Hint Resolve unsigned_range_2: ints.

(* Specifications: *)
Theorem signed_range:
forall i, min_signed <= signed i <= max_signed.
Theorem repr_unsigned:
forall i, repr (unsigned i) = i.
Theorem signed_range:
forall i, min_signed <= signed i <= max_signed.
Theorem repr_unsigned:
forall i, repr (unsigned i) = i.