proposition: Lemma lee_dsubr_addr x y z : z \is a fin_num -> (x <= y - z) = (x + z <= y).
proof: Proof. by move=> ?; rewrite !dual_addeE leeNl leeNr lee_subl_addr ?fin_numN. Qed.
imports: HB(structures) mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra) signed