- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Fri, 25 Oct 2002 19:21:53 +0200
- To: "Dan Connolly" <connolly@w3.org>, "Pat Hayes" <phayes@ai.uwf.edu>
- Cc: "Ian Horrocks" <horrocks@cs.man.ac.uk>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, "Jeremy Carroll" <jjc@hplb.hpl.hp.com>, <www-archive@w3.org>
We *know* that that sort of reasoner (horn clause like) is going to be incomplete wrt any sort of OWL semantics that the WG wants ... I think it is quite a plausible position to say Large OWL = all the semantic anyone might possibly expect. e.g. we use some set theory, you get that bit of set theory (student/employee cases) we use some arithmetic, you get that bit of arithmetic (test case with minCardinalities adding up) you use some property properties, they really are property properties (transitivity etc). i.e. Large OWL seems strongly extensional in nature overall, and so making it extensional in this respect seems cool to me. It does seem cleaner to then put that requirement back down on rdfs if there are no reasons not to. [I am no where near deeply committed to this position]. Jeremy > I wonder if the bit about inference engines is really aesthetic... > I can't quite put my finger on it, but it seems to me that > the IF semantics are expressible as horn clauses while > the IFF semantics are not. > > As long as the IFF semantics can be captured as so called > "closure rules" (which are horn clauses, right?), then > yes, it's a coin-toss... I kinda lean toward IF on > the grounds that it's less constraining (and in some > sense more expressive...) but I asked TimBL about > this and he expects IFF semantics. Jeremy
Received on Friday, 25 October 2002 13:22:05 UTC