Most formalisms for representing common-sense knowledge allow incomplete and potentially inconsistent information. When strong negation is also allowed, contradictory conclusions can arise. A criterion for deciding between them is needed. The aim of this paper is to investigate an inherent…

Ontology integration is the problem of combining data sources in the SemanticWeb. Concepts in source ontologies are captured in terms of concepts de ned in a global ontology. When some of these ontologies are inconsistent, the knowledge engineer often has…

Defeasible Logic Programming (DeLP) is a knowledge representation formalism that combines results from Logic Programming and Defeasible Argumentation to provide reasoning based on contradictory and potentially incomplete information. DeLP allows information representation by using weak rules and provides an argumentation…

Negative information can be represented in several classes of logic programs. These approaches were first motivated by the search for an appropriate declarative semantics for negation as failure. Recently, some formalizations of monotonic negation were also introduced in logic programming…

We identify different kinds of relevance relations between formulas that emerge in the process of belief revision. Informal definitions for alternative notions of relevance are suggested and a set of schemas and intuitive postulates for formalizing these notions are proposed.