# Subsumption in EL w.r.t. hybrid TBoxes

##### Sebastian BrandtSebastian Brandt,  Jörg ModelJörg Model
Sebastian Brandt, Jörg Model
Subsumption in EL w.r.t. hybrid TBoxes
Proceedings of the 28th Annual German Conference on Artificial Intelligence, KI 2005, Lecture Notes in Artificial Intelligence, 2005. Springer
• KurzfassungAbstract
In the area of Description Logic (DL) based knowledge representation, two desirable features of DL systems have as yet been incompatible: firstly, the support of general TBoxes containing general concept inclusion (GCI) axioms, and secondly, non-standard inference services facilitating knowledge engineering tasks, such as build-up and maintenance of terminologies (TBoxes). In order to make non-standard inferences available without sacrificing the convenience of GCIs, the present paper proposes hybrid TBoxes consisting of a pair of a general TBox F interpreted by descriptive semantics, and a (possibly) cyclic TBox T interpreted by fixpoint semantics. F serves as a foundation of T in the sense that the GCIs in F define relationships between concepts used as atomic concept names in the definitions in T. % Our main technical result is a polynomial time subsumption algorithm for hybrid EL-TBoxes based on a polynomial reduction to subsumption w.r.t. cyclic EL-TBoxes with fixpoint semantics. By virtue of this reduction, all non-standard inferences already available for cyclic EL-TBoxes become available for hybrid ones.
• Forschungsgruppe:Research Group: Automatentheorie
The final publication is available at Springer.
@inproceedings{ BrandtModel-KI2005,
author = {Sebastian {Brandt} and J{\"o}rg {Model}},
booktitle = {Proceedings of the 28th Annual German Conference on Artificial Intelligence, {KI 2005}},
publisher = {Springer-Verlag},
series = {Lecture Notes in Artificial Intelligence},
title = {Subsumption in {$\cal EL$} w.r.t.\ hybrid TBoxes},
year = {2005},
}