From Conjunctive Queries to Instance Queries in Ontology-Mediated Querying

From Conjunctive Queries to Instance Queries in Ontology-Mediated Querying

Cristina Feier, Carsten Lutz, Frank Wolter

Proceedings of the Twenty-Seventh International Joint Conference on Artificial Intelligence
Main track. Pages 1810-1816. https://doi.org/10.24963/ijcai.2018/250

We consider ontology-mediated queries (OMQs) based on expressive description logics of the ALC family and (unions) of conjunctive queries, studying the rewritability into OMQs based on instance queries (IQs). Our results include exact characterizations of when such a rewriting is possible and tight complexity bounds for deciding rewritability. We also give a tight complexity bound for the related problem of deciding whether a given MMSNP sentence (in other words: the complement of a monadic disjunctive Datalog program) is equivalent to a constraint satisfaction problem.
Keywords:
Knowledge Representation and Reasoning: Description Logics and Ontologies
Multidisciplinary Topics and Applications: Databases