1530s, from Medieval Latin commutativus, from Latin commutat-, past participle stem of commutare (see commute (v.)).
commutative Of or relating to binary operations for which changing the order of the inputs does not change the result of the operation. For example, addition is commutative, since a + b = b + a for any two numbers a and b, while subtraction is not commutative, since a - b ` a - b unless both a and b are zero. See also associative, distributive. |