ruct (Int.cmp op i j); inv H; auto.
Qed.

Definition Zcmp (op: comparison) : Z -> Z -> Prop :=
 match op with
 | Ceq => eq
 | Cne => (fun i j => i<>j)
 | Clt => Z.lt
 | Cle => Z.le
 | Cgt => Z.gt
 | Cg

Lemma int_cmp_repr: forall op i j, repable_signed i -> repable_signed j -> Int.cmp op (