Is Your Ontology as Hard as You Think? Rewriting Ontologies into Simpler DLs

<p>We investigate cases where an ontology expressed in a seeminglyhard DL can be polynomially reduced to one in a simpler logic,while preserving reasoning outcomes for classification and fact entailment.Our transformations target the elimination of inverse roles, universaland existential restrictions, and in the best case allow us to rewritethe given ontology into one of the OWL 2 profiles. Even if an ontologycannot be fully rewritten into a profile, in many cases our transformationsallow us to exploit further optimisation techniques. Moreover, theelimination of some out-of-profile axioms can improve the performanceof modular reasoners, such as MORe. We have tested our techniques onboth classification and data reasoning tasks with encouraging results.</p>