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Re: Representing the Differences Between two Models

From: Arnold deVos <adv@langdale.com.au>
Date: Sat, 31 Mar 2001 20:13:15 +1000
Message-ID: <000d01c0b9cb$38f1bc40$b12d18cb@cockatoo>
To: "Brian McBride" <bwm@hplb.hpl.hp.com>
Cc: "RDF interest group" <www-rdf-interest@w3.org>
Hi Brian,

thanks for the pointer to the issue.

I suppose many experimenters have found that some concept of "context" is
essential to their RDF applications. The various API's introduce the
'Model', N3 has {}'s but the M&S just has its bagID which does not quite do
the same thing IMHO.

The issue says a quoting syntax like parseType="Quote|Statements|whatever"
would be a convenience but I think it introduces something new to the RDF
Model: the missing concept of "context".

Cheers,
Arnold
--
Arnold deVos
Langdale Consultants
adv@langdale.com.au



----- Original Message -----
From: "Brian McBride" <bwm@hplb.hpl.hp.com>
To: "Arnold deVos" <adv@langdale.com.au>
Cc: "RDF interest group" <www-rdf-interest@w3.org>
Sent: Saturday, March 31, 2001 7:11 PM
Subject: Re: Representing the Differences Between two Models


> 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 05:24:10 GMT

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