anchor.diff:  	{refactor_undo, Reply} ->
   	    Reply
       end.
  +    
  +
  +start_processes(SearchPaths) ->
  +    start_undo_process(),
  +    start_error_logger(),
  +    refac_ast_server:start_ast_server(SearchPaths).
  +    
  +stop_processes() ->
  +    stop_undo_process(),
  +    unregister(refactor_undo),
  +    stop_error_logger(),
  +    unregister(error_logger),
  +    refac_ast_server:stop_ast_server(),
  +    unregister(ast_server).
  +
       
   start_undo_process() ->
       spawn_link(wrangler_distel, undo_init, []).
  
positive.code: 		       undo_loop(lists:sublist(History1,15)); %%KEEP 15 HISTORY VERSIONS. IS THIS ENOUGH?
  	stop -> ok    
      end.
  		       
  
negative.code: -export([ rename_fun/5, rename_var/5, rename_mod/3, generalise/7, move_fun/6, tuple_to_record/8,
           duplicated_code_in_buffer/3, duplicated_code_in_dirs/3, expression_search/5, fun_extraction/6, fold_expression/3, tuple_funpar/5,
  	 instrument_prog/2, uninstrument_prog/2, add_a_tag/5,register_pid/7, fun_to_process/5,
  	 start_processes/1, stop_processes/0, error_logger/1,
           undo/0, undo_init/0]).
  
  
  rename_var(Fname, Line, Col, NewName, SearchPaths) ->
      case check_undo_process() of
  	ok -> Res=wrangler:rename_var(Fname, Line, Col, NewName, SearchPaths),
  	      case Res of 
  		  {ok, _} ->
  		      check_error_logger();
  		  {error, _} -> ok
  	      end,
  	      Res;		
  	{error, Reason} ->
  	    {error, Reason}
      end.
  