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Re: another revision of semantics document

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Thu, 22 Aug 2002 10:04:18 -0400
To: phayes@ai.uwf.edu
Cc: www-webont-wg@w3.org
Message-Id: <20020822100418Q.pfps@research.bell-labs.com>

[Note:  I will be using Pat's abbreviations for lists and restrictions
throughout.  I have also included owl:Thing and owl

Pat's claim just before Section 2.3 is incorrect.

The claim is that OWL entailment, as defined in my semantics document
is the same as entailment over OWL structure interpretations (which I will
call OWL/RDF structure entailment.

This is not correct, for several reasons.

OWL entails
	SubClassOf(sub=C super=unionOf(C C))
	C rdf:type owl:Class .
does not OWL structure entail
	C rdfs:subClassOf _:u .
	_:u owl:unionOf [C C] .
because of the definition of rdfs:subClassOf in the RDFS model theory.


	ObjectProperty(foo Symmetric)
	SubClassOf(sub=owl:Thing super=restriction(foo value=a))
	Individual(a type=A)
	Individual(b type=B)
	DifferentIndividuals(a b)
	DisjointClasses(A B)
	Class(C complete restriction(oof minCardinality(3)))

does not OWL entail

	Individual(a type=C)

but the translation into RDF does produce an OWL/RDF structural entailment,
because there are three different classes (A, B, and rdfs:Resource) in the
domain of discourse and each of them is related to a via foo.

Received on Thursday, 22 August 2002 10:04:28 UTC

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