proposition: Lemma vbasis_mem v U : v \in (vbasis U) -> v \in U.
proof: Proof. exact: basis_mem (vbasisP _). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)