A | B | A xor B --+---+-------- F | F | F F | T | T T | F | T T | T | FThe output is thus true if the inputs are not equal. If one input is false, the other is passed unchanged whereas if one input is true, the other is inverted.
In Boolean algebra, exclusive or is often written as a plus in a circle: "⊕". The circle may be omitted suggesting addition modulo two.
In digital logic, an exclusive or logic gate is drawn like a normal inclusive or gate but with a curved line across both inputs: exclusive or gate (img:http://upload.wikimedia.org/wikipedia/commons/e/e0/XOR.jpg).