- From: Jan Grant <Jan.Grant@bristol.ac.uk>
- Date: Fri, 28 Jun 2002 10:40:48 +0100 (BST)
- To: pat hayes <phayes@ai.uwf.edu>
- cc: Dan Connolly <connolly@w3.org>, Jeremy Carroll <jjc@hplb.hpl.hp.com>, w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
On Fri, 28 Jun 2002, pat hayes wrote: > > >On Wed, 2002-06-26 at 04:08, Jeremy Carroll wrote: > >[...] > >> Any interpretation of any > >> > >> > >aaa [rdfs:range] yyy > >> > >yyy [rdfs:subClassOf] zzz > >> > >> > >> is an interpretation of > >> > >> > >aaa [rdfs:range] zzz > > > >I don't think our specs say that. > > > > > >> thus the closure rule holds. > >> > >> (Not) Proof: > >> > >> Ahh, it depends on rdfs:range not being in the domain of discourse. > >> neglecting that little factette and invalidating the proof ... > >> > >> Whenever > >> iii aaa jjj . > >> then > >> jjj [rdf:type] yyy . > >> hence > >> jjj [rdf:type] zzz . > >> > >> hence > >> > >> aaa [rdfs:range] zzz . > >> > >> == > > > >Where does that last step come from? Which part of our > >spec allows you to conclude the rdfs:range triple? > > Right, exactly: it doesn't, and shouldn't. Jeremy: remember that a > class isn't just its extension. That's true, but is a subClassOf declaration just making a claim about a subset relationship between extensions? If yyy [rdfs:subClassOf] zzz . then every yyy _is_ a zzz (not just everything in the extension of yyy is in the extension of zzz). If rdfs:subClassOf is pronounced "rdfs:subSETOf" then we ought to consider fixing the spelling. > Even if the range of aaa had exactly > the same members as yyy, it still wouldn't follow that yyy *was* the > range of aaa. > > Pat -- jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/ Tel +44(0)117 9287088 Fax +44 (0)117 9287112 RFC822 jan.grant@bris.ac.uk and Nostradamus never dreamed of the Church of the Accellerated Worm
Received on Friday, 28 June 2002 05:43:32 UTC