A Resolution−Based Decision Procedure for SHOIQ

Abstract

We present a resolution-based decision procedure for the description logic SHOIQ—the logic underlying the Semantic Web ontology language OWL-DL. Our procedure is goal-oriented, and it naturally extends a similar procedure for SHIQ, which has proven itself in practice. Extending this procedure to SHOIQ using existing techniques is not straightforward because of nominals, number restrictions, and inverse roles—a combination known to cause termination problems. We overcome this difficulty by using basic superposition calculus extended with custom simplification rules.