Definition:Univalent Relation

Definition
Let $\mathcal R$ be a relation on a set $S$.

Then $\mathcal R$ is univalent iff:


 * $\mathcal R \circ \mathcal R^{-1} \subseteq \Delta_S$

That is, $\mathcal R$ composed with its inverse $\mathcal R^{-1}$ is a subset of the diagonal relation on $S$.