01299nas a2200145   4500008004100000245007100041210006700112520079600179100002000975700001800995700002301013700002701036700001801063856007201081       2015                        eng d00aThe Combined Approach to Query Answering Beyond the OWL 2 Profiles0 aCombined Approach to Query Answering Beyond the OWL 2 Profiles3 a<p>Combined approaches have become a successful technique for CQ answering over ontologies. Existing algorithms, however, are restricted to the logics underpinning the OWL 2 profiles. Our goal is to make combined approaches applicable to a wider range of ontologies. We focus on RSA: a class of Horn ontologies that extends the profiles while ensuring tractability of standard reasoning. We show that CQ answering over RSA ontologies without role composition is feasible in NP. Our reasoning procedure generalises the combined approach for ELHO and DL-LiteR using an encoding of CQ answering into fact entailment w.r.t. a logic program with function symbols and stratified negation. Our results have significant practical implications since many out-of-profile Horn ontologies are RSA.</p>
1 aFeier, Cristina1 aCarral, David1 aStefanoni, Giorgio1 aGrau, Bernardo, Cuenca1 aHorrocks, Ian  uhttp://www.cs.ox.ac.uk/isg/people/cristina.feier/ijcai_rsafinal.pdf