anchor.diff:  node_max(#list{max = Max}) ->
       Max.
   
  +
   %% node_kill_range(Node) ->
   %%     case Node of
   %% 	#leaf{} ->
  
positive.code: 	    
  	    %% Include L, while preserving Min =< Max.
  	    tree_node(minpos(L, Min),
  		      max(L, Max),
  		      refac_syntax:type(Node),
  		      refac_syntax:get_attrs(Node),
  		      Subtrees)
  
negative.code: build_list_list([L | Ls], Min, Max, Ack) ->
      Node = build_list(L),
      Min1 = minpos(node_min(Node), Min),
      Max1 = lists:max([node_max(Node), Max]),
      build_list_list(Ls, Min1, Max1, [Node | Ack]);
  build_list_list([], Min, Max, Ack) ->
      {lists:reverse(Ack), Min, Max}.
  