DaRLing: A Datalog rewriter for OWL 2 RL ontological reasoning under SPARQL queries
This addresses a gap for semantic web applications needing robust OWL 2 RL reasoning tools, though it is incremental as it builds on existing fragments and methods.
The authors tackled the lack of freely available, maintained systems for OWL 2 RL ontological reasoning that support SPARQL queries and handle properties like sameAs without unique name assumptions, by presenting DaRLing, a Datalog rewriter that demonstrated practical applicability in experiments.
The W3C Web Ontology Language (OWL) is a powerful knowledge representation formalism at the basis of many semantic-centric applications. Since its unrestricted usage makes reasoning undecidable already in case of very simple tasks, expressive yet decidable fragments have been identified. Among them, we focus on OWL 2 RL, which offers a rich variety of semantic constructors, apart from supporting all RDFS datatypes. Although popular Web resources - such as DBpedia - fall in OWL 2 RL, only a few systems have been designed and implemented for this fragment. None of them, however, fully satisfy all the following desiderata: (i) being freely available and regularly maintained; (ii) supporting query answering and SPARQL queries; (iii) properly applying the sameAs property without adopting the unique name assumption; (iv) dealing with concrete datatypes. To fill the gap, we present DaRLing, a freely available Datalog rewriter for OWL 2 RL ontological reasoning under SPARQL queries. In particular, we describe its architecture, the rewriting strategies it implements, and the result of an experimental evaluation that demonstrates its practical applicability. This paper is under consideration in Theory and Practice of Logic Programming (TPLP).