Re: CCAT Conceptual Catalogue and Ontologies
phayes@cs.uiuc.edu (Pat Hayes)
Date: Tue, 6 Sep 1994 13:01:52 -0500
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To: fritz@rodin.wustl.edu (Fritz Lehmann)
From: phayes@cs.uiuc.edu (Pat Hayes)
Subject: Re: CCAT Conceptual Catalogue and Ontologies
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>..... CCAT can, in addition, have
>ontologies expressed in Conceptual Graphs which cannot be expressed
>in current KIF (like "actors", Sowa-contexts, connected structures,
>planarity, standard numbers, transitive closures, Buchi automata,
>Montague grammars, power structures, Propositional Dynamic Logics,
>etc.)
Well now, "cannot" is a very strong word. How many of these could be
expressed as KIF ontologies, I wonder? (If you are going to point to the
expressive wonders of higher-order logic, I will challenge you to show me
how Sowa's CG's can quantify over relations and functions with enough
frisson to eliminate nonstandard models of arithmetic.)
By the way, this is the kind of reason why we need a model theory for CGs
which is precise (and stable) enough to allow some metamathematics to
actually be done.
Best wishes
Pat
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