X = Y (X is equal to Y, if X and Y match) X == Y (X is literally equal to Y, if X and Y are identical) X \== Y (X is not literally equal to Y - for arbitrary terms X and Y) X =:= Y (the value of X equals the value of Y) X =\= Y (the value of X is not equal to the value of Y) X is Y (if X matches the value of Y, where X is a variable or a constant, and Y is an arithmetic expression)