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Re: Moving forward

From: Jos De_Roo <jos.deroo.jd@belgium.agfa.com>
Date: Tue, 19 Mar 2002 17:08:21 +0100
To: pfps@research.bell-labs.com
Cc: "jos.deroo.jd" <jos.deroo.jd@belgium.agfa.com>, "phayes" <phayes@ai.uwf.edu>, "jonathan" <jonathan@openhealth.org>, "www-webont-wg" <www-webont-wg@w3.org>
Message-ID: <OFE879EDFB.3B1493B1-ONC1256B81.0050427D@agfa.be>


> The range of rdf:type is rdfs:Class, so either
>
>    :John a ( owl:intersectionOf ( :Person :Student ) ) .
>
> is a contradiction (if lists and classes are disjoint), or
>
>    ( owl:intersectionOf ( :Person :Student ) ) a rdfs:Class .
>
> which just gets us back to the first entailment.
>
> So I don't think that your distinction is defensible.
>
>
> Either you believe that these extra classes should exist or you believe
> that they shouldn't.  About the only viable intermediate point would be
to
> have another category that would include restrictions and boolean class
> combinations and have these exist but not have other kinds of classes
> exist.

I see and guess that that is what was meant with owl:Class and owl:List

  owl:Class a rdfs:Class .
  owl:Class rdfs:subClassOf rdfs:Class .   #@ so we have MT rdfs9
entailment

  owl:List a rdfs:Class .
  owl:List rdfs:subClassOf owl:Class .     #@@ so contradiction is ruled
out

  owl:intersectionOf a rdf:Property .
  owl:intersectionOf rdfs:domain owl:List .#@@@ that is a bit more restricted
  owl:intersectionOf rdfs:range owl:List .


I think the distinction is meaningful
if we have derived
  aaa a ( intersectionOf (bbb) )

we have only derived that *one* triple
and *not* the two triples
  aaa a _:x .
  _:x intersectionOf (bbb) .

and that is quite different from a truth preservation perspective, no?

--
Jos
Received on Tuesday, 19 March 2002 11:09:05 GMT

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