Chapter I

Introduction

c_

CHAPTER I: INTRODUCTION

A. Artificial Intelligence / 3B. The AI Handbook / 12C. The AI Literature / 14

Chapter II

Search

CHAPTER II: SEARCH

A. Overview / 21B. Problem Representation / 32

1. State-space Representation / 322. Problem-reduction Representation / 363. Game Trees / 43

C. Search Methods / 461. Blind State-space Search / 462. Blind AND/OR Graph Search / 543. Heuristic State-space Search / 58

a. Basic Concepts in Heuristic Search / 58b. A*—Optimal Search for an Optimal Solution /c. Relaxing the Optimality Requirement / 67d. Bidirectional Search / 72

64

4. Heuristic Search of an AND/OR Graph / 745. Game Tree Search / 84

a. Minimax Procedure / 84b. Alpha-Beta Pruning / 88c. Heuristics in Game Tree Search / 94

D. Sample Search Programs / 1091. Logic Theorist / 1092. General Problem Solver / 1133. Gelernter's Geometry Theorem-proving Machine /4. Symbolic Integration Programs / 1235. STRIPS / 1286. ABSTRIPS / 135

119

Chapter 111

Representation of Knowledge

CHAPTER III: REPRESENTATION OF KNOWLEDGE

A. Overview / 143B. Survey of Representation Techniques / 153C. Representation Schemes / 160

1. Logic / 1602. Procedural Representations / 1723. Semantic Networks / 1804- Production Systems / 1905. Direct (Analogical) Representations / 2006. Semantic Primitives / 2077. Frames and Scripts / 216

Chapter IV

Understanding Natural Language

CHAPTER IV: UNDERSTANDING NATURAL LANGUAGE

A. Overview / 225B. Machine Translation / 233C. Grammars / 239

1. Formal Grammars / 2392. Transformational Grammars / 2453. Systemic Grammar / 2494. Case Grammars / 252

D. Parsing / 2561. Overview of Parsing Techniques / 2562. Augmented Transition Networks / 2633. The General Syntactic Processor / 268

E. Text Generation / 273F. Natural Language Processing Systems / 281

1. Early Natural Language Systems / 2812. Wilks 's Machine Translation System / 2883. LUNAR / 2924. SHRDLU / 2955. MARGIE / 3006. SAM and PAM / 3067. LIFER / 316

Chapter V

Understanding Spoken Language

CHAPTER V: UNDERSTANDING SPOKEN LANGUAGE

A. Overview / 325B. Systems Architecture / 332C. The ARPA SUR Projects / 343

1. HEARSAY / 3432. HARPY / 3493. HWIM / 3534. The SRI/SDC Speech Systems / 358

Bibliography

Indexes

PREFACE

Artificial Intelligence is of growing interdisciplinary interest andpractical importance. People with widely varying backgrounds and pro-fessions are discovering new ideas and new tools in this young science.Theory-minded psychologists have developed new models of the mindbased on the fundamental concepts of Al—symbol systems and infor-mation processing. Linguists are also interested in these basic notions,as well as in AI work in computational linguistics, aimed at producingprograms that actually understand language. And philosophers, inconsidering the progress, problems, and potential of this work towardnonhuman intelligence, have sometimes found new perspectives on theage-old problems of the nature of mind and knowledge.

In other spheres of activity, people often first come across AI in theform of some "expert" system that is being applied experimentally intheir own area—chemical data interpretation, symbolic integration,infectious disease diagnosis, DNA sequencing, computer systems debug-ging, structural engineering, computer-chip design, and so on. As thecost of computation continues to fall, many new computer applicationsbecome viable. Since, for many of these, there are no mathematical"cores" to structure the calculational use of the computer, such areaswill inevitably be served by symbolic models and symbolic inferencetechniques. Yet those who understand symbolic computation have beenspeaking largely to themselves for the first 25 years of Al's history. Wefeel that it is urgent for AI to "go public" in the manner intended bythis three-volume Handbook of Artificial Intelligence.

Prefacexii

Since the Handbook project began in 1975, dozens of researchershave labored to produce short, jargon-free explanations of AI pro-gramming techniques and concepts. With these volumes, we have triedto build bridges to be crossed by engineers, by professionals andscientists in other fields, and by our own colleagues in computer science.We have tried to cover the breadth and depth of AI, presenting generaloverviews of the scientific issues, as well as detailed discussions ofparticular techniques and exemplary computer systems. And, mostimportant, we have presented the key concepts—search, divide-and-conquer, semantic nets, means-ends analysis, hierarchical planning, ATNs,procedural knowledge, blackboard architecture, scripts and frames, goal-directed and data-driven processing, learning, and many more—in thecontext of their actual application in AI. If they were presented moreabstractly, the unique perspective afforded by AI research on theseuniversal ideas would be lost. Throughout, we have tried to keep inmind the reader who is not a specialist in AI.

In short, we have tried to present a survey of AI research that ismotivated historically and scientifically, without attempting to present anew synthesis of this young, multifaceted, rapidly changing field. Onecan view these Handbook volumes as an encyclopedia of AI programmingtechniques, their successful applications, some of their limitations, andthe computational concepts that have been used to describe them.Readers from different fields will interpret these data in different-ways—yfe hope that many of you will find useful new ideas and newperspectives.

The Handbook contains several different kinds of articles. Key AIconcepts and techniques are described in core articles (e.g., heuristicsearch, semantic nets). Important individual AI programs (e.g., SHRDLU,MACSYMA, PROSPECTOR) are presented in separate articles that indi-cate, among other things, the designer's goals, the techniques employed,and the reasons why the program is important. The problems andapproaches in each major area are discussed in overview articles, whichshould be particularly useful to those who seek a summary of theunderlying issues that motivate AI research.

We intend that the Handbook of Artificial Intelligence be a livingand changing reference work. In particular, we hope that our colleagueswill take time to alert us to errors we have made, of omission orcommission, and that we have an opportunity to correct these in futureeditions.

Preface xin

Acknowledgments

Many people have contributed to the Handbook project. On pagesix-x is an alphabetical list of those who have been involved so far,including article contributors, reviewers, and the chapter editors whohave spent months working the individual chapters into coherent pre-sentations of a particular AI subarea. The following is as accurate areconstruction as possible of the contributions to this first volume overthe last five years.

The "Search" chapter was written by Anne Gardner, starting fromsome articles prepared for a problem seminar in the spring of 1975.Background material was made available by Nils Nilsson, who also readearlier drafts, as did Bruce Buchanan, Lewis Creary, James Davidson,Ira Pohl, Reid Smith, Mark Stefik, and David Wilkins.

"Representation of Knowledge" was edited by Avron Barr and JamesDavidson. The article on logic was written by Robert Filman, semanticnets by Douglas Appelt, semantic primitives by Anne Gardner, andframes by James Bennett. Mark Stefik carefully reviewed an early draftof this chapter.

Anne Gardner, James Davidson, and Avron Barr edited "Under-standing Natural Language." Articles were worked on by Janice Aikins,Rodney Brooks, William Clancey, Paul Cohen, Gerard Dechen, RichardGabriel, Norman Haas, Douglas Hofstadter, Andrew Silverman, PhillipSmith, Reid Smith, William van Melle, and David Wilkins. Neil Gold-man reviewed an early draft of the chapter. Terry Winograd madebackground material available and also reviewed an early draft.

"Understanding Spoken Language" was prepared by Lawrence Fagan,Paul Cohen, and Avron Barr, with helpful comments from James Ben-nett, Lee Erman, and Donald Walker.

The professional editor responsible for the form of the final copy,including electronic typesetting and page design, was Dianne Kanerva.Earlier in the project's history, professional editing on several chapterswas done by Helen Tognetti. Ellen Smith also assisted in this impor-tant work.

The book was set in Computer Modern fonts (Knuth, 1979) and wasproduced directly on a computer-driven phototypesetting device. Pub-lisher William Kaufmann and his staff have been patient and helpfulthroughout this process.

Prefacexiv

The Advanced Research Projects Agency of the Department of De-fense and the Biotechnology Resources Program of the National Insti-tutes of Health supported the Handbook project as part of their long-standing and continuing efforts to develop and disseminate the scienceand technology of AI. Earlier versions of Handbook material weredistributed as technical reports of the Stanford Computer ScienceDepartment. The electronic text-preparation facilities available to Stan-ford computer scientists on the SAIL, SCORE, and SUMEX computerswere used.

We wish specially to acknowledge Anne Gardner, whose scholarshipduring the early years of the Handbook project was invaluable, andinspirational.

Finally, let us not forget that many of the programs describedherein as landmark events in the history of AI were labored over single-handedly by graduate students trying to implement their thesis ideas.These AI systems have consistently been among the most complex andinnovative computer programs of their day. They stand as a tribute tothe caliber and creativity of those who have been drawn to AI research.

inn ii nim ii in*New Doc *

"

"

"

NAME INDEX

Pages where the work is discussed are italicized.

Abelson, R. P., 15, 149, 212-215, 216,217, 219, 221, 222, 232, 255, 300-302,305, SO6, 308-310, 313-315, 365, 383

Adelson-Velskiy, G. M., 95, 96, 99, 102,103, 104, 108, 365

Aho, A. V., 68, 71, 365Aikins, J. S., 217, 220, 365Akmajian, A., 248, 365, 369Allen, J., 16, 365Amarel, S., 27, 30, 365Anderson, J., 15, 180, 185, 189, 193, 195,

365Appelt, D. E., 232, 280, 365, 381Arbuckle, T., 99, 105, 108, 366Arlaaarov, V. L., 96, 99, 102-104, 108,

365Artsouni, G. 8., 2SSAtkin, L. R., 95, 96, 99, 100, 102, 103,

108, 384

Bahl, L. R., 329, 365Baker, J. K., 329, 849, 365, 366Baker, R., 204, 366Bar-Hillel, Y, 2SS, 286, 238, 366Barnett, J., 327, 333, 358, 366, 379Barrow, H. G., 318, 321, 366Barstow, D. R., 16, 194, 366Bartlett, F. C, 216, 307, 315, 366Baudet, G. M., 91, 93, 366Beasley, C, 195, 365Belsky, M. A., 99, 105, 108, 366Berliner, H. J., 95, 96, 98, 99-100, 102,

108, 104, 106-107, 108, 366Bernstein, A., 99, 105, 108, 366Bernstein, M. 1., 198, 333, 358, 366, 367Bloom, S., 127, 377

Bobrow, D. G., 15, 147, 148, 152, 158,217, 219, 220-221, 222, 281, 232, 267,284, 367

Boden, M., 15, 152, 232, 287, 299, 367Bolles, R. C, 318, 321, 366Booth, A, D., 281, 234, 238, 367, 376Borgida, A., 186, 378Bott, M. F., 226, 367Bower, G., 15, 180, 185, 189, 193, 365Brachman, R. J., 147, 152, 184, 217, 221,

222, 367Bratko, L, 95, 103, 107, 108, 367, 378Bresnan, J., 248, 367Britten, I). H. V., 284Brooks, Ft., 367Brown, J. S., 368Brown, R. H., 16, 387Bruce, 8.,, 254, 255, 367Buchanan, B. G., 16, 151, 195, 369, 376Bullwinkle, C, 221, 367Burger, J, F., 228, 384Burton, R. R., 818, 367, 368

Carbonell, J. R., 186, 368Chafe, W. L., 368Chang, C. L., 80, 81, 83, 368Charness, N., 95, 108, 368Charniak, E., 15, 222, 232, 248, 255, 262,

291, 299, 368, 385Chomsky, C, 282, 372Chomsky, N., 227, 229, 287, 289, 243,

244, 245, 247, 248, 368Clippinger, J. H., Jr., 279, 368Codd, E. F., 292, 369Cohen, P. R., 186, 232, 280, 369, 378Cohen, P. S., 329, 365

Name Index390

"

"

"

Colby, K. M., 15, 257, 369, 383Cole, A. G., 329, 365Cole, R. A., 331, 369Collins, A. M., 15, 147, 152, 186, 232,

367, 368, 372Conway, M. E., 267, 369Crocker, S. D., 95, 100, 101, 104, 108,

372Culicover, P. W., 248, 369

Davies, D. J. M., 176, 369Davis, R., 16, 147, 151, 194, 195, 197,

198, 199, 369de Champeaux, D., 78, 369Deo, N., 64, 66, 381Derkson, J. A., 176, 382Dijkstra, E. W., 64, 66, 369Dixon, J. K., 91, 93, 98, 102, 108, 384Donskoy, M. V., 96, 99, 102-104, 108,

365Doran, J. E., 60, 63, 67, 71, 369, 370Doyle, J., 178, 377Dreyfus, H. L., 370Duda, R. 0., 196, 197, 370

Eastlake, D. E., 95, 100, 101, 104, 108,372

Eastman, C. M., 202, 370Elcock, E. W., 122, 370Engelman, E., 127, 377Erman, L. D., 196, 197, 331, 336, 342,

848, 845, 348, 370, 381Ernst, G., 30, 63, 113, 117, 118, 370, 379

Fahlman, S. E., 204, 222, 370Feigenbaum, E. A., 14, 16, 29, 30, 63,

198, 232, 287, 336, 343, 370, 376, 380Feldman, J., 14, 29, 30, 232, 287, 370Fennell, R. D., 336, 343, 345, 370, 381Fikes, R. E., 42, 128, 134, 169, 176, 188,

370, 381Fillmore, C, 252, 255, 371Filman, R. E., 169, 170, 205, 371Findler, N. V., 16, 152, 189, 371Flanagan, J., 325, 371Flavell, J. H., 145, 147, 371Forgie, J., 327, 379Forgy, C, 197, 371, 377Fox, M., 348, 371Fraser, 8., 267, 367Frege, G., 200Frey, P. W., 95, 102, 104, 108, 371Friedman, J., 268, 278, 371

Fuller, S. H., 91, 93, 371Funt, B. V., 208, 205, 206, 371

Garvey, T. D., 129, 134, 318, 321, 366,372

Gaschnig, J. G., 59, 63, 91, 93, 371, 372Gelernter, H., 119, 122, 201, 372Gelperin, D., 65, 66, 372Gentner, D., 147, 372Gerberich, C. L., 122, 372Gillman, R, 333, 358, 366Gillogly, J. J., 91, 93, 97, 98, 99, 102,

103, 108, 371, 372Gilmore, P. C, 122, 372Goldman, N., 278, 279, 804, 305, 372,

383Goldstein,, I. P., 217, 221, 372Good, I. J., 27, 30, 372Green, B. F., Jr., 282, 372Green, C. C, 155, 168, 170, 327, 372,

379Greenblatt, R. D., 95, 100, 101, 104, 108,

372Griffith, A. K., 97, 108, 372Grishman, R., 262, 372Gross-, B. J., 232, 373, 381

Hall, P. A. V., 64, 66, 373Halliday, M. A. K., 249, 251, 373, 378Hansen, J. R., 122, 372Hanson, A. R., 16, 336, 343, 373Harman, G., 248, 373Harris, L. R., 69, 71, 97, 100, 102, 108,

232, 373Hart, P. E., 64, 66, 134, 169, 196, 197,

370, 373Hawkinson, L. 8., 217, 220, 385Hayes, P. J., 148, 170-171, 172, 175, 177,

179, 186, 200, 201, 373, 374, 377Hayes-Roth, 8., 336, 343, 374Hayes-Roth, F., 16, 199, 331, 336, 343,

845, 348, 370, 374, 385Hays, D. G., 238, 374Hearst, E., 96, 108, 374Hedrick, C, 195, 374Heidorn, G. E., 374Hendrix, G. G., 184, 186, 188, 232, 816,

318, 321, 370, 374, 381Heny, F., 248, 365Herskovits, A., 289, 291, 387Hewitt, C, 172, 1 75, 176, 178, 179, 374Hilf, F., 257, 369Hillier, F„ S., 64, 66, 374

391Name Index

"

"

"

Hofstadter, D., 4, 15, 374Hopcroft, J. E., 68, 71, 241, 244, 365,

374Hudson, R. A., 251, 374

Jackendofr, R., 207, 374, 375Jackson, P. C, 15, 30, 42, 375Jakobovits, L., 248, 384Jelinek, F., 329, 365Johnson-Laird, P. N., 207, 378Josselson, H. H., 238, 375

Kadane, J. 8., 59, 63, 68, 71, 384Kameny, 1., 333, 358, 366Kaplan, R. M., 219, 221, 232, 260, 261,

267, 268, 272, 293, 294, 367, 375, 388Kaplan, S. J., 232, 375Karp, R. M., 69, 71, 375Kata, J., 248, 375Kay, M., 219, 221, 232, 268, 272, 367,

375Kellogg, C, 228, 375King, J. J., 194, 197, 199, 369Kister, J., 99, 103, 108, 375Klatt, D. H., 326, 327, 330, 375, 379Klein, S., 274, 275, 375, 384Kline, P., 195, 365Kling, R., 129, 134, 372Knuth, D. E., xiii, 86, 87, 89, 90, 91, 93,

269, 375Kopec, D., 95, 107, 108, 367Kotok, A., 104, 108, 375Kowalski, R., 25, 30, 73, 74, 81, 83, 175,

375Kremers, J. H., 318, 321, 366Kuipers, 8., 222, 376

Landsbergen, S. P. J., 232, 376Lanta, K, 318, 321, 366Laughery, K, 282, 372Lawler, E. W., 64, 66, 376Lea, W., 16, 232, 325, 326, 329-331, 335,

344, 348, 376Lederberg, J., 16, 376Lehnert, W. C, 16, 212, 376Lenat, D. 8., 16, 194, 195, 196, 197, 369,

376Lesser, V. R., 196, 197, 331, 336, 342,

845, 348, 370, 376Levi, G., 81, 83, 376Levine, M. D., 336, 343, 376Levinson, S., 325, 371Levy, D., 101, 108, 376

Lewis, B. L., 329, 365Licklider, J. C. R., 327, 379Lieberman, G. J., 64, 66, 374Lindsay, R. K., 16, 281, 282, 376Locke, W. N., 238, 376Long, R. E., 228, 384Loveland, D. W., 122, 372Lowerre, 8., 342, 849, 352, 377Lyons, J., 243, 244, 248, 377

Mann, W., 280, 377Manna, Z., 171, 377Manove, M., 127, 377Marcus, M. P., 16, 230, 262, 377Martelli, A., 66, 74, 83, 377Martin, W. A., 217, 220, 385Mathias, J., 238, 374Matuzceck, D., 267, 377McCarthy, J., 148, 170, 177, 201, 377McConlogue, K., 384McCord, M., 251, 377McCorduck, P., 5, 14, 15, 377McDermoM, D. V., 15, 175, 176, 178,

368, 377, 384McDermoM, J., 194, 197, 371, 376, 377McDonald, D., 280, 378Mcintosh, A., 251, 378McKeown, K., 280, 378Mercer, R. L., 329, 365Michie, D., 59, 63, 67, 71, 95, 103,

107-108, 367, 370, 378Miller, G. A., 207, 378Minker, J., 31, 385Minsky, M., 14, 29, 30, 159, 216, 217,

220, 222, 231, 232, 287, 307, 315, 378Mittman, 8., 96, 108, 378Montanari, U., 74, 83, 377Moore, E. F., 64, 66, 378Moore, J.„ 197, 280, 377Moore, R, C, 178-179, 378Moore, R„ W., 86, 87, 89, 90, 91, 93, 375Moses, J., 125, 127, 378Munson, J., 327, 379Myopolous, J., 186, 378

Nash-Webber, B. L., 293, 294, 326, 378,379, 388

Neely, R., 848, 381Newborn, M., 91, 93, 96, 101, 108, 379Newell, A., 4, 14, 29-81, 63, 98, 100,

105, 10S, 108, 109, HI, 112, 118, 117,118, 121, 157, 169, 193, 197, 827, 331,335, 351, 370, 377, 379

Name Index392

"

"

"

Rulifson, J., 176, 382Nievergelt, J., 64, 66, 381

Sacerdoti, E. D., 185, 139, 176, 318, 321,374, 381, 382

Oettinger, A. G., 285, 238, 380

Sagalowici, D., 176, 318, 321, 374, 381Samlowski, W., 255, 382

Paige, J. M., 285, 380Paxton, W. H., 361, 380Perrault, C. R., 232, 369Petrick, S. R., 260, 380Pitrat, J., 107, 108, 380Plath, VV., 380

Samuel, A. L., 27, 31, 45, 95, 97, 102,104, 108, 382

Postal, P., 243-245, 248, 375, 381Prawita, D., 169, 381Propp, V., 307, 315, 381Pylyshyn, Z., 201, 206, 381

Quillian, M. R., 156, 180, 185, 228, 230,275, 276, 381

Rabiner, L., 325, 371Raphael, 8., 15, 27, 31, 64, 66, 17S, 185,

228, 288, 373, 381Reboh, R., 176, 381Reddy, D. R., 327, 331, 336, 342, S4S,

845, 348, 849, 352, 370, 377, 379, 381Reifler, E., 285Reingold, E. M., 64, 66, 381Reiter, R., 176, 381Richens, R. H., 284Rieger, C, SOS, 305, 381, 383Riesbeck, C. K., 15, 196, 261, 262, SOS,

305, 806, 315, 368, 381, 383Riseman, E. M., 16, 336, 343, 373Roberts, M. de V., 99, 105, 108, 366Roberts, R. 8., 217, 221, 372Robinson, A. E., 232, 381Robinson, J. J., 232, 359, 381, 382Rochester, N., 122, 372Rosenberg, A., 325, 371Rosenberg, R. S., 254, 255, 385Ross, R., 59, 63, 378

Schubert, L. K., 383Schwarca, R. M., 384Searle, J. R., 7, 383Self, J., 251, 383Shannon, C. E., 27, 31, 94-99, 108, 108,

383Shaw, J. C, 29, 30, 98, 1 05, 108, 109,

111, 112, US, 118, 379Shortliffe, E. H., 195, 197, 369, 383Shoup, J., 329, 330, 333, 344, 376, 383Siklossy, L., 16, 383Simmons, R. F., 182, 186, 189, 228, 254,

256, 274, 277, 287, 375, 383, 384, 387

Slocum, J., 182, 186, 277, 318, 321, 374,384

Sloman, A., 200, 205, 206, 384Smirnov-Troyansky, P. P., 288Smith, B. C, 152, 367Stefik, M., 184, 217, 221, 384

Nii, H. P., 336, 343, 380 Rumelhart, D. E., 15, 149, 180, 185, 189,Nilsson, N. J., 7, 15, SO, 31, 35, 38, 42, 207, 215, 255, 306, 307, 315, 336, 343,

45, 51, 53, 56, 57, 58, 60, 63, 64, 65, 380, 38266, 71, 75, 78, 83, 87, 93, 102, 108, Russell, 8., 111, 112, 386128, 134, 169, 171, 197, 370, 373, 380 Russell, S. W., 212, 382. See also S.

Norman, D., 15, 149, 180, 185, 189, 207, Weber.215, 219, 221, 232, 255, 367, 380 Rustin, R., 232, 382

Novak, G. S., 221, 380 Rychener, M. D., 193, 195, 196, 382

Pitrat, J., 107, 108, 380 Sandewall, E. J., 63, 382Plath, VV., 380 Scha, R. J. H., 382Pohl, 1., 24, 51, 52, 53, 59, 63, 67, 69, Schank, R. C, 14, 15, 149, 211, 212-215,

71, 72, 73, 380 216, 217, 219, 220, 221, 222, 281, 232,Polya, G., 29, 31, 381 257, 238, 254, 255, 278, 291, 800,Post, E., 190, 381 301-303, 305, 806, 309, 310, 313-315,Postal, P., 243-245, 248, 375, 381 382, 383

Simon, H., 4, 14, 15, 29-80, 31, 59, 63,68, 71, 98, 100, 105, 106, 108, 109,111, 112, US, 118, 121, 149, 157, 169,285, 379, 380, 384

Sint, L., 75, 369Sirovich, F., 81, 83, 376Slagle, J. R., 80, 81, 83, 87, 91, 93, 98,

102, 108, 128, 127, 368, 384Slate, D. J., 95, 96, 99, 100, 102, 103,

108, 384

393Name Index

"

"

"

Walden, W. E., 99, 103, 108, 375, 385Waldinger, R. J., 176, 381, 382Walker, D. E., 186, 361, 385Walta, D. L., 232, 385Wasow, T., 248, 369Waterman, D., 16, 195, 199, 385Weaver, W., 226, 284, SS7, 238, 288, 804,

385Weber, S., 257, 369. See also S. W.

Russell.Weiaenbaum, J., 228, 285, 286, 386Welin, C. W., 255, 386Wells, M., 99, 103, 108, 375Weyhrauch, R. W., 169-171, 371, 386Whitehead, A. N., 111, 112, 386Wilber, M., 176, 381Wilensky, R., 232, SIS, 314, 315, 386Wilkins, D., 95, 107, 108, 386Wilks, Y., 149, 207, 209, 210, 215, 232,

257, 238, 248, 254, 255, 262, 279, 288,289, 291, 299, 368, 386, 387

Winograd, T., 9, 14, 31, 147, 150-152,156, 158, 159, 173, 176, 177, 179, 189,199, 207, 215, 217, 219, 221, 222, 227,2SO-252, 244, 251, 260, 261, 262, 267,276, 287, 291, 295, 296, 298, 299, 819,367, 385, 387

Stein, P., 99, 103, 108, 375Steinberg, S., 248, 384Sugar, L., 186, 378Suppes, P., 171, 384Sussman, G., 175, 176, 299, 384, 385Sutherland, G. L., 197, 370Saolovita, P., 217, 229, 385

Winston, P. H., 15, 16, 87, 90, 93, 199,387

Wolf, H. C, 318, 321, 366Wolf, J., 329, 342, 353, 354, 356, 357,

387Wolf, A. K., 282, 372Wong, H. K., 278, 387Wood, D. E., 64, 66, 376

Taylor, 8., 254, 255, 385Tenenbaum, J. M., 318, 321, 366Thompson, C, 374

Woods, W., 178, 184, 186, 280, 260, 261,268, 266, 267, 292, 293, 294, 327, 329,342, 858, 354, 356, 357, 379, 387, 388

Thompson, F. 8., 228, 385Thompson, H., 219, 221, 232, 367Thorndyke, P. W., 306, 315, 385Thorp, E., 103, 108, 385

Yngve, V., 28S, 278, 275, 388

Turing, A. M., 4, 99, 103, 108, 385

Ulam, S., 99, 103, 108, 375Ullman, J. D., 68, 71, 241, 244, 365, 374

Vanderbrug, G., 31, 385Vere, S., 195, 385Vincens, P., 325, 385