The retrieval problem is one of the main reasoning tasks for knowledge base systems. Given a knowledge base K and a concept C, the retrieval problem consists of finding all indivi...
Abstract. Ontologies and rules are usually loosely coupled in knowledge representation formalisms. In fact, ontologies use open-world reasoning while the leading semantics for rule...
W3C currently extends the SPARQL query language with so-called entailment regimes, which define how queries are evaluated using logical entailment relations. We describe a sound a...
In: Proceedings of the Sixth International Conference On Flexible Query Answering Systems (FQAS-04), Springer-Verlag LNAI 3055, pp. 203-216. c 2004 by Springer-Verlag. To model qu...
Abstract. There is currently great interest in integrating knowledge discovery research into mainstream database systems. Such an enterprise is nontrivial because knowledge discove...