(* This is a rather vacuous lemma, since the premise is simply True *)
(* Lemma Int64_eq_repr_signed32_nonzero: forall i, Int.eq i Int.zero = false -> Int64.eq (Int64.repr (Int.signed i)) Int64.zero = false. *)

Lemma Int64_eq_repr_unsigned32_nonzero:
forall i, i <> Int.zero ->
Int64.repr (Int.unsigned i) <> Int64.zero.