From: Tim Berners-Lee ([email protected])
Date: 01/09/01
----- Original Message ----- From: "Peter F. Patel-Schneider" <[email protected]> To: <[email protected]> Cc: <[email protected]>; <[email protected]> Sent: Tuesday, January 09, 2001 2:07 PM Subject: Re: Joint Committee telecon today (semantics for domain and range) > > From: Dan Connolly <[email protected]> > Subject: Re: Joint Committee telecon today (semantics for domain and range) > Date: Tue, 09 Jan 2001 12:59:06 -0600 > > > "Peter F. Patel-Schneider" wrote: > > > > > > As promised, I have a new version of the semantics for DAML+OIL. It is > > > enclosed below. > > > > > > The ONLY substantive changes are the last two lines, which read > > > > > > <domain,?P,?C> if <x,y> in IR(?P) then x in IC(?C) > > > <range,?P,?C> if <x,y> in IR(?P) then y in IC(?C) > > > > > > NOTE: This does not correspond to the current RDFS intended meaning for > > > these constructs. > > > > Intended by whom? ;-) > > I meant intended meaning in the sense that it is what is alluded to in the > RDFS documentation, but not fully specified there. > > > It corresponds to what I intend, and at least one of the RDFS > > editors (Guha). It does not correspond to the way some > > folks have interpreted the RDFS spec. > > I should double-check that this is on the RDF IG issues list... > > no time just now. Please remind me if you get a chance... > > The RDFS documentation has a completely different meaning for multiple > domains. I know that there appears to be consensus to change RDFS in this > manner, but I think that we need to attach caveats to every definition of > domain and range until the change is made. :-( The specified RDFS meaning is in fact meaningless - the domain means something along the lines that whatever the real:domain is, that this rdfs:domain is a subClass of it, in other words that there exists some class such that all subjects of the predicate are in it and the given rdfs:domain value is a subclass of it, which is always true as the Class Thing always has these characteristics. So I don't see anyone defending the wording in the RDFS spec. tim
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