- From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Date: Wed, 19 Sep 2001 21:07:34 +0100
- To: Pat Hayes <phayes@ai.uwf.edu>
- Cc: w3c-rdfcore-wg@w3.org
At 12:15 PM 9/19/01 -0500, Pat Hayes wrote: >If anyone wants to focus, I'd suggest looking at the stuff on RDF >entailment. Here's a question that occurred to me, for example. Suppose we >know that >aaa rdf:type bbb . >and also >bbb rdfs:subClassOf ccc . >Now, it follows that aaa is in fact a member of the class ccc; but do we >want to say that this means that >aaa rdf:type ccc > >must be true? If we do, that table of RDF entailment rules would need some >more entries. Right now it reflects the view that being in a class doesn't >necessarily mean having that class as a type, only having some subclass of >it as a type. Hmmm... From above: 1. <I(aaa),I(bbb)> in IEXT(I(rdf:type)) 2. <I(bbb),I(ccc)> in IEXT(I(rdfs:subClassOf)) From 1. and 5th rule of RDFS interpretation: 3. I(aaa) in ICEXT(I(bbb)) From 2. and 6th rule of RDFS interpretation: 4. ICEXT(I(bbb)) subset ICEXT(I(ccc)) Then by 3 and 4: 5. I(aaa) in ICEXT(I(ccc)) Which is the condition for aaa rdf:type ccc QED? If I'm right, these means no change is needed unless aaa is NOT of rdf:type ccc. #g ------------------------------------------------------------ Graham Klyne MIMEsweeper Group Strategic Research <http://www.mimesweeper.com> <Graham.Klyne@MIMEsweeper.com> ------------------------------------------------------------
Received on Wednesday, 19 September 2001 16:16:34 UTC