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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: Thu, 21 Aug 2008 20:53:20 -0400 (EDT)
Message-Id: <20080821.205320.169796284.pfps@research.bell-labs.com>
To: alanruttenberg@gmail.com
Cc: public-owl-wg@w3.org

It appears to me that this would mean that the RDF graph

	ex:foo rdf:type rdf:Property
	ex:foo rdf:type owl:Class

would reverse-map to

	Ontology ( Declaration( Class ( ex:foo ) ) )

I don't think that it is a good idea to perform such drastic surgery in
the reverse mapping - throwing away the indication that ex:foo is to be
considered a property.


Further, I expect that almost all RDF graphs that contain

	ex:foo rdf:type rdf:Property

will also use ex:foo *as* a property, perhaps like

	ex:subject ex:foo ex:object

The proposed change would not result in graphs like this being
acceptable OWL 2 DL.


So how many RDF graphs are there in the wild that would benefit from
this change?  I don't think that there are many, if any.


Peter F. Patel-Schneider
Bell Labs Research


PS: Of course, repairs could perform effective fix-ups for many graphs
that are not acceptable OWL 2 DL in this way.



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: Thu, 21 Aug 2008 19:52:07 -0400

> On Aug 21, 2008, at 1:39 PM, Peter F. Patel-Schneider wrote:
> >
> > I don't see anything in the issue record
> >   http://www.w3.org/2007/OWL/tracker/issues/137
> > that shows your repair or how to implement it.
> 
> You are right, I suggested the fix in previous emails and at the TC
> http://www.w3.org/2007/OWL/meeting/2008-08-13#line0510
> 
> I've added the pointers to the issue record.
> 
> The proposal was to modify the reverse mapping rules in table 4
> 
> In each of the "If G contains this pattern" where there are two
> triples listed and one of them is either x rdf:type rdfs:Class  or x
> rdf:type rdfs:Property, remove the other triple. This effects all the
> entries but the first and last. 
> 
> For example:
> 
> If G contains: rdf:type owl:InverseFunctionalProperty. x rdf:type rdf:Property
> Then delete from G:  x rdf:type rdf:Property
> 
> would change to:
> 
> If G contains:  x rdf:type rdf:Property
> Then delete from G:  x rdf:type rdf:Property
> 
> -Alan
> 
> 
> On Aug 21, 2008, at 1:39 PM, Peter F. Patel-Schneider wrote:
> 
> > I don't see anything in the issue record
> >   http://www.w3.org/2007/OWL/tracker/issues/137
> > that shows your repair or how to implement it.
> >
> > peter
> >
> >
> > 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: Thu, 21 Aug 2008 13:20:31 -0400
> >
> >> I have suggested a repair recently. I proposed we implement it or say
> >> why we can't.
> >> The use case is RDF files that can be be profitably used if coupled with
> >> additional structure in an OWL file.
> >> Importing such files without repairing the mapping issue prevents this
> >> because such files (those that use rdfs:class where owl:class would
> >> suffice) would be syntactically invalid.
> >>
> >> -Alan
> >>
> >> On Aug 21, 2008, at 12:17 PM, Peter F. Patel-Schneider wrote:
> >>
> >>>
> >>> From: Alan Ruttenberg <alanruttenberg@gmail.com>
> >>> Subject: Re: ISSUE-137 (rdfstypesbackward): Table 4 in RDF mapping
> >> introduces incompatibility with OWL 1
> >>> Date: Sat, 2 Aug 2008 22:13:24 -0400
> >>>
> >>>> I clarified in the issue description that A imports B.
> >>>> -Alan
> >>>>
> >>>> On Aug 2, 2008, at 10:02 PM, OWL Working Group Issue Tracker wrote:
> >>>>
> >>>>> ISSUE-137 (rdfstypesbackward): Table 4 in RDF mapping introduces
> >>>>> incompatibility with OWL 1
> >>>>>
> >>>>> http://www.w3.org/2007/OWL/tracker/issues/137
> >>>>>
> >>>>> Raised by: Alan Ruttenberg
> >>>>> On product:
> >>>>>
> >>>>> In OWL 1 one could have Ontology A, B with
> >>>>>
> >>>>> A:  :foo rdf:type rdfs:Class
> >>>>> B:  :foo rdf:type owl:Class
> >>>>>
> >>>>> In OWL 2, A  would be rejected as syntactically invalid because no
> >>>>> part of the reverse mapping handles the single triple with
> >> rdfs:Class
> >>>>>
> >>>>> An analogous situation arises with rdf:Property
> >>>
> >>> This issue has been sitting for a while with no action.
> >>>
> >>> I propose that this issue be closed by noting the incompatibility.
> >>>
> >>> Peter F. Patel-Schneider
> >>> Bell Labs Research
> 
Received on Friday, 22 August 2008 00:54:05 GMT

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