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Re: substantive semantics change?

From: pat hayes <phayes@ihmc.us>
Date: Wed, 12 Nov 2003 11:29:57 -0600
Message-Id: <p06001f09bbd81d39df9a@[10.1.31.1]>
To: Jeremy Carroll <jjc@hpl.hp.com>
Cc: w3c-rdfcore-wg@w3.org

>I was just double checking, and I seem to have previously misread the LC2
>semantics ... (if I looked at it all?? - I thought I had, but ...)
>
>http://www.w3.org/TR/2003/WD-rdf-mt-20031010/#entail
>[[
>I satisfies E if I(E)=true, and a set S of RDF graphs (simply) entails a graph
>E if every interpretation of the vocabulary of (S union E) which satisfies
>every member of S also satisfies E
>]]
>
>and similarly for the other entailments.
>This seems to cause the relevant test cases to be correct.
>
>(i.e. introducing rdf:_1 on the RHS is sufficient to trigger the existence of
>the relevant triples)

Yes, exactly.

>
>  and the changes made in response to Herman's comments would hence be (closer)
>to editorial.
>
>I was asked about the following entailment:
>
>*empty*
>
>rdfs-entails
>
>_:a rdf:type rdfs:ContainerMembershipProperty .
>
>This would appear to be false in the LC2 docs, and true in the latest editors
>draft.

Right, spot on.

>However, since if that is the case, this entailment was in the transitive
>closure of the LC2 entailment this is probably an improvement (albeit a
>substantive one).

Well, OK, I confess that this particular case only occurred to me 
recently ( apparently after it occurred to you) which is why I did 
not mention it in my earlier message.

Reverting to procedure for the moment, I was under the strong 
impression that 'no change to any test cases' was the currently 
applicable criterion for 'substantial change', perhaps also including 
'no substantial affect on OWL'. Since Herman's comments, to which I 
am trying to respond, are as I understand it spoken with the voice of 
the Webont WG, I take it that checking the latter with Herman is 
prima facia sufficient for that part of the process.

Pat

>Once Pat comments on these issues, I will consult further with the HP
>developers and get back to the WG - for now I do not see much of an issue
>(i.e. the change I see at the moment is smaller, and better motivated - I
>would still like to see a WG decision to make a substantive change).
>
>It remains unclear to me when or why this aspect of the semantics changed -
>the LC1 document does not appear to contain the entailments.
>cf:
>http://www.w3.org/TR/2003/WD-rdf-mt-20030905/#change
>
>but that's water under the bridge.
>
>
>Jeremy


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Received on Wednesday, 12 November 2003 12:29:59 EST

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