Antisymmetric relation

In mathematics, a relation R on a set X is antisymmetric if there is no pair of distinct elements of X each of which is related by R to the other. More formally, R is antisymmetric precisely if for all a and b in X if R(a, b) with a ≠ b, then R(b, a) must not hold, or, equivalently, if R(a, b) and R(b, a), then a = b. (The definition of antisymmetry says nothing about whether R(a, a) actually holds or not for any a.)

Antisymmetric relation

In mathematics, a relation R on a set X is antisymmetric if there is no pair of distinct elements of X each of which is related by R to the other. More formally, R is antisymmetric precisely if for all a and b in X if R(a, b) with a ≠ b, then R(b, a) must not hold, or, equivalently, if R(a, b) and R(b, a), then a = b. (The definition of antisymmetry says nothing about whether R(a, a) actually holds or not for any a.)