From: "Hans Teijgeler" <hans.teijgeler@quicknet.nl>Date: December 6, 2007 1:42:54 AM ESTTo: "Hendler, Jim" <hendler@cs.rpi.edu>Subject: rdfs:Class vs owl:ClassHi Jim,I'm involved in OWL for some years now, and I am still in the dark when to use rdfs:Class and when owl:Class (or whether to use rdfs:Class at all).In the W3C Recommendation "OWL Web Ontology Language Reference", par. 3.1 I read: "NOTE: owl:Class is defined as a subclass of rdfs:Class. The rationale for having a separate OWL class construct lies in the restrictions on OWL DL (and thus also on OWL Lite), which imply that not all RDFS classes are legal OWL DL classes. In OWL Full these restrictions do not exist and therefore owl:Class and rdfs:Class are equivalent in OWL Full.".But nowhere can I find which RDFS classes are illegal OWL DL classes. Do you know where to find that? What do they (you included) mean with 'RDFS classes' in this sentence?I am also in the dark why I can have <rdfs:Class rdf:ID="Opera"/> as well as <owl:Class rdf:ID="Opera">. What is the essential difference?In the OWL documents the user plays an important role, whereas in the RDF Schema document the word 'user' does not occur at all. Isn't <rdfs:Class rdf:ID="Opera"/> a user-defined RDFS class?Is there anything I can do with rdfs:Class that I cannot do with owl:Class? And the reverse?Can I have an owl:Restriction for an rdfs:Class?Do you see any flaws in attached graph?I hope you can help me with some simple answers.Regards,Hans____________________OntoConsultHans TeijgelerLaanweg 281871 BJ SchoorlThe Netherlands+31-72-509 2005No virus found in this outgoing message.
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