KR2020Proceedings of the 17th International Conference on Principles of Knowledge Representation and ReasoningProceedings of the 17th International Conference on Principles of Knowledge Representation and Reasoning

Rhodes, Greece. September 12-18, 2020.

Edited by

ISSN: 2334-1033
ISBN: 978-0-9992411-7-2

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Published by

Copyright © 2020 International Joint Conferences on Artificial Intelligence Organization

Finite Controllability for Ontology-Mediated Query Answering of CRPQ

  1. Diego Figueira(Univ. Bordeaux, CNRS, Bordeaux INP, LaBRI, UMR 5800, France)
  2. Santiago Figueira(Universidad de Buenos Aires, Argentina, CONICET, Argentina)
  3. Edwin Pin Baque(Universidad de Buenos Aires, Argentina, CONICET, Argentina)


  1. Computational aspects of knowledge representation-General
  2. Description logics-General
  3. Ontology formalisms and models-General
  4. Ontology-based data access, integration, and exchange-General


Finite ontology mediated query answering (FOMQA) is the variant of ontology mediated query answering (OMQA) where the represented world is assumed to be finite, and thus only finite models of the ontology are considered. We study the property of finite-controllability, that is, whether FOMQA and OMQA are equivalent, for fragments of C2RPQ.

C2RPQ is the language of conjunctive two-way regular path queries, which can be regarded as the result of adding simple recursion to Conjunctive Queries. For graph classes S, we consider fragments C2RPQ(S) of C2RPQ as the queries whose underlying graph structure is in S.

We completely classify the finitely controllable and non-finitely controllable fragments under: inclusion dependencies, (frontier-)guarded rules, frontier-one rules (either with or without constants), and more generally under guarded-negation first-order constraints.

For the finitely controllable fragments, we show a reduction to the satisfiability problem for guarded-negation first-order logic, yielding a 2EXPTIME algorithm (in combined complexity) for the corresponding (F)OMQA problem.