exclusive or

exclusive or
EOR
xor

   <logic> (XOR, EOR) /X or, E or/ A two-input {Boolean logic}
   {function} whose result is true if one input is true and the
   other is false.  The {truth table} is

   	A | B | A xor B
   	--+---+--------
   	F | F |    F
   	F | T |    T
   	T | F |    T
   	T | T |    F

   The 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: "&oplus;".  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).

   (2006-12-13)