- From: Sören Auer <auer@informatik.uni-leipzig.de>
- Date: Thu, 28 Sep 2006 10:58:27 -0400
- To: Bijan Parsia <bparsia@isr.umd.edu>, public-owl-dev@w3.org
Bijan Parsia wrote: > Just out of curiosity, what fragment of OWL does your translation > handle? I believe LUMB turns out to be in hornSHIQ: Good question. I'm not able to say that in two words. The algorithm first makes some subsumption inferences (currently on the basis of explicit subClassOf, oneOf, intersectionOf and unionOf axioms/descriptions). Classification is done with regard to almost all OWL axioms and descriptions, by generating a DB view for each description/axiom on a triple table and combining these views as needed. In case of mutual recursion, there is currently some approximation used for computation of an initial class extend, which is refined by a second run. We didn't use some fix point algorithm due to performance reasons and for many practical scenarios this doesn't seem to be needed. Non-unique names assumption turns out to be problematic, OWLDB does not check if certain individuals are the same. But I guess that won't be very problematic, when an individual is listed twice (for classes/properties of course it's a bigger deal). I think it's a bit hard to compare the OWLDB approach to classic DL reasoners, since only subsumption and classification are supported, both with a different set of (in some cases only partially) supported OWL descriptions/axioms. Let me know if you want to have a glance at the paper I'm currently writing once I have a first draft (might take 2-3 more weeks). Cheers, Sören
Received on Thursday, 28 September 2006 14:58:59 UTC