The DReW System for Nonmonotonic DL-Programs

Abstract

Nonmonotonic DL-programs provide a loose integration of Description Logic (DL) ontologies and Logic Programming (LP) rules with negation, where a rule engine can query an ontology with a native DL reasoner. However, in most systems for DL-programs, the overhead of an external DL reasoner might be considerable. Datalog-rewritable DL ontologies, such as most fragments of OWL 2 RL, OWL 2 EL, and OWL 2 QL, can be rewritten to Datalog programs, so that DL-programs can be reduced to Datalog ¬ , i.e., Datalog with negation, under both well-founded and answer set semantics. We developed the reasoner DReW that uses the Datalog-rewriting technique. In addition to DL-programs, DReW can also answer conjunctive queries under DL-safeness conditions over Datalog-rewritable ontologies as well as reason on terminological default logics over such ontologies.KeywordsDatalog Rewriting (DReW)Terminological Default LogicConjunctive Queries (CQ)Datalog ProgramLoose IntegrationThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.