Encapsulates the work that will be done for case 5 of __embed_frond,
    since it gets used in more than one place.

def __do_case_5_work(d_w, d_u, case_1, case_2, case_3, dfs_data):
    """Encapsulates the work that will be done for case 5 of __embed_frond,
    since it gets used in more than one place."""
    # --We should only ever see u-cases 1 and 2
    if case_3:
        # --We should never get here
        return False

    comp_d_w = abs(d_w)

    #if case_1:
    # --Add the frond to the left side
    __insert_frond_LF(d_w, d_u, dfs_data)

    # --Add uw to Lm
    m = dfs_data['FG']['m']
    Lm = L(m, dfs_data)
    if comp_d_w < Lm['u']:
        Lm['u'] = d_w
    if d_u > Lm['v']:
        Lm['v'] = d_u

    # --Case 2 requires a bit of extra work
    if case_2:
        Lm['u'] = d_w
        x_m1 = fn_x(m-1, dfs_data)
        while comp_d_w < x_m1:
            merge_Fm(dfs_data)
            m = dfs_data['FG']['m']
            x_m1 = fn_x(m-1, dfs_data)
    #else:
        #print "Case 5 work, u-case 1"

    return True