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Re: question about OWL-S and XML Schema version

From: Jos de Bruijn <jos.de-bruijn@uibk.ac.at>
Date: Wed, 16 Jul 2003 09:42:13 +0200
Message-ID: <3F1501D5.8050507@uibk.ac.at>
To: "Terry R. Payne" <trp@ecs.soton.ac.uk>
CC: "'David Martin'" <martin@ai.sri.com>, "'Grit Denker'" <Grit.Denker@sri.com>, www-ws@w3.org
Dear all,

I have looked at the schema at 
http://www.w3.org/2001/XMLSchema-datatypes.xsd and all it does is take 
data types from the http://www.w3.org/2001/XMLSchema namespace and put 
them in the http://www.w3.org/2001/XMLSchema-datatypes namespace. So the 
correct namespace would still be http://www.w3.org/2001/XMLSchema.
It makes no sense for a reasoning engine to retrieve a schema for 
XMLSchema. The schema should be expressed in another schema language and 
we can keep on going.
The reasoning engine should have built-in support for XMLSchema. This is 
what is assumed when the http://www.w3.org/2001/XMLSchema is used. A 
reasoning engine for daml is also assumed to have the knowledge to cope 
with daml. It cannot depend on the retrieval of a schema for daml.

Best,

Jos de Bruijn

Terry R. Payne wrote:

>Dave,
>	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
>
>
>_______________________________________________________________________
>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
>>    
>>
>Of
>  
>
>>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
>>    
>>
>XMLSchema
>  
>
>>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
>>    
>>
>would
>  
>
>>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
>>    
>>
>
>
>
>  
>

-- 
Jos de Bruijn

Institute of Computer Science
University of Innsbruck
Technikerstraße 13
A-6020 Innsbruck
Austria
 
Tel:      +43 512 507 6475
Fax:      +43 512 507 9872
Email:    jos.de-bruijn@uibk.ac.at
Homepage: http://homepage.uibk.ac.at/~c703239/

Next Web Generation research group
http://www.nextwebgeneration.org/
Received on Wednesday, 16 July 2003 03:42:20 GMT

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