@inproceedings{
Title = {Conjunctive Queries for a Tractable Fragment of OWL 1.1},
Booktitle = {6th International and 2nd Asian Semantic Web Conference (ISWC2007+ASWC2007)},
Year = {2007},
Month = {November},
Pages = {309--322},
Abstract = {Despite the success of the Web Ontology Language OWL, the development of expressive means for querying OWL knowledge bases is still an open issue. In this paper, we investigate how a very natural and desirable form of queries – namely conjunctive ones – can be used in conjunction with OWL such that one of the major design criteria of the latter – namely decidability – can be retained. More precisely, we show that querying the tractable fragment EL++ of OWL 1.1 is decidable. We also provide a complexity analysis and show that querying unrestricted EL++ is undecidable.},
Url = {http://data.semanticweb.org/conference/iswc-aswc/2007/tracks/research/papers/309}
}