A practical approach to modelling and validating integrity constraints in the Semantic Web.

Efforts have been made in the Semantic Web to combine rules with ontologies. One result of these efforts is the development of the Semantic Web Rule Language (SWRL) which is designed to integrate closely with the Web Ontology Language (OWL). Both SWRL and OWL adhere to the open-world semantics of first-order logic, and thus are not suitable for modelling integrity constraints in applications where complete knowledge about some parts of the domain can be assumed. In this paper, we investigate this problem and present a practical approach to modelling and validating constraints in the Semantic Web. Building on existing work, we show that by employing a constraint semantics for both OWL and SWRL, we can model common constraints as OWL axioms or SWRL rules. We also show that by using a query reduction technique, we can validate constraints using existing OWL/SWRL reasoners. Finally, we demonstrate the usefulness of our approach via a real-world case study.