proposition: Lemma eqid_eq0 m n (I : 'cV[R]_n) : (I == (0 : 'cV_m))%IS = (I == 0).
proof: Proof. by rewrite subid_le0 sub0id andbT. 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