Re: Good and Bad IS-A email@example.com (Pat Hayes)
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Date: Wed, 26 Jul 1995 14:42:46 -0500
To: firstname.lastname@example.org (Fritz Lehmann), email@example.com, firstname.lastname@example.org
From: email@example.com (Pat Hayes)
Subject: Re: Good and Bad IS-A hierarchies
Cc: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Thanks, Fritz. I am aware of what is-a heirarchies accomplish, and the way
in which they allow the statement of compact generalizations and achieve
dramatic speedups when they can be constructed. I was Cohn's doctoral
adviser, in fact.
My point was not that is-a is a Bad Thing, but that sometimes there are
genuinely incompatible axioms which you have to choose between. This isnt
any kind of heirarchy, and certainly not a classification heirarchy on the
property names involved. Life is not a box of chocolates.
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