- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Wed, 23 Jul 2003 13:53:33 -0400 (EDT)
- To: jjc@hpl.hp.com
- Cc: www-webont-wg@w3.org
From: Jeremy Carroll <jjc@hpl.hp.com> Subject: TEST: 6 of 7: empty universe example, Date: Wed, 23 Jul 2003 19:20:15 +0300 > > Peter? > (for book-keeping) > > I had some outstanding actions on this one. > > At one point it seemed that I would need to make owl:Thing finite but > non-empty to get different behaviour in DL and Full; it now appears that > owl:Thing can be empty in DL, os I have reduced the test to > > owl:Thing owl:equivalentClass owl:Nothing > > http://www.w3.org/2002/03owlt/editors-draft/draft/proposedByFunction#Thing-001 > http://www.w3.org/2002/03owlt/editors-draft/draft/proposedByFunction#Thing-002 > > this test is slightly different from the one that I was actioned to produce. > > Jeremy Hmm. There may have been a slight glitch here at some time. Right now, neither the direct semantics nor the rdfs semantics require that the OWL DL universe of discourse is non-empty. As Pat pointed out empty universes can cause problems in languages with quantification. I don't think that these problems surface in OWL. peter
Received on Wednesday, 23 July 2003 13:53:43 UTC