anchor.diff:  
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
  --spec is_element(iblt(), key()) -> boolean().
  +-spec is_element(iblt(), ?RT:key()) -> boolean().
   is_element(#iblt{ hfs = Hfs, table = T, col_size = ColSize }, Key) ->
       Found = lists:foldl(
                 fun({ColNr, Col}, Count) ->
  
positive.code: % @doc lists all correct entries of this structure
  %     correct entries can be retrieved out of pure cells
  %     a pure cell := count = 1 and check_sum(keySum)=keyHashSum and check_sum(valSum)=valHashSum
  -spec list_entries(iblt()) -> [{key(), value()}].
  list_entries(IBLT) ->
      p_list_entries(IBLT, []).
  
  -spec p_list_entries(iblt(), [{key(), value()}]) -> [{key(), value()}].
  p_list_entries(#iblt{ table = T } = IBLT, Acc) ->
      case get_any_entry(T, []) of
          [] -> Acc;
          L ->
              NewIBLT = lists:foldl(fun({Key, Val}, NT) -> 
                                            delete(NT, Key, Val) 
                                    end, IBLT, L),
              p_list_entries(NewIBLT, lists:append([L, Acc]))
      end.
  
  % tries to find any pure entry 
  -spec get_any_entry(table(), [{key(), value()}]) -> [{key() | value()}].
  get_any_entry([], Acc) -> 
      Acc;
  get_any_entry([{_, Col} | T], Acc) ->
      Result = [{Key, Val} || {Count, Key, KCheck, Val, ValCheck} <- Col, 
                              is_pure({Count, Key, KCheck, Val, ValCheck})],
      if 
          Result =:= [] -> get_any_entry(T, lists:append([Result, Acc]));
          true -> Result
  
negative.code: 
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
  -spec get(iblt(), ?RT:key()) -> value() | not_found.
  get(#iblt{ table = T, hfs = Hfs, col_size = ColSize }, Key) ->
      p_get(T, Hfs, ColSize, Key).
  
  -spec p_get(table(), ?REP_HFS:hfs(), non_neg_integer(), ?RT:key()) -> value() | not_found.
  p_get([], _, _, _) -> not_found;
  p_get([{ColNr, Col} | T], Hfs, ColSize, Key) ->
      Cell = lists:nth((?REP_HFS:apply_val(Hfs, ColNr, Key) rem ColSize) + 1, Col),
  