Suppose you have a series of column pivots:
\begin{equation} \qty(P_{r_2} M_{11} P_{r_1} \dots) \end{equation}
you can combine all row permutations and column permutations down
Suppose you have a series of column pivots:
\begin{equation} \qty(P_{r_2} M_{11} P_{r_1} \dots) \end{equation}
you can combine all row permutations and column permutations down