def convex_elim(ordered_points):
    """ Helping function for convex_hull() which eliminates repeating points

        pre: ordered_points is a list of points sorted in nondecreasing order.
             ordered_points comprises of tuples of the form (x, y) where x represents
             the x-axis location and y represents the y-axis location of the point
             on the cartesian plane
        post: retruns a list with distinct points of ordered_points
    """

    new_lst = []

    for i in range(len(ordered_points) - 1):

        if ordered_points[i] != ordered_points[i + 1]:
            new_lst.append(ordered_points[i])

    new_lst.append(ordered_points[-1])

    return new_lst