anchor.diff:  
   add_old_backtracks([#state{pstates=PStates}|_] = Trace, ClockMap) ->
     Nexts = get_all_nexts(PStates),
  -  ?debug("Backtrack points: For all processes: ~p\n", [Nexts]),
  +  ?debug("Backtrack points: Forall processes: ~p\n", [Nexts]),
     add_old_backtracks(Nexts, Trace, ClockMap).
   
   get_all_nexts(PStates) ->
  
positive.code:    exit];
  p(c) ->
    [rec,
     {send, m},
     exit];
  p(d) ->
    [rec,
     {send, m},
     exit].
  
  
  
negative.code: 
  %%------------------------------------------------------------------------------
  
  %% Sample Inputs
  
  %% M1 : INDEPENDENT SENDER RECEIVER PAIRS
  
  %% The following program has 5 processes: m1 (main), a & b (sender), c & d
  %% (receiver). Run with test(m1).
  
  %% main() ->
  %%     Parent = self(),
  