anchor.diff:  recursive_insert(Vertex, Value, [H | T], L) ->
       recursive_insert(Vertex, Value, T, L ++ [H]).
   
  +%% Private
  +%% @doc the place for the insertion has been found, so now the TimeStamps are compared to see where to insert.
   add_element({Value, TimeStamp}, [{Value1, TimeStamp1} | T], L) ->
       case TimeStamp >= TimeStamp1 of
           true ->
  
positive.code: add_element(Insert, [], L) ->
      {ok, Insert, L ++ [Insert]}.
  
  recursive_remove(_, [], L) ->
      L;
  recursive_remove({Value, TimeStamp}, [{Value, TimeStamp} | T], L) ->
  
negative.code: recursive_remove(Vertex, [H | T], L) ->
      recursive_remove(Vertex, T, L ++ [H]).
  
  %% @doc given an rga, this mehtod looks for all tombstones and removes them, returning the tombstone free rga.
  purge_tombstones(Rga) ->
      lists:foldl(fun({Value, TimeStamp}, L) ->
          case Value == deleted of
  