RE: Literals (Re: model theory for RDF/S)

> -----Original Message-----
> From: ext Graham Klyne [mailto:GK@ninebynine.org]
> Sent: 03 October, 2001 11:52
> To: Stickler Patrick (NRC/Tampere)
> Cc: www-rdf-logic@w3.org
> Subject: RE: Literals (Re: model theory for RDF/S)
> 
> 
> At 10:25 AM 10/3/01 +0300, Patrick.Stickler@nokia.com wrote:
> >But those URIs and literal values retain their full identity disjunct
> >from any other URIs or literal values, right?
> >
> >Does this mean that in the (new?) RDF graph model, a resource node
> >can have multiple labels?
> 
> No, just zero or one label for each graph node.  But these 
> may or may not 
> be interpreted as the same thing in the domain of interpretation.
> 
> Remember that a graph node is just part of the syntactic 
> structure as far 
> as the model theory is concerned.  The interpretation 
> (mapping) functions 
> LX and IS yield corresponding values;  two nodes may be thus 
> mapped to the 
> same value.

Fair enough. As long as that equivalence is a matter of interpretation
and not lost in the actual realization of the graph, then I can sleep
easy at night ;-)
 
> ...
> 
> I think there's still an open question about the nature of 
> this value.  On 
> the web, one can retrieve several different values using the 
> same URI (e.g. 
> via content negotiation).  How is this captured?
> 
> One thought I have is to map a graph node to a thing called a 
> "resource", 
> and have an extension set associated with each resource that 
> corresponds to 
> the "entities" that can be retrieved using the URI, or are otherwise 
> associated with the resource.  Under this approach, equivalence of 
> resources means that they have the same extension sets.  This 
> is similar to 
> the treatment of RDF classes, and I think it sits more easily 
> with RFC 2396 
> description of a resource as a "conceptual mapping" separate from 
> particular associated entities.

This sounds intuitively right to me, though I am often a
bit lost in the details of the MT semantics and so have little
idea how that would be defined in a formal fashion.

Still, it seems "correct" insofar as I've understood your
natural language description...

Regards,

Patrick

--
Patrick Stickler                      Phone:  +358 3 356 0209
Senior Research Scientist             Mobile: +358 50 483 9453
Nokia Research Center                 Fax:    +358 7180 35409
Visiokatu 1, 33720 Tampere, Finland   Email:  patrick.stickler@nokia.com

Received on Wednesday, 3 October 2001 05:15:48 UTC