anchor.diff:  -spec(register_pid/7::(filename(), integer(), integer(), integer(),integer(), string(), [dir()]) ->
       {error, string()}|{ok, [filename()]}).
   register_pid(FileName, StartLine, StartCol, EndLine, EndCol, RegName, SearchPaths) ->
  -    case check_undo_process() of 
  +    case initial_checking(SearchPaths) of 
   	ok ->
   	    Res = wrangler:register_pid(FileName, {StartLine, StartCol}, {EndLine, EndCol}, RegName, SearchPaths),
   	    check_wrangler_error_logger(),
  
positive.code: -spec(tuple_funpar/5::(filename(), integer(), integer(), string(), [dir()]) ->
  	     {error, string()} | {ok, [filename()]}).
  tuple_funpar(Fname, Line, Col, Number, SearchPaths) ->
      case check_undo_process() of
  	ok -> Res = wrangler:tuple_funpar(Fname, Line, Col, Number, SearchPaths),
  	      check_wrangler_error_logger(),
  	      Res;
  
negative.code:       (filename(), integer(), integer(), [dir()]) -> {ok, [{integer(), integer(), integer(), integer(), syntaxTree(), {syntaxTree(), integer()}}]}
  							 | {error, string()}).
  fold_expr_by_loc(FName, Line, Col, SearchPaths) ->
      case initial_checking(SearchPaths) of
        ok -> Res = wrangler:fold_expr_by_loc(FName, Line, Col, SearchPaths),
  	    check_wrangler_error_logger(),
  	    Res;
  