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RE: MT RDFS closure rule bug?

From: pat hayes <phayes@ai.uwf.edu>
Date: Fri, 28 Jun 2002 01:12:46 -0500
Message-Id: <p05111b2bb941adb6c8b6@[65.217.30.113]>
To: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
Cc: w3c-rdfcore-wg@w3.org

>Pat
>
>I saw in
>
>http://lists.w3.org/Archives/Public/www-webont-wg/2002Jun/0178.html
>
>that you argued against Jos for the truth of basic set theoretic facts from
>nothing.
>
>My range and domian rules seem to me to be of a similar truth status.

I don't see that they are. In fact, your entailments aren't even 
valid, because two different classes can have the same class 
extension. I see range and domain as being particular individual 
classes 'attached' to a property. That attachment needn't be 
inherited under superset.

So its not just a matter of asserting things with no antecedents (the 
closure rules already do a lot of that), but what things should be 
asserted at all.

Pat


>(There may
>be a choice, and that choice depends upon how we regard the representation of
>logical facts within the domain of discourse. Given that webont 
>wants to be able
>to represent such facts without having to explicitly assert them, 
>then shouldn't
>we be taking the same position in RDF Core too?)
>
>Jeremy
>
>>  -----Original Message-----
>>  From: w3c-rdfcore-wg-request@w3.org
>>  [mailto:w3c-rdfcore-wg-request@w3.org]On Behalf Of Jeremy Carroll
>>  Sent: 26 June 2002 10:09
>>  To: pat hayes
>>  Cc: w3c-rdfcore-wg@w3.org
>>  Subject: RE: MT RDFS closure rule bug?
>>
>>
>>
>>
>>  >
>>  > >Pat,
>>  > >
>>  > >don't we need RDFS closure rules that add range and domain constraints
>>  > >e.g.
>>  > >
>>  > >aaa [rdfs:range] yyy
>>  > >yyy [rdfs:subClassOf] zzz
>>  > >
>>  > >then add
>>  > >
>>  > >aaa [rdfs:range] zzz
>>  > >
>>  > >
>>  > >and similarly for rdfs:domain.
>>  >
>>  > NO. That would be disastrous for the datatyping and in any case not
>>  > make sense. Why do want them?
>>  >
>>  >
>>
>>  We don't *want* them, they are just true!
>>  Or maybe I've been talking to Peter too much!
>>
>>  Any interpretation of any
>>
>>  > >aaa [rdfs:range] yyy
>>  > >yyy [rdfs:subClassOf] zzz
>>
>>
>>  is an interpretation of
>>
>>  > >aaa [rdfs:range] zzz
>>
>>
>>  thus the closure rule holds.
>>
>>  (Not) Proof:
>>
>>  Ahh, it depends on rdfs:range not being in the domain of discourse.
>>  neglecting that little factette and invalidating the proof ...
>>
>>  Whenever
>>  iii aaa jjj .
>>  then
>>  jjj [rdf:type] yyy .
>>  hence
>>  jjj [rdf:type] zzz .
>>
>>  hence
>>
>>  aaa [rdfs:range] zzz .
>>
>>  ==
>>
>>  I smell danger.
>>
>>
>>  Jeremy
>>
>>
>>
>>
>>
>>


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Received on Friday, 28 June 2002 02:12:46 EDT

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