Posted by Jock on December 01, 2005 at 09:21:58 from 84.64.216.142 user Jock.
In Reply to: Re: Paradox posted by John Nichols on December 01, 2005 at 01:45:38:
It's a truth table, but not quite as simple as the one you've posted.
Let A be the correct door. Let B be the wrong one, but to kee pthings simple we'll refer to it as the door that is not A or NOT A.
If you ask the guards directly 'which is the correct door?', You get told:
'A' = from the guard who speaks the truth and 'NOT A' from the one who lies.
If you ask one of the guards the question about what the other guard would say you get told:
'NOT A' by both guards,
(one guard truthfully reports the lie that would be said by the other, the other guard lies about the truth that would be said by the truthfull one)
So NOT (NOT A) is true,
so A is true
so it's the other door to the one indicated!