anchor.diff:  
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
  --spec search(key(), key_values(), pos_integer(), pos_integer()) -> {'none', pos_integer()} | {value(), pos_integer()}.
  -
  -search(Key, KeyValues, Upper, Limit) when Upper =< Limit ->
  +-spec search(key(), key_values(), pos_integer()) -> {'none', pos_integer()} | {value(), pos_integer()}.
  +
  +search(Key, KeyValues, Upper) when Upper =< ?BINARY_SEARCH_FROM_LENGTH ->
       sequential_search(Key, KeyValues, 0);
  -search(Key, KeyValues, Upper, _Limit) ->
  +search(Key, KeyValues, Upper) ->
       binary_search(Key, KeyValues, 1, Upper).
   
   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  
positive.code: 
  -spec lookup_1(key(), tree()) -> 'none' | {'value', value()}.
  
  lookup_1(Key, {_, IsLeaf, KeyValues, ChildTrees}) ->
      {Value, Pos} = sequential_search(Key, KeyValues, 0),
      case Value == none of
          true ->
              case IsLeaf of
  
negative.code:     TreeOut = {KeyNo + 1, IsLeaf, insert_into_key_values(KeyValue, KeyValues, []), Trees ++ [nil]},
      TreeOut;
  insert_into_tree({Key, _} = KeyValue, {KeyNo, false = IsLeaf, KeyValues, Trees} = _Tree, KeyNoMin, KeyNoMax) ->
      {ValueFound, TreeUpperPos} = search(Key, KeyValues, KeyNo),
      case ValueFound of
          none ->
              TreeUpper = lists:nth(TreeUpperPos, Trees),
  