Expressive OWL Reasoning with Logic Programs

The Web Ontology Language OWL is the W3C standard for model- ing ontologies for the web. It is based on description logics , a fragment of first- order logic. Traditionally, however, logic programming has always been an alter- native ontology modeling paradigm, and is frequently being used in large research projects and industrial applications, e.g., by means of the F-Logic reasoning en- gine OntoBroker or the TRIPLE query, inference, and transformation language and system. Naturally, it is desirable to investigate the in teroperability between both paradigms. In this paper, we do so by studying an expressive fragement of OWL DL for which reasoning can be reduced to the evaluation of Horn logic programs. Building on the KAON2 algorithms for transforming OWL DL into disjunctive Datalog, we give a detailed accout of how and to what extent OWL DL can be employed in standard logic programming systems. En route, we derive a novel, simplified characterization of the supported fragm ent of OWL DL.