#[global]
Instance Op_eqb : BinOp eqb :=
  {| TBOp := Z.eqb; TBOpInj := eqb_eq |}.

(* Specifications: *)
Lemma eq_int_inj : forall n m : int, n = m <-> (φ n = φ m)%uint63.
Lemma eq_int_inj : forall n m : int, n = m <-> (to_Z n = to_Z m)%sint63.