- From: patrick hayes <phayes@ai.uwf.edu>
- Date: Fri, 14 Jun 2002 22:06:06 -0500
- To: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
- Cc: w3c-rdfcore-wg@w3.org
>At 08:15 AM 6/14/02 -0500, Dan Connolly wrote: >>Second, would somebody please show how this helps with layering? >> >>i.e. show how it relates to the example in... >> >># Layering OWL on RDF: the case for unasserted triples >>Jonathan Borden (Thu, May 30 2002) >>http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002May/0145.html > >The example in the referenced document uses additional statements: > > owl:List rdf:type rdf:Unasserted . > owl:first rdf:type rdf:Unasserted . > owl:rest rdf:type rdf:Unasserted . > owl:nil rdf:type rdf:Unasserted . > >but Guha has explained that that approach is non-monotonic. > >The revised proposal simply defines triples using certain URIs to be >unasserted, regardless of any other triples that may appear in the >graph, so there's no question that adding a new triple makes a truth >out of a falsehood. > >Referring to my suggestion, the properties used above as owl:List, >owl:first, owl:rest, owl:nil would be given URIs of the form: > > http://www.w3.org/2002/06-rdf-unasserted#List > http://www.w3.org/2002/06-rdf-unasserted#first > http://www.w3.org/2002/06-rdf-unasserted#rest > http://www.w3.org/2002/06-rdf-unasserted#nil > >Actually, I don't think List and nil need to be given this >unasserted treatment. I now agree. I think we should only require that *properties* are unasserted. This has a beneficial side-effect in any case regarding back-compatibility, since then it anything rdf-entailed by an unasserted triple is also unasserted; so that an RDF engine that ignores unassertion won't cause any 'harm' to one that pays attention to it. Pat -- --------------------------------------------------------------------- IHMC (850)322 0319 cell 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax
Received on Friday, 14 June 2002 23:06:05 UTC