On Conjunctive Query Answering in EL.
Riccardo Rosati · IRIS Research product catalog (Sapienza University of Rome) · 2007
In this paper we study conjunctive query answering in the description logics of the EL family [2, 3, 7, 6, 5], in particular we consider the DLs EL, ELH, EL, and EL. The EL family has been recently defined in order to identify DLs both having interesting expressive abilities and allowing for tractable reasoning. While the standard reasoning tasks (like concept subsumption and instance checking) have been analyzed in the past for such logics, almost no result is known about answering conjunctive queries in the logics of the EL family, with the exception of the lower complexity bounds which are immediate consequence of the results in [8] (and of the characterization of instance checking in [7, 3]). More specifically, we present the following results: