A Sound and Complete Backward Chaining Algorithm for Existential Rules

Mélanie KönigMélanie König, Michel LeclèreMichel Leclère, Marie-Laure MugnierMarie-Laure Mugnier, Michaël ThomazoMichaël Thomazo

Mélanie König, Michel Leclère, Marie-Laure Mugnier, Michaël Thomazo
A Sound and Complete Backward Chaining Algorithm for Existential Rules
Proceedings of the 6th International Conference on Web Reasoning and Rule Systems (RR 2012), 122-138, 2012. Springer

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KurzfassungAbstract
We address the issue of Ontology-Based Data Access which consists
of exploiting the semantics expressed in ontologies while querying data. Ontologies are represented in the framework of existential rules, also known as Datalog+/-.We focus on the backward chaining paradigm, which involves rewriting the query (assumed to be a conjunctive query, CQ) into a set of CQs (seen as a union of CQs). The proposed algorithm accepts any set of existential rules as input and stops for so-called finite unification sets of rules (fus). The rewriting step relies on a graph notion, called a piece, which allows to identify subsets of atoms from the query that must be processed together. We first show that our rewriting method computes a minimal set of CQs when this set is finite, i.e., the set of rules is a fus. We then focus on optimizing the rewriting step. First experiments are
reported.
Forschungsgruppe:Research Group: Computational LogicComputational Logic

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-33203-6_10.

@inproceedings{KLMT2012,
  author    = {M{\'{e}}lanie K{\"{o}}nig and Michel Lecl{\`{e}}re and
               Marie-Laure Mugnier and Micha{\"{e}}l Thomazo},
  title     = {A Sound and Complete Backward Chaining Algorithm for Existential
               Rules},
  booktitle = {Proceedings of the 6th International Conference on Web Reasoning
               and Rule Systems (RR 2012)},
  publisher = {Springer},
  year      = {2012},
  pages     = {122-138},
  doi       = {10.1007/978-3-642-33203-6_10}
}