anchor.diff:              {E, Reason}
       end.
   
  +%% Extract filename/forms pairs for included forms.
  +
   files([{attribute, _, file, {Path, _}} | T], Acc) ->
       {Body, Rest} = lists:splitwith(fun({attribute, _, file, _}) -> false;
                                         (_) -> true
  
positive.code: 
  pp(Forms, {error, Reason}) ->
      erlang:error({forms, Reason, Forms}).
  
  include({attribute, _, include_lib, Path}, Files) ->
      Inc = filename:basename(Path),
  
negative.code: 
  include(T, _) ->
      [T].
  
  %% Extract abstract code.
  
  abstract_code(Beam) ->
      case beam_lib:chunks(Beam, [abstract_code]) of
  