- From: Dan Connolly <connolly@w3.org>
- Date: 22 Apr 2002 17:51:30 -0500
- To: Pat Hayes <phayes@ai.uwf.edu>
- Cc: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>, Lynn Andrea Stein <las@olin.edu>, w3c-rdfcore-wg@w3.org
On Mon, 2002-04-22 at 17:35, Pat Hayes wrote: > >[...] > > > >> RDF/xml has special syntax for containers, but experience > >> trying to exploit it to come to intuitive conclusions > >> has exposed problems. Take the class above... say > >> Continent is the subject of that oneOf property. > >> If we know > >> > >> ex:Bob daml:differentIndividualFrom ex:Eurasia. > >> ex:Bob daml:differentIndividualFrom ex:Africa. > >> ex:Bob daml:differentIndividualFrom ex:North_America. > >> ex:Bob daml:differentIndividualFrom ex:South_America. > >> ex:Bob daml:differentIndividualFrom ex:Australia. > >> ex:Bob daml:differentIndividualFrom ex:Antarctica. > >> > >> ex:NotContinent daml:complementOf ex:Continent. > >> > >> then we should be able to conclude > >> > >> ex:Bob rdf:type ex:NotContinent. > >> > >> Now this works perfectly well* when the oneOf claim > >> is spelled out long-hand using first/rest/nil. > > [To Dan:] > Well, that isn't clear. Sigh... I should have known better than to make that claim without working out the details... > After all, it is RDF-legal to add some other > rest/first/rest chains to the same bnodes, Well, first and rest are UniqueProperties. i.e. if :x ont:first :y. and :x ont:first :z. then :y ont:equivalentTo :z. So if you add other first/rest chains, you claim the relevant gizmos denote the same thing. If that's not the case, you've contradicted yourself. > so the daml:list is just > as dependent on a closed-world assumption I don't see any closed world reasoning in saying that first/rest are functional/unique properties. > as the RDF container syntax > would be in this context. I bet that your (and Jos) code would break, > or act unpredictably, if given a branching daml:list. Well, 'unpredictably' is probably a reasonable way to characterize the behaviour of a prover when given inconsistent input. But I don't see why this case is special in that respect. -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Monday, 22 April 2002 18:51:42 UTC