proposition: Lemma sub_mulidr m n p (I: 'cV[R]_m) (J: 'cV[R]_n) (K: 'cV[R]_p) : (J <= K -> J *i I <= K *i I)%IS.
proof: Proof. by move=> h; rewrite mulidC (mulidC _ _ _).2 sub_mulidl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice fingroup) mathcomp(matrix bigop zmodp mxalgebra poly) ssrcomplements