Georgy Maximovich Adelson-Velsky, (Гео́ргий Макси́мович Адельсо́н-Ве́льский, January 8, 1922 - April 26, 2014)
was a Soviet and Israeli mathematician, computer scientist and computer chess pioneer, most famous for inventing the AVL tree along with Evgenii Landis^{[1]}, and as co-author of the ITEP Chess Program and Kaissa. Adelson-Velsky and his fellow Alexander Kronrod were the last students of Nikolai Luzin at Moscow State University, where he graduated in 1949 under Israel Gelfand on Spectral Analysis of Ring of Bounded Linear Operators^{[2]}^{[3]}.

In the 90s, Adelson-Velsky emigrated to Israel and lived in Ashdod^{[4]}, at times affiliated with the Technion, and Mathematics & Computer Science department of Bar-Ilan University^{[5]}. Georgy Adelson-Velsky died on April 26, 2014, aged 92, in Giv'atayim, Israel ^{[6]}^{[7]}.

Only in 1955 did a real opportunity arise for A.S. Kronrod to work with an electronic computer. It was the M2 computer constructed by I.S. Bruk, M.A. Kartsev, and N.Ya. Matyukhin in the laboratory of the Institute of Energy named after Krzhizhanovsky and directed by I.S. Bruk. This laboratory later became the to Institute for Electronic Control Machines. The mathematics/machine interface was developed by A.L. Brudno, a great personal and likeminded friend of A.S. Kronrod.

When he started with enthusiasm to program the M2 machine, A.S. Kronrod quickly came to the conclusion that computing is not the main application of computers. The main goal is to teach the computer to think, i.e., what is now called "artificial intelligence" and in those days "heuristic programming".

A.S. Kronrod captivated a large group of mathematicians and physicists (G.M. Adelson Velsky, A.L. Brudno, M.M. Bongard, E.M. Landis, N.N. Konstantinov, and others). Although some of them had arrived at this kind of problems on their own, they unconditionally accepted his leadership. In the room next to the one housing the M2 machine the work of the new Kronrod seminar started. At the gatherings there were heated discussions on pattern recognition problems (this work was led by M.M. Bongard; versions of his program "Kora" are still functioning), transportation problems (the problem was introduced to the seminar and actively worked on by A.L. Brudno), problems of automata theory, and many other problems.

Intellectual Foundations

Quote from Biography AS Kronrod by Alexander Yershov ^{[17]}

In 1958, Kronrod, Adelson-Velsky, and Landis selected "Snap" ("подкидного дурака") as the intellectual foundations for the development of the game heuristic programming. The program itself was a fiasco - but the basic principles (board games, search techniques and limited depth) were formulated. Further research laboratories in the field of game theory culminated in the first ever chess duel between the program of the Institute of Soviet and American best program developed at Stanford University under the direction of J. McCarthy. By telegraph match was played in four games ended 3-1 in favor of our institute. At the time, chess became a guinea pig for all programmers interested in artificial intelligence.

Anecdote by Yefim Dinitz from his talk at Shimon Even's retiring party, November 2003 ^{[19]}, revised version in Dinitz' Algorithm: The Original Version and Even's Version^{[20]}^{[21]}:

The following anecdote sheds some light on how things were done in the USSR. Shortly after the "iron curtain" fell in 1990, an American and a Russian, who had both worked on the development of weapons, met. The American asked: "When you developed the Bomb, how were you able to perform such an enormous amount of computing with your weak computers?". The Russian responded: "We used better algorithms."

This was really so. Russia had a long tradition of excellence in Mathematics. In addition, the usual Soviet method for attacking hard problems was to combine pressure from the authorities with people's enthusiasm. When Stalin decided to develop the Bomb, many bright mathematicians, e.g. Israel Gelfand and my first Math teacher, Alexander Kronrod, put aside their mathematical studies and delved deeply into the novel area of computing. They have assembled teams of talented people, and succeeded. The teams continued to grow and work on the theory of computing.

The supervisor of my M.Sc. thesis was Georgy Adelson-Velsky, one of the fathers of Computer Science. Among the students in his group were M. Kronrod (one of the future "Four Russians", i.e. the four authors of^{[22]}), A. Karzanov (the future author of the O(n3) network flow algorithm^{[23]}) and other talented school pupils of A. Kronrod. This was in 1968, long after the Bomb project completed. The work on the foundations of the chess program "Kaissa", created by members of A. Kronrod's team under guidance of Adelson-Velsky, was almost finished; "Kaissa" won the first world championship in 1974. Adelson-Velsky's new passion became discrete algorithms, which he felt had a great future.

The fundamental contribution of Adelson-Velsky to Computer Science was AVL-trees. He (AV) and Evgenii Landis (L) published a paper about AVL-trees in early 60's, consisting of just a few pages. Besides solving an important problem, it presented a bright approach to data structure maintenance. While this approach became standard in the USSR, it was still not known in the West. No reaction followed their publication during a couple of years, until another paper, 15 pages long, was published by a researcher, which understood how AVL-trees work and explained this to the Western community, in its language. Since then, AVL-trees and the entire data structure maintenance approach became a corner-stone of Computer Science.

One of my teachers, Georgy Adelson-Velsky, wrote an excellent report, "How did chess programs influence the development of programming". He lectured it in a strange way - at a congress in geophysics. In particular, the famous AVL trees were invented for chess programs at ITEP. I happened to be in Canada with Adelson-Velsky, at the University of Waterloo, where we were invited. There are three Faculties of Computational Mathematics, one way or another related to computer science and programming. One of them is, more or less, department of AVL trees. Can you imagine the scene when Adelson-Velsky himself (AVL stands for Adelson-Velsky and Evgenii Landis - two authors) comes to a department bearing his name, with a head of the department, three full professors, and six assistant professors, a myriad of graduate students and all who study his works. We were seated at a place of honor. Adelson-Velsky did not speak English and I translated. They asked the fundamental question: "How do you feel about the AVL-tree today?". This was 20, maybe 30 years after the invention. Then Adelson-Velsky, a typical scientist, small and hunchbacked with glasses, said with his high voice: "Yes, AVL-trees - this was a mistake of my youth". I replied to him "Georgy Maximovich, should I translate that directly?". His honesty has always distinguished the crystal. He said yes, and I translated. Soon the department head said "You know, our guests are tired from the journey and need to rest". God forbid again Adelson-Velsky says that AVL-trees are nonsense again - their monthly salary exceeds two or three years' of Adelson's income ...

1967 - first international match of chess programs. Competed the program ITEP and the program of Stanford University, made under the management John McCarthy. McCarthy is famous fact that in 1952 on the beach in San Diego together with Alan Turing devised the word combination of "Artificial Intelligence", and fact that he is the author of the language Lisp - the first programming language, specially created for the tasks in the problems of artificial intelligence. Regulations of the match - four games. From the side of Stanford played one and the same version, from the ITEP side - two, which were being distinguished by the depth of search. Moves were transferred by the telegraph once a week (this to those- that times from "yadernogo" institute!). Match continued entire year and ended with the score the 3:1 in favor of ITEP.

1970 - the mechanic mathematical department of MGU finished the entire group of the students of Alexander Kronrod and Georgy Adelson-Velsky, that was being occupied in the famous seminar for discrete algorithms. Sums of the seminar: For Georgy Adelson-Velsky it was forbidden to teach in MGU

Adelson-Velsky, an extremely capable and animated scientist and a real pleasure to meet, generally led our technical discussions. His eyes seemed to glisten with enthusiasm when he spoke. Discussions centered around probabilistic analyses of various aspects of the minimax algorithm and parallel search of chess trees. Our first joint seminar on alpha-beta analysis and the impact of computer technology was attended by about thirty people, including Leonid Kantorovich, winner of the 1975 Nobel Prize in Economics for his work on linear programming.

^Yefim Dinitz (2006). Dinitz' Algorithm: The Original Version and Even's Version. Theoretical Computer Science, Springer, pdf, transliteration of names adapted

Home * People * Georgy Adelson-VelskyGeorgy Maximovich Adelson-Velsky, (Гео́ргий Макси́мович Адельсо́н-Ве́льский, January 8, 1922 - April 26, 2014)was a Soviet and Israeli mathematician, computer scientist and computer chess pioneer, most famous for inventing the AVL tree along with Evgenii Landis

^{[1]}, and as co-author of the ITEP Chess Program and Kaissa. Adelson-Velsky and his fellow Alexander Kronrod were the last students of Nikolai Luzin at Moscow State University, where he graduated in 1949 under Israel Gelfand onSpectral Analysis of Ring of Bounded Linear Operators^{[2]}^{[3]}.In the 90s, Adelson-Velsky emigrated to Israel and lived in Ashdod

^{[4]}, at times affiliated with the Technion, and Mathematics & Computer Science department of Bar-Ilan University^{[5]}. Georgy Adelson-Velsky died on April 26, 2014, aged 92, in Giv'atayim, Israel^{[6]}^{[7]}.^{[8]}## Table of Contents

## Computer Chess

Since the late 50s, at Kronrod's Institute of Theoretical and Experimental Physics, Georgy Adelson-Velsky worked along with Kronrod, Alexander Brudno, Mikhail Bongard, Evgenii Landis, Nikolay Konstantinov, Vladimir Arlazarov et al. on heuristic and game programming, where they elaborated on the foundations of computer chess. Since 1963^{[9]}at ITEP, Georgy Adelson-Velsky co-developed the ITEP Chess Program, along with Vladimir Arlazarov, Anatoly Uskov and Alexander Zhivotovsky, advised by Russian chess master Alexander Bitman and three-time world champion Mikhail Botvinnik^{[10]}.At the end of 1966 a four game match began between the Kotok-McCarthy-Program, running on a IBM 7090 computer, and the ITEP Chess Program on a Soviet M-2

^{[11]}computer. The match played over nine months was won 3-1 by the ITEP program. In 1971, along with Mikhail Donskoy and Vladimir Arlazarov, Georgy Adelson-Velsky became primary author of Kaissa, winner of the first computer chess championship 1974 in Stockholm.## Photos

Soviet-American computer science conference, Urgench, 1979

^{[12]}^{[13]}^{[14]}## Quotes

## Official Information

by Mikhail Donskoy (1999) on Kaissa^{[15]}Georgy Adelson-Velsky - one of the first Soviet programmers (together with Alexander Kronrod, Alexander Brudno, Evgenii Landis and others). He was occupied by the programs, connected with nuclear physics at ITEP, where he devised many algorithms which became classical. Especially the equilibrium binary trees, which in the entire world are called AVL trees after the names of the authors - Adelson-Velsky and Landis. After short-term teaching at MGU he worked at IPU and VNIISI (All-Union Scientific Research Institute of Sanitary Testing) on discrete algorithms, network planning and artificial intelligence. He now lives in Israel and works at Technion on NP problems of complete tasks.## Remembering A.S. Kronrod

Quote fromRemembering A.S. Kronrodby Evgenii Landis and Isaak Yaglom^{[16]}:Only in 1955 did a real opportunity arise for A.S. Kronrod to work with an electronic computer. It was the M2 computer constructed by I.S. Bruk, M.A. Kartsev, and N.Ya. Matyukhin in the laboratory of the Institute of Energy named after Krzhizhanovsky and directed by I.S. Bruk. This laboratory later became the to Institute for Electronic Control Machines. The mathematics/machine interface was developed by A.L. Brudno, a great personal and likeminded friend of A.S. Kronrod.When he started with enthusiasm to program the M2 machine, A.S. Kronrod quickly came to the conclusion that computing is not the main application of computers. The main goal is to teach the computer to think, i.e., what is now called "artificial intelligence" and in those days "heuristic programming".A.S. Kronrod captivated a large group of mathematicians and physicists (G.M. Adelson Velsky, A.L. Brudno, M.M. Bongard, E.M. Landis, N.N. Konstantinov, and others). Although some of them had arrived at this kind of problems on their own, they unconditionally accepted his leadership. In the room next to the one housing the M2 machine the work of the new Kronrod seminar started. At the gatherings there were heated discussions on pattern recognition problems (this work was led by M.M. Bongard; versions of his program "Kora" are still functioning), transportation problems (the problem was introduced to the seminar and actively worked on by A.L. Brudno), problems of automata theory, and many other problems.## Intellectual Foundations

Quote fromBiography AS Kronrodby Alexander Yershov^{[17]}In 1958, Kronrod, Adelson-Velsky, and Landis selected "Snap" ("подкидного дурака") as the intellectual foundations for the development of the game heuristic programming. The program itself was a fiasco - but the basic principles (board games, search techniques and limited depth) were formulated. Further research laboratories in the field of game theory culminated in the first ever chess duel between the program of the Institute of Soviet and American best program developed at Stanford University under the direction of J. McCarthy. By telegraph match was played in four games ended 3-1 in favor of our institute. At the time, chess became a guinea pig for all programmers interested in artificial intelligence.## Hashing

Quote from Mikhail Donskoy'slife cycle of a programmer^{[18]}:When I was in high school I learned to program on the M-20 ... In the group of programmers at Institute of Theoretical and Experimental Physics, where computing work was done on nuclear physics on the M-20, they came up with arrays, lists, the need for subroutines and more. One of my teachers, Georgy Adelson-Velsky came up with a hash memory. Details can be found in another of my teachers - Alexander Kronrod "Conversations about programming". Even before Dijkstra's basic principles of structured programming was known, Alexander Brudno published the book "Programming in meaningful notation." There was also created the first chess program ... The chess program ITEP, the predecessor of Kaissa fit in memory of M-20, namely in 4096 cells, each of which has a 48-bit ...## AVL Trees

## Dinitz

Anecdote by Yefim Dinitz from his talk at Shimon Even's retiring party, November 2003^{[19]}, revised version inDinitz' Algorithm: The Original Version and Even's Version^{[20]}^{[21]}:The following anecdote sheds some light on how things were done in the USSR. Shortly after the "iron curtain" fell in 1990, an American and a Russian, who had both worked on the development of weapons, met. The American asked: "When you developed the Bomb, how were you able to perform such an enormous amount of computing with your weak computers?". The Russian responded: "We used better algorithms."

This was really so. Russia had a long tradition of excellence in Mathematics. In addition, the usual Soviet method for attacking hard problems was to combine pressure from the authorities with people's enthusiasm. When Stalin decided to develop the Bomb, many bright mathematicians, e.g. Israel Gelfand and my first Math teacher, Alexander Kronrod, put aside their mathematical studies and delved deeply into the novel area of computing. They have assembled teams of talented people, and succeeded. The teams continued to grow and work on the theory of computing.

The supervisor of my M.Sc. thesis was Georgy Adelson-Velsky, one of the fathers of Computer Science. Among the students in his group were M. Kronrod (one of the future "Four Russians", i.e. the four authors of

^{[22]}), A. Karzanov (the future author of the O(n3) network flow algorithm^{[23]}) and other talented school pupils of A. Kronrod. This was in 1968, long after the Bomb project completed. The work on the foundations of the chess program "Kaissa", created by members of A. Kronrod's team under guidance of Adelson-Velsky, was almost finished; "Kaissa" won the first world championship in 1974. Adelson-Velsky's new passion became discrete algorithms, which he felt had a great future.

The fundamental contribution of Adelson-Velsky to Computer Science was AVL-trees. He (AV) and Evgenii Landis (L) published a paper about AVL-trees in early 60's, consisting of just a few pages. Besides solving an important problem, it presented a bright approach to data structure maintenance. While this approach became standard in the USSR, it was still not known in the West. No reaction followed their publication during a couple of years, until another paper, 15 pages long, was published by a researcher, which understood how AVL-trees work and explained this to the Western community, in its language. Since then, AVL-trees and the entire data structure maintenance approach became a corner-stone of Computer Science.

## Ershov and Shura-Bura

Quote fromThe Early Development of Programming in the USSRby Andrey Ershov, Mikhail R. Shura-Bura^{[24]}At the end of the 1950's a group of Moscow mathematicians began a study of computerized chess. Sixteen years later, the studies would lead to victory in the first world chess tournament for computer programs held in Stockholm during the 1974 IFIP Congress. An important component of this success was a deep study of the problems of information organization in computer memory and of various search heuristics. G. M. Adelson-Velsky and E. M. Landis invented the binary search tree ("dichotomic inquiry") and A. L. Brudno, independent of J. McCarthy, discovered the (α,β)-heuristic for reducing search times on a game tree.## Donskoy

Quote by Mikhail Donskoy from a Radio Liberty interview on an anecdote concerning Georgy Adelson-Velsky and AVL trees^{[25]}^{[26]}:One of my teachers, Georgy Adelson-Velsky, wrote an excellent report, "How did chess programs influence the development of programming". He lectured it in a strange way - at a congress in geophysics. In particular, the famous AVL trees were invented for chess programs at ITEP. I happened to be in Canada with Adelson-Velsky, at the University of Waterloo, where we were invited. There are three Faculties of Computational Mathematics, one way or another related to computer science and programming. One of them is, more or less, department of AVL trees. Can you imagine the scene when Adelson-Velsky himself (AVL stands for Adelson-Velsky and Evgenii Landis - two authors) comes to a department bearing his name, with a head of the department, three full professors, and six assistant professors, a myriad of graduate students and all who study his works. We were seated at a place of honor. Adelson-Velsky did not speak English and I translated. They asked the fundamental question: "How do you feel about the AVL-tree today?". This was 20, maybe 30 years after the invention. Then Adelson-Velsky, a typical scientist, small and hunchbacked with glasses, said with his high voice: "Yes, AVL-trees - this was a mistake of my youth". I replied to him "Georgy Maximovich, should I translate that directly?". His honesty has always distinguished the crystal. He said yes, and I translated. Soon the department head said "You know, our guests are tired from the journey and need to rest". God forbid again Adelson-Velsky says that AVL-trees are nonsense again - their monthly salary exceeds two or three years' of Adelson's income ...## The chronology of the events

Quotes by Mikhail Donskoy on the History of Kaissa^{[27]}1963 - beginning of the works on the first Soviet chess program in the Institute of Theoretical and Experimental Physics (ITEP) in the laboratory under Alexander Kronrod's management. The first authors - Georgy Adelson-Velsky, Vladimir Arlazarov, Alexander Bitman, Alexander Zhivotovsky, Anatoly Uskov, A. Leman, M. Rozenfeld.1967 - first international match of chess programs. Competed the program ITEP and the program of Stanford University, made under the management John McCarthy. McCarthy is famous fact that in 1952 on the beach in San Diego together with Alan Turing devised the word combination of "Artificial Intelligence", and fact that he is the author of the language Lisp - the first programming language, specially created for the tasks in the problems of artificial intelligence. Regulations of the match - four games. From the side of Stanford played one and the same version, from the ITEP side - two, which were being distinguished by the depth of search. Moves were transferred by the telegraph once a week (this to those- that times from "yadernogo" institute!). Match continued entire year and ended with the score the 3:1 in favor of ITEP.1969 - a letter in support of mathematician Esenin-Volpin (son of poet) and his incorrect psychiatric confinement, among others signed by Alexander Kronrod and Georgy Adelson-Velsky. As a result, the laboratory was disbanded and its major portion under Vladimir Arlazarov's management, but without Kronrod, after a certain time he settled in Institute of Control Sciences (ICF).1970 - the mechanic mathematical department of MGU finished the entire group of the students of Alexander Kronrod and Georgy Adelson-Velsky, that was being occupied in the famous seminar for discrete algorithms. Sums of the seminar:For Georgy Adelson-Velsky it was forbidden to teach in MGU## Visit from Canada

Tony Marsland and Monty Newborn on Georgy Adelson-Velsky in their report of their USSR visit, December 1980^{[28]}:Adelson-Velsky, an extremely capable and animated scientist and a real pleasure to meet, generally led our technical discussions. His eyes seemed to glisten with enthusiasm when he spoke. Discussions centered around probabilistic analyses of various aspects of the minimax algorithm and parallel search of chess trees. Our first joint seminar on alpha-beta analysis and the impact of computer technology was attended by about thirty people, including Leonid Kantorovich, winner of the 1975 Nobel Prize in Economics for his work on linear programming.## See also

## Selected Publications

^{[29]}^{[30]}^{[31]}^{[32]}^{[33]}## 1957 ...

1957).The Banach mean on groups. Uspekhi Matematicheskikh Nauk, Vol. 12, No. 6## 1960 ...

1962).An algorithm for the organization of information. Proceedings of the USSR Academy of Sciences, 146: 263–266. (Russian) English translation by Myron J. Ricci in Soviet Mathematics Doklady, No. 3^{[34]}## 1970 ...

1970).Programming a Computer to Play Chess. Russian Mathematical Surveys, Vol. 25, pp. 221-262.1975).Some Methods of Controlling the Tree Search in Chess Programs. Artificial Intelligence, Vol. 6, No. 4, pp. 361-371. ISSN 0004-3702. Reprinted (1988) in Computer Chess Compendium pp. 129-135.^{[35]}1977).On the Structure of an Important Class of Exhaustive Problems and Methods of Search Reduction for them. Advances in Computer Chess 11979).Algorithms of adaptive search. Machine Intelligence 9 (eds. Jean Hayes Michie, Donald Michie and L.I. Mikulich), pp. 373-384. Ellis Horwood, Chichester## 1980 ...

1981).On a probabilistic approach tо verification of the Shannon game model. Avtomatika i Telemekhanika, No. 9, 138–1441983). Машина играет в шахматы, pdf (book with detailed explanations of Kaissa algorithms, language: Russian)1987).On validity of Shannon's game model. Avtomatika i Telemekhanika, No. 1, 171–1731988).Algorithms for Games. Springer-Verlag, New York, NY. ISBN 3-540-96629-3. amazon.com## 2000 ...

2002).Project scheduling in AND-OR graphs: a generalization of Dijkstra’s algorithm. Mathematics of Operations Research, Vol. 27, No. 3## Forum Posts

## External Links

Interview with Georgy Adelson-Velsky (pdf) by Eugene Dynkin, Moscow, September 1, 1990

## References

1962).An algorithm for the organization of information. Proceedings of the USSR Academy of Sciences, 146: 263–266. (Russian) English translation by Myron J. Ricci in Soviet Mathematics Doklady, No. 31981).A brighter future for Soviet computer chess?ICCA Newsletter, Vol. 4, No. 1, pdfComputer chess pioneer Adelson-Velsky at chalkboard in Moscow 1980by Monroe Newborn, History of Computer Chess from The Computer History Museum1987).Remembering A.S. Kronrod. (2002). Translation by Viola Brudno, Edited by Walter Gautschi, zipped ps2006).Dinitz' Algorithm: The Original Version and Even's Version. Theoretical Computer Science, Springer, pdf,transliteration of names adapted1970).On economical construction of the transitive closure of a directed graph. Doklady Akademii Nauk (in English) 194, No. 11, 1209-12101974).Determining the maximal flow in a network by the method of preflows. Soviet Mathematics - Doklady, Vol. 15, No. 11980).The Early Development of Programming in the USSR. in Nicholas C. Metropolis (ed.)A History of Computing in the Twentieth Century. Academic Press, preprint pp. 441981).A brighter future for Soviet computer chess?ICCA Newsletter, Vol. 4, No. 1, pdf## What links here?

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