proposition: Lemma dimvS U V : (U <= V)%VS -> \dim U <= \dim V.
proof: Proof. exact: mxrankS. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)