f o r c e d la b o r . I ts u s a g e
o r ig in a te s f r o m K a r e l C a p e k ’ s 1 9 2 0 s p la y R o s s u m ’ s U n iv e r s a l R o b o ts in w h ic h
R o s s u m , a n E n g lis h m a n , m a s s - p r o d u c e d a u to m a ta . T h e p la y w a s b a s e d o n a s h o r t
s to r y b y C a p e k ’ s b r o th e r . T h e r o b o ts in th e p la y w e r e n o t m e c h a n ic a l b u t g r o w n
c h e m ic a lly . C a p e k d is m is s e d “ m e ta l c o n tr a p tio n s r e p la c in g h u m a n b e in g s ” a s “ a
g r a v e o f f e n c e a g a in s t lif e ” . O n e o f th e e a r lie s t f ilm r o b o ts w a s th e r e p lic a M a r ia in
F r itz L a n g ’ s 1 9 2 7 c la s s ic M e tr o p o lis . T h e a c a d e m ic tu r n e d s c ie n c e f ic tio n w r ite r
I s a a c A s im o v ( 1 9 2 0 – 1 9 9 2 ) in tr o d u c e d th e te r m r o b o tic s w h e n h e n e e d e d a w o r d to
d e s c r ib e th e s tu d y o f r o b o ts in R u n a r o u n d [ 1 9 4 2 ] . A s im o v w a s o n e o f th e f ir s t
a u th o r s to d e p a r t f r o m th e F r a n k e n s te in p lo t o f m a d s c ie n tis t c r e a tin g a m o n s te r a n d
to c o n s id e r th e s o c ia l im p lic a tio n s o f r o b o ts .
A n e x a m p le o f a n a u to m a to n f r o m th e d a r k a g e s is a v e n d in g m a c h in e f o r h o ly w a te r
p r o p o s e d b y H e r o o f A le x a n d r ia a r o u n d 1 1 A D . A m o d e r n r e in c a r n a tio n is H o a r e ’ s
c h o c m a c h in e [ H o a r e , 1 9 8 5 ] d e v e lo p e d to m o tiv a te th e c o m p u ta tio n a l m o d e l C S P
( C o m m u n ic a tin g S e q u e n tia l P r o c e s s e s ) . T h e w o r d a u to m a to n , o f te n u s e d to d e s c r ib e
c o m p u te r s o r o th e r c o m p le x m a c h in e s , c o m e s f r o m th e s a m e G r e e k r o o t a s
a u to m o b ile m e a n in g s e lf - m o v e r . M o d e r n s c ie n c e o w e s m u c h to th e G r e e k tr a d itio n .
A n a ly s is o f th e f o r m s o f a r g u m e n t b e g a n w ith E m p e d o c le s a n d th e im p o r ta n c e o f
o b s e r v a tio n s te m s f r o m H ip p o c r a te s . T h e m is s in g in g r e d ie n ts o f G r e e k s c ie n c e
c o m p a r e d w ith th e s c ie n c e o f to d a y w e r e s u p p lie d b y th e A g e o f R e a s o n . T h e s e w e r e
V I P re fa c e
th e n e e d f o r d e lib e r a te ly c o n tr iv e d o b s e r v a tio n - e x p e r im e n ts ; th e n e e d f o r in d u c tiv e
a r g u m e n t to s u p p le m e n t d e d u c tio n ; a n d th e u s e o f m a th e m a tic s to m o d e l o b s e r v e d
p h e n o m e n a . T h e m o s t im p o r ta n t le g a c y o f s e v e n te e n th c e n tu r y s c ie n c e is te c h n o lo g y ,
th e a p p lic a tio n o f s c ie n c e . T e c h n o lo g y h a s e x p a n d e d h u m a n c a p a b ility , im p r o v e d
c o n tr o l o v e r th e m a te r ia l w o r ld , a n d r e d u c e d th e n e e d f o r h u m a n la b o r . W illin g s la v e s
a r e , p e r h a p s , th e u ltim a te g o a l o f te c h n o lo g y .
I n d u s tr ia l r o b o ts a p p e a r e d in th e la te 1 9 5 0 s w h e n tw o A m e r ic a n s , D e v o l a n d
E n g e lb e r g e r , f o r m e d th e c o m p a n y U n im a tio n . T a k e - u p w a s s lo w a n d U n im a tio n d id
n o t m a k e a p r o f it f o r th e f ir s t f o u r te e n y e a r s . T h e s itu a tio n c h a n g e d in th e m id - 1 9 8 0 s
w h e n th e a u to m o b ile in d u s tr y , d is s a tis f ie d w ith tr a d e u n io n d is r u p tio n o f p r o d u c tio n ,
tu r n e d to r o b o t a s s e m b ly . H o w e v e r , th e in d u s tr ia l r o b o t in d u s tr y o v e r e x te n d e d a s
g o v e r n m e n ts c u r ta ile d tr a d e u n io n p o w e r a n d th e m a r k e t s a tu r a te d . M a n y f ir m s ,
in c lu d in g U n im a tio n , c o lla p s e d o r w e r e b o u g h t o u t b y e n d p r o d u c t m a n u f a c tu r e r s .
T o d a y , th e b ig p r o d u c e r is J a p a n w ith 4 0 0 0 0 0 in s ta lle d r o b o ts c o m p a r e d to th e U S
w ith o v e r 7 0 0 0 0 a n d th e U K w ith le s s th a n 1 0 0 0 0 .
W ith p r e - C o p e r n ic a n m e n ta lity , p e o p le w ill o n ly f r e e ly a d m it th a t h u m a n s p o s s e s s
in te llig e n c e . ( T h is , p o s s ib ly , s h o u ld b e q u a lif ie d to m e a n m o s t h u m a n s o n m o s t
o c c a s io n s .) H u m a n s c a n s e e , h e a r , ta lk , le a r n , m a k e d e c is io n s , a n d s o lv e p r o b le m s . I t
s e e m s r e a s o n a b le th a t a n y o n e a tte m p tin g to r e p r o d u c e a s im ila r a r tif ic ia l c a p a b ility
w o u ld f ir s t a tte m p t e m u la tin g th e h u m a n b r a in . T h e id e a th a t A r tif ic ia l I n te llig e n c e
( A I ) s h o u ld tr y to e m u la te th e h u m a n n e r v o u s s y s te m ( b r a in c e lls a r e n e r v e c e lls ) w a s
a lm o s t ta k e n f o r g r a n te d b y th e tw e n tie th c e n tu r y p io n e e r s o f A I . U p u n til th e la te
1 9 6 0 s ta lk o f e le c tr o n ic b r a in s w a s c o m m o n p la c e .
F r o m R o s s u m ’ s U n iv e r s a l R o b o ts in C a r e l K a p e k ’ s v is io n to H A L in th e f ilm 2 0 0 1 ,
in te llig e n t m a c h in e s p r o v id e s o m e o f th e m o s t p o te n t im a g e s o f th e la te tw e n tie th
c e n tu r y . T h e 1 9 8 0 s w e r e , in d e e d , a g o o d tim e f o r A I r e s e a r c h . I n th e 1 9 7 0 s A I h a d
b e c o m e s o m e th in g o f a b a c k w a te r in g o v e r n m e n ta l f u n d in g , b u t a ll th a t c h a n g e d
d r a m a tic a lly b e c a u s e o f th e J a p a n e s e F if th G e n e r a tio n I n itia tiv e . A t th e b e g in n in g o f
th e 1 9 8 0 s , M I T I , th e J a p a n e s e e q u iv a le n t o f th e D e p a r tm e n t f o r T r a d e a n d I n d u s tr y ,
a n n o u n c e d th a t J a p a n w a s to c o n c e n tr a te o n k n o w le d g e b a s e d s y s te m s a s th e c u ttin g
e d g e o f in d u s tr ia l d e v e lo p m e n t. T h is s e n t tr e m o r s o f c o m m e r c ia l f e a r th r o u g h th e
c o r r id o r s o f p o w e r o f e v e r y c o u n tr y th a t h a d a c o m p u tin g in d u s tr y . T h e s e
g o v e r n m e n ts h a d s e e n n a tio n a l in d u s tr ie s s u c h a s s h ip b u ild in g , a u to m o b ile
m a n u f a c tu r in g , a n d c o n s u m e r e le c tr o n ic s c r u m b le u n d e r in te n s iv e J a p a n e s e
c o m p e titio n . I n w h a t r e tr o s p e c tiv e ly s e e m s to b e a h a lf h e a r te d a tte m p t to ta r g e t
r e s e a r c h f u n d s to in d u s tr ia lly r e le v a n t in f o r m a tio n te c h n o lo g y , a f e w n a tio n a l a n d
m u ltin a tio n a l r e s e a r c h p r o g r a m s w e r e in itia te d . A m a jo r b e n e f ic ia r y o f th is f u n d in g
w a s A I . O n s h o r t tim e s c a le s , c o m m e r c ia l p r o d u c ts w e r e s u p p o s e d to s p r in g f o r th f u lly
a r m e d f r o m b a s ic r e s e a r c h .
G r e a t a d v a n c e s in c o m p u te r h a r d w a r e w e r e m a d e in th is d e c a d e w ith c o m p u tin g
p o w e r in c r e a s in g a th o u s a n d f o ld . A c o m p u te r d e f e a te d th e w o r ld b a c k g a m m o n
c h a m p io n a n d a c o m p u te r c a m e in jo in t f ir s t in a n in te r n a tio n a l c h e s s to u r n a m e n t,
b e a tin g a g r a n d m a s te r a lo n g th e w a y . T h is , h o w e v e r , d id n o t a u g u r th e a g e o f th e
in te llig e n t m a c h in e . G e n u in e p r o g r e s s in A I h a s b e e n p a in f u lly s lo w a n d in d u s tr ia l
ta k e - u p h a s b e e n m a in ly lim ite d to a f e w w e ll- p u b lic iz e d e x p e r t s y s te m s .
P re fa c e V II
I n th e m id - 1 9 8 0 s , it w a s e n v is a g e d th a t e x p e r t s y s te m s th a t c o n ta in th o u s a n d s o f r u le s
w o u ld b e w id e ly a v a ila b le b y th e e n d o f th e d e c a d e . T h is h a s n o t h a p p e n e d ; in d u s tr ia l
e x p e r t s y s te m s a r e r e la tiv e ly s m a ll a n d n a r r o w ly f o c u s e d o n s p e c if ic d o m a in s o f
k n o w le d g e , s u c h a s m e d ic a l d ia g n o s is . A s r e s e a r c h e r s tr ie d to b u ild m o r e e x te n s iv e
e x p e r t s y s te m s m a jo r p r o b le m s w e r e e n c o u n te r e d .
T h e r e a r e tw o r e a s o n s w h y g a m e p la y in g is th e o n ly a r e a in w h ic h A I h a s , a s y e t,
a c h ie v e d its g o a l. T h o u g h c o m p le x , c h e s s is a h ig h ly r e g u la r , c o d if ia b le p r o b le m
c o m p a r e d w ith , s a y , d ia g n o s is . F u r th e r , th e a lg o r ith m s u s e d b y c h e s s p la y in g
p r o g r a m s a r e n o t u s u a lly b a s e d o n e x p e r t s y s te m s . R a th e r th a n s o lic itin g k n o w le d g e
f r o m c h e s s e x p e r ts , s u c c e s s f u l g a m e p la y in g p r o g r a m s r e ly m a in ly o n g u id e d b r u te
f o r c e s e a r c h o f a ll p o s s ib le m o v e s u s in g h ig h ly p o w e r f u l c o n v e n tio n a l m u ltip r o c e s s o r
m a c h in e s . I n r e a lity , A I h a s m a d e a s m u c h p r o g r e s s a s o th e r b r a n c h e s o f s o f tw a r e
e n g in e e r in g . T o a la r g e e x te n t, its d r a m a tic c h a n g e s o f f o r tu n e , b o o m a n d b u s t, a r e
d u e to f a n a tic a l p r o p o n e n ts w h o p r o m is e to o m u c h . T h e tim e s c a le p r e d ic tio n s o f th e
J a p a n e s e n o w lo o k v e r y f a n c if u l in d e e d . A I h a s b e e n o v e r s o ld m o r e th a n o n c e .
A c o m m o n r e a c tio n to th e e a r ly e f f o r ts in A I w a s th a t s u c c e s s f u l r e p lic a tio n o f h u m a n
s k ills w o u ld d im in is h h u m a n b e a r e r s o f s u c h s k ills . A s ig n if ic a n t o u tc o m e o f A I
r e s e a r c h is h o w d if f ic u lt th e s im p le s t s k ills w e ta k e f o r g r a n te d a r e to im ita te . A I is a
lo n g - te r m p r o b le m , a m a r a th o n , a n d n o t a s p r in t c o m p e titio n w ith th e J a p a n e s e .
E x p e r t s y s te m s a r e o n ly a n e a r ly s ta g in g p o s t o n th e w a y to d e v e lo p in g in te llig e n t
m a c h in e s .
A I p io n e e r e d m a n y id e a s th a t h a v e m a d e th e ir w a y b a c k in to m a in s tr e a m c o m p u te r
s c ie n c e . T h e s e in c lu d e tim e s h a r in g , in te r a c tiv e in te r p r e te r s , th e lin k e d lis t d a ta ty p e ,
a u to m a tic s to r a g e m a n a g e m e n t, s o m e c o n c e p ts o f o b je c t- o r ie n te d p r o g r a m m in g ,
in te g r a te d p r o g r a m d e v e lo p m e n t e n v ir o n m e n ts , a n d g r a p h ic a l u s e r in te r f a c e s .
W h a te v e r e ls e it a c h ie v e d , th e J a p a n e s e I n itia tiv e p r o v o k e d a c h a in o f in c r e a s e d
g o v e r n m e n ta l f u n d in g f o r I n f o r m a tio n T e c h n o lo g y r e a c tio n a r o u n d th e w o r ld f r o m
w h ic h m a n y , in c lu d in g th e a u th o r s , b e n e f ite d .
A c c o r d in g to J e n n in g s e t a l. [ 1 9 9 8 ] , th e f a s h io n f o r a g e n ts “ d id n o t e m e r g e f r o m a
v a c u u m ” ( w h o w o u ld h a v e im a g in e d it w o u ld ? ) C o m p u te r s c ie n tis ts o f d if f e r e n t
s p e c ia liz a tio n s a r tif ic ia l in te llig e n c e , c o n c u r r e n t o b je c t- o r ie n te d p r o g r a m m in g
la n g u a g e s , d is tr ib u te d s y s te m s , a n d h u m a n - c o m p u te r in te r a c tio n c o n v e r g e d o n s im ila r
c o n c e p ts o f a g e n t. J e n n in g s e t a l. [ 1 9 9 8 ] s ta te , “ O b je c t- o r ie n te d p r o g r a m m e r s f a il to
s e e a n y th in g n o v e l o r n e w in th e id e a o f a g e n ts ,” y e t th e y f in d s ig n if ic a n t d if f e r e n c e s
b e tw e e n a g e n ts a n d o b je c ts . T h is is b e c a u s e th e ir c o m p a r is o n o n ly c o n s id e r s
( e s s e n tia lly ) s e q u e n tia l o b je c t- o r ie n te d p r o g r a m m in g la n g u a g e s s u c h a s J a v a . H a d
th e y c o n s id e r e d c o n c u r r e n t o b je c t- o r ie n te d p r o g r a m m in g la n g u a g e s th e y w o u ld h a v e
f o u n d f e w e r d if f e r e n c e s .
T h r e e la n g u a g e s h a v e b e e n p r o m o te d f o r a g e n t d e v e lo p m e n t: J a v a , T e le s c r ip t, a n d
A g e n t- T C L . N o n e o f th e s e a r e c o n c u r r e n t o b je c t- o r ie n te d la n g u a g e s . J a v a , f r o m
S U N M ic r o s y s te m s , is a d v o c a te d f o r a g e n t d e v e lo p m e n t b e c a u s e it is p la tf o r m
in d e p e n d e n t a n d in te g r a te s w e ll w ith th e W o r ld W id e W e b . J a v a d o e s , h o w e v e r ,
f o llo w th e tr a d itio n o f in te r p r e te d , A I la n g u a g e s b u t is it n o t s y m p a th e tic to s y m b o lic
p r o g r a m m in g . T e le s c r ip t, f r o m G e n e r a l M a g ic , w a s th e f ir s t c o m m e r c ia l p la tf o r m
V III P re fa c e
d e s ig n e d f o r th e d e v e lo p m e n t o f m o b ile a g e n ts . T h e e m p h a s is is o n m o b ility r a th e r
th a n A I a p p lic a tio n s . A g e n t- T C L [ G r a y e t a l., 1 9 9 6 ] is a n e x te n s io n o f T C L ( T o o l
C o m m a n d L a n g u a g e ) w h ic h a llo w s m o b ile c o d e . W h ile s tr in g b a s e d , T C L d o e s n o t
h a v e a tr a d itio n o f A I a p p lic a tio n s . P r o g r a m s a r e n o t in d u c tiv e ly d e f in e d , a s is th e
c a s e w ith L is p o r P r o lo g .
T h is m o n o g r a p h d e s c r ib e s a c o n c u r r e n t, o b je c t- o r ie n te d , a g e n t p r o g r a m m in g
la n g u a g e th a t is d e r iv e d f r o m th e A I tr a d itio n . A w o r k in g k n o w le d g e o f P r o lo g is
n e c e s s a r y to f u lly a p p r e c ia te th e a r g u m e n ts . T h e m o n o g r a p h is d iv id e d in to tw o p a r ts .
T h e f ir s t p a r t, C h a p s . 1 – 5 , d e s c r ib e s th e e v o lu tio n o f th e p a r a d ig m o f G u a r d e d
D e f in ite C la u s e s ( G D C ) . I f th e p a r a d ig m is s e r io u s , a n d m o r e th a n a f a s h io n , th e n it is
n e c e s s a r y to to d e s c r ib e its a p p lic a tio n s . T h is is d o n e in th e s e c o n d p a r t o f th e
m o n o g r a p h , C h a p s . 6 – 1 0 . T o s e t th e p a r a d ig m in c o n te x t, C h a p . 1 p r o v id e s a n
ir r e v e r e n t s u r v e y o f th e is s u e s o f A I . C h a p . 2 c o m p le te s th e b a c k g r o u n d to th e
p a r a d ig m w ith a r e tr o s p e c tiv e r a tio n a le f o r th e J a p a n e s e F if th G e n e r a tio n I n itia tiv e .
C h a p . 3 d e s c r ib e s h o w th e p a r a d ig m e v o lv e d f r o m P r o lo g w ith th e e n v ir o n m e n t
c h a n g e o f m u ltip r o c e s s o r m a c h in e s . I n c lu d e d in th is c h a p te r is a c h r o n o lo g y o f th e
s ig n if ic a n t d e v e lo p m e n ts o f G D C . C h a p . 4 e x p lo r e s th e m a n if e s ta tio n s o f th e v ita l
in g r e d ie n t o f th e p a r a d ig m - e v e n t d r iv e n s y n c h r o n iz a tio n . C h a p . 5 c o m p a r e s a n d
c o n tr a s ts th e la n g u a g e e v o lv e d w ith a c to r la n g u a g e s . T h e m a in d if f e r e n c e is th a t
G D C is a n a c to r la n g u a g e w ith th e a d d itio n o f in d u c tiv e ly d e f in e d m e s s a g e s .
T h e s e c o n d p a r t o f th e b o o k b e g in s w ith C h a p . 6 , w h ic h illu s tr a te s th e a d v a n ta g e s o f
G D C in p a r a lle l a n d d is tr ib u te d s e a r c h . C h a p . 7 d e s c r ib e s th e s p e c ia liz a tio n to
d is tr ib u te d c o n s tr a in t s o lv in g . C h a p . 8 g e n e r a liz e s th e c h a p te r s o n s e a r c h to m e ta -
in te r p r e ta tio n . A n a f f in ity f o r m e ta - in te r p r e ta tio n h a s lo n g b e e n a d is tin g u is h in g
f e a tu r e o f A I la n g u a g e s . C h a p . 9 d e s c r ib e s h o w th e o v e r h e a d o f m e ta - in te r p r e ta tio n
c a n b e a s s u a g e d w ith p a r tia l e v a lu a tio n . C h a p . 1 0 c o n c lu d e s w ith th e a p p lic a tio n o f
G D C to r o b o tic s a n d m u lti- a g e n t s y s te m s .
W h ile G D C a s s u c h is n o t im p le m e n te d , it d if f e r s o n ly m a r g in a lly f r o m K L 1 C , a
la n g u a g e d e v e lo p e d b y th e J a p a n e s e F if th G e n e r a tio n C o m p u te r S y s te m s I n itia tiv e .
T h e I n s titu te f o r N e w G e n e r a tio n C o m p u te r T e c h n o lo g y ( I C O T ) p r o m o te d th e F if th
G e n e r a tio n C o m p u te r S y s te m s p r o je c t u n d e r th e c o m m itm e n t o f th e J a p a n e s e
M in is tr y o f I n te r n a tio n a l T r a d e a n d I n d u s tr y ( M I T I ) . S in c e A p r il 1 9 9 3 , I C O T h a s
b e e n p r o m o tin g th e f o llo w - o n p r o je c t, I C O T F r e e S o f tw a r e ( I F S ) , to d is s e m in a te th e
r e s e a r c h :
A c c o r d in g to th e a im s o f th e P r o je c t, I C O T h a s m a d e th is s o ftw a r e ,
th e c o p y r ig h t o f w h ic h d o e s n o t b e lo n g to th e g o v e r n m e n t b u t to
I C O T its e lf, a v a ila b le to th e p u b lic in o r d e r to c o n tr ib u te to th e
w o r ld , a n d , m o r e o v e r , h a s r e m o v e d a ll r e s tr ic tio n s o n its u s a g e th a t
m a y h a v e im p e d e d fu r th e r r e s e a r c h a n d d e v e lo p m e n t in o r d e r th a t
la r g e n u m b e r s o f r e s e a r c h e r s c a n u s e it fr e e ly to b e g in a n e w e r a o f
c o m p u te r s c ie n c e .
A I T E C , th e J a p a n e s e R e s e a r c h I n s titu te f o r A d v a n c e d I n f o r m a tio n T e c h n o lo g y , to o k
o v e r th e d u tie s o f I C O T in 1 9 9 5 . T h e s o u r c e s o f K L 1 a n d a n u m b e r o f a p p lic a tio n s
c a n b e o b ta in e d v ia th e A I T E C h o m e p a g e : h ttp ://w w w .ic o t.o r .jp /A I T E C . K L 1 C r u n s
P re fa c e IX
u n d e r L in u x a n d a ll th e G D C p r o g r a m s in th is m o n o g r a p h w ill r u n w ith little o r n o
m o d if ic a tio n .
D e s p ite th e ir b e s t e f f o r ts , th e r e a d e r w ill f in d th a t th e a u th o r s ’ c y n ic is m s h o w s
th r o u g h s in c e th e y , lik e B e r n a r d S h a w , b e lie v e th a t a ll p r o g r e s s in s c ie n tif ic e n d e a v o r
d e p e n d s o n u n r e a s o n a b le b e h a v io r . I n S h a w ’ s v ie w th e c o m m o n p e r c e p tio n o f
s c ie n c e a s a r a tio n a l a c tiv ity , in w h ic h o n e c o n f r o n ts e v id e n c e o f f a c t w ith a n o p e n
m in d , is a p o s t- r a tio n a liz a tio n . F a c ts a s s u m e s ig n if ic a n c e o n ly w ith in a p r e - e x is tin g
in te lle c tu a l s tr u c tu r e th a t m a y b e b a s e d a s m u c h o n in tu itio n a n d p r e ju d ic e a s o n
r e a s o n . H u m ility a n d r e tic e n c e a r e s e ld o m m u c h in e v id e n c e a n d th e s c ie n tif ic h e r o e s
o f te n tu r n o u t to b e in te lle c tu a l b u llie s w ith e g o s lik e c a r b u n c le s .
T h e a u th o r s a r e v e r y g r a te f u l to J e a n M a r ie W ille r s a n d P e te r L a n d in f o r th e o n e r o u s
ta s k o f p r o o f r e a d in g e a r lie r d r a f ts o f th is m o n o g r a p h . T h a n k s a r e a ls o d u e to o u r
e d ito r s a t S p r in g e r - V e r la g , I n g r id B e y e r , A lf r e d H o f m a n n , a n d A n d r e w R o s s . E a c h
a u th o r w o u ld lik e to s a y th a t a n y s e r io u s o m is s io n s o r m is c o n c e p tio n s th a t r e m a in a r e
e n tir e ly th e f a u lt o f th e o th e r a u th o r .
J a n u a r y 1 9 9 9 M a tth e w M H u n tb a c h
G r a e m A R in g w o o d