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Re: Fwd: Nonstructural restrictions

From: Carsten Lutz <clu@tcs.inf.tu-dresden.de>
Date: Fri, 28 Mar 2008 10:52:20 +0100 (CET)
To: Alan Ruttenberg <alanruttenberg@gmail.com>
Cc: "Web Ontology Language ((OWL)) Working Group WG" <public-owl-wg@w3.org>
Message-id: <Pine.LNX.4.64.0803281048080.6666@frege.inf.tu-dresden.de>

On Thu, 27 Mar 2008, Alan Ruttenberg wrote:
>
> Begin forwarded message:
>
>> Resent-From: public-owl-dev@w3.org
>> From: "Marco Colombetti" <colombet@elet.polimi.it>
>> Date: March 26, 2008 12:11:47 PM EDT
>> To: <public-owl-dev@w3.org>
>> Subject: Nonstructural restrictions
>> Archived-At: 
>> <http://www.w3.org/mid/002e01c88f5c$18ecbb70$7c46fea9@lapcolombetti>
>> 
>> Hi.
>> 
>> In http://www.webont.org/owl/1.1/owl_specification.html  ?OWL 1.1 Web 
>> Ontology Language - Structural Specification and Functional-Style Syntax - 
>> Editor's Draft of 23 May 2007?.
>> 
>> in Section 7 ?Nonstructural Restrictions on Axioms?,
>> 
>> I find that:
>> Only simple object properties are allowed to occur in Ax in
>> ObjectMinCardinality, ObjectMaxCardinality, ObjectExactCardinality, and 
>> ObjectExistsSelf classes, and
>> ObjectPropertyFunctional, 
>> InverseFunctionalObjectProperty,ObjectPropertyIrreflexive, 
>> ObjectPropertyAsymetric, andDisjointObjectProperty axioms.
>> I wonder whether composite properties should also be forbidden in 
>> ObjectPropertyReflexiveaxioms, given that these are equivalent 
>> toSubObjectPropertyOf(owl:Thing,ObjectExistsSelf(P)).

This argument sounds odd: we clearly would have to disallow composite
properties in ObjectPropertyReflexive if we could express
ObjectExistsSelf (for which we have to disallow composite properties)
in terms of ObjectPropertyReflexive. However, Marco's encoding is the
other way round: it expresses ObjectPropertyReflexive in terms of
ObjectExistsSelf. Nothing can be deduced from that.

greetings,
 		Carsten

--
*      Carsten Lutz, Institut f"ur Theoretische Informatik, TU Dresden       *
*     Office phone:++49 351 46339171   mailto:lutz@tcs.inf.tu-dresden.de     *
Received on Friday, 28 March 2008 09:53:05 GMT

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