proposition: Lemma leb_le : forall n m, (n <=? m)%uint63 = (φ (n)%uint63 <=? φ (m)%uint63)%Z.
proof: Proof. intros. apply Bool.eq_true_iff_eq. rewrite leb_spec. rewrite <- Z.leb_le. apply iff_refl. Qed.
imports: ZArith Uint63 ZifyBool