Inconsistent-tolerant Base Revision through Argument Theory Change

MARTÍN O. MOGUILLANSKY; RENATA WASSERMANN; MARCELO A. FALAPPA

LOGIC JOURNAL OF THE IGPL (PRINT)

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2012 vol. 20 p. 154 - 186

1367-0751

Reasoning and change over inconsistent knowledge bases (KBs) is of utmost relevancein areas like medicine and law. Argumentation may bring the possibilityto cope with both problems. Firstly, by constructing an argumentation framework(AF) from the inconsistent KB, we can decide whether to accept or rejecta certain claim through the interplay among arguments and counterarguments.Secondly, by handling dynamics of arguments of the AF, we might deal withthe dynamics of knowledge of the underlying inconsistent KB.Dynamics of arguments has recently attracted attention and although someapproaches have been proposed, a full axiomatization within the theory of beliefrevision was still missing. A revision arises when we want the argumentationsemantics to accept an argument. Argument Theory Change (ATC) encloses therevision operators that modify the AF by analyzing dialectical trees -argumentsas nodes and attacks as edges- as the adopted argumentation semantics.In this article, we present a simple approach to ATC based on propositionalKBs. This allows to manage change of inconsistent KBs by relying upon classicalbelief revision, although contrary to it, consistency restoration of the KB isavoided. Subsequently, a set of rationality postulates adapted to argumentationis given, and finally, the proposed model of change is related to the postulatesthrough the corresponding representation theorem. Though we focus on propositionallogic, the results can be easily extended to more expressive formalismssuch as first-order logic and description logics, to handle evolution of ontologies.