- From: Drew McDermott <drew.mcdermott@yale.edu>
- Date: Fri, 6 Feb 2004 15:05:25 -0500 (EST)
- To: public-sws-ig@w3.org
> >[Drew McDermott] >> It's not clear whether you mean > > > > What are the advantages ... that will outweigh consistency checking > > and classification? > > or [the other thing Florian might have meant] > > > [Florian Probst] > that's what I would like to know. The current goal is to pull Owl-S back to the Owl-DL corral. The details have been entrusted to the capable hands of Bijan Parsia. > > In either case, you seem to be assuming that consistency checking and > > inference are unavailable or ineffectual in Owl-Full? Am I correct? > [Florian Probst] > correct :-) > What I would like to learn is why OWL-S is developed using OWL-Full > constructs rather than only using OWL-DL constructs. > Can I infer from your question, that consistency checking and > classification is possible with OWL-Full? > regards I don't know if classification is possible in Owl-Full, because I rarely think in terms of classification. I mentally translate Owl to predicate calculus, and then ask how hard various inference problems are in that framework. Apparently the answers are: Consistency checking: we have at least one example of finding inconsistencies in a DAML+OIL ontology, by Richard Waldinger and company using the Snark first-order theorem prover. Of course consistency checking in first-order logic is undecidable, but on the other hand you don't have to be in a big hurry for the results, so if a theory is inconsistent chances are good that a general-purpose theorem prover will figure that out in less than a week. Inference: *Many* kinds of inference can be done reasonably fast using a first-order inference engine on Owl-Full-style axioms. What do you want to do? Classification: In its most general form the classification problem is determining whether for some term R and a predicate Q, Q(R) holds. Is that right? So any problem at all is a classification problem in a general enough logic. (The goal G is equivalent to Q(R) if Q(x) is defined to be G.) This is not meant to be a criticism of anything, merely an observation that the term "classification" has little use outside a DL. -- -- Drew McDermott Yale University CS Dept.
Received on Friday, 6 February 2004 15:05:37 UTC