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RE: SEM: circular primitive

From: Jeremy Carroll <jjc@hplb.hpl.hp.com>
Date: Tue, 23 Apr 2002 13:01:24 +0100
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
Cc: <connolly@w3.org>, <jonathan@openhealth.org>, <www-webont-wg@w3.org>
Message-ID: <JAEBJCLMIFLKLOJGMELDOEMKCDAA.jjc@hplb.hpl.hp.com>


> -----Original Message-----
> From: www-webont-wg-request@w3.org
> [mailto:www-webont-wg-request@w3.org]On Behalf Of Peter F.
> Patel-Schneider
> Sent: 23 April 2002 10:51
> To: jjc@hplb.hpl.hp.com
> Cc: connolly@w3.org; jonathan@openhealth.org; www-webont-wg@w3.org
> Subject: RE: SEM: circular primitive 
> 
> 
> From: "Jeremy Carroll" <jjc@hplb.hpl.hp.com>
> Subject: RE: SEM: circular primitive 
> Date: Tue, 23 Apr 2002 10:20:10 +0100
> 
> [...]
> 
> > Showing that I am still playing the game according to my preferred
> > rules of discussing concrete cases in sufficient, but hopefully
> > not exhaustive detail, let us consider Peter's child case.
> > 
> > (In this case I fear it is exhausting but not exhaustive!)
> > 
> > > R:
> > > 
> 
> KB1:
> > >      John rdf:type Person .
> > >      Bill rdf:type Person .
> > >      John child Bill .
> 
> > > entailing
> 
> KB2:
> > >      John rdf:type _:1 .
> > >      _:1 rdf:type daml:Restriction .
> > >      _:1 rdf:onProperty child .
> > >      _:1 rdf:hasClass :_1 .
> 
> > I personally think this, as stated, is false. But like Jonathan
> > I think it points to an important use case, for which I will give
> > my treatment.
> 
> > I think R is false because:
> >   If R is true then the premises also entail that
> 
> KB3:
> >   Bill rdf:type _:1 .
> 
> Please explain.  It is true that KB1 entails KB3, of course, because, there
> is a type for Bill, namely Person.  However, how can KB1 entail KB2 plus
> KB3 (taken as a single graph)?  Bill does not have a child, so he does not
> satisfy the conditions on _:1 in KB2.


I took you to arguing that KB1 entails KB2.
Hence KB1 entails KB1 plus KB2 (taken as a single graph). 
   (KB1 is ground)
KB1 plus KB2 entail KB2 plus KB3.
  (because given that John rdf:type _:1 . the restriction restricts Bill, the object of the child property).

Is that enough?

Or do I need to go further?

> 
> > and hence
> >   
> >   Bill child _:x .
> >   _:x rdf:type _:1 .
> > 
> > and I do not think that the premises should license the first triple 
> > of such a conclusion.
> 
> peter
> 
> 
Jeremy
Received on Tuesday, 23 April 2002 08:02:20 GMT

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