anchor.diff:      lists:flatten(lists:reverse(usage_options_reverse(OptSpecList, []))).
   
   usage_options_reverse([{Name, Short, Long, _ArgSpec, Help} | Tail], Acc) ->
  -    Prefix = 
  -        case Long of 
  +    Prefix =
  +        case Long of
               undefined ->
                   case Short of
                       % Neither short nor long form (non-option argument).
  
positive.code:             case lists:keyfind(Long, ?OPT_LONG, OptSpecList) of
                  {Name, _Short, Long, undefined, _Help} ->
                      parse(OptSpecList, [Name | OptAcc], ArgAcc, ArgPos, Args);
                  
                  {_Name, _Short, Long, _ArgSpec, _Help} = OptSpec ->
                      % The option argument string is empty, but the option requires
                      % an argument, so we look into the next string in the list.
  
negative.code:     false;
  is_float_arg([]) ->
      true.
  
  
  %% @doc  Show a message on stdout indicating the command line options and
  %%       arguments that are supported by the program.
  