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Re: Cardinality Restrictions and Punning

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 21 Dec 2007 11:08:44 -0500 (EST)
Message-Id: <20071221.110844.138033351.pfps@research.bell-labs.com>
To: jjc@hpl.hp.com
Cc: public-owl-wg@w3.org

The examples from Jeremy and Michael show where punning is weaker than
identity.

Many such examples can be had, including

	SameIndividual(owl:Thing owl:Nothing)

which is inconsistent in OWL 1.0 Full but consistent in OWL 1.1 DL and
in OWL 1.0 DL.

What is new in the examples is that OWL 1.0 DL did not allow punning
between data and object properties.  Aside from this expansion of
punning, I don't see anything new here.

peter



From: Jeremy Carroll <jjc@hpl.hp.com>
Subject: Re: Cardinality Restrictions and Punning
Date: Fri, 21 Dec 2007 15:41:28 +0000

> Jeremy Carroll wrote:
> > 
> > Hmmm, this is tricky, harder than I thought.
> 
> Michael Schneider came to my rescue!
> 
> http://lists.w3.org/Archives/Public/public-owl-dev/2007OctDec/0261
> 
> Simplifying his comment.
> 
> > Some examples. I'm struggling as to the discussion.
> > 
> > Example 1:
> > Consistent:
> This is consistent in OWL 1.1 DL, but inconsistent in OWL 1.0 Full.
> So this presents a difficulty with OWL 1.1 Full semantics since we 
> either have to break compatibility with OWL 1.0 Full or OWL 1.1 DL, both 
> of which are important.
> 
> > [punning on eg:p]
> > 
> > eg:a rdf:type owl:Thing .
> > eg:a eg:p   eg:a .
> > eg:p rdf:type owl:ObjectProperty .
> > eg:p rdf:type owl:DataProperty .
> > _:r rdf:type owl:DataRestriction .
> > _:r owl:maxCardinality "0"^^xsd:int .
> > _:r owl:onProperty eg:p .
> > eg:a rdf:type _:r .
> > 
> 
> In OWL 1.0 Full:
> 
> Since eg:p is a DataProperty eg:a is a literal, and has at least one 
> literal eg:p value, and is hence not in the restriction _:r.
> 
> So I retract my earlier agreement with Peter of not seeing a problem.
> (Well I didn't see it)
> 
> Jeremy
Received on Friday, 21 December 2007 16:32:28 GMT

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