class C1 a where {
  type T1 a;
}

class C2 a where {
  type T2 a;
}

instance C1 Int where {
  type T1 Int = Bool;
}

instance C2 Bool where {
  type T2 Bool = Unit;
}

instance C2 (T1 Int) where {
  type T2 (T1 Int) = Int;
}