*
     * In that explanation's notation, our `overlap` check would be `x1 < y2 && y1 < x2`. We've
     * flipped one part of the check so that we're using "less than" in both cases (rather than a
     * mix of "less than" and "greater than"). We've also switched to "strictly less than" rather
     * than "less than or equal to" because of *handwave* the difference between "endpoints of
     * inclusive ranges" and "Cuts."
     */