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Home -> Community -> Usenet -> comp.databases.theory -> Re: Storing data and code in a Db with LISP-like interface
"Neo" <neo55592_at_hotmail.com> wrote in message
news:1145746437.660905.240120_at_g10g2000cwb.googlegroups.com...
>
> Ok, I see. Suppose we start with the following:
>
> subtype(doctor, human).
> subtype(engineer, human).
> named_instance(john, doctor).
> named_instance(mary, doctor).
>
> And now comes along an alien named bob, who has all the major
> characteristics of a doctor, but he is not a human. How do I handle
> this situation?
>
If this is true, then an alien can be a doctor and Bob can be an alien. Therefore, we can no longer say, for certain, that 'just because john is a doctor, therefore he is human,' because there are now alien doctors. The ruleset change is small.
subtype(doctor, alien). subtype(doctor, human). subtype(engineer, human). named_instance(john, doctor).
--
--- Nick Malik [Microsoft]
MCSD, CFPS, Certified Scrummaster
http://blogs.msdn.com/nickmalik
Disclaimer: Opinions expressed in this forum are my own, and not
representative of my employer.
I do not answer questions on behalf of my employer. I'm just a
programmer helping programmers.
--
Received on Fri Apr 28 2006 - 11:23:34 CDT
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