0 is the false value, 1 or the others are considered as true.

x not x
0 1
1 0

x y x and y x or y x xor y
0 0 0 0 0
1 0 0 1 1
0 1 0 1 1
1 1 1 1 0

=
< or <=
> or >=

/!\ Parentheses are important.