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Re: RDF named graph use case and requirement

From: Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk>
Date: Mon, 26 Sep 2011 14:17:28 +0100
Message-ID: <CAPRnXtnnVAiGVbGMCQmoaM++52VNgAVvdf=i6epAj7_uHT+4FA@mail.gmail.com>
To: Graham Klyne <GK@ninebynine.org>
Cc: Luc Moreau <L.Moreau@ecs.soton.ac.uk>, W3C provenance WG <public-prov-wg@w3.org>
On Fri, Sep 23, 2011 at 07:26, Graham Klyne <GK@ninebynine.org> wrote:


> If one wants to be able to treat these as two different descriptions made by
> different people, even if they have the same text, then one must choose a
> different modeling approach in RDF, such as:

So you are saying that if we are to use graph literals as a way to
represent named graphs, but we want to somewhat describe that two
different processes produced the same named graph *structure*, we need
to introduce two prov:entities, as otherwise RDF semantics means they
are the same node.

As you stated, the same argument can be used for other literals, which
is why if in the workflow example two process executions both output
the string value "Fred", those two Freds will have to be expressed as
two entities with two different identities within the provenance
assertions. (Both can have attribute value="Fred")


This sounds all in line with how PROV is at the moment. So you could
have two entities, which have the characterising attribute "graph"
pointing to the very same graph literal.  Each of these entities can
then have independent histories and wasGeneratedBy statements.



-- 
Stian Soiland-Reyes, myGrid team
School of Computer Science
The University of Manchester
Received on Monday, 26 September 2011 13:18:25 GMT

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