43 search results - page 2 / 9 » Inverse Roles Make Conjunctive Queries Hard |
LPAR
2007
Springer
14 years 1 months ago
2007
Springer
We study the data complexity of instance checking and conjunctive query answering in the EL family of description logics, with a particular emphasis on the boundary of tractability...
DLOG
2006
13 years 8 months ago
2006
The novel context of accessing and querying large data repositories through ontologies that are formalized in terms of expressive DLs requires on the one hand to consider query an...
KR
2010
Springer
14 years 6 days ago
2010
Springer
Description Logics (DLs) are knowledge representation formalisms that provide, for example, the logical underpinning of the W3C OWL standards. Conjunctive queries (CQs), the stand...
AAAI
2006
13 years 8 months ago
2006
Description Logics (DLs) are the formal foundations of the standard web ontology languages OWL-DL and OWL-Lite. In the Semantic Web and other domains, ontologies are increasingly ...
CP
2010
Springer
13 years 6 months ago
2010
Springer
We study the expressibility problem: given a finite constraint language Γ on a finite domain and another relation R, can Γ express R? We prove, by an explicit family of example...