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The definition of entailment in the Direct Semantics document

From: Mike Smith <msmith@clarkparsia.com>
Date: Thu, 15 Jan 2009 10:29:22 -0500
Message-ID: <42485a40901150729l28910b28na41f3fbcb04076d2@mail.gmail.com>
To: "W3C OWL Working Group" <public-owl-wg@w3.org>


I believe, after review of test case [WebOnt-Class-005], that the
definition of entailment [1] in the OWL 2 Direct Semantics document
differs from the definition used by the WebOnt WG.  The entailment
test case is repeated below.  In WebOnt, this was a negative
entailment test (i.e., O did not entail O').  I believe that with the
current definitions, it would be a positive entailment test.   If the
group agrees with this analysis, we can accept the change in
definition or tweak the Direct Semantics document to match the
previous (WebOnt) meaning.

 ClassAssertion( owl:Thing x )

 Declaration( Class( C ) )
 ClassAssertion( UnionOf( C ComplementOf( C ) ) x )

Mike Smith

Clark & Parsia

[1] http://www.w3.org/2007/OWL/wiki/Direct_Semantics#Inference_Problems
Received on Thursday, 15 January 2009 15:30:03 UTC

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