That is not a problem, just pick the same equality that your .compareTo method uses. You could pick -0 < 0, and -0 ≠ 0, or -0 = 0. You should never pick -0 < 0

That is not a problem, just pick the same equality that your .compareTo method uses. You could pick -0 < 0, and -0 ≠ 0, or -0 = 0. You should never pick -0 < 0 (via compareTo), but -0 = 0 (via equals).