Let $X$ and $Y$ each be a D17: Finite set such that

(i)	$N, M \in \mathbb{N}$ are each a D996: Natural number
(ii)	\begin{equation} |X| = N, \quad |Y| = M \end{equation}
(iii)	$X \times Y$ is the D191: Binary cartesian set product of $X$ and $Y$
(iv)	$\mathcal{B} : = \{ R : R \subseteq X \times Y \}$ is the D5348: Set of binary relations on $X \times Y$

Then \begin{equation} |\mathcal{B}| = 2^{N M} \end{equation}