Re: object algebra

"Neo" <neo55592_at_hotmail.com> wrote in message news: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.

This statement is true but not applicable. It is impossible to encode external predicates by definition. If they were encodable they wouldn't be external anymore.

> > > 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.

All of Bob's eyes have the same color as all of Mary's eyes. What is the problem?

Marshall Received on Sat Feb 28 2004 - 21:28:51 CET