A D4424: Binary endorelation $B = (X \times Y, R)$ is transitive if and only if
\begin{equation}
\forall \, x, y, z \in X
\left( (x, y), (y, z) \in R \quad \implies \quad (x, z) \in R \right)
\end{equation}
A D4424: Binary endorelation $B = (X \times Y, R)$ is transitive if and only if
\begin{equation}
\forall \, x, y, z \in X
\left( x R y, y R z \quad \implies \quad x R z \right)
\end{equation}