proposition: Lemma r2vK : cancel r2v v2r.
proof: Proof. exact: svalP r2v_subproof. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)