proposition: Lemma limgD f : {morph lfun_img f : U V / U + V}%VS.
proof: Proof. move=> U V; apply/eqP; rewrite unlock eqEsubv /subsetv /= -genmx_adds. by rewrite !genmxE !(eqmxMr _ (genmxE _)) !addsmxMr submx_refl. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)