anchor.diff:                  false ->
                       error
               end
  -    end.
  +    end;
  +
  +find_prefix(_, []) ->
  +    error.
   
   %%-------------------------------------------------------------------------
   %% @doc
  
positive.code:     end;
  
  update([H | T], F, {I0, I1, Data})
      when is_integer(H), H >= I0, H =< I1 ->
      I = H - I0 + 1,
      {Node, Value} = erlang:element(I, Data),
      case Node of
  
negative.code: %% @end
  %%-------------------------------------------------------------------------
  
  map(F, [] = Node) when is_function(F, 2) ->
      Node;
  
  map(F, Node) when is_function(F, 2) ->
      map_node(F, [], Node).
  
  