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Re: Representing the Differences Between two Models

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Sat, 31 Mar 2001 10:11:39 +0100
Message-ID: <3AC59F4B.BBDCECDE@hplb.hpl.hp.com>
To: Arnold deVos <adv@langdale.com.au>
CC: RDF interest group <www-rdf-interest@w3.org>
Hi Arnold,

It is interesting you also should find the need for this.  I think TimBL
mentioned at the recent interest group meeting in Boston that he was
doing something similar, though if I remember correctly he was using
'quoting' rather than 'statements'.

There is an issue on the issues list page:

  http://www.w3.org/2000/03/rdf-tracking/#rdfms-quoting

so this will be addressed by the new RDFCore WG.  I'll add a link from
the issue to your message.

Brian




Arnold deVos wrote:
> 
> Here is a proposal [1] for representing the difference between two RDF
> models as an RDF model.   In the electric power industry have a use case for
> this in exchanging power system models between utilities [2].  I would
> imagine there are others who have giant models like us and sometimes  need
> to handle only the differences.
> 
> Something like this requires quoting of RDF statements.  I know this is
> supposed to be covered by rdf:bagID, but I couldn't see how to use that in
> this case without creating a self-contradictory model.  Therefore I am
> floating an (application-specific?) extension to the syntax,
> parseType="Statements".  This is supposed to be similar to the braces in N3
> [3].
> 
> Here is an illustration of a difference model using this extension:
> 
> <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>      xmlns:cim="http://iec.ch/TC57/2000/CIM-schema-cimu09a#"
>      xmlns:dm=http://iec.ch/TC57/2001/Differences>
>  <rdf:Description about="">
>   <!-- Content: (literal-property|resource-property)* -->
>   <dm:preconditions parseType="Statements">
>    <!-- Content: (definition|description)* -->
>   </dm:preconditions>
>   <dm:forwardDifferences parseType="Statements">
>    <!-- Content: (definition|description)* -->
>   </dm:forwardDifferences>
>   <dm:reverseDifferences parseType="Statements">
>    <!-- Content: (definition|description)* -->
>   </dm:reverseDifferences>
>  </rdf:Description>
> </rdf:RDF>
> 
> Here is a short definition of the parseType used above:
> 
> * The content model of a property element with rdf:parseType="Statements" is
> the same as the content model of the rdf:RDF element.
> 
> * The content generates the same RDF statements as if it appeared in an
> rdf:RDF element.  Note: these statements may duplicate or contradict others
> outside the enclosing element.  RDF processors are not entitled to eliminate
> such duplicates. The statements are in a separate "context".
> 
> * The value of a property element with rdf:parseType="Statements" is a
> collection of resources of type rdf:Statement, representing the generated
> statements.
> 
> - Arnold
> 
> [1] http://www.langdale.com.au/CIMXML/DifferenceModelsR03.pdf (Sorry only in
> PDF for the moment.)
> 
> [2] http://www.langdale.com.au/CIMXML
> 
> [3] http://www.w3.org/DesignIssues/Notation3.html
Received on Saturday, 31 March 2001 04:11:08 GMT

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