Existential Rules: A Common Ground for Ontologies and Databases

19^th March 2013, 16:00 G12
Dr. Markus Kroetzsch
Department of Computer Science
University of Oxford
UK

Abstract

Existential rules -- in essence: first-order Horn logic -- have recently attracted a lot of interest in the areas of knowledge representation, reasoning, and ontologies. The same kind of rules are known as Tuple-Generating Dependencies in databases, where they have a variety of applications, e.g., in information exchange, data integration, and query answering under constraints. The renewed interest in this established formalism is fuelled by a wealth of recently discovered language fragments for which query answering is decidable. In this talk, we give an overview of recent results in this area, and we discuss some of our own results on guarded and acyclic rule languages. The latter also have been proposed for applications in Ontology-Based Data Access (OBDA), where ontological models are used to augment the query capabilities of databases. We present recent experimental results which suggest that similar principles can be exploited for reasoning in the Web Ontology Language OWL.