# Definition:Symmetric Relation/Definition 3

## Definition

Let $\mathcal R \subseteq S \times S$ be a relation in $S$.

$\mathcal R$ is symmetric if and only if it is a subset of its inverse:

$\mathcal R \subseteq \mathcal R^{-1}$

## Also see

• Results about symmetry of relations can be found here.