- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Sat, 03 Apr 2004 13:39:48 +0100
- To: Yuzhong Qu <yzqu@seu.edu.cn>
- Cc: Dan Brickley <danbri@w3.org>, www-rdf-logic@w3.org
I think with Qu's, Evan's and Dan's replies, I stand corrected. Jeremy Yuzhong Qu wrote: > As to the reasoning complexity, > > OWL DL has a difficult entailment problem, as inference in SHOIN(D) is of worst-case nondeterministic exponential time (NExpTime) complexity. > > Inference in SHIF(D) is of worst-case deterministic exponential time (ExpTime) complexity, and OWL Lite has the same complexity. > > Reference > [1] Ian Horrocks, Peter F. Patel-Schneider, and Frank van Harmelen. From SHIQ and RDF to OWL: The making of a web ontology language. Journal of Web Semantics, 1(1):7-26, 2003 > [2] Stephan Tobies. Complexity Results and Practical Algorithms for Logics in Knowledge Representation. PhD thesis, LuFG Theoretical Computer Science, RWTHAachen,Germany, 2001. > > > Yuzhong Qu > > P.S. The complexity may be the most important element. > > ----- Original Message ----- > From: "Dan Brickley" <danbri@w3.org> > To: "ror" <galvinr@tcd.ie> > Cc: <www-rdf-logic@w3.org> > Sent: Friday, April 02, 2004 8:59 PM > Subject: Re: types of OWL > > > >>* Dan Brickley <danbri@w3.org> [2004-04-02 07:53-0500] >> >>>* ror <galvinr@tcd.ie> [2004-04-02 13:16+0100] >>> >>>>Hello, >>>> >>>>I've been trying to find the underlying differences between the different >>>>types of OWL languages i.e: OWL DL, OWL Lite and OWL full. >>>> >>>>Are all of these languages forms of Description Logic? As far as I can gather >>>>OWL Lite is less expressive to suit users who want to incorporate semantics >>>>into their applications without the over complexity of OWL DL and full. >>>> >>>>Does OWL lite use different forms of axioms than full or DL >>>> >>>>If someone could set me straight on the differences I would be very grateful! >>> >>>Here's a sketch. >>> >>>"Full" is the full OWL language, an RDF-based language that extends RDFS with >>>constructs useful for describing the terms used in Ontologies. "OWL DL" >>>is a profile of that language created with special care to make it easy >>>to work with in the Description Logic tradition. "OWL Lite" goes further in >>>that direction, by ommiting some constructs known to be tough to work with >>>using DL techniques. >> >>Re-reading your question, I guess you were looking for more details. I >>think the basic situation is that things from DL that aren't in Lite >>were taken out on the basis of their being known to be difficult to >>implement. My understanding is that someone should be well on their way >>to implementing OWL Lite by studying the published DL literature, whereas >>complete reasoning with DL is more researchy... >> >>Dan >> >> >>
Received on Saturday, 3 April 2004 07:41:06 UTC