- From: Alan Ruttenberg <alanruttenberg@gmail.com>
- Date: 2007年12月12日 09:33:24 -0500
- To: Jeremy Carroll <jjc@hpl.hp.com>
- Cc: Semantic Web <semantic-web@w3.org>
- Message-Id: <934EB966-57F0-4CC5-A428-589CBB0F847B@gmail.com>
A consequence of this will be that rdf clients that are unaware of this convention will load all the named graphs in to one. Is this an acceptable consequence? -Alan On Dec 12, 2007, at 9:02 AM, Jeremy Carroll wrote: > > > Suggestion: create a new attribuite rdf:graph="URIRef" to provide > for named graph support in RDF/XML. > > > === > > I have noticed that both POWDER and OWL 1.1 want to use reification > in order to give metadata about triples (or more generally, parts > of graphs). > > It is known and documented (in RDF Semantics) that reification > reifies statements rather than triples, and so, at least according > to the formal semantics, the attempts to use reification in this > way, do not work. > > One of the motivations for the named graphs view of the world, was > to address such use cases. > > Unfortunately, the only serialization of named graphs suggested > uisng RDF/XML, is to have multiple files with one graph per file, > which is, at least, awkward. > > I think maybe we should change that, by updating RDF/XML to have an > additional attribute rdf:graph that can appear on typed nodes, > rdf:Description, and property elements. > > The value of the attribute is a (relative) URI that is resolved in > the normal way against the current inscope base URI. > > The semantics is that the triple(s) generated by this part of the > XML (and all its descendents) are added *both* to the RDF graph > corresponding to the file, and to the RDF graph named by the > attribute. > > If an RDF/XML file uses a URI as the value of an rdf:graph > attribute, then the RDF/XML file claims to give a complete > definition of the graph with that name. > > To give an example: > > > <rdf:RDF xml:base="http://example.org/powder"> > <owl:Class rdf:ID="RC" rdf:graph="#p"> > <rdfs:comment>The class of resources on on example.org</ > rdfs:comment> > </owl:Class> > > <owl:Class rdf:ID="Blue"> > <rdfs:comment>The set of all things that are blue</rdfs:comment> > </owl:Class> > > <rdf:Description rdf:about="#RC > > <rdfs:subClassOf rdf:resource="#Blue" rdf:graph="#p" /> > </rdf:Description> > > <rdf:Description rdf:about="#p" rdf:graph="#p"> > <foaf:maker rdf:resource="http://example.com/foaf.rdf#david" /> > <dcterms:issued>2007年12月04日</dcterms:issued> > <wdr:validUntil>2008年12月03日</wdr:validUntil> > </rdf:Description> > > </rdf:RDF> > > This then corresponds to teh following graphs: > > with > @prefix eg: http://example.org/powder# > > http://example.org/powder: > eg:RC rdf:type owl:Class . > eg:RC rdfs:comment "The class of resources on on example.org" . > eg:Blue rdf:type owl:Class . > eg:Blue rdfs:comment "The set of all things that are blue" . > eg:RC rdfs:subGraphOf eg:Blue . > eg:p foaf:maker <http://example.com/foaf.rdf#david> . > eg:p dcterms:issued "2007年12月04日" . > eg:p validUntil "2008年12月03日" . > > > http://example.org/powder#p: > eg:RC rdf:type owl:Class . > eg:RC rdfs:comment "The class of resources on on example.org" . > eg:RC rdfs:subGraphOf eg:Blue . > eg:p foaf:maker <http://example.com/foaf.rdf#david> . > eg:p dcterms:issued "2007年12月04日" . > eg:p validUntil "2008年12月03日" . > > The semantics says that eg:p is interpreted as the graph given > above (the syntactic object) and that that group has foaf:maker > being whatever #david refers to, etc etc. > > thoughts? > > Jeremy > > > >
Received on Wednesday, 12 December 2007 14:33:42 UTC