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Re: log:forSome (Was: Model-specific identity for anon resources, and its representation: A new issue?

From: pat hayes <phayes@ai.uwf.edu>
Date: Thu, 21 Jun 2001 14:27:32 -0500
Message-Id: <v04210113b757fa52f60d@[205.160.76.206]>
To: jos.deroo.jd@belgium.agfa.com
Cc: aswartz@upclink.com, Jan.Grant@bristol.ac.uk, w3c-rdfcore-wg@w3.org
> > > I think/hack that both anonymous *terms* can be *unified*
> > > which is NOT the same as equality
> >
> > Then your hack only seems to works when we can unify anonymous
> > terms, or they have some sort of UniqueProperty attached. How do
> > we solve the general case?
>
>There was some related discussion in the telecon
>this afternoon, and I was kind of unable to explain
>my point...(I'm really hopeless in that respect)
>
>The thing about anonymous nodes is that they
>are ***variables***
>if they would be constants, we would be able
>to identify them with ***URI constants***
>Now they are actually existentially quantified
>variables, something like: there exists an _:a
>or (using existing vocab): this log:forSome _:a
>So I think we should say that *explicitly*
>is the testresults (and in the model theory)
>(the general case?)

Well, logically they seem to be like existentially quantified 
variables, yes. But you CANT unify distinct existentially quantified 
variables (validly) !  They would be distinct skolem constants, which 
do not unify in general. (They do if they are existential variables 
bound by the same quantifier, but then they would be the same skolem 
constant :-)

Pat

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Received on Thursday, 21 June 2001 15:27:33 EDT

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