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Re: revised version of semantics document

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Thu, 22 Aug 2002 02:04:53 +0200
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: phayes@ai.uwf.edu, www-webont-wg@w3.org
Message-ID: <OF304E4673.72CF31BF-ONC1256C1C.0081905C@agfa.be>

[couldn't wait till after my holiday and a pity to miss the telecon]

> The revised version of the semantics document also has serious flaws, at
> least as far as I can see.
>
>
> For example, as far as I can see
>
>       John rdf:type Student .
>       John rdf:type Employee .
>
> does not entail
>
>       John rdf:type _:x .
>       _:x intersectionOf _:l1 .
>       _:l1 owl:first Student .
>       _:l1 owl:rest _:l2 .
>       _:l2 owl:first Employee .
>       _:l2 owl:rest owl:nil .
>
> because there is no requirement that there be an element of the domain 
of
> discourse whose class extension is the intersection of Student and
> Employee.

the one that I can go with is

  :John a :Student .
  :John a :Employee .
  :C owl:intersectionOf ( :Student :Employee ) .
OWL-entails
  :John a :C .

as all models of the premis are also models of the conclusion
and no new existentials are introduced in the entailment rules
(the lists in the conclusions are identical clones)

-- ,
Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

PS assuming above entailment, the owl:sameClassAs derivation
   that we had in proof tree of

     http://www.w3.org/2002/03owlt/intersectionOfP
     http://www.w3.org/2002/03owlt/intersectionOfX
   OWL-entails
     http://www.w3.org/2002/03owlt/intersectionOfC

   is now gone as well
   -- http://www.agfa.com/w3c/euler/etc5-proof.n3
Received on Wednesday, 21 August 2002 20:05:38 GMT

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