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RE: question about OWL-S and XML Schema version

From: Terry R. Payne <trp@ecs.soton.ac.uk>
Date: Wed, 16 Jul 2003 08:25:25 +0100
To: "'David Martin'" <martin@ai.sri.com>, "'Grit Denker'" <Grit.Denker@sri.com>
Cc: <www-ws@w3.org>
Message-ID: <028201c34b6b$6d0d06e0$0100a8c0@ecs.soton.ac.uk>

	I just looked at this (I didn't check with my recent spate of
changes) and indeed there could be a problem, specifically as this URL
refers to just the html of a doc.

A little digging reveals that the schema itself is in [1]

[1] http://www.w3.org/2001/XMLSchema-datatypes.xsd

But the issue is that of what it means to resolve a URL and a namespace.
Many people (including myself) work on the (broken) assumption that URLs
can be resolved and the information retrieved by a simple http request.
It's not totally valid, but works for now.

Looking at the schema, it does define the namespace to be
http://www.w3.org/2001/XMLSchema, but this presupposes that your
reasoning engine has already retrieved the schema definition in [1] that
defines this namespace... Ah, but on closer inspection, the
targetNamespace defined in [1] is:

[2] http://www.w3.org/2001/XMLSchema-datatypes

i.e. the schema URL minus the extension!

I'm never sure what the exact difference of default namespace and target
namespace is, so unless anyone can clarify off the top of their head,
I'll investigate.

I suspect that we should probably change the namespace in the daml-s
docs to either [1] or [2]...


Terry R. Payne, PhD.      | http://www.ecs.soton.ac.uk/~trp/index.html
University of Southampton | Voice: +44(0)23 8059 8343 [Fax: 8059 2865]
Southampton, SO17 1BJ, UK | Email: terry@acm.org / trp@ecs.soton.ac.uk

> -----Original Message-----
> From: www-ws-request@w3.org [mailto:www-ws-request@w3.org] On Behalf
> David Martin
> Sent: 16 July 2003 00:11
> To: Grit Denker
> Cc: www-ws@w3.org
> Subject: question about OWL-S and XML Schema version
> [Note: the original message wasn't posted on www-ws.]
> Grit Denker wrote:
> > Hi All,
> >
> >we tried to load the latest version of Process.daml into our
> >DAML+OIL-plugin for Protege and ran into
> >
> ><daml:DatatypeProperty rdf:ID="invocable">
> >  <rdfs:comment>Invocable is a flag that tells whether the
> >CompositeProcess
> >bottoms out in atomic processes. (If so, it is
> >"invocable".)</rdfs:comment>
> >  <rdfs:domain rdf:resource="#CompositeProcess" />
> >  <rdfs:range rdf:resource="http://www.w3.org/2001/XMLSchema#boolean"
> ></daml:DatatypeProperty>
> >
> >The referenced range does not (yet) seem to be fully defined (the web
> >page hardly contains any information yet).
> >Is this a bug or a reference to upcoming XMLSchema?
> >Shouldn't the range resource be
> >http://www.w3.org/2000/10/XMLSchema#boolean?
> >That would at least have substantial definitions.
> >
> >Could somebody please clarify this for me? We would like to know
> >whether we need to extend our plugin.
> >
> Hi Grit -
> With the latest release (0.9) of DAML-S/OWL-S, we changed the
> namespace to
> http://www.w3.org/2001/XMLSchema
> as you have noticed.
> This was done at the suggestion of a knowledgable user who said it
> make life much easier for him, and also because it seemed obvious that
> we should employ the most recent completed release.
> I'm not really an expert on XML Schema, but I believe this namespace
> does represent the most recent completed release.  If that's not
> correct, someone please respond with the correct info.
> I don't know why the document at http://www.w3.org/2001/XMLSchema_ _
> is so impoverished.  But it is my impression that that's the correct
> namespace to use.  Take a look at the document here:
>     http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/datatypes.html
> for better documentation of the datatypes.  Note that this document
> references the above namespace.
> Finally, I must admit I never considered whether this change would
> affect the work on the plugin.  The only resulting change we made in
> DAML-S/OWL-S files was this:
>    changing uriReference to anyURI.
> Regards,
> David
Received on Wednesday, 16 July 2003 03:26:22 UTC

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