A Contraint Logic Programming Scheme for Taxonomic Reasoning

This paper presents a novel scheme for constraint logic programming, based on an abstract model of constraints that takes as primitive the notions of atomic constraint and substitution. It is shown that the constraint model generalizes the constraint languages of Höhfeld and Smolka [8], and fits well in the general framework proposed by Saraswat [17]. The semantics of the proposed logic programming scheme is an immediate generalization of the semantics of Horn clause logic, and we show that it possesses simple characterizations of the operational, declarative and fixed-point semantics. The main motivation for this work was to formalize the notion of useful and concise answers to queries to hierarchic type systems. The paper ends with a simple example illustrating this application.