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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 14:30:23 -0400 (EDT)
Message-Id: <20080822.143023.86510351.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 14:19:18 -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?

> 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.

> 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
Received on Friday, 22 August 2008 18:31:43 GMT

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