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Re: missing (and incorrect) RDFS axioms

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Sat, 9 Nov 2002 14:01:39 +0100
To: "pat hayes <phayes" <phayes@ai.uwf.edu>
Cc: Dan Connolly <connolly@w3.org>, w3c-rdfcore-wg@w3.org
Message-ID: <OFE223CD61.72B1F68D-ONC1256C6C.00475342-C1256C6C.00479AB3@agfa.be>


I think rdfs:range is good to make type derivations
using rdfs rule3
  {?p rdfs:range ?C. ?s ?p ?o} => {?o a ?C}.
but in this case it's for
  ?x a rdfs:Resource.
which is trivially true
(I've built that one in)

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


                                                                                                                   
                    pat hayes                                                                                      
                    <phayes@ai.uwf       To:     Dan Connolly <connolly@w3.org>                                    
                    .edu>                cc:     w3c-rdfcore-wg@w3.org, Jos De_Roo <jos.deroo.jd@belgium.agfa.com> 
                                         Subject:     Re: missing (and incorrect) RDFS axioms                      
                    2002-11-09                                                                                     
                    06:32 AM                                                                                       
                                                                                                                   
                                                                                                                   




>On Fri, 2002-11-08 at 13:40, Dan Brickley wrote:
>>
>>
>>
>>  > rdf:object          rdfs:range  rdfs:Resource .                   *
>>
>>  ...did we agree that all literals are resources?
>
>regardless, it's redundant to say range Resource.
>Please let's don't.

Well, strictly its not actually *redundant*, since range has 'if'
semantics. So for example if we don't say that the range of
rdf:object is rdfs:Resource, it is quite possible for rdf:object to
not have ANY range. There are no closure rules that conclude a range
assertion, note. Are you OK with that?  I am, myself, but I can see
that it might seem odd to some customers. And I guess that it would
be OK to err on the side of redundancy.

I was leaning towards putting those rdfs:Resource ranges in, in fact,
together with a note that they produce no useful conclusions but are
put in just for completeness' sake. It wouldn't require your engines
to do anything new, and after all these rules aren't meant to be
process rules.

Comments?

Pat



>
>--
>Dan Connolly, W3C http://www.w3.org/People/Connolly/


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Received on Saturday, 9 November 2002 08:02:20 EST

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