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