void main() {
    ArrayList<Integer> numbers = new ArrayList<>(List.of(1, 5, 9));
    numbers.remove(1);
    IO.println(numbers);

    ArrayList<Integer> a = new ArrayList<>(List.of(1000));
    ArrayList<Integer> b = new ArrayList<>(List.of(1000));
    IO.println(a.get(0) == b.get(0));
    IO.println(a.get(0).equals(b.get(0)));
}

// From Groundwork, chapter 7 (ch07-arrays-and-lists), box 13.
// This example is from Groundwork, licensed CC BY-NC-SA 4.0.
// Run with: java ch07_13.java