- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Thu, 04 Jul 2002 11:22:58 +0100
- To: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Cc: RDF Core <w3c-rdfcore-wg@w3.org>
At 20:44 03/07/2002 +0100, Graham Klyne wrote: >At 04:58 PM 7/3/02 +0100, Brian McBride wrote: [...] >But I do think this is a matter of taste, rather than a forced outcome. Yup, but its beginning to give me the heebee jeebees. >As for: >>http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Jul/0011.html > >I'm inclined to say "relax", but I'd be too tentative to be convincing. > >If we have: > > a someProp "lit" . > b someProp "lit" . >|= > a someProp _:x . > b someProp _:x . > >I think it's pretty clear that: > > _:a dc:title "4th July" . > _:b dc:date "4th July" . > dc:title rdfs:subPropertyOf dc:property . > dc:date rdfs:subPropertyOf dc:property . >|= > _:a dc:property _:l . > _:b dc:property _:l . > >So the problem you raise is what happens when different datatypes are >applied to dc:title and dc:date? If the datatypes have no literal->value >mappings in common, then I think that simply means the graph is not >satisfiable. I.e. there is no (DT-)interpretation that satisfies the >antecedent so the entailment is trivially valid. Right. The logic survives, as best I can understand it, but is this the behaviour we want to specify? Would someone ever want to build a language on top of RDFS which had some notion of a TOP property. If they did, what would the implications for datatypes be? Are we willing to accept the constraint that all subProperties of a property must have the same datatype constraint? Or is there some magic in the model theory that can allow them not to? I need to find time to sit and think about this. Brian
Received on Thursday, 4 July 2002 06:23:40 UTC