text: """
  Example 2.11 (Rule X).
  
  From "Multi-Winner Voting with Approval Preferences"
  by Martin Lackner and Piotr Skowron
  https://arxiv.org/abs/2007.01795
  """
  
  from abcvoting import abcrules
  from abcvoting import misc
  from abcvoting.preferences import Profile
  from abcvoting.output import output, DETAILS
  
  output.set_verbosity(DETAILS)
  
  # the running example profile (Example 1)
  num_cand = 8
  a, b, c, d, e, f, g = range(7)  # a = 0, b = 1, c = 2, ...
  approval_sets = [
      {a, b},
      {a, b},
      {a, b},
      {a, c},
      {a, c},
      {a, c},
      {a, d},
      {a, d},
      {b, c, f},
      {e},
      {f},
      {g},
  ]
  profile = Profile(num_cand, cand_names="abcdefgh")
  profile.add_voters(approval_sets)
  committeesize = 4
  #
  
  print(misc.header("Example 11", "*"))
  
  print(misc.header("Input (election instance from Example 1):"))
  print(profile.str_compact())
  
  committees = abcrules.compute_rule_x(profile, 4, algorithm="standard-fractions")
  
  # verify correctness
  a, b, c, d, e, f, g = range(7)  # a = 0, b = 1, c = 2, ...
  assert committees == [{a, b, c, d}]
  