anchor.diff:  %% @end
   %%--------------------------------------------------------------------
   input_par_prompts() ->
  -    ["operation name:", "new argument name:",  "new argument index:", "generator:"].
  +    ["operation name:", "new argument name:",  "new argument index:"].
   
   %%--------------------------------------------------------------------
   %% @private
  
positive.code: %% @end
  %%--------------------------------------------------------------------
  transform(_Args=#args{current_file_name=File, 
                        user_inputs=[OpName, NewArgName,Index, NewArgGen]}) ->
      Op  = list_to_atom(OpName),
      Nth = list_to_integer(Index),
      ?FULL_TD_TP([rule1(Op, NewArgName, Nth),
                   rule2(Op, NewArgName, Nth),
                   rule3(Op, NewArgName, Nth),
                   rule4(Op, NewArgGen, Nth)
                  ],
                  [File]).
  
  
  rule1(Op, NewArg, Nth) ->
      ?RULE(?T("f@(Args@@) -> Body@@;"),
  
negative.code:               ?TO_AST("{call, M@, F@, [Args1@@,"++NewArgGen++"(), Args2@@]}",
                       wrangler_syntax:get_pos(_This@))
            end,
             ?PP(F@)==Op andalso api_refac:is_expr(_This@)).
  
  
  add_op_arg(FileName, OpName, NewArgName, Index, NewArgGen, SearchPaths, Editor, TabWidth) ->
  