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RE: [OWLWG-COMMENT] Punning and the "properties for classes" use case

From: Michael Schneider <schneid@fzi.de>
Date: Mon, 5 Nov 2007 10:24:32 +0100
Message-ID: <0EF30CAA69519C4CB91D01481AEA06A04A8E83@judith.fzi.de>
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <public-owl-dev@w3.org>

Hi again, Peter!

I see that I still have several concrete problems in understanding punning,
before I can answer your other mails. Here is the next question:

Peter F. Patel-Schneider wrote:

>Well, in OWL 1.1, it is true that 
>
>	Declaration(Individual(a))
>	Declaration(OWLClass(a))
>	Declaration(Individual(b))
>	Declaration(OWLClass(b))
>	SameIndividual(a b)
>
>does not entail
>
>	EquivalentClasses(a b)

My question is /not/ about this claim, but about RDF mapping. I want to
know: Given an OWL-1.1 ontology in functional style syntax, in which punning
is used. How is such an ontology mapped to RDF? As an example, let's take
the above six axioms:

  Declaration(Individual(a))
  Declaration(OWLClass(a))
  Declaration(Individual(b))
  Declaration(OWLClass(b))
  SameIndividual(a b)
  EquivalentClasses(a b)

How do these axioms get mapped to RDF? I can imagine two different mappings:

A: Each URI ref in the functional syntax version gets directly mapped to the
same URI ref in the resulting RDF graph:

  <a> owl11:declaredAs owl11:Individual .
  <a> owl11:declaredAs owl:Class .
  <b> owl11:declaredAs owl11:Individual .
  <b> owl11:declaredAs owl:Class .
  <a> owl:sameAs <b> .
  <a> owl:equivalentClass <b> .
  
B: The URI refs get explicitly separated:

  <a_Thing> owl11:declaredAs owl11:Individual .
  <a_Class> owl11:declaredAs owl:Class .
  <b_Thing> owl11:declaredAs owl11:Individual .
  <b_Class> owl11:declaredAs owl:Class .
  <a_Thing> owl:sameAs <b_Thing> .
  <a_Class> owl:equivalentClass <b_Class> .

As far as I understand it: If punning allows to denote semantically
unrelated individuals and classes by the same URI ref in functional syntax,
than mapping A would change the original semantics of the ontology, while
this semantics would be preserved by mapping B. But otherwise, if an
individual and a class having the same name are intended to be the same
entity, than mapping A would be a correct mapping, while B would also allow
interpretations where the individual and the class are semantically
unrelated.

So only one of these mappings should be allowed. But I cannot find out from
the "RDF mapping" draft which mapping is correct. Probably, I have only
overlooked the important bits in the draft?

Cheers,
Michael

--
Dipl.-Inform. Michael Schneider
FZI Forschungszentrum Informatik Karlsruhe
Abtl. Information Process Engineering (IPE)
Tel  : +49-721-9654-726
Fax  : +49-721-9654-727
Email: Michael.Schneider@fzi.de
Web  : http://www.fzi.de/ipe/eng/mitarbeiter.php?id=555

FZI Forschungszentrum Informatik an der Universität Karlsruhe
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Received on Monday, 5 November 2007 09:25:15 GMT

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