- From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
- Date: Thu, 06 Feb 2003 19:35:13 +0000
- To: www-webont-wg@w3.org
Pat, The changes I am suggesting are detailed in the last para of: http://lists.w3.org/Archives/Public/www-archive/2003Jan/att-0107/01-t#semantics i.e. [[ RDFS compatible semantics are clarified to say that: + owl:TransitiveProperty, owl:SymmetricProperty, owl:InverseFunctionalProperty are all sub classes of owl:ObjectProperty (Also for the DL semantics) + In OWL full it is clarified that owl:ObjectProperty is the same class as rdf:Property. ]] The motivation is syntactic. Currently to declare that t is a transitive property you must say in OWL Lite, OWL DL that: <owl:TransitiveProperty rdf:about="#t"/> <owl:ObjectProperty rdf:about="#t"/> i.e. you must declare that <#t> refers to an object property as well as a transitive one. I would prefer if the second part could be omitted, since I believe that will more intelligible to users. Whereas in OWL DL *only* object properties can be transitive properties, there are example transitive datatype properties in OWL Full (e.g. the empty one, or one which just relates non-literals to literals). Hmmm, this is a bit tricky ... In OWL Full: <owl:DatatypeProperty rdf:about="#p"> <rdfs:domain> <owl:Class> <owl:complementOf rdf:resource="&rdfs;Literal"/> </owl:Class> </rdfs:domain> <rdfs:range rdf:resource="&rdfs;Literal"/> </owl:DatatypeProperty> OWL-full-entails <owl:TransitiveProperty rdf:about="#p"/> Because there are no cases of x p y, and y p z. The above is not an OWL DL entailment, because of the type mismatch (p is a datatype property in the first, and an object property in the second). Also in OWL Full, p is an ObjectProperty but that is uninteresting (in OWL Full). I *think* the changes work .... Jeremy
Received on Thursday, 6 February 2003 14:35:21 UTC