Extended Well-Founded Semantics for Paraconsistent Logic Programs.

This paper presents a declarative semantics of logic programs which possibly contain inconsistent information. We introduce a multi-valued interpretation of logic programs and present the extended well-founded semantics for paraconsistent logic programs. In this setting, a meaningful information is still available in the presence of an inconsistent information in a program and any fact which is affected by an inconsistent information is distinguished from the others. The well-founded semantics is also extended to disjunctive paraconsistent logic programs. 1 Introduction Recent studies have greatly enriched an expressive power of logic programming as a tool for knowledge representation. Handling classical negation as well as negation by failure in a program is one of such extension. An extended logic program, which is introduced by Gelfond and Lifschitz [GL90], distinguishes two types of negation and enables us to deal with explicit negation as well as default negation in a pro...