proposition: Lemma eq_in_map2_mx (f g : R -> S -> T) (M : 'M[R]_(m, n)) (M' : 'M[S]_(m, n)) : (forall i j, f (M i j) (M' i j) = g (M i j) (M' i j)) -> map2_mx f M M' = map2_mx g M M'.
proof: Proof. by move=> fg; apply/matrixP => i j; rewrite !mxE. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg countalg finalg zmodp)