fun outer() {
  var x = "value";
  fun middle() {
    fun inner() {
      print(x);
      x = "new value";
    }

    print("create inner closure");
    print(x);
    return inner;
  }

  print("return from outer");
  return middle;
}

var mid = outer(); # expect: return from outer
var inner2 = mid();
# expect: create inner closure
# expect: value
inner2(); # expect: value
mid();
# expect: create inner closure
# expect: new value