proposition: Lemma projv_proj U w : projv U (projv U w) = projv U w.
proof: Proof. exact: daddv_pi_proj (capv_compl _). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)