Let $A, B \in \mathbb{C}^{N \times M}$ each be a D999: Complex matrix.
Then
\begin{equation}
\text{Trace}(A B)
= \text{Trace} (B A)
\end{equation}
| ▶ | R5554: Real matrix trace is commutation invariant for two real matrices |
| ▶ | R5575: Traces of complex matrix gramians coincide |