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Re: Action needed: subClassOf on datatypes

From: Jos De_Roo <jos.deroo@agfa.com>
Date: Wed, 3 Sep 2003 00:07:56 +0200
To: "Jan Grant <Jan.Grant" <Jan.Grant@bristol.ac.uk>
Cc: Jeremy Carroll <jjc@hplb.hpl.hp.com>, "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>, pat hayes <phayes@ihmc.us>, w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>, w3c-rdfcore-wg-request@w3.org
Message-ID: <OFE03F3FFD.AE5802BD-ONC1256D95.0078F756-C1256D95.00799BFB@agfa.be>

Jan - to me 1. and 2. look OK and I'm looking forward to test those...

Jos De Roo, AGFA http://www.agfa.com/w3c/jdroo/

PS I had a wrong [1] pointer in
   oops... can't look up in the archive (a previous message)
   It should have been
   [1] http://www.agfa.com/w3c/euler/xsd-rules

                      Jan Grant                                                                                                         
                      <Jan.Grant@bristol        To:       Jeremy Carroll <jjc@hplb.hpl.hp.com>                                          
                      .ac.uk>                   cc:       pat hayes <phayes@ihmc.us>, w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>, "Peter F. 
                      Sent by:                   Patel-Schneider" <pfps@research.bell-labs.com>                                         
                      w3c-rdfcore-wg-req        Subject:  Re: Action needed: subClassOf on datatypes                                    
                      2003-09-02 12:57                                                                                                  

On Tue, 2 Sep 2003, Jeremy Carroll wrote:

> Summary:
> Prefer c++
> modify  the test case to say that the case is D-consistent with the
> empty graph, not that it is D-entailed by it;
> add D-inconsistent test using a different rdfs:subClassOf triple between
> xsd datatypes.
> pat hayes wrote:
> > (a) modify the test case doc by deleting the test case;
> Not particularly OK, well unless the semantics doc discusses
> rdfs:subClassOf in datatyping clearly. i.e. this should not be left as an
> exercise for the reader.
> > (b) modify the test case to say that this only follows under the
> > strengthened extensional semantic conditions on rdfs:subClassOf
> > described in section 4.1 of the semantics document;
> not good
> > (c) modify  the test case to say that the case is D-consistent with the
> > empty graph, not that it is D-entailed by it;
> OK
> Also add a test case showing that
> xsd:string rdfs:subClassOf xsd:integer .
> is inconsistent.
> > (d) modify the semantics of D-interpretations to insist that datatype
> > class subsetting *is* treated extensionally, so that the rule rdfD4 is
> > valid and the test case is OK. This can be done by adding the following
> > semantic condition on D-interpretations:
> Prefer (c) to this.
> (Another option is to explicitly list rdfs:subClassOf relationships
> xsd datatypes as true by fiat).

This last option seemed the "obvious" one to me: that a datatype
definition might well include subClassOf "axiomatic triples".

The test case document currently doesn't have explicit
"consistent/inconsistent" test cases; these have usually been encoded
using entailment or non-entailment of false graphs.

So the new test cases would be that:

             xsd:integer rdfs:subClassOf xsd:decimal .
]] DOES NOT rdfs+D(xsd:integer, xsd:decimal)-entail
[[ FALSE ]] (the "false" graph)

             xsd:integer rdfs:subClassOf xsd:string .
]] rdfs+D(xsd:integer, xsd:string)-entails
[[ FALSE ]]

... is that ok?

jan grant, ILRT, University of Bristol. http://www.ilrt.bris.ac.uk/
Tel +44(0)117 9287088 Fax +44 (0)117 9287112 http://ioctl.org/jan/
It's a sad fact that the word "semantics" seems to have lost all meaning.
Received on Tuesday, 2 September 2003 18:08:21 UTC

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