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Re: rule rdfD4 not correct, may affect test case

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Tue, 02 Sep 2003 09:30:10 +0100
Message-ID: <3F545512.4080601@hplb.hpl.hp.com>
To: pat hayes <phayes@ihmc.us>
Cc: Jan Grant <Jan.Grant@bristol.ac.uk>, w3c-rdfcore-wg@w3.org

I agree with Pat and hope Jan can fix this before publication.


pat hayes wrote:

> Jan, my apologies for not grasping the point of your message earlier.
> The rule rdfD4 (when ddd's value class is a subclass of eee's value 
> space, you can conclude ddd rdfs:subClassOf eee ) isn't actually valid 
> any more, since we made subClassOf non-extensional.  So I think we 
> should delete this rule.  This will affect the xsd: test case we were 
> tal.king about recently, since now it is *never* valid to conclude a 
> subClassOf relation from the empty graph.
> An alternative would be to modify the semantics of datatyping to insist 
> that they are treated extensionally, but that would be hokey.
> Another cheap fix to the test cases doc would be to say in that case 
> that we were assuming the extensional interpretation for subClassOf, but 
> that is kind of tacky since the semantics doc says explicitly that those 
> assumptions are not rdf/s/D-valid.
> Sorry I didn't catch this earlier, guys, particularly as Jan already 
> caught it and I told him to drop it.
> Pat
Received on Tuesday, 2 September 2003 04:36:06 UTC

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