- From: Jeremy Carroll <jjc@hpl.hp.com>
- Date: Mon, 26 May 2003 15:58:22 +0300
- To: www-webont-wg@w3.org
peter: >The RDFS-compatible semantics for OWL DL heavily depends on owl:Class (more >precisely, on IOC, the class extension of owl:Class). If the distinction >between owl:Class and rdfs:Class was removed the semantics would be quite >different. >I'm not even sure that an RDFS-compatible semantics for OWL DL, as distinct >from an RDFS-compatible semantics for OWL full, would even be possible. In >particular, how could one arrange it so that the appropriate lists and >descriptions existed? It is clear that all references to owl:Class would need to be deleted, making the rdfs compatible semantics more dependent on IOC, which would remain a distinguished subset of rdfs:Class within OWL DL. The correspondence theorem would get harder :( There seem to be five references to :Class in S&AS rdfs compatible semantics. Apart from the correspondence theorem the hardest text to rework would be the introductory text, because it is quite hard to articulate what rdfs:Class means. [[ There are two different styles of using OWL. In the more free-wheeling style, called OWL Full, the three parts of the OWL universe are identified with their RDF counterparts, namely the class extensions of rdfs:Resource, rdfs:Class, and rdf:Property. In OWL Full, as in RDF, elements of the OWL universe can be both an individual and a class, or, in fact, even an individual, a class, and a property. In the more restrictive style, called OWL DL here, the three parts are different from their RDF counterparts and, moreover, pairwise disjoint. ]] Possible additional sentence at end of extract [[ In the <a link to section 4>syntax of OWL DL</a> rdfs:Class can only be used to refer to only those classes in IOC, hence rdfs:Class is syntactically used as the name of IOC in both styles of OWL. ]] (IOC would need to be introduced earlier, currently where owl:Class is introduced) In the OWL DL section further discussion of this would be necessary - the OWL DL section is quite difficult to change - I am still thinking what it would take. Jeremy
Received on Monday, 26 May 2003 09:58:18 UTC