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Re: Datatypes, datatype classes, URIs and uniqueness

From: pat hayes <phayes@ai.uwf.edu>
Date: Wed, 11 Dec 2002 12:57:26 -0600
Message-Id: <p05111b05ba1d3a6d202b@[10.0.100.86]>
To: Brian McBride <bwm@hplb.hpl.hp.com>
Cc: w3c-rdfcore-wg@w3.org

>At 18:19 09/12/2002 -0600, pat hayes wrote:
>
>[...]
>
>>>I think that it would be better to say that datatype URIs denote
>>>the datatype class, the instance of rdfs:Datatype, and that the class
>>>extension is the value space of the datatype.
>>
>>that would be clearer. I will rephrase this to make it clear there 
>>is no ambiguity.
>
>Hmmm, I'm not so sure about that.  I think that datatypes as 
>interpretation properties will be used, and it was Patrick that 
>argued that he didn't want multiple uri's, and Pat's rather neat 
>model theory trick that allows a resource to have both a class and a 
>property extension.
>
>If we say that the URI denotes the class, I wonder if we run into 
>problems with the fact that its up to xsd to say what the URI 
>denotes and into issues with the using the same uri for both the 
>class and the property.
>
>My mental model was that the URI denoted the datatype, as specified 
>by the xsd folks - its their uri after all, and we define what the 
>class extension of that URI is.

I think that we are all in violent agreement here. Denoting a class 
in RDFS *is* denoting a thingie with a class extension. So in the 
case of datatypes, the datatype *is* the RDFS class. Its also a 
datatype, and the point is that there is no incompatibility or 
ambiguity involved.

>
>Brian
>
>
>>Pat
>>
>>>I.e. the URI denotes just
>>>one thing, the class, and that class happens to have associated with it
>>>the semantics which capture the lexical space and L2V mapping.
>>>
>>>Saying the datatype URI means two things, a datatype and the value space
>>>of the datatype as a class (set) seems to violate the fundamental
>>>uniqueness principle of URIs.
>>>
>>>Or am I just confused...
>>>
>>>Patrick
>>>
>>>[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, 
>>>patrick.stickler@nokia.com]
>>
>>
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Received on Wednesday, 11 December 2002 13:57:31 EST

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