CW 270

M. Bruynooghe, H. Vandecasteele, A. de Waal and M. Denecker
Detecting Unsolvable Queries for definite Logic Programs

Abstract

In logic programming, almost no work has been done so far on proving that certain queries cannot succeed. Work in this direction could be useful for queries which seem to be non-terminating. Such queries are not exceptional, e.g.\ in planning problems. The paper develops some methods, based on abduction, goal-directedness, tabulation, and constraint techniques, for proving failure of queries for definite logic programs. It also reports some experiments with various tools.