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 …