- From: pat hayes <phayes@ai.uwf.edu>
- Date: Thu, 16 Aug 2001 13:37:31 -0700
- To: Dan Connolly <connolly@w3.org>
- Cc: w3c-rdfcore-wg@w3.org
>pat hayes wrote: >[...] > > I will try to get the damn thing completely done, except for the > > Proofs appendix, by the end of the week, at which point it should be > > puttable on a website. (Also I could re-do the powerpoint slides to > > fit this new version if y'all think that would be useful.) > > > > Any feedback welcome. > >[...] > > > Name: RDF_Model_Theory_postF2F.html > >| <comment> When considering RDFS we will require interpretations >| to have extra structure. </comment> > >I'd rather not take that approach. I'd rather that the model >theory were a model theory for all of RDF, no more, and no less. >I don't want to give the impression that folks should tinker >with the core model theory when they introduce new vocabulary. > >New vocabularies should just be specified as constraints >on the core interpretation structure, not changes to it. Well, OK, but what IS the 'new' vocabulary? RDF and RDFS seem to be so entwined together that I think of them as one language. Without RDFS, RDF is really *very* simple. >| in particujlar, the notion of a 'class', so we will need to >| assume that the universe of >| interpretations contains classes as elements. > >Why? It seems to me that IEXT(rdf:type) completely captures >the notion of 'class'. Anything we want to say about 'class' >can be said by way of IEXT(rdf:type), no? >| 5. A subset IC of IR, containing classes > >| 6. A mapping ICEXT from IC to the powerset of (IR union LV) , >| ie the set of subsets of elements >| of IR or XL. > >ICEXT(c) is just the set { x: <x,c> \in IEXT(rdf:type) }, no? >an IC is (at least) the set { y: exists x where <x,y> \in IEXT(rdf:type) >} >right? > >yup... you say as much later in the document: > >| >> <x,y> is in IEXT(I(rdf:type)) iff x is in ICEXT(y) Indeed. I thought of this as a semantic constraint on the meaning of 'type', but you could regard it as defining classes in terms of rdf:type, I guess. This is really only a stylistic difference. OK, give me a couple of days and I'll do a variant that defines ICEXT this way. Pat --------------------------------------------------------------------- (650)859 6569 w (650)494 3973 h (until September) phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Thursday, 16 August 2001 16:36:49 UTC