sclass AverageAndMinMax > Average {
  gettable double min = infinity();
  gettable double max = negativeInfinity();
  
  void add(double d) {
    super.add(d);
    if (d < min) min = d;
    if (d > max) max = d;
  }
  
  toString {
    ret "avg=" + super.toString() + (isEmpty() ? "" : ", min/max=" + min + "/" + max);
  }
}