PhD Seminar: Combined complexity of Answering Ontology-Mediated Queries with a Covering Axiom
We are interested in the problem of efficiently determining the data complexity of answering queries mediated by non-Horn description logic ontologies and constructing their optimal rewritings to standard database queries. In general, this problem is known to be extremely complex. In our research, we focus on conjunctive queries mediated by a simple covering axiom stating that one class is covered by the union of two other classes.
During the talk, we discuss the current progress towards solution of the problem from different directions. Also, we consider a particular result about combined complexity of answering ontology-mediated queries with a covering axiom.