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Re: semantics of daml:equivalentTo [was: Comments on Annotated DAML 1.6]

From: Peter F. Patel-Schneider <pfps@research.bell-labs.com>
Date: Fri, 13 Oct 2000 13:37:00 -0400
To: phayes@ai.uwf.edu
Cc: www-rdf-logic@w3.org
Message-Id: <20001013133700I.pfps@research.bell-labs.com>
From: pat hayes <phayes@ai.uwf.edu>
Subject: Re: semantics of daml:equivalentTo [was: Comments on Annotated    DAML   1.6]
Date: Fri, 13 Oct 2000 12:00:45 -0500

> >From: Jeff Heflin <heflin@cs.umd.edu>
> >Subject: Re: semantics of daml:equivalentTo [was: Comments on 
> >Annotated  DAML   1.6]
> >Date: Thu, 12 Oct 2000 15:29:56 -0400
> >
> > > I'd just like to elaborate on Jim's message. I believe that equivalentTo
> > > is the DAML version of the SHOE <DEF-RENAME> element. In SHOE,
> > > DEF-RENAME allows an ontology to provide an alias for a term defined
> > > elsewhere. Essentially, it means that both terms reference the same
> > > concept, and thus any assertion that is made using one term is also true
> > > if the other term was substituted in its place. This is really easy to
> > > implement: you keep a hash table that matches aliases with the base
> > > terms (used in the original definitions) that they renamed, and upon
> > > parsing a document or issuing a query you can perform the necessary
> > > substitutions to rephrase it in only base terms.
> > > Jeff

> There is 
> a reasonably well-defined meaning for equality (=identity = 
> equivalence) which is pretty much what Jeff says above: it means that 
> the terms refer to the same thing. So to assert
>   equivalentTo(X, Y)
> is to claim that X and Y have the same denotation. Now, this in turn 
> is just as clear or as murky as the notion of denotation is for X and 
> Y. 
> 
> Pat Hayes

It is my belief that Jeff's belief is that equivalentTO should be much more
like the other option I outlined, namely that X is given the definition
that Y has and that X can have no other definition.

peter
Received on Friday, 13 October 2000 13:38:03 GMT

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