- From: Jim Hendler <hendler@cs.umd.edu>
- Date: Thu, 30 May 2002 19:46:43 -0400
- To: "Jonathan Borden" <jonathan@openhealth.org>, "WebOnt WG" <www-webont-wg@w3.org>
- Cc: "pat hayes" <phayes@ai.uwf.edu>, <guha@guha.com>
John - w/due respect, did you mean this for WOWG or for RDF-logic, which is where that was posted. -JH At 7:17 PM -0400 5/30/02, Jonathan Borden wrote: >Pat, did you reall write: >http://lists.w3.org/Archives/Public/www-webont-wg/2002May/att-0302/00-part ? > >Now I agree that the mechanism you proposed to indicate darkness e.g. > >owl:List a owl:Dark > >is problematic from a monoticity perspective, but to suggest that > >[[ > but the exact details do not matter to the point being made here. >]] > >and that _dark triples themselves are inherently nonmonotonic_ is going a >bit to far, eh? > >For example than triples, are rather than dark, let's consider: colored >triples, and so a triple becomes a quad: > >subject predicate object color . > >where color is a URIref just like the others. > >Now assume that for all current RDF documents, the parser generates a color >rdf:White, which corresponds to an asserted triple in the MT. > >Now suppose that the color of the triples (really quads but go with this), >is a function of some attribute on the <rdf:RDF> root element of any RDF >document e.g. > ><rdf:RDF color="red"> > <rdf:Description rdf:ID="foo"> > <ex:shape rdf:resource="#square"> > </rdf:Description> ></rdf:RDF> > >which generates the following N-Quad: > ><#foo> ex:shape <#square> rdf:red . > >of course the color doesn't need to be rdf:red, but could be any URI, but >that really doesn't matter. > >So what could possibly be nonmonotonic about that? > >Now assume that dark triples are triples with the color rdf:black. > >Are you really suggesting that triples are monotonic, but quads are >_inherently nonmonotonic_ ? Surely not. > >So, as with everything, the exact details do matter to the point being made >here, and to suggest that dark triples are inherently nonmonotonic can only >be true if your specific definition of what a dark triple is and how it is >created causes the nonmonotonicity. > >Jonathan -- Professor James Hendler hendler@cs.umd.edu Director, Semantic Web and Agent Technologies 301-405-2696 Maryland Information and Network Dynamics Lab. 301-405-6707 (Fax) Univ of Maryland, College Park, MD 20742 240-731-3822 (Cell) http://www.cs.umd.edu/users/hendler
Received on Thursday, 30 May 2002 19:47:25 UTC