- From: Phil Archer <parcher@icra.org>
- Date: Thu, 17 Jan 2008 16:37:08 +0000
- To: Jeremy Carroll <jjc@hpl.hp.com>
- CC: public-powderwg@w3.org
Jeremy, Can I just ask a quick question about what you've written in the OWL wiki. Your Example of POWDER Full is in two parts - one that is an "OWLed up" version of the primary example DR and another which expresses the sub class relationship. Is your view of POWDER Full (or of a DR-S) that it is both of these or just one of them? It looks to me as if an RDF/XML instance as shown below, which is the sub class relationship plus the attributions triples, does the whole thing? hence the point about each DR having to exist as a separate document? Phil. <rdf:RDF> <rdf:Description rdf:about=""> <foaf:maker rdf:resource="http://authority.example.org/foaf.rdf#me" /> <dcterms:issued>2007-07-02</dcterms:issued> <wdr:validFrom>2008-07-07</wdr:validFrom> <wdr:validUntil>2008-07-07</wdr:validUntil> <dc:description>Textual information to display to end users </dc:description> <wdr:URISet rdf:nodeID="URIs"> <owl:intersectionOf rdf:parseType="Collection"> <owl:Restriction> <owl:onProperty rdf:resource="&wdr;includeHosts" /> <owl:hasValue>example.org</owl:hasValue> </owl:Restriction> </owl:intersectionOf> </wdr:URISet> <owl:Class rdf:nodeID="descriptors"> <owl:intersectionOf rdf:parseType="Collection"> <owl:Restriction> <owl:onProperty rdf:resource="&ex;property1" /> <owl:hasValue>value 1</owl:hasValue> </owl:Restriction> <owl:Restriction> <owl:onProperty rdf:resource="&ex;property2" /> <owl:hasValue>value 2</owl:hasValue> </owl:Restriction> </owl:intersectionOf> </owl:Class> <owl:Restriction> <owl:onProperty rdf:resource="&wdr;hasURI"/> <owl:someValuesFrom rdf:nodeID="URIs"/> <rdfs:subClassOf rdf:nodeID="descriptors"/> </owl:Restriction> </rdf:RDF> Jeremy Carroll wrote: > > > I didn't make much progress on Friday over and above what I've already > pointed to. > > http://www.w3.org/2007/OWL/wiki/POWDER > > I need to do other work, and hope to work on the powder stuff again > either Thursday or Friday this week. > > On the validity issue, my current thought is as follows. > > - Each DR should be in its own document (at least notionally: i.e. there > is a URL that if you do a get you get the DR - that's not to exclude the > case where mutliple DRs are listed together in a single file, in > addition to the individual files). > - The validity refers to the validity of the file (and hence of the > individual DR). > - The subclass relationship corresponding to a DR necessarily follows, > even if the DR is invalid (But invalid DRs may or may not be true). > - To work out the formal meaning of a set of powder files, the first > step is to take the RDF merge of the valid files, and then take the RDF > semantics for that merge. > > This follows the named graphs paradigm, in leaving 'difficult' stuff > (e.g. time) outside the formal treatment, but providing a pragmatic > treatment (ignore invalid files). > > I still need to think through the relationship with packages. > Unless the discussion indicates that the above approach is misguided, > I'll write it up, as part of the proposed formal treatment, and include > it in the wiki page. > > Jeremy >
Received on Thursday, 17 January 2008 16:37:22 UTC