Let $X_1, \ldots, X_{N + 1}$ each be a D11: Set such that

(i)	$X : = \prod_{n = 1}^{N + 1} X_n$ and $Y : = (\prod_{n = 1}^N X_n) \times X_{N + 1}$ are each a D326: Cartesian product

Then \begin{equation} |X| = |Y| \end{equation}

Let $X_1, \ldots, X_{N + 1}$ each be a D11: Set such that

(i)	$\prod_{n = 1}^{N + 1} X_n$ and $(\prod_{n = 1}^N X_n) \times X_{N + 1}$ are each a D326: Cartesian product

Then \begin{equation} \left| \prod_{n = 1}^{N + 1} X_n \right| = \left| \left( \prod_{n = 1}^N X_n \right) \times X_{N + 1} \right| \end{equation}