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RE: Type of (the denotation of) a plain literal

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Fri, 17 Jan 2003 11:59:52 +0100
To: "Jos De_Roo" <jos.deroo@agfa.com>, <pfps@research.bell-labs.com>
Cc: <w3c-rdfcore-wg@w3.org>
Message-ID: <BHEGLCKMOHGLGNOKPGHDIEONCAAA.jjc@hpl.hp.com>


My understanding of the relationship between xsd:string and untyped literals
is as follows:

1: we don't know, and we are intending to work with XML Schema WG after last
call to find out.

2: if there is any relationship then the test case
> > > but
> > > :Jenny :age "11"
> > > does not entail
> > > :Jenny :age "11"^^xsd:string
would be incorrect (entailment both ways would hold).

3: the semantics document should say clearly (I don't know if it does) that
the denotation of an untyped literal without a language identifier is the
unicode string.
(Dan felt strongly about this, and no one else objected)

4: that concepts document does not equate untyped literals without a
language identifier with unicode strings.

We have also not assigned a datatype or an rdfs class for the class of all
untyped literals. I believe this to be a minor error that we may wish to
consider fixing at some point. (It makes it difficult to state certain range
constraints.)

Jeremy



> -----Original Message-----
> From: w3c-rdfcore-wg-request@w3.org
> [mailto:w3c-rdfcore-wg-request@w3.org]On Behalf Of Jos De_Roo
> Sent: 17 January 2003 00:41
> To: pfps@research.bell-labs.com
> Cc: Jos De_Roo; w3c-rdfcore-wg@w3.org
> Subject: Re: Type of (the denotation of) a plain literal
>
>
>
>
> > > but
> > > :Jenny :age "11"
> > > does not entail
> > > :Jenny :age "11"^^xsd:string
> > > nor does the latter entail the former
> > >
> > > -- ,
> > > Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
> >
> > My view is that in XSD datatype entailment it does!  At least modulo a
> > cleanup of the RDF MT with respect to untyped literals.
> >
> > This is because I believe, based on a close examination of the
> XML Schema
> > Datatyping document, that the L2V mapping for xsd:string takes Unicode
> > strings to themselves.
>
> I'm maybe abstracting too much from the APPROVED testcase
>
>
> <test:NegativeEntailmentTest rdf:about
> ="http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/Manifest.r
> df#test009">
>
>    <test:status>APPROVED</test:status>
>    <test:approval rdf:resource
> ="http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Oct/0131.html" />
>    <test:description>
>      From decisions listed in
> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Oct/0098.html
>    </test:description>
>
>    <test:premiseDocument>
>       <test:NT-Document rdf:about
> ="http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/test009a.nt" />
>    </test:premiseDocument>
>
>    <test:conclusionDocument>
>       <test:NT-Document rdf:about
> ="http://www.w3.org/2000/10/rdf-tests/rdfcore/datatypes/test009b.nt" />
>    </test:conclusionDocument>
>
> </test:NegativeEntailmentTest>
>
>
> rewriting the special case of "abc"^^xsd:string as "abc"
> could work I think, but I see a lot of trouble when
> "abc" would be interpreted as a typed literal
> (especially for legacy cases)
>
>
> -- ,
> Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/
>
>
Received on Friday, 17 January 2003 06:01:05 EST

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