Yeah, I haven't quite got the hang of it myself. The encoding of formal logic in English sentences is fraught with ambiguity until you grok the specific style used.
Here's an example (SPOILER ALERT: with solution) of what I mean. The English version is just a verbose translation of a simple Boolean table.
==================================
Black-Hat Chuck
==================================
:date: 2014-02-01 10:56
:summary: A solution to the Three Hats puzzle.
I recently ran across a `cool puzzle site`_. Here is one of the puzzles
and a solution:
There are 3 black hats and 2 white hats in a box. Three men (we will
call them A, B, & C) each reach into the box and place one of the
hats on his own head. They cannot see what color hat they have
chosen. The men are situated in a way that A can see the hats on B &
C's heads, B can only see the hat on C's head and C cannot see any
hats. When A is asked if he knows the color of the hat he is wearing,
he says no. When B is asked if he knows the color of the hat he is
wearing he says no. When C is asked if he knows the color of the hat
he is wearing he says yes and he is correct. What color hat and how
can this be?
.. class:: attribution caption
~ `Three Hats`_
Solution
------------
I'm going to call the three men Alan, Bob, and Chuck.
First, let's imagine what Alan might be able to see. There are four
possibilities.
=========== =============
Bob's Hat Chuck's Hat
=========== =============
White White
Black White
White Black
Black Black
=========== =============
Since there are only two white hats, if Alan sees that both Bob's and
Chuck's hats are white his own hat would have to be black. In other
words, by admitting that he can't tell which hat he is wearing Alan is
saying that either or both of Bob's and Chuck's hats are black. If we
eliminate the case of both hats being white we are left with three
possibilities.
=========== =============
Bob's Hat Chuck's Hat
=========== =============
Black White
White Black
Black Black
=========== =============
From this it should be easy to see that if Bob sees that Chuck's hat is
white his own hat would have to be black. Bob would be uncertain of the
color of his own hat only if Chuck's hat is black. So Chuck, being no
dummy, can conclude that his own hat is black.
It's an elegant puzzle with a very simple and satisfying solution.
.. _cool puzzle site: http://wuriddles.com/
.. _Three Hats: http://wuriddles.com/easy.shtml#3hats
Here's an example (SPOILER ALERT: with solution) of what I mean. The English version is just a verbose translation of a simple Boolean table.