Exploiting conjunctive queries in description logic programs

Thomas Eiter, Giovambattista Ianni, Thomas Krennwallner, Roman Schindlauer
2008 Annals of Mathematics and Artificial Intelligence  
We present cq-programs, which enhance nonmonotonic description logics (dl-) programs by conjunctive queries (CQ) and union of conjunctive queries (UCQ) over Description Logics knowledge bases, as well as disjunctive rules. dl-programs had been proposed as a powerful formalism for integrating nonmonotonic logic programming and DL-engines on a clear semantic basis. The new cq-programs have two advantages: First, they offer increased expressivity by allowing general (U)CQs in the body. And second,
more » ... this combination of rules and ontologies gives rise to strategies for optimizing calls to the DL-reasoner, by exploiting (U)CQ facilities of the DL-reasoner. To this end, we discuss some equivalences which can be exploited for program rewriting. Experimental results for a cq-program prototype show that this can lead to significant performance improvements.
doi:10.1007/s10472-009-9111-3 fatcat:giussqfoizhrdlaaibwiysgeha