Conjunctive Query Answering for the DL SHIQ Conjunctive Query Answering for the Description Logic SHIQ

Abstract

Conjunctive queries play an important role as an expressive query language for Description Logics (DLs). Although modern DLs usually provide for transitive roles, conjunctive query answering over DL knowledge bases is only poorly understood if transitive roles are admitted in the query. In this paper, we consider unions of conjunctive queries over knowledge bases formulated in the prominent DL SHIQ and allow transitive roles in both the query and the knowledge base. We show decidability of query answering in this setting and establish two complexity bounds: regarding combined complexity, we prove that there is a deterministic algorithm for query answering that needs time single exponential in the size of the KB and double exponential in the size of the query, which is optimal. Regarding data complexity, we prove co-NP-completeness.

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Cite this paper

@inproceedings{Glimm2007ConjunctiveQA, title={Conjunctive Query Answering for the DL SHIQ Conjunctive Query Answering for the Description Logic SHIQ}, author={Birte Glimm and Ian Horrocks and Carsten Lutz and Ulrike Sattler}, year={2007} }