BibSonomy publications for /user/eswc2008/restrictingWed May 28 14:49:54 CEST 2008Berlin, HeidelbergProceedings of the 5th European Semantic Web ConferenceJuneLNCSRestricting and forgetting in DL-Lite2008dl-lite restricting ontology description forgetting logic formal-languages-2 Description logics form the foundation of ontologies used in the Semantic Web. To support reuse and integration of ontologies in Semantic Web applications, it is often necessary to restrict ontologies to a subset of their concepts and roles, or equivalently to forget a complementary subset of concepts and roles from the ontologies. We present the first detailed account of this problem for description logics, in particular for the DL-Lite family of description logics. Specifically, we present a semantic definition of forgetting that generalises the standard definition for classical logic. We introduce algorithms for forgetting concepts roles from both DL-Lite TBoxes and ABoxes. We prove the algorithms are sound and complete with respect to the semantics, and demonstrate how they can be used to speed-up query answering in DL-Lite knowledge bases.