W3C home > Mailing lists > Public > w3c-rdfcore-wg@w3.org > September 2003

rule rdfD4 not correct, may affect test case

From: pat hayes <phayes@ihmc.us>
Date: Mon, 1 Sep 2003 18:48:50 -0700
Message-Id: <p06001a1abb79a3b400db@[10.0.1.4]>
To: Jan Grant <Jan.Grant@bristol.ac.uk>, w3c-rdfcore-wg@w3.org

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
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Received on Monday, 1 September 2003 21:48:40 EDT

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