Botoeva, E. and Kontchakov, Roman and Ryzhikov, Vladislav and Wolter, F. and Zakharyaschev, Michael (2016) Games for query inseparability of description logic knowledge bases. Artificial Intelligence 234 , pp. 78-119. ISSN 0004-3702.
|
Text
aij-final.pdf - Author's Accepted Manuscript Download (578kB) | Preview |
Abstract
We consider conjunctive query inseparability of description logic knowledge bases with respect to a given signature---a fundamental problem in knowledge base versioning, module extraction, forgetting and knowledge exchange. We give a uniform game-theoretic characterisation of knowledge base conjunctive query inseparability and develop worst-case optimal decision algorithms for fragments of Horn-ALCHI, including the description logics underpinning OWL 2 QL and OWL 2 EL. We also determine the data and combined complexity of deciding query inseparability. While query inseparability for all of these logics is P-complete for data complexity, the combined complexity ranges from P- to ExpTime- to 2ExpTime-completeness. We use these results to resolve two major open problems for OWL 2 QL by showing that TBox query inseparability and the membership problem for universal conjunctive query solutions in knowledge exchange are both ExpTime-complete for combined complexity. Finally, we introduce a more flexible notion of inseparability which compares answers to conjunctive queries in a given signature over a given set of individuals. In this case, checking query inseparability becomes NP-complete for data complexity, but the ExpTime- and 2ExpTime-completeness combined complexity results are preserved.
Metadata
| Item Type: | Article |
|---|---|
| Keyword(s) / Subject(s): | Description logic, Knowledge base, Conjunctive query, Query inseparability, Games on graphs, Computational complexity |
| School: | Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences |
| Depositing User: | Roman Kontchakov |
| Date Deposited: | 11 Feb 2016 11:13 |
| Last Modified: | 09 Aug 2023 12:37 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/14142 |
Statistics
Additional statistics are available via IRStats2.
Archive Staff Only (login required)
