Scientists at Glasgow University have established a world first by cracking the communication code of our brains. Pioneering research in the field of cognitive neuroimaging has revealed how brains process what we see. The work has been led by Prof Philippe Schyns, the head of Glasgow's school of psychology, with more than a little help from Voltaire and Salvador Dali. How Dali's mind worked is a matter of continuing conjecture. But one of his works has helped unlock how our minds work.

The extent to which parallels between brains and machines may profitably be drawn has been discussed by many writers including MacKay (ref. 1) and Sluckin (ref.

If ability to perform complex calculations were a sufficient criterion, then even a conventional digital computor could lay claim to more intelligence than any of usand perhaps we had better let it make away with the word and be done with it.

C. COOPER 21 3 Data representation--the key to conceptualisation: D. B. VIGOR 33 MECHANISED MATHEMATICS 45 4 An approach to analytic integration using ordered algebraic expressions: L. I. HODGSON 47 5 Some theorem-proving strategies based on the resolution principle: J. L DARLINGTON 57 MACHINE LEARNING AND HEURISTIC PROGRAMMING 73 6 Automatic description and recognition of board patterns in Go-Moku: A. M. MURRAY and E. W. Etcomc

A programming language based on sets; motivation and examples.

In order to be able to view the situation objectively we feel that it would be useful to preface this with a historical review of the development of ideas in this twenty-year-old field. By considering the most important ideas and techniques that are employed in the (currently) best program available, we hope to convince the reader that progress has been very slow despite the multiplicity of programs (and their associated literature) which have appeared since 1950. HISTORICAL REVIEW The most important paper that has appeared on the subject of computer chess is one written by Claude Shannon in 1948 and published two years later (Shannon 1950). Shannon's paper does not describe an actual program, but offers many suggestions for those who are interested in writing one. In this respect Shannon's paper may be compared with one by Jack Good which was also full of sound ideas which could well be included in a successful chess program (Good 1967). Shannon stressed the importance of having a good evaluation function. The features which he considers necessary for inclusion in the evaluation function included material, mobility, five aspects of pawn-structure, four of the positions of pieces, and four of commitments of pieces, attacks and options. He appreciated that such an evaluation function should be used only in the middle-game, and that different principles applied to the opening and endgame phases of chess. He suggested that the values of the coefficients of the function should be determined by'some experimental procedure', and the fact that this statement has never been followed in practice is very surprising.

The equivalence problem for program schemes, or for programs, is reduced to the proving of a theorem in second-order logic. This work extends Manna's first-order logic reductions. Some examples of the technique are given together with a suggested method for obtaining proofs in special cases by firstorder methods. INTRODUCTION Several workers in recent years have considered using techniques and ideas of various mathematical theories of computation for proving interesting results about computer programs. This paper is concerned with two of these approaches.

Networks as models of word storage: G. R. Kiss