Re: object algebra

From: Neo <neo55592_at_hotmail.com>
Date: 28 Feb 2004 08:54:13 -0800
Message-ID: <4b45d3ad.0402280854.760d07b_at_posting.google.com>


> ...Set theory knows nothing of what Date calls the "external predicate."

Just because we typically don't encode "external predicates" using RDM, does mean Set Theory's is not capable of it.

> > Number = {5, 6, blue, peach} ???
>
> Sure. Why wouldn't they?

Given EyeColor = {red, brown, NOT_APPLICABLE} Given the table:
Person EyeColor
------ --------------
Mary NOT_APPLICABLE
Bob NOT_APPLICABLE

Then, Mary.EyeColor equals Bob.EyeColor leading an AI program to conclude that Mary and Bob have the same EyeColor. This examplifies Date's conclusion: "3VL suffers from the very serious ("showstopper") problem that it does not match reality, that is results that are correct according to 3VL are sometimes incorrect in the real world". Received on Sat Feb 28 2004 - 17:54:13 CET

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