- From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
- Date: Thu, 26 Sep 2002 23:49:43 -0400 (EDT)
- To: phayes@ai.uwf.edu
- Cc: horrocks@cs.man.ac.uk, www-webont-wg@w3.org
From: pat hayes <phayes@ai.uwf.edu> Subject: OWL question Date: Thu, 26 Sep 2002 21:46:48 -0500 > Guys, should the following entailment be valid? (Intuitively, I mean; > Im looking for guidance here.) > > AAA rdf:type owl:Restriction . > AAA owl:sameClassAs owl:Nothing . > > ?entails? > > AAA owl:cardinality <xsd:integer: 0> > > More generally, are there any valid OWL entailments with a conclusion > of the form > > AAA <restriction-property> BBB . > > but the antecedent does not mention a restriction property? I ask > because the only-if semantic conditions on restrictions seem to > suggest not, which seems odd. > > Pat Well one might think that this is something that one might want to infer. However, there are several reasons why it is not a good idea. 1/ It verges on the extensionality principle, which, as we have discussed, causes problems in OWL/RDF. 2/ OWL/RDF restrictions are compound constructs that are much more like syntax than anything else. It is rather strange to infer that some resource *is* a piece of syntax. So, in sum, it is the peculiarities of OWL/RDF that make the semantic conditions on restrictions be only-if. peter
Received on Thursday, 26 September 2002 23:49:58 UTC