- From: <tarod@softhome.net>
- Date: Fri, 16 Nov 2001 15:50:54 GMT
- To: www-rdf-interest@w3.org
Sorry, I think that's a problem of OIL, an inference problem, but I don't understand why that should be considered in RDFS. When I specify some domains I want to specify where I can add this property, the property date should appear in document and event. I don't want to say that a object with date is a document AND an event. I want to say that is one of both. RDF should not know anything about inference, that's another problem. Regards, Marc >On the intended semantics of rdfs:domain, we believe that this should >be changed to intersection semantics as well. The reason for this is >exactly the same as TBL's argument about range restrictions. If you >add a local domain restriction that says, for example, that the domain >restriction on "ISBN-number" should be "book", then given the union >semantics, this has no effect at all if elsewhere it has already been >asserted that the domain restriction on "ISBN-number" is "document". >If I assert rdfs:domain(p,s) and I know that p(y,x), then I should be >able to assume rdf:type(y,s) in exactly the same way as with range: > > rdf:type(y,s) <= rdfs:domain(p,s) & p(y,x) > >With union semantics, this cannot be inferred. In fact, given that you >can't know about all the other domain restrictions that have been made >"elsewhere", then rdfs:domain(p,s) becomes completely meaningless. > >To summarize, we agree with TBL's view that the current definitions of >domain and range are lacking, and would propose to allow both to be >used multiple times, using intersection semantics.
Received on Friday, 16 November 2001 11:25:59 UTC