anchor.diff:  %%%-------------------------------------------------------------------
   %%% @author  <>
  -%%% @copyright (C) 2013, 
  +%%% @copyright (C) 2013,
   %%% @doc
   %%%
   %%% @end
  
positive.code:                     {reply, added, State#state{right=NewPid}};
                  true ->
                      gen_server:call(Right, {add, Data}),
                      {reply, added, State}                
              end
      end;
  
  
negative.code: -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
           terminate/2, code_change/3]).
  
  -define(SERVER, ?MODULE).
  
  -record(state, {left = nil, value, right = nil}).
  
  