Re:

Yeah. If we had a standard way of talking about graphs (you know, there is that n...d graph concept whose name I am not sure we know:-) than we could of course talk about triples that are restricted to that profile file (if the semantics of those animals are defined in a way that sameAs does not mean automatic membership for other triples, which is one of the issue with reification...). But, well, alas!, sigh...

Ivan

On Aug 12, 2010, at 11:24 , Toby Inkster wrote:

> On Fri, 6 Aug 2010 07:40:04 +0200
> Ivan Herman <ivan@w3.org> wrote:
> 
>> This was discussed several times on the mailing list and I fully
>> understand your issues. Here is the reason I was in favour of the
>> current setup, but I am absolutely open to discussion because, well,
>> it does complicate processing (speaking as an implementer).
> 
> FWIW, I agree with your reasoning for the current vocab. Prefix and term
> mappings are semantically a relationship between two strings.
> 
> Imagine this:
> 
> 	<http://xmlns.com/foaf/0.1/> rdfa:prefix "foaf" .
> 
> Now, the following is also true (probably):
> 
> 	<http://xmlns.com/foaf/0.1/>
> 	  a owl:Ontology ;
> 	  owl:sameAs <http://dbpedia.org/resource/FOAF_(software)> .
> 
> Thus it follows that:
> 
> 	<http://dbpedia.org/resource/FOAF_(software)>
> 	  rdfa:prefix "foaf" .
> 
> Thus an RDFa processor could expand 'foaf:name' to:
> 
> 	<http://dbpedia.org/resource/FOAF_(software)name>
> 
> Which we wouldn't want to happen.
> 
> In RDF terms, when we're defining prefixes and terms we're not
> describing the underlying resources - we're just talking about
> the xsd:strings. We're not even talking about xsd:anyURIs, because
> say, "htt" is a valid expansion for a prefix, which might be used
> as follows:
> 
> 	prefix="h: htt"
> 	property="h:p://xmlns.com/foaf/0.1/"
> 
> So I'd recommend keeping the current pattern, though I think the
> range of rdfa:uri should be changed to xsd:string for the above
> reason.
> 
> Another argument against switching to
> 
> 	<http://xmlns.com/foaf/0.1/> rdfa:prefix "foaf" .
> 
> would be the fact that you'd lose the owl:FunctionalProperty-ness of
> rdfa:prefix and rdfa:term.
> 
> -- 
> Toby A Inkster
> <mailto:mail@tobyinkster.co.uk>
> <http://tobyinkster.co.uk>
> 
> 


----
Ivan Herman, W3C Semantic Web Activity Lead
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