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Re: Datatype Defaulting in OWL

From: Sean B. Palmer <sean@miscoranda.com>
Date: Thu, 22 Nov 2007 08:55:26 +0000
Message-ID: <b6bb4d890711220055i42c0a5eas7700cdeecc10de1c@mail.gmail.com>
To: "Bijan Parsia" <bparsia@cs.man.ac.uk>
Cc: "SW-forum Web" <semantic-web@w3.org>, "public-owl-wg Group WG" <public-owl-wg@w3.org>

On Nov 22, 2007 8:45 AM, Bijan Parsia <bparsia@cs.man.ac.uk> wrote:

> The problem is that the "5" *does* have a type: Plain literal. Of
> the top of my head, that type is the same as xsd:string but disjoint
> from xsd:integer.

Yeah, RDF Semantics says, Informatively:

"the value space and lexical-to-value mapping of the XSD datatype
xsd:string  sanctions the identification of typed literals with plain
literals without language tags for all character strings which are in
the lexical space of the datatype, since both of them denote the
Unicode character string which is displayed in the literal"
- http://www.w3.org/TR/2004/REC-rdf-mt-20040210/#DtypeRules

> So, either one needs a kind of macro, or some sort of type coercion.

The best I can find in the literature is this:

http://www.w3.org/TR/swbp-xsch-datatypes/#sec-use-amapping
- 3.6 Value Approximate Mapping

As far as I understand it, with aeq you can map some values from
plain/xsd:string to xsd:integer, but I'm not sure what the exact
machinery for doing so would be. In other words, how to go from the
rough idea of aeq in that WG note draft to something that I can
actually use in my ontology... :-)

Perhaps there should be a SWBP note for people who want to understand
how best to formalise entailments in a new RDF application, language,
specification, etc.?

[reordered]
> If you are really curious about the OWL perspective,
> public-owl-dev would be the right cc.

Thanks!

-- 
Sean B. Palmer, http://inamidst.com/sbp/
Received on Thursday, 22 November 2007 09:01:59 GMT

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