anchor.diff:       {tickets, [parallel], [otp_5939, otp_6023, otp_6606, otp_7230]},
        {zip, [parallel], [zip_unzip, zip_unzip3, zipwith, zipwith3]},
        {misc, [parallel], [reverse, member, dropwhile, takewhile,
  -			 filter_partition, suffix, subtract,
  +			 filter_partition, prefix, suffix, subtract,
   			 hof]}
       ].
   
  
positive.code: 	 zip_unzip/1, zip_unzip3/1, zipwith/1, zipwith3/1,
  	 filter_partition/1, 
  	 otp_5939/1, otp_6023/1, otp_6606/1, otp_7230/1,
  	 suffix/1, subtract/1, droplast/1, hof/1]).
  
  %% Sort randomized lists until stopped.
  %%
  
negative.code:     ?line L2 = lists:sort(L2),
      ok.
  
  %% Test lists:prefix/2.
  prefix(Config) when is_list(Config) ->
      true = lists:prefix([], []),
      true = lists:prefix([], lists:seq(1, 10)),
      true = lists:prefix([a], [a,b]),
      true = lists:prefix(lists:seq(1, 10), lists:seq(1, 100)),
  
      false = lists:prefix([a], []),
      false = lists:prefix([a], [b]),
      false = lists:prefix([a], [b,a]),
  
      ok.
  
  %% Test lists:suffix/2.
  suffix(Config) when is_list(Config) ->
      ?line true = lists:suffix([], []),
  