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