proposition: Lemma nil_basis : basis_of 0 (Nil vT).
proof: Proof. by rewrite /basis_of span_nil eqxx nil_free. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)