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Re: A Model Theoretic Semantics for DAML-ONT (now, an Axiomatic Semantics)

From: pat hayes <phayes@ai.uwf.edu>
Date: Wed, 29 Nov 2000 16:48:02 -0600
Message-Id: <v04210110b64b376fd4ad@[205.160.76.86]>
To: Dan Connolly <connolly@w3.org>
Cc: www-rdf-logic@w3.org
>Guha wrote:
> >
> > Ora,
> >
> >  I think they *are* supposed to be disjoint.
>
>That's good, since you can deduce that they're disjoint
>from this semantics
>
>DAML-ONT Axioms
>http://www.ksl.stanford.edu/people/dlm/DAML-Ont-kif-axioms-001127.html
>Tue, 28 Nov 2000 05:16:36 GMT
>
>er... at least I think you can... where did the
>axioms about what a class is (set of singletons)
>and what a property is (a set of pairs) go?
>They were in an earlier draft, no?
>
>Anyway, the proof goes:
>
>	Every class is a set of singletons
>	Every property is a set of pairs
>	nothing is both a singleton and a pair
>	=> the intersection of classes and properties is empty.

That would be valid, certainly, but why is a class a set of 
singletons? (Shouldn't a class be allowed to be a set of anything? 
What is the utility of restricting it to singletons? For example, 
couldnt I have a class of, say, people, rather than singletons of 
people?)

Pat

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Received on Wednesday, 29 November 2000 17:46:38 UTC

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