static double doubleMin(Iterable<Double> l) {
  double min = infinity();
  fOr (double d : l)
    min = Math.min(min, d);
  ret min;
}

static double doubleMin(double... l) {
  double min = infinity();
  fOr (double d : l)
    min = Math.min(min, d);
  ret min;
}