Definition:Euclidean Relation/Left-Euclidean

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

$\mathcal R$ is left-Euclidean :


 * $\tuple {x, z} \in \mathcal R \land \tuple {y, z} \in \mathcal R \implies \tuple {x, y} \in \mathcal R$