anchor.diff:  build_list([T | Ts], Min, Max, Ack) ->
       Node = build_tree(T),
       Min1 = minpos(node_min(Node), Min),
  -    Max1 = max(node_max(Node), Max),
  +    Max1 = lists:max([node_max(Node), Max]),
       build_list(Ts, Min1, Max1, [Node | Ack]);
   build_list([], Min, Max, Ack) ->
       list_node(Min, Max, lists:reverse(Ack)).
  
positive.code: 	{_, L, _} when is_integer(L) ->
  	    L;
  	Pos ->
  	    refac_io:format("Node:\n~p\n", [Node]),
  	    exit({bad_position, Pos})
      end.
  
  
negative.code: node_max(#list{max = Max}) ->
      Max.
  
  
  %% node_kill_range(Node) ->
  %%     case Node of
  %% 	#leaf{} ->
  