Knowledge and reasoning in program synthesis

Abstract

Program synthesis is the construction of a computer program from given specifications. An automatic program synthesis system must combine reasoning and programming ability with a good deal of knowledge about the subject matter of the program. This ability and knowledge must be manifested both procedurally (by programs) and structurally (by choice of representation). We describe some of the reasoning and programming capabilities of a projected synthesis system. Special attention is paid to the introduction of conditional tests, loops, and instructions with side effects in the program being constructed. The ability to satisfy several interacting goals simultaneously proves to be important in many contexts. The modification of an already existing program to solve a somewhat different problem has been found to be a powerful approach. We illustrate these concepts with hand simulations of the synthesis of a number of pattern-matching programs. Some of these techniques have already been implemented, some are in the course of implementation, while others seem equivalent to well-known unsolved problems in artificial intelligence.