proposition: Lemma conjuMmx (m n : nat) (V : 'M[F]_m) (W : 'M_(m, n)) (f : 'M_n) : V \in unitmx -> row_free W -> stablemx W f -> conjmx (V *m W) f = conjmx V (conjmx W f).
proof: Proof. move=> Vu rfW Wf; rewrite conjMmx ?stablemx_unit//. by rewrite /row_free mxrankMfree// -/(row_free V) row_free_unit. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(div fintype tuple finfun bigop fingroup perm) mathcomp(ssralg zmodp matrix mxalgebra poly polydiv)