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Re: proposal to close ISSUE-137 (rdfstypesbackward): Table 4 in RDF mapping introduces incompatibility with OWL 1

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 22 Aug 2008 14:42:06 -0400 (EDT)
Message-Id: <20080822.144206.262889525.pfps@research.bell-labs.com>
To: alanruttenberg@gmail.com
Cc: public-owl-wg@w3.org

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Subject: Re: proposal to close ISSUE-137 (rdfstypesbackward): Table 4 in RDF mapping introduces incompatibility with OWL 1
Date: Fri, 22 Aug 2008 14:37:51 -0400

> On Aug 22, 2008, at 2:30 PM, Peter F. Patel-Schneider wrote:
> 
> > From: Alan Ruttenberg <alanruttenberg@gmail.com>
> > Subject: Re: proposal to close ISSUE-137 (rdfstypesbackward): Table 4 in RDF mapping introduces incompatibility with OWL 1
> > Date: Fri, 22 Aug 2008 14:19:18 -0400
> >
> >>
> >> On Aug 22, 2008, at 2:04 PM, Peter F. Patel-Schneider wrote:
> >>
> >>> From: Alan Ruttenberg <alanruttenberg@gmail.com>
> >>>>
> >>>> Document at ex:ontology:
> >>>> 	ex:foo rdf:type rdf:Property
> >>>> 	ex:subject ex:foo ex:object
> >>>>
> >>>> Document at ex:cleanup
> >>>> Ontology(ex:cleanup
> >>>>      Import(ex:ontology)	
> >>>>      Declaration(ObjectProperty(ex:foo))
> >>>>
> >>>> Would the reverse mapping, after the change, result in there being an
> >>>> error when ex:cleanup is parsed (and hence ex:ontology is parsed?).
> >>>>
> >>>> My understanding is that without the change ex:ontology would be
> >>>> syntactically invalid, but if ex:ontology was the single triple
> >>>>
> >>>> Document at ex:ontology:
> >>>> 	ex:subject ex:foo ex:object
> >>>>
> >>>> it would be valid.
> >>>>
> >>>> -Alan
> >>>
> >>> I don't understand what you want to do.
> >>>
> >>> Do you want to say that ex:ontology is a valid OWL 2 DL ontology?  It
> >>> isn't, and it isn't a valid OWL 1 DL ontology in RDF graph form
> >>> either, so there is no backward compatibility issue.
> >>
> >> I want to know if an OWL tool that implements the specification will
> >> load ex:cleanup, and therefore ex:ontology, will result in an OWL 2
> DL
> >> ontology or not (e.g. by there being an issue with syntax).
> >
> > That depends on the tool, I would think.  Would you want an OWL RL
> tool
> > to produce an OWL 2 DL ontology?
> 
> That isn't the question I asked. The point of my question and the
> specification is that the answer to the question I asked not depend on
> the tools.

Yes, but which kind of tool?  Some OWL tools don't need to produce OWL 2
DL ontologies, so I don't them expect to do is.

> >> In OWL 1, the triples that formed the import closure
> >>
> >> ex:foo rdf:type rdf:Property
> >> ex:subject ex:foo ex:object
> >> ex:foo rdf:type owl:ObjectProperty
> >> ex:cleanup rdf:type owl:Ontology
> >> ex:cleanup owl:imports ex:ontology
> >>
> >> would be a valid OWL 1 DL ontology in RDF graph form
> >
> > Actually this is *not* a valid OWL 1 ontology in RDF graph form.  It
> > is missing typing for ex:ontology, at least, as well as typing for
> > ex:subject and ex:object.
> 
> Yes. I omitted them because they were not germane to the issue, but you
> are correct in pointing this out.
> However, the question still remains for OWL 2.

What question?  The above graph is not valid for OWL 2, either, of course.

> (actually - have to check about the case of ex:ontology typing in OWL 1,
> but again, that's aside from the point)
> 
> >> In OWL 2 the reverse mapping introduces something new compared to OWL
> 1
> >> by virtue of, for the most part, the reverse mapping considering
> parsing
> >> and determining syntactic validity of each document separately.
> >>
> >> I want to ensure that cases such as the above, where validity was
> >> checked on the imports closure, don't become invalid in OWL 2.
> >>
> >> -Alan
> >
> > peter

peter
Received on Friday, 22 August 2008 18:48:00 GMT

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