procedure 0
  repeat 4 times
    forward 2
    right 90
#display: x=0, y=0, grid=32

procedure 1
  paint 0
  fill black
  forward 2
  paint 0
  fill white
  forward 2
#display: x=0, y=0, grid=32

procedure 2
  repeat 4 times
    paint 1
#display: x=-109, y=361, grid=32

procedure 3
  repeat 2 times
    paint 2
    right 180
    left 90
    forward 4
    right 90
#display: x=-117, y=269, grid=32

procedure 4
  repeat 4 times
    paint 3
    left 90
    forward 4 with pen up
    right 90
#display: x=33, y=255, grid=32