proposition: Lemma addvSr U V : (V <= U + V)%VS.
proof: Proof. by rewrite /subV vs2mxD addsmxSr. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)