- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Thu, 10 Apr 2003 17:12:51 +0200
- To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, <geoff@sover.net>
- Cc: <www-rdf-logic@w3.org>

I think S&AS may be wrong about this. Peter: [[ Because of OWL's embedding on top of RDF there are actually several options that could arise here. 1/ One could have the semantic constraint on owl:intersectionOf that if the extension of x is the same as the intersection of the extensions of a and b then x owl:intersectionOf [a b] 2/ One could have the semantic constraint that if x owl:intersectionOf [a b] then the extension of x is the same as the intersection of the extensions of a and b 3/ One could have the semantic constraint that if x owl:intersectionOf [a b] then the extension of x is a subset of the intersection of the extensions of a and b ]] Option 1 might have been a better choice than option 2 (if I understood Peter's earlier message) E.g. Consider <owl:Class rdf:about="#AandB"> <owl:equivalentClass> <owl:Class> <owl:intersectionOf rdf:parseType="Collection"> <owl:Class rdf:about="#A"/> <owl:Class rdf:about="#B"/> </owl:intersectionOf> </owl:Class> </owl:equivalentClass> </owl:Class> This corresponds to the abstract syntax form EquivalentClasses(<#AandB> intersectionOf(<#A> <#B>) ) which directly entails Class( <#AandB> complete <#A> <#B> ) which corresponds to <owl:Class rdf:about="#AandB"> <owl:intersectionOf rdf:parseType="Collection"> <owl:Class rdf:about="#A"/> <owl:Class rdf:about="#B"/> </owl:intersectionOf> </owl:Class> i.e. option 1 but the rdfs compatible semantics has taken option 2. Is this a bug? Does someone need to make a last call comment? Or have I misunderstood? Jeremy

Received on Thursday, 10 April 2003 11:13:21 UTC