A Defeasible Ontology Language S. Heymans and Dirk Vermeir   View Paper (PDF)   Return to Ontology Languages Abstract We extend the description logic with a preference order on the axioms. With this strict partial order certain axioms can be overruled, if defeated with more preferred ones. Furthermore, we impose a preferred model semantics, thus effectively introducing nonmonotonicity into . Since a description logic can be viewed as an ontology language, or a proper translation of one, we obtain a defeasible ontology language. Finally, we argue that such a defeasible language may be usefully applied for learning and integrating ontologies. DiSC'03 © 2003 Association for Computing Machinery