noncomputable def BregmanMinc.rankInSubset {n : ℕ} (S : Finset (Fin n)) (j : Fin n) (τ : Equiv.Perm (Fin n)) : ℕ

$\text{rankInSubset}(S, j, \tau)$: the rank (1-indexed) of $j$ within the subset $S$ when elements are ordered by the inverse permutation $\tau^{-1}$.

noncomputable def BregmanMinc.relevantRows {n : ℕ} (A : Matrix (Fin n) (Fin n) ℝ) (σ : Equiv.Perm (Fin n)) (i : Fin n) : Finset (Fin n)

Set of indices $k$ such that the entry $A_{i, \sigma(k)} = 1$; these are the positions in the permutation $\sigma$ whose row $i$ contributes a $1$ in $A$.