Integrating rules and description logics with circumscription for the semantic web

In this paper, we propose DLclog, a new hybrid formalism combining Description Logics(DL) and Logic Programming(LP) for Semantic Web serving as an extension to DL + log[17]. By DLclog, users can reason nonmonotonically with DL ontology. We introduce negative dl-atoms to the bodies of the rules, and extend Nonmonotonic Semantics (NM-Semantics) of DL + log to evaluate dl-atoms with circumscriptive models of DL ontology in the sense of parallel circumscription. In this way, negative dl-atoms are treated nonmonotonically, while the formalism still remains faithful to NM-Semantics, DL and LP. We also present a decision procedure for the extended semantics based on a restricted form of DLclog, in which DL ontologies are written with ALCIO or ALCQO and roles are not allowed to occur in negative dl-atoms.