y PHP

$a and $b	And	true if both $a and $b are true.
$a or $b	Or	true if either $a or $b is true.
$a xor $b	Xor	true if either $a or $b is true, but not both.
! $a	Not	true if $a is not true.
$a && $b	And	true if both $a and $b are true.
$a || $b	Or	true if either $a or $b is true.
Worried Wallaby