反對稱的
antisymmetricA {relation} R is antisymmetric if, for all x and y, x R y and y R x => x == y. I.e. no two different elements are mutually related. {Partial orders} and {total orders} are antisymmetric. If R is also {symmetric}, i.e. x R y => y R x then x R y => x == y I.e. different elements are not related. (1995-04-18)