Let $A \in \mathbb{C}^{N \times N}$ be a D6159: Complex square matrix such that

(i)	$A$ is an D5948: Upper triangular complex matrix
(ii)	\begin{equation} A = \begin{bmatrix} A_{1, 1} & A_{1, 2} & \cdots & A_{1, N} \\ 0 & A_{2, 2} & \vdots & A_{2, N} \\ \vdots & \cdots & \ddots & \vdots \\ 0 & 0 & \cdots & A_{N, N} \end{bmatrix} \end{equation}

Then \begin{equation} \text{Det} A = \prod_{n = 1}^N A_{n, n} \end{equation}