proposition: Lemma memv_proj U w : projv U w \in U.
proof: Proof. exact: memv_pi. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)