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Re: possible semantic bugs concerning domain and range

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Mon, 23 Sep 2002 20:35:57 -0400 (EDT)
Message-Id: <20020923.203557.128869524.pfps@research.bell-labs.com>
To: jonathan@openhealth.org
Cc: www-webont-wg@w3.org

From: "Jonathan Borden" <jonathan@openhealth.org>
Subject: Re: possible semantic bugs concerning domain and range
Date: Mon, 23 Sep 2002 20:07:52 -0400

> Peter F. Patel-Schneider wrote:
> 
> >
> > Yes, and you get that, because ex:OddInteger is still a range of foo.
> > However, ex:integer is also a range of foo.
> >
> > Think of what happens if you assert
> >
> >  foo rdfs:range ex:OddInteger .
> >  ex:OddInteger rdfs:subClassOf ex:Integer .
> >  foo rdfs:range ex:Integer .
> >
> > Aside from the actual rdfs:range stuff, this has the same interpretations
> > as
> >
> >  foo rdfs:range ex:OddInteger .
> >  ex:OddInteger rdfs:subClassOf ex:Integer .
> >
> > so why shouldn't a range of foo be ex:Integer?
> >
> 
> because
> 
> (first we are not asserting
> foo rdfs:range ex:Integer .
> as a premise)


This is supposed to be a rationale?  By the same reasoning, we should not
conclude

	John rdf:type Person .

from 

	John rdfs:type Student .
	Student rdfs:subClassOf Person .

>
> ex:EvenInteger rdfs:subClassOf ex:Integer .
> ex:EvenInteger owl:DisjointWith ex:OddInteger .
> 
> hence if
> 
> foo rdfs:range ex:OddInteger .
> 
> then
> 
> NOT foo rdfs:range ex:EvenInteger .
> 
> but if
> 
> foo rdfs:range ex:Integer
> 
> then
> 
> foo rdfs:range ex:EvenInteger .
> 
> (triple speak is getting tedious ...)
> 
> that is to say, that rdfs:range should chain _down_ rdfs:subClassOf but _not
> up_ rdfs:subClassOf

What?  This is nonsense.  

Using this bizare reasoning I could conclude that

	p rdfs:range owl:Nothing .

for every OWL object-valued property.  Which would imply that there are no
triples for any OWL object-valued property.

> Jonathan

peter
Received on Monday, 23 September 2002 20:36:06 GMT

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