def glider(width, height):
  """Populate the board with a glider at upper left."""

  initial_state = [
    [ False
      for y in range(0, height) ]
    for x in range (0, width)
  ]
  initial_state[1][0] = True
  initial_state[2][1] = True
  initial_state[0][2] = True
  initial_state[1][2] = True
  initial_state[2][2] = True

  return initial_state