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Re: How does RDF/OWL formalism relate to meanings?

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Sun, 11 Apr 2004 23:22:31 -0400
Message-Id: <A1EE0522-8C30-11D8-9E7D-0003936A0B26@isr.umd.edu>
Cc: public-sw-meaning@w3.org
To: "John Black" <JohnBlack@deltek.com>

On Apr 11, 2004, at 11:04 PM, John Black wrote:
[snip]
> In the RDF Semantics Recomendation it states:
>
> "1.2 URI references, Resources and Literals.
> This document does not take any position on the way that URI references
> may be composed from other expressions, e.g. from relative URIs or
> QNames; the semantics simply assumes that such lexical issues have been
> resolved in some way that is globally coherent, so that a single URI
> reference can be taken to have the same meaning wherever it occurs."
> - http://www.w3.org/TR/rdf-mt/#urisandlit
>
> What is the effect of the language, "...so that a single URI
> reference can be taken to have the same meaning wherever it occurs."?
> How important is this assumption to RDF semantics?

Upon reflection, that isn't the best wording.

Roughly: In the *graph* there are only absolute URIs. There also are no 
contexts, so every node labeled with the same uri is equivalent.

*Between* graphs, however, URIs can behave quite differently (until you 
merge them).

I'd say it's pretty important :)

Note that URIs in literals (e.g., in literals of datatype xsd:anyURI) 
are exempt from this merging. So the above text isn't quite right if 
you try to read it in full generality.

Cheers,
Bijan Parsia.
Received on Sunday, 11 April 2004 23:23:10 GMT

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