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RE: Proposal to resolve ISSUE-86

From: Michael Smith <msmith@clarkparsia.com>
Date: Wed, 26 Mar 2008 17:22:35 -0400
To: Boris Motik <boris.motik@comlab.ox.ac.uk>
Cc: 'Alan Ruttenberg' <alanruttenberg@gmail.com>, "'Peter F. Patel-Schneider'" <pfps@research.bell-labs.com>, public-owl-wg@w3.org
Message-Id: <1206566555.14866.57.camel@msmith-laptop-wired.int.clarkparsia.com>

On Wed, 2008-03-26 at 19:53 +0000, Boris Motik wrote:

> Some of the existing proposals were similar; however, they also proposed to include the following triple in order to axiomatize
> $$pseudoblank$$P and P as inverse of each other:
> 
> (15) <$$pseudoblank$$P, owl:inverseOf, P>
> 
> Note, however, that we do not really need this additional triple: on the OWL Full side, we can simply repeat the semantic conditions
> of owl:inverseOf for owl:inverseObjectPropertyExpression. In other words, we just say that a triple of the form <x,
> owl:inverseObjectPropertyExpression, y> places a constraint on an interpretation that IEXT(x) = Inverse(IEXT(y)).

Yes, but doesn't including the additional triple make the behavior of
existing (i.e., OWL 1.0 and RDFS) tools match what we want?


> Finally, note that we need both owl:inverseOf and owl:inverseObjectPropertyExpression. To understand why, consider the following
> example ontology.
> 
> (16) InverseObjectProperties( InverseObjectProperty( P1 ) P2 )
> 
> The mapping should then produce the following RDF triples:
> 
> (17) <$$pseudo$$1, owl:inverseOf, P2>
> (18) <$$pseudo$$1, owl:inverseObjectPropertyExpression, P1>
> 
> This is good so, because this allows us to properly deserialize the triples: we know that (17) is to be transformed into
> InverseObjectProperties() (i.e., an axiom), and we also know that (18) is to be transformed into InverseObjectProperty() (i.e., a
> property expression). Without an explicit distinction between owl:inverseOf and owl:inverseObjectPropertyExpression, we would not be
> able to correctly reverse this mapping.

Though not syntactically equivalent, each of the possible reverse
mappings are logically equivalent, correct?  I.e., do I correctly
understand that this is another RDF round-tripping bug, present in OWL
1.0, and that you introduced owl:inverseObjectPropertyExpression to
resolve it?


Thanks,
-- 
Mike Smith

Clark & Parsia
Received on Wednesday, 26 March 2008 21:23:16 GMT

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