Proving Failure of Queries for Definite Logic Programs Using XSB-Prolog

TL;DR

This paper demonstrates how to prove query failure in definite logic programs by leveraging XSB-Prolog's tabulation, improved backtracking, and failure analysis, offering an alternative to model generation methods.

Contribution

It shows how to achieve failure proofs using direct execution in XSB-Prolog, replacing complex model generation with enhanced control and analysis techniques.

Findings

Effective failure proving with XSB-Prolog's tabulation.

Improved backtracking and failure analysis techniques.

Comparable results to previous model-based approaches.

Abstract

Proving failure of queries for definite logic programs can be done by constructing a finite model of the program in which the query is false. A general purpose model generator for first order logic can be used for this. A recent paper presented at PLILP98 shows how the peculiarities of definite programs can be exploited to obtain a better solution. There a procedure is described which combines abduction with tabulation and uses a meta-interpreter for heuristic control of the search. The current paper shows how similar results can be obtained by direct execution under the standard tabulation of the XSB-Prolog system. The loss of control is compensated for by better intelligent backtracking and more accurate failure analysis.