DIP: A Defeasible-Inference Platform for OWL

Abstract. The preferential approach to nonmonotonic reasoning was consolidated in depth by Krause, Lehmann and Magidor (KLM) for propositional logic in the early 90’s. In recent years, there have been ef-forts to extend their framework to Description Logics (DLs) and a solid theoretical foundation has already been established towards this aim. Despite this foundation, and the fact that many of the desirable aspects of the approach generalise favourably to certain DLs, implementations thereof remain unpublished. We present a defeasible-reasoning system for OWL ontologies demonstrating that we need not devise new deci-sion procedures for certain preferential DLs. Our reasoning procedures are composed purely of classical DL decision steps which allows us to immediately hinge upon existing OWL and DL systems for defeasible-reasoning tool support.