anchor.diff:  %% ===Update or add a value in a trie.===
   %% @end
   %%-------------------------------------------------------------------------
  +
  +update(Key, _, Initial, [] = Node) ->
  +    store(Key, Initial, Node);
   
   update([H | T], _, Initial, {I0, I1, Data})
       when H < I0 ->
  
positive.code:             (Value /= error);
          _ ->
              false
      end.
  
  %%-------------------------------------------------------------------------
  %% @doc
  
negative.code: %% Traverses in alphabetical order.
  %% @end
  %%-------------------------------------------------------------------------
  
  itera(F, A, []) when is_function(F, 4) ->
      A;
  
  itera(F, A, Node) when is_function(F, 4) ->
      {trie_itera_done, NewA} = itera(F, {trie_itera_done, A}, [], Node),
  