Start
  ps_0
    ps_1
      p
        'q'@(1:1-1:2)
        q
        'r'@(1:2-1:3)
        r
        's'@(1:3-1:4)
        s_1
        't'@(1:4-1:5)
        t_1
        'u'@(1:5-1:6)
        u_2
        'v'@(1:6-1:7)
        v_2
    p
      'q'@(1:7-1:8)
      q
      'r'@(1:8-1:9)
      r
      's'@(1:9-1:10)
      s_0
        '1'@(1:10-1:11)
      't'@(1:11-1:12)
      t_0
        '1'@(1:12-1:13)
      'u'@(1:13-1:14)
      u_0
        '1'@(1:14-1:15)
      'v'@(1:15-1:16)
      v_0
        '1'@(1:16-1:17)
  Eof@(1:17-1:17)=''