proposition: Lemma sub_addid0r m n (I : 'cV[R]_m) : (I <= I +i (0 : 'cV[R]_n))%IS.
proof: Proof. apply/subidP; exists (pid_mx m). by rewrite pid_mx_row mul_row_col mul1mx mulmx0 addr0. 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