- From: Pat Hayes <phayes@ai.uwf.edu>
- Date: Fri, 15 Feb 2002 20:57:32 -0500
- To: "Smith, Michael K" <michael.smith@eds.com>
- Cc: webont <www-webont-wg@w3.org>
>Thanks, Pat. That is what I was looking for. At least I understand better >what's being said. Though it still doesn't quite compute. > >The N-Triples doc and the description of graphs in the MT are certainly >simple. But from the previous version of the RDF Model and Syntax >Specification I had thought there were restrictions on the permitted >triples. For example, that a predicate must be a Property. Well, theres an ambiguity here about what "must be" means. Since being in an RDFS class is a semantic issue and not a matter of syntax, it doesn't make sense to interpret this 'must be' as a syntactic restriction. It is a semantic one, which is just another way of saying that if you assert a triple S P O . then you can *infer* P rdf:type rdfs:Property . as indeed you can (cf. closure rule rdf1 , http://www.w3.org/TR/rdf-mt/#rdfsclosdef) >Not that this example causes a problem for the model theory. >If foo is a class and not a property, I(<foo,foo,1>) is false. True, but I don't see that as a problem. If you assert this, then you are saying that it isn't false, which is exactly where the 'restriction' comes from. > >Maybe I just need to wait for these docs to be finished. If I read the >referenced decision below it does not specify the single place where the >syntax of RDF will be defined. OK, fair enough; that issue is rather cloudy at the moment. The WG is working seriously on providing a single coherent overall view of RDFS and making sure that the various documents are aligned in terminology and, er, attitude. We havn't quite finished yet.... > The RDF/XML is incomplete in its ability to >express RDF. The editor of the RDF Syntax WD will include in that document >a clear statement of the RDF graph structures that RDF/XML is unable to >represent. Right, we know this needs to be done carefully. >Perhaps as a part of that effort, the RDF Syntax WD will provide >a complete syntax for RDF triples. Right. Pat -- --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Friday, 15 February 2002 20:57:29 UTC