W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > November 2002

Re: More on XSD in RDF

From: pat hayes <phayes@ai.uwf.edu>
Date: Sat, 30 Nov 2002 21:57:38 -0600
Message-Id: <p05111b0cba0f138d6f26@[10.0.100.247]>
To: "Patrick Stickler" <patrick.stickler@nokia.com>
Cc: w3c-rdfcore-wg@w3.org

>Excellent summary, Jeremy. And this definitely touches on my concerns about
>the basis being used for certain entailment tests involving relations between
>datatypes -- as to where those relationships are defined and whether those
>relationships sync with the RDF definition for rdfs:Datatype.
>
>My impression is that while there is evidently a problem with 
>equality in XML Schema
>simple datatypes, it is not per se a problem with RDF Datatyping.
>
>I.e., it should be sufficient to (a) note the problems in XML Schema 
>and (b) submit
>suggestions to the XML Schema WG, but I don't see how this impacts the current
>RDF datatyping model.
>
>If XML Schema says that xsd:float and xsd:decimal have disjunct value spaces,
>we may wish to disagree and consider that a bug, but that doesn't affect how
>those datatypes are modeled in RDF. It simply means that the assertion
>
>    xsd:decimal rdfs:subClassOf xsd:decimal .
>
>(and/or visa versa) is (possibly) in conflict with the XML Schema spec.
>So what. That's not RDF's problem and RDF is not creating the problem.
>If the XML Schema spec says "1.0"^^xsd:decimal != "1.0"^^xsd.float  (and
>my understanding is that it does say this) then applications should respect
>that if they are using those datatypes.
>
>If the XML Schema datatype relations are either broken or ill 
>defined, then fix them.
>
>The RDF datatyping model is then providing a benefit to the XML community by
>shining a light on the problem.

I absolutely agree. It is not our job to fix or even to clarify XSD 
datatyping. We can state our requirements in terms of what 
information a datatype-savvy inference engine would require and what 
inferences it can draw as a result, without once making any 
substantial claims about what the actual data obtained from XSD would 
actually be. If Dan and Jeremy wish to help XML Schema get their 
house in order, then all strength to them. In the meantime, however, 
we should get on with our job.

Pat

>Eh?
>
>Patrick
>
>[Patrick Stickler, Nokia/Finland, (+358 40) 801 9690, 
>patrick.stickler@nokia.com]
>
>
>----- Original Message -----
>From: "ext Jeremy Carroll" <jjc@hplb.hpl.hp.com>
>To: <w3c-rdfcore-wg@w3.org>
>Sent: 25 November, 2002 10:18
>Subject: More on XSD in RDF
>
>
>>
>>
>>  I was looking over XSD again.
>>  It seems to me as though the recommendation to use XSD within RDF raises
>>  more questions than we have currently been considering. IMO, it may knock
>>  us off target (and probably should).
>>
>>  I have begun working on what I think would be a set of answers ...
>>
>>  See:
>>
>>  http://sealpc09.cnuce.cnr.it/jeremy/xsd-rdf-2002-11-25/
>>
>>  or maybe (the supposedly equal)
>>
>>
>>  http://sealpc09.cnuce.cnr.it/jeremy/xsd-rdf-2002-11-25/index2.html
>>
>>  (I have a stylesheet issue - in the tables red text may only come out in
>>  purple with a strikethrough, whereas the green text comes out in purple
>>  without the strikethrough).
>>
>>  Jeremy
>>


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Received on Saturday, 30 November 2002 23:54:40 EST

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