An Efficient Direct Implementation of Equivalence Relations in OWL

Hans-Ulrich Krieger

Research Report DFKI GmbH DFKI Research Reports (RR) 11-01 2011.


This paper presents a direct implementation of the three equivalence relations for TBox, RBox, and ABox in OWL and has been realized in the forward chaining engine HFC. The technique obviates the combinatorial explosion in a semantic repository during materialization, when applying the OWL entailment rules from ter Horst (2005) that are used in, e.g., Jena or OWLIM. Although the approach requires some work when starting up a repository and and querying its content, it massively pays off in the end by showing a smaller memory footprint and allowing faster inferences, as our measurements have shown. As a nice side effect of this approach, the "cleanup" of ontologies can even lead to smaller repositories, as more equivalence relation instances are added. Our decision to add such functionality in \hfc\ was motivated by experiences we have gained in former projects that have dealt with information extraction from natural language texts, represented in description logic ontologies.


EquivalenceRelation.pdf (pdf, 354 KB )

Deutsches Forschungszentrum für Künstliche Intelligenz
German Research Center for Artificial Intelligence