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Re: Latest iteration of RDF Datatyping WD (ship it!)

From: Pat Hayes <phayes@ai.uwf.edu>
Date: Wed, 17 Apr 2002 17:51:46 -0500
Message-Id: <p0510150eb8e3ab6b0615@[65.217.30.94]>
To: Patrick Stickler <patrick.stickler@nokia.com>
Cc: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>, w3c-rdfcore-wg@w3.org
>On 2002-04-16 11:07, "ext Jos De_Roo" <jos.deroo.jd@belgium.agfa.com> wrote:
>
>>
>>
>>>>  this sounds like a union...
>>>>  and I don't see that as explained in
>  >>> http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2002Mar/0151.html
>  >>> and as I still think we should have
>>>>    rdfd:range rdfs:subPropertyOf rdfs:range .
>>>
>>>  I would not recommend that. That would re-introduce all the
>>>  range-inheritance problems assocaited with datatyping. The basic idea
>>>  of the current proposal is to keep range-assignment (ie rdfs:Range)
>>>  and datatyping (rdfd:Range) quite separate, so you can have either
>>>  one without the other (or both if you choose to). That is the only
>>>  way I can see to allow the kind of Dublin-Core sloppiness in a
>>>  rational framework.
>>
>>  agreed, we currently have something like
>>
>  > http://www.agfa.com/w3c/euler/rdfd-rules.n3
>
>Right. Though, not meaning to shake things up... ;-)
>
>Rules 2, 3, 5a, and 5b in the above have been removed in
>the latest draft and a new rule added (see below).
>
>Rule 3 above follows from the rdfs:range of
>rdfd:datatype defined in Rule 0, and thus is
>unnecessary.
>
>Rules 2, 5a and 5b have been removed. Both because they
>are unnecessary insofar as the datatyping interpretation
>is concerned and also because while all three idioms
>may all identify the same datatyped literal pairing,
>they do not have identical meaning.
>
>It is similar to the well known "morning star" versus
>"evening star" example, where both identify the same thing
>but do not really have identical meaning. One idiom thus
>does not imply another idiom as their total meaning will
>not be the same.

Oh, bad reasoning. We have an extensional language here, so we 
shouldnt be invoking intensional examples to block valid inferences. 
BUt since I can no longer see rules 5a/b, I don't know what the point 
was here :-)

>The present rules, as defined in the current revision of
>the WD are:
>
>--
>
>### rules for RDFD entailment
>
>@prefix log: <http://www.w3.org/2000/10/swap/log#> .
>@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
>@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
>@prefix rdfd: <http://www.w3.org/2002/rdf-datatyping#> .
>@prefix : <rdfd-rules#> .
>
># :rule0 (same as before)
>
>rdfd:Datatype a rdfs:Class;
>    rdfs:subClassOf rdf:Property .
>
>rdfd:datatype a rdf:Property;
>    rdfs:domain rdf:Property;
>    rdfs:range rdfd:Datatype.
>
>rdfd:lex a rdf:Property;
>    rdfs:domain rdfs:Resource;
>    rdfs:range rdfs:Literal .
>
>{
>    :rule1 .
>    ?d a rdfd:Datatype
>}
>log:implies
>{
>    ?d rdfs:domain ?d ;
>       rdfs:subPropertyOf rdfd:lex  # added this
>} .

Not sure that is a good idea. I had this in an earlier version and 
took it out, for a technical reason that I can now no longer 
reconstruct exactly. I know it caused trouble, though.  Its not 
strictly valid according to the current MT, in any case (since the 
semantic conditions on subProperty are not iff, just if), so I'd lean 
to omitting it.

Let me get back to you on this.

Pat
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Received on Wednesday, 17 April 2002 18:51:50 EDT

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