W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > January 2002

Re: Datatyping Summary

From: Graham Klyne <Graham.Klyne@MIMEsweeper.com>
Date: Wed, 30 Jan 2002 20:58:24 +0000
Message-Id: <5.1.0.14.2.20020130204759.038c8ec0@joy.songbird.com>
To: Dan Connolly <connolly@w3.org>
Cc: Jeremy Carroll <jjc@hplb.hpl.hp.com>, RDF core WG <w3c-rdfcore-wg@w3.org>
At 11:41 AM 1/30/02 -0600, Dan Connolly wrote:
> > Lets look at the example query first:
> >
> > [[[
> >    _:f <dc:Title> "10" .
> >    <mary> <age> "10" .
> >
> > Given a query:
> >
> >    (?x <dc:Title> ?y) & (?z <age> ?y)
> >
> > existing applications will return:
> >
> >    ?x = _:f, ?y = "10", ?z = <mary>
> >
> > ]]]
> >
> > RDF Query is of course, still an active research area, rather than one 
> where
> > there is any stable deployed code base. (There is deployed code, but it is
> > in development).
> >
> > Hence, discussion about query semantics would perhaps be better placed on
> > rdf-query, but ...
>
>Not so... The query above is clearly analagous
>to an entailment test; i.e. it's clearly within the scope of our
>model theory spec, and soon to be in scope of our test cases spec.

It is?  When I try to turn that into an entailment test, I seem to end up 
with either the original statement, or something that isn't covered in 
present RDF;  the nearest I can get is this:

Does this:
     _:f <dc:Title> "10" .
     <mary> <age> "10" .

entail this?:
     _:x <dc:Title> _:y .
     _:z <age> _:y .
     _:x = _:f .
     _:y = "10" .
     _:z = <mary> .

and even this uses something that is not (currently) defined in RDF, namely 
'='.  What, exactly, should we take '=' to mean?

Is this even remotely close to what you're suggesting here?

#g


------------------------------------------------------------
Graham Klyne                    MIMEsweeper Group
Strategic Research              <http://www.mimesweeper.com>
<Graham.Klyne@MIMEsweeper.com>
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Received on Wednesday, 30 January 2002 16:27:49 EST

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