[techtalk] This talk of N-ary trees and other things...

David Merrill david at lupercalia.net
Fri Mar 23 21:43:46 EST 2001

On Fri, Mar 23, 2001 at 04:54:47PM -0800, Nancy Corbett wrote:
> ---
> Knights and Knaves problem. 
> Suppose you visit a strange island with three types of people. Knights,
> who always tell the truth, Knaves, who always lie and Normals who
> sometimes lie and sometimes tell the truth. It is also the custom that
> normals marry only normals, and knights marry only knaves. 
> You meet two couples, Mr. and Mrs. Smith and Mr. and Mrs. Brown. They tell
> you the following: 
> Mr. Brown: Mr. Smith is a knight. 
> Mrs. Brown: My husband is right, Mr. Smith is  a knight. 
> Mrs. Smith: That?s true, my husband is indeed a knight. 
> Can you determine which type each person must be? Explain.
> ---


Mr. and Mrs. Brown are normals. A knight and a knave would not agree.
If Mrs. Smith were a knave, her husband would be a knight and she
would not call him so. And if she were a knight, she would not call
her knave husband a knight! So are they *all* normals?

Dr. David C. Merrill                     http://www.lupercalia.net
Linux Documentation Project                   david at lupercalia.net
Collection Editor & Coordinator            http://www.linuxdoc.org
                                       Finger me for my public key

fortune: cpu time/usefulness ratio too high -- core dumped.

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