Similarity-based Reasoning in Qualified Logic Programming

TL;DR

This paper introduces SQLP(R,D), a new logic programming scheme that unifies similarity-based and qualified logic programming, enabling flexible approximate reasoning with compatibility to existing systems.

Contribution

The paper proposes SQLP(R,D), a more expressive scheme that subsumes SLP and QLP(D), and demonstrates its transformability into existing QLP(D) programs for practical implementation.

Findings

SQLP(R,D) unifies SLP and QLP(D) frameworks.

Programs in SQLP(R,D) can be transformed into equivalent QLP(D) programs.

Existing QLP(D) systems can support similarity-based reasoning efficiently.

Abstract

Similarity-based Logic Programming (briefly, SLP ) has been proposed to enhance the LP paradigm with a kind of approximate reasoning which supports flexible information retrieval applications. This approach uses a fuzzy similarity relation R between symbols in the program's signature, while keeping the syntax for program clauses as in classical LP. Another recent proposal is the QLP(D) scheme for Qualified Logic Programming, an extension of the LP paradigm which supports approximate reasoning and more. This approach uses annotated program clauses and a parametrically given domain D whose elements qualify logical assertions by measuring their closeness to various users' expectations. In this paper we propose a more expressive scheme SQLP(R,D) which subsumes both SLP and QLP(D) as particular cases. We also show that SQLP(R,D) programs can be transformed into semantically equivalent QLP(D) programs. As a consequence, existing QLP(D) implementations can be used to give efficient support for similarity-based reasoning.