Additional comments on a problem in concurrent programming
control
Citation for published version (APA):
Bruijn, de, N. G. (1967). Additional comments on a problem in concurrent programming control. Communications
of the ACM, 10(3), 137-138. https://doi.org/10.1145/363162.363167
DOI:
10.1145/363162.363167
Document status and date:
Published: 01/01/1967
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F o r m a t E f f e c t o r s i n I S O 7 a n d A S C I I EDITOR:
B a c k s p a c e is awkward to deal with. B u t c o m p o u n d c h a r a c t e r s do n o t necessarily require backspacing. One way is to define cer- t a i n graphics as n o n s p a e i n g [see B a r r o n , D. W. Comput. J. 7
(1965), 281]. A n o t h e r way is to h a v e a f o r m a t effector w h i c h in- h i b i t s the spacing forward w h e n the following graphic is p r i n t e d . T h u s to u n d e r l i n e a n x one has nospaee, x, underline. T h i s is nmre general t h a n h a v i n g speeiM n o n s p a e i n g graphics, a n d requires no more c h a r a c t e r s t h a n using backspace.
3"he a d v a n t a g e s of using nospaee i n s t e a d of backspace are: 1. I t gives prior w a r n i n g of a compound symbol.
2. I t avoids the necessity for line r e c o n s t r u c t i o n .
3. I t e n t a i l s less n m v e m e n t on p r i n t e r s , a n d c o n s e q u e n t l y is p r o b a b l y m e c h a n i c a l l y simpler.
I s u b m i t therefore t h a t in ISO7 and in any revision of A S C I I , a place be found for the f o r m a t effector "nospaee."
I would p o i n t out t h a t c h a r a c t e r - b y - c h a r a c t e r p r i n t e r s Mmost i n e v i t a b l y h a v e a nospaee m e c h a n i s m , w h i c h is a u t o m a t i c a l l y en- gaged w h e n t h e p r i n t i n g h e a d reaches t h e r i g h t - h a n d margin. M y proposal a m o u n t s to h a v i n g a control c h a r a c t e r w h i c h a c t i v a t e s this m e c h a n i s m . As a n a l t e r n a t i v e to h a v i n g a single " n o s p a c e " effective for j u s t the next graphic, there could be two format, ef- fectors: " s t o p - s p a c i n g " and " s t a r t - s p a c i n g . " Use of these m i g h t be m e c h a n i c a l l y easier, and more c o m p a c t for o v e r p r i n t e d se- quences of four or nmre graphics, b u t i t is less s u i t e d for the m o s t c o m m o n ease of two o v e r p r i n t e d graphics.
M y basic p o i n t is t h a t if ISO7 c o n t a i n s "backspace" only, t h e n the o p p o r t u n i t y is lost for o v e r p r i n t i n g graphics on devices w h i c h do not h a v e back-space m e c h a n i s m s , b u t do h a v e no-space m e c h a - nisms.
1. C. PYLE
Atomic Energy Research Establishment Harwell, Dideot, Berks., England
" P f i n i n i - B a c k u s F o r m " S u g g e s t e d EDITOR :
K n u t h , in a r e c e n t L e t t e r to the E d i t o r of C A C M [1], m a k e s t h e p o i n t t h a t t h e m e t a s y n t a c t i c n o t a t i o n used in, e.g., the ALGOi~ 60 r e p o r t [2] s h o u l d be renamed. I n p a r t i c u l a r , he observes the well- acceded fact t h a t the so-cMled B a c k u s N o r m a l F o r m is, indeed, n o t a n o r m a l form in a n y sense. T h e purpose of t h i s l e t t e r is to observe t h a t B a c k u s was n o t the first to use the f o r m w i t h which his n a m e has become associated, a l t h o u g h he did, indeed, discover i t i n d e p e n d e n t l y .
Dr. A l e x a n d e r Wilhelmy has called to m y a t t e n t i o n [3] a work b y PSn. ini [4]. PK.nini was a scholar who flourished b e t w e e n 400 B.C. and 200 B.C. ; p e r h a p s his m o s t significant work was the com- p i l a t i o n of a g r a m m a r of S a n s k r i t . I n order to describe the ( r a t h e r complicated) rules of g r a m m a r , he i n v e n t e d a n o t a t i o n w h i c h is e q u i v a l e n t in its power to t h a t of Backus, a n d has m a n y s i m i l a r p r o p e r t i e s : given the use to w h i c h the n o t a t i o n was p u t , i t is pos- sible to i d e n t i f y s t r u c t u r e s e q u i v M e n t to the B a c k u s " [ " and to
the use of the m e t a - b r a c k e t s " < " and ">" enclosing s u g g e s t i v e names. P ~ n i n i avoided the necessity for the c h a r a c t e r " : : = " b y w r i t i n g the r e c t a - r e s u l t on t h e r i g h t r a t h e r t h a n the l e f t (see, e.g., [5] and [6] for a s i m i l a r n o t a t i o n ) .
Since it is t r a d i t i o n a l in professional circles to give c r e d i t where credit is due, and since t h e r e is clear evidence t h a t PKnini was the earlier i n d e p e n d e n t i n v e n t o r of the n o t a t i o n , m a y I sug- gest the n a m e "P~xfini-Baekus F o r m " as b e i n g a more desirable one? N o t only does i t give due credit, b u t i t also avoids the misuse of the word " N o r m a l . "
REFERENCES :
1. KNUTIt, ])ONALD E. B a c k u s n o r m a l form vs. B a c k u s N a u r form. Comm. ACM 7, 12 (Dee. 1964), 735-736.
2. NAUR, P. [ED.]. Revised r e p o r t on the a l g o r i t h m i c l a n g u a g e A L G O L 60. Comm. ACM 6, 1 (Jan. 1963), 1-17.
3. WILHELMY, A. P r i v a t e e o m m u u i c a t i o n d a t e d 5 N o v e m b e r 1966.
4. KXVYA'riRTItA, NXRXYA.NA RS_MA ACXRYA (ED.) P~I)inimuni- p r a n i t a b a~tadhySyisfitrapS~thab vSrtikapS~thasamalafhkrtat ). B o m b a y , I n d i a , 1954 (See also [7], supplied b y D r . D o n a l d K n u t h . ) [K~vya, N . R . A . (ED.) P S . n i n i - - R e a d i n g of R u l e s in E i g h t C h a p t e r s , E m b e l l i s h e d b y His Pupils].
5. IRONS, E. T. M a i n t e n a n c e m a n u a l for P S Y C O - - p a r t one. I n s t i t u t e for Defense Analyses, P r i n c e t o n , N . J .
6. INGERMAN, P. Z. A Syntax-Oriented Translator. Academic Press, New York, 1966.
7. PKNIN[. The AshtddhydyL E d i t e d and t r a n s l a t e d i n t o E n g l i s h b y Srisa C h a n d r a Vasu, Delhi, I n d i a , 1962.
PETER ZILAHY INGERMAN
Manager, Language Systems Standards & Research Radio Corporation of America Cherry Hill, N . J . 08034
A d d i t i o n a l C o m m e n t s o n a P r o b l e m i n C o n c u r r e n t P r o g r a m m i n g C o n t r o l
EDITOR:
I n D. E. K n u t h ' s solution [Comm. ACM 8, 5 (May, 1966), 321- 322, L e t t e r to t h e Editor] of D i j k s t r a ' s p r o b l e m [Comm. ACM 8, 9
(Sept. 1965), 569] i t is n o t quite easy to check t h a t a n y c o m p u t e r waiting for its critical section has to w a i t a t m o s t 2 N-I t u r n s (the word " t u r n " refers to a c o m p u t e r p e r f o r m i n g its critical section). I t occurred to me t h a t b y a small change in his p r o g r a m t h a t n u m - b e r can be reduced to ½N(N-- 1), w i t h t h e e x t r a a d v a n t a g e t h a t for this new p r o g r a m i t is easier to see why and how i t works. T h e change consists of replacing
L3: k := i; critical section ; k := i f i = 1 t h e n N e l s e i - - 1 ; b y L3: critical section; i f control [k] = 0 V k = i t h e n k := i f k = i t h e n N e l s e k-- 1 ; and requiring t h a t the initial value of k is one of t h e n u m b e r s 1, . - . , N, i n s t e a d of O.
W i t h these a l t e r a t i o n s we find:
(i) If a t a c e r t a i n m o m e n t k h a s a v a l u e i, a n d if control [i] ~ O, t h e n k does n o t change its v a l u e before c o m p u t e r i p e r f o r m s its critical section.
(ii) I n a t i m e i n t e r v a l where k is c o n s t a n t , no c o m p u t e r can p a s s its critical section twice. A s s u m i n g c o m p u t e r j passes twice, we h a v e j ~ k a n d control [k] ~ 0 (otherwise k would h a v e c h a n g e d t h e first time) ; c o m p u t e r k does n o t pass its critical s e c t i o n before j does (for otherwise t h e v a l u e of k would change before j gets its second t u r n ) ; hence control [k] ~ 0 all the time b e t w e e n the V o l u m e 10 / N u m b e r 3 / March, 1967 C o m m u n i c a t i o n s o f t h e AClVl 137
two t u r n s of j , a n d this m e a n s t h a t j c a n n o t g e t to L2 a f t e r its first t u r n .
F r o m (i) and (iN), i t follows t h a t if c o m p u t e r i has control [i] ~ 0, t h e n i t has to w a i t at m o s t N ( N - 1 ) turns. T h e actual m a x i m u m i s ½N(N--1), however. T h i s we prove for i = 1. (iii) If j has one of t h e values 2, -. • , N , t h e n the following holds. In a time i n t e r v a l t h r o u g h o u t w h i c h control [1] ~ 0 a n d j > k > 1, c o m p u t e r j can pass its critical section a t m o s t once. F o r , a f t e r its first passage we c a n n o t have k = j , (even if j = N t h e value of k c a n n o t j u m p f r o m 1 to N u n d e r these circumstances) and f r o m t h a t m o m e n t on we h a v e j > k >_ 1, w h i c h implies t h a t j c a n n o t g e t to L2 before control [1] = 0.
F r o m (i), (it), and (iii), i t follows t h a t in a time i n t e r v a l where control [1] ~ 0, c o m p u t e r j can have a t m o s t N - j + 1
t u r n s (2 < j < N ) . Hence c o m p u t e r 1 has to w a i t a t m o s t
~-~2 ( N - j + 1 ) = ½N(N--1) turns. I t is n o t difficult to show t h a t t h i s waiting period can indeed occur.
N. G. DE BRUIJN
Technological University Eindhoven, The Netherlands
Call for I n f o r m a t i o n : L a w a n d D a t a P r o c e s s i n g
EDITOR :
I am w r i t i n g this l e t t e r in the hope t h a t y o u r r e a d e r s will be kind enough to help me help t h e m and the d a t a processing com- m u n i t y .
I a m now engaged in a survey s t u d y and collection of m a t e r i a l in the broad field of law and dat'~ processing. T h e results of the s t u d y and the a c c o m p a n y i n g b i b l i o g r a p h y are expected to have a wide circulation. U n f o r t u n a t e l y , published works in this field are s c a t t e r e d among m a n y journals in different fields and even incomplete bibliographies are difficult to come by. M a n y works a p p e a r to exist in unpublished form and i n f o r m a t i o n a b o u t court decisions and actual experience in this field are n o t readily avail- able.
I would g r e a t l y a p p r e c i a t e hearing f r o m any r e a d e r who has i n f o r m a t i o n a b o u t u n p u b l i s h e d works or p u b l i c a t i o n s n o t widely known, bibliographies in the field, court decisions, personal ex- periences w i t h legal p r o b l e m s concerning d a t a processing, or a n y i n f o r m a t i o n w h i c h m i g h t be useful to t h e s t u d y . A n y assistance will be g r a t e f u l l y acknowledged in t h e s t u d y . I would also like to learn of a n y legal p r o b l e m s in this area w h i c h y o u r readers feel have n o t been t r e a t e d in the available l i t e r a t u r e and which are n e v e r t h e l e s s i m p o r t a n t to t h e m .
If t h e i r firm's lawyers are n o t regular readers of the Communi- cations of the ACM, I hope y o u r readers will bring m y r e q u e s t to t h e i r a t t e n t i o n also.
JOHN F . BANZHAF I I I
Computer Program L, brary 509 Fifth Ave.
New York, N . Y . 10017
A e s o p a n d t h e Referee: A F a b l e
EDITOR:
Once upon a time, a referee received a p a p e r for review. The p a p e r was l a d e n w i t h T h e o r e m s which were p r o v e d b y reference to u n p u b l i s h e d technical r e p o r t s and " t o be p u b l i s h e d " docu- m e n t s . As the referee looked at the piles of u n r e a d journals on his desk, he decided t h a t he did n o t have the time required to d e c i p h e r the T h e o r e m s and he p u t the p a p e r aside. M a n y moons passed and he finally received a p r o d d i n g l e t t e r f r o m t h e editor. The pile of u n r e a d journals was even larger, so he d e v o t e d even less time to the review. W h e n he had found several i n s t a n c e s of poor n o t a - tion or missing references and had suggested m i n o r changes, his
j o b was complete. M a n y moons passed and t h a t p a p e r joined t h e piles of u n r e a d journals across t h e country.
Question: Were t h e T h e o r e m s correct???
Morals: (1) Referees should s p e n d real time, n o t j u s t t u r n - a r o u n d time a t t h e i r jobs. (2) A u t h o r s should include copies of e v e r y cited technical r e p o r t or u n p u b l i s h e d d o c u m e n t w i t h copies of t h e i r papers. R . Y . K A I N University of Minnesota Minneapolis, Minnesota 55455 Character
Or
I
L e f t p a r e n - thesis* ( Plus + G r e a t e r than > Less t h a n < R i g h t p a r e n - thesis* ) N o t Semicolon Quote Equals* = Colon UnderscoreM o r e o n P r o c e s s i n g 6 4 - C h a r a c t e r Cards
EDITOR: This l e t t e r is in reply to R o b e r t F. R o s i n ' s l e t t e r , " B r i d g i n g the E q u i p m e n t G a p for P r o c e s s i n g 64-Character C a r d s " [Comm. ACM 9, 9 (Sept. 1966), 694].The s u g g e s t i o n for o v e r p r i n t i n g two s y m b o l s to s u p p l y e x t r a c h a r a c t e r s especially for P L / I and E B C D I C is i m p r a c t i c a l since only a m i n o r i t y of p o t e n t i a l users have space suppression equip- m e n t on t h e i r p r i n t e r s . T h e r e is, however, a clear need for some scheme for a large n u m b e r of users.
I have m a d e a p r o g r a m available for 1401 (and 360 in 1401 mode) on the I B M P r o g r a m L i b r a r y ( P r o g r a m N u m b e r 01.4.203) called L A T C H (List All T h e C H a r a c t e r s ) w h i c h uses a double line t o p r i n t special c h a r a c t e r s for P L / I and E B C D I C c h a r a c t e r sets.
D e t a i l s of t h e s y m b o l s used are l i s t e d below. T h e y m a y be user-modified.
EBCDIC
Represen- g-Line Repre- Comments
ration sentation
1 / O n e over one 11~ 1 \ N o t e : c o n c a t e n a t i o n 11
/
/ Gives visual impression of l e f t L p a r e n t h e s i s .
P e r i o d over a m p e r s a n d ( " R e - ~z s e m b l e s " principle)
G N o r m a l c o n v e n t i o n (also in T FORTRAN and P L / I 48 charac-
t e r set)
L N o r m a l c o n v e n t i o n (also in T FORTRAN and P L / I 48 c h a r a c t e r
set)
1 One o v e r slash resembles right, / p a r e n t h e s i s
Seven resembles " n o t " symbol ; P e r i o d o v e r s e v e n P e r i o d over c o m m a C o m m a o v e r b l a n k (blank) - - D a s h o v e r d a s h P e r i o d over period " R e s e m b l e s " p r i n c i p l e ; P e r i o d (break) - - - - o v e r d a s h
*Some of these special symbols are available in correct form on some machines. TOM SCrIARF
A / S Datasentralen Boks 3654 Oslo 1, Norway Letters are continued on page 148
LETTERS
cont'd, from p.
138
S h o u l d T h e r e B e a C S U n d e r g r a d u a t e P r o g r a m ? EDITOR :
H a v i n g read the r e p o r t s of the two s y m p o s i a on the i m p a c t of c o m p u t i n g on u n d e r g r a d u a t e m a t h e m a t i c s i n s t r u c t i o n [Comm. ACM 9, 9 (Sept. 1966)], I m u s t c o m m e n t .
I n the r e m a r k s of Professor G i v e n s a n d Professor M u r r a y t h e r e is l i t t l e to w h i c h I t a k e exception. P r o f e s s o r Atchison, however, says, " I t s h o u l d be recognized t h a t t h e r e are still some people who are q u e s t i o n i n g w h e t h e r t h e r e should be a n u n d e r g r a d u a t e pro- g r a m in C o m p u t e r Science."
I a m one of t h e m , a n d in f a c t I w a n t to argue t h a t t h e r e s h o u l d n o t be s u c h a program.
P r o b a b l y e v e r y u n d e r g r a d u a t e n o w a d a y s s h o u l d l e a r n some- t h i n g a b o u t c o m p u t e r s and t h e i r uses, as p a r t of his knowledge of m a n ' s tools; c e r t a i n l y e v e r y o n e who i n t e n d s to go i n t o science s h o u l d l e a r n t h e r u d i m e n t s of n u m e r i c a l a n a l y s i s a n d p r o g r a m m i n g . F u r t h e r m o r e , i t is r i g h t a n d i n e v i t a b l e t h a t t h e existence of com- p u t e r s a n d of c o m p u t e r - o r i e n t e d m e t h o d s s h o u l d influence the c o n t e n t of m a t h e m a t i c s courses. Professor M u r r a y h a s t r e a t e d t h i s m a t t e r q u i t e well.
M y opinion, however, is t h a t the c o m p u t e r professional needs to know, or a t l e a s t to e n c o u n t e r , a l m o s t e v e r y t h i n g t h a t is in t h e m o d e r n u n d e r g r a d u a t e m a t h e m a t i c s curriculum. If he adds to t h i s c u r r i c u l u m (which should, obviously, include a good course in logic) a course or two in physics or electronics, a n d p e r h a p s a look a t some field s u c h as p s y c h o l o g y or economics, i n w h i c h he m a y s o m e d a y h a v e to do c o m p u t i n g , he is n o t going to h a v e m u c h t i m e l e f t over.
I h a v e read the p a p e r w h i c h outlines the C3S p r e l i m i n a r y recom- m e n d a t i o n s . T h i s c u r r i c u l u m c o n t a i n s a g r e a t deal of w o r t h w h i l e m a t e r i a l , b u t m o s t of it belongs a t the g r a d u a t e level, where i t can be done b e t t e r a n y way. I s i m p l y do n o t see t h a t m u c h of i t can be i n c l u d e d in a n u n d e r g r a d u a t e p r o g r a m e x c e p t b y s k i m p i n g on basic science a n d b y excluding f r o m t h e s t u d e n t ' s experience all b u t the m o s t p e r f u n c t o r y c o n t a c t w i t h n o n t e c h n i c a l s u b j e c t s .
P r o f e s s o r M u r r a y p u t s the m a t t e r succinctly, "College a n d u n i v e r s i t y e d u c a t i o n s h o u l d be aimed a t the i n t e l l e c t u a l develop- m e n t of the s t u d e n t . Indeed, i t is because the i m p a c t of c o m p u t e r s is significant for t h e b r o a d d e v e l o p m e n t of the s t u d e n t t h a t changes are r e q u i r e d . "
We h a v e h e a r d a good deal of m u t t e r i n g a b o u t the social re- s p o n s i b i l i t i e s of the c o m p u t i n g profession. A p a r t of t h i s responsi- bility, I feel, is to a b s t a i n f r o m p r e s s u r i n g t h e colleges a n d uni- v e r s i t i e s i n t o answering t h e supposed needs of i n d u s t r y b y g r i n d i n g o u t narrow, s e m i - l i t e r a t e t e c h n i c i a n s .
T h e would-be c o m p u t e r s c i e n t i s t c a n l e a r n a b o u t s y n t a x - d i r e c t e d compilers on t h e j o b or in g r a d u a t e school. I n college, Birkhoff a n d M a e L a n e , A r i s t o t l e , a n d T. S. E l i o t will do h i m more good.
L . FULKERSON
I B M Watson Research Center Yorktown Heights, N. Y. 10598 A R e p l y to Fulkerson's C o m m e n t s
EDITOR:
I would like to offer a few c o m m e n t s c o n c e r n i n g Mr. F u l k e r - s o n ' s L e t t e r on a n u n d e r g r a d u a t e c u r r i c u l u m in c o m p u t e r science. F i r s t , l e t me s a y t h a t all of the p o i n t s m a d e b y M r . F u l k e r s o n are v e r y f a m i l i a r to all of us on t h e C u r r i c u l u m C o m m i t t e e , in f a c t some m e m b e r s m a y e v e n agree w i t h him. T h e f a c t s are, how- ever, t h a t n u m e r o u s u n d e r g r a d u a t e p r o g r a m s are b e i n g e s t a b - lished a n d t h e C u r r i c u l u m C o m m i t t e e feels a n o b l i g a t i o n to p r o p a - gate t h e b e s t ideas possible for s u c h programs. We h a v e stressed, a n d will c o n t i n u e to stress, t h a t s u c h p r o g r a m s m a y n o t be ap- p r o p r i a t e a t all schools a n d t h a t t h e y s h o u l d emphasize t h e e d u c a - t i o n a l r a t h e r t h a n t h e t r a i n i n g philosophy. P e r h a p s the b e s t an-
swer as to w h e t h e r or n o t there s h o u l d be a n u n d e r g r a d u a t e p r o g r a m in c o m p u t e r science will be revealed a f t e r the passage of a few more years. C e r t a i n l y t h i s is the a p p r o a c h we h a v e a- d o p t e d here a t the U n i v e r s i t y of M a r y l a n d . We are first s e t t i n g u p our M a s t e r s Degree program, w i t h the i n t e n t of d e v e l o p i n g a D o c t o r a l p r o g r a m next. A f t e r these h a v e b e e n established, we can consider t h e question of a n u n d e r g r a d u a t e program. T h i s is t h e a p p r o a c h b e i n g t a k e n b y m a n y schools.
Now I will t r y to c o m m e n t explicitly on some of Mr. F u l k e r - s o n ' s points. I c e r t a i n l y agree w i t h h i m t h a t e v e r y u n d e r g r a d u a t e s h o u l d l e a r n s o m e t h i n g a b o u t c o m p u t e r science. Our C u r r i c u l u m C o m m i t t e e i n c o n j u n c t i o n w i t h t h e E d u c a t i o n C o m m i t t e e is now considering a lower level c o m p u t e r course for all college s t u d e n t s , b u t i t is n o t in our c u r r e n t suggested curriculum, a n d p r o b a b l y will n o t get i n t o our n e x t p u b l i c a t i o n .
I do n o t concur w i t h Mr. F u l k e r s o n ' s opinion t h a t i t is neces- s a r y for a c o m p u t e r professional to know or a t l e a s t e n c o u n t e r a l m o s t e v e r y t h i n g in the m o d e r n u n d e r g r a d u a t e m a t h e m a t i c s curriculum. A l t h o u g h t h e r e is m u c h t h a t is m a t h e m a t i c a l , in- cluded in or necessary for c o m p u t e r science, we h a v e h a d consider- able t e s t i m o n y , i n c l u d i n g t h a t of m a n y well qualified m a t h e m a - ticians, to the effect t h a t m u c h of c o m p u t e r science depends v e r y l i t t l e on t h e m a t h e m a t i c s p r e s e n t l y b e i n g t a u g h t in our u n i v e r s i - ties. On t h e o t h e r h a n d , a g r e a t m a n y m a t h e m a t i c a l concepts are needed w h i c h are seldom f o u n d in m a t h e m a t i c s programs. I t is m y opinion t h a t a p o t e n t i a l c o m p u t e r science maj or, d e p e n d i n g on w h a t he is going to do, s h o u l d get one or more courses in m a t h e - m a t i c s b e y o n d the calculus, b u t I a m sure you know t h a t m a n y people t h i n k t h a t e v e n this m u c h is n o t needed. I regard this as s o m e t h i n g of a n average a n s w e r to the a m o u n t of m a t h e m a t i c s needed for a n u n d e r g r a d u a t e m a j o r in c o m p u t e r science. Our C u r r i c u l u m C o m m i t t e e has discussed t h i s p o i n t a t some l e n g t h , a n d we feel t h a t i t is e n t i r e l y possible for the u n d e r g r a d u a t e to take t h i s m u c h m a t h e m a t i c s , a sufficient a m o u n t of c o m p u t e r science, a n d considerable a d d i t i o n a l m a t e r i a l , M1 w i t h i n the nor- mM B a c h e l o r of Science degree r e q u i r e m e n t s .
R e l a t i v e to Mr. F u l k e r s o n ' s r e m a r k t h a t m o s t of the c u r r i c u l u m m a t e r i a l belongs a t the g r a d u a t e level, I s u s p e c t t h a t too m u c h u n d e r g r a d u a t e level m a t e r i a l in c o m p u t e r science is a l r e a d y b e i n g offered a t t h e g r a d u a t e level. M o s t of the m a t e r i a l we propose is indeed Mready b e i n g t a u g h t successfully a t t h e u n d e r g r a d u a t e level. A more a d e q u a t e u n d e r g r a d u a t e e d u c a t i o n in c o m p u t e r s c i e n c e - - e v e n a good m i n o r - - w o u l d m a k e b e t t e r g r a d u a t e pro- g r a m s possible. I t is m y opinion t h a t t h e c o m p u t e r science m a t e - rim is in t h e process of d r i f t i n g f r o m t h e h i g h e r e d u c a t i o n M levels to t h e lower ones as is typicM in all areas.
I h a v e s p e n t a considerable a m o u n t of t i m e t h i n k i n g a b o u t the i n t e l l e c t u a l d e v e l o p m e n t of a possible u n d e r g r a d u a t e s t u d e n t in c o m p u t e r science. I would agree t h a t his i n t e l l e c t u a l d e v e l o p m e n t is e x t r e m e l y i m p o r t a n t , b u t i t seems to me t h a t i t is e n t i r e l y pos- sible t h a t a n u n d e r g r a d u a t e s t u d e n t m a y e v e n be b e t t e r p r e p a r e d i n t e l l e c t u a l l y b y t a k i n g a good u n d e r g r a d u a t e m a j o r in c o m p u t e r science t h a n b y t a k i n g a n u n d e r g r a d u a t e m a j o r in a more t r a d i - t i o n a l science or e n g i n e e r i n g s u b j e c t . I t is conceivable to me t h a t a good u n d e r g r a d u a t e p r o g r a m in c o m p u t e r science m a y do a b e t t e r job t h a n a t r a d i t i o n a l m a j o r in i m p a r t i n g to the s t u d e n t wisdom, knowledge, a n d t h e a b i l i t y to organize his t h o u g h t s a n d facts for f u t u r e a p p l i c a t i o n to t h i s real a n d s o m e w h a t d i s o r g a n - ized world. I t is m y c o n j e c t u r e t h a t the newer d e v e l o p m e n t s in t h e c o m p u t e r a n d i n f o r m a t i o n sciences m a y well yield v e r y significant new a p p r o a c h e s to the i n t e l l e c t u a l r e a l m s of knowledge. S u c h a b r o a d a p p r o a c h , if we c a n indeed achieve this in c o m p u t e r science, and I t h i n k we can, will n o t yield a s e m i - l i t e r a t e t e c h n i c i a n , b u t a n e d u c a t e d i n t e l l e c t u a l .
WILLIAM F . ATCHISON
Computer Science Department Universily of Maryland College Park, Md. 20740
