Chess Life and Review (February):84-85.

Distributed systems are multi-processor information processing systems whichdo not rely on the central shared memory for communication. The importanceof distributed systems has been growing with the advent of "computer networks"of a wide spectrum: networks of geographically distributed computers at one end,and tightly coupled systems built with a large number of inexpensive physicalprocessors at the other end. Both kinds of distributed system are made availableby the rapid progress in the technology of large-scale integrated circuits. Yetlittle has been done in the research on semantics and programming methodologiesfor distributed information processing systems.Our main research goal is to understand and describe the behaviour of suchdistributed systems in seeking the maximum benefit of employing multi-processorcomputation schemata.Hayes, J.E., D. Michie, and L. I. Mikulich (Eds.), Machine Intelligence 9, Ellis Horwood.

in D Michie (ed.), Expert Systems in the Micro-Electronic Age, pp. 242-270, Edinburgh: Edinburgh University Press

D.Michie (Ed.), Expert systems in the micro- electronic age.Edinburgh: Edinburgh University Press, 153-167

A program called "AM" is described which carries on simple mathematics research,defining and studying new concepts under the guidance of a large body ofheuristic rules. The 250 heuristics communicate via an agenda mechanism, aglobal priority queue of small tasks for the program to perform, and reasons whyeach task is plausible (for example, "Find generalizations of 'primes', because'primes' turned out to be so useful a concept"). Each concept is represented asan active, structured knowledge module. One hundred very incomplete modulesare initially supplied, each one corresponding to an elementary set-theoreticconcept (for example, union). This provides a definite but immense space whichAM begins to explore. In one hour, AM rediscovers hundreds of common concepts(including singleton sets, natural numbers, arithmetic) and theorems (for example,unique factorization).Summary of Ph.D. dissertation.Hayes, J.E., D. Michie, and L. I. Mikulich (Eds.), Machine Intelligence 9, Ellis Horwood.

Cognitive Science 3(3):177-212.

Technometrics, 21(2)

Cognitive Science, vol. 3, No. 1, pp. 67-90.

To choose their actions, reasoning programs must be able to make assumptions and subsequently revise their beliefs when discoveries contradict these assumptions. The Truth Maintenance System (TMS) is a problem solver subsystem for performing these functions by recording and maintaining the reasons for program beliefs. Such recorded reasons are useful in constructing explanations of program actions and in guiding the course of action of a problem solver. This paper describes (1) the representations and structure of the TMS, (2) the mechanisms used to revise the current set of beliefs, (3) how dependency-directed backtracking changes the current set of assumptions, (4) techniques for summarizing explanations of beliefs, (5) how to organize problem solvers into "dialectically arguing" modules, (6) how to revise models of the belief systems of others, and (7) methods for embedding control structures in patterns of assumptions. We stress the need of problem solvers to choose between alternative systems of beliefs, and outline a mechanism by which a problem solver can employ rules guiding choices of what to believe, what to want, and what to do.Artificial Intelligence 12(3):231-272