[chbot] chock fish answer - ** spoiler **

[Volker Kuhlmann]

On Sat 06 Dec 2014 19:45:56 NZDT +1300, Mark Atherton wrote:

> Ask "which fork would your sister tell me to choose"
> 
> Either sister should respond with the incorrect branch.

Key is to ask the other sister. I see this as two single-input logic
gates in series. The honest sister's is non-inverting, the lieing
sister's is inverting. The result is the same regardless of which one is
first, and the answer is inverted. This is why I didn't think it's
complex or compound. There are several ways to phrase the question.

It reminds me of another riddle:

A pretty maiden is held prisoner by a bad king. Walking through the
court yard, covered in black and white stones, she says "it's boring
here, I want out". The king responds "OK, I'll put a black and a white
stone in a bag, and you can pick one. If it's the white one, I'll let
you go". She observes the king putting two black stones into the bag.
How does she get out?

She takes one stone, and without anyone seeing it, drops it. Then she
laments "how really foolish of me, but I have an idea: let's just look
at the other stone".

Key is again to ask one about the other, making the result dependent on
both. Never mind the story.

Volker

-- 
Volker Kuhlmann
http://volker.top.geek.nz/	Please do not CC list postings to me.