anchor.diff:                                              Backtrack ++ [{P, dummy, []}]
                                       end,
                                   ?debug("    NewBacktrack: ~p\n",[NewBacktrack]),
  -                                {done,
  -                                 PreSI#trace_state{backtrack = NewBacktrack}}
  +                                {continue,
  +                                 PreSI#trace_state{backtrack = NewBacktrack},
  +                                 NewClockVector}
                           end;
                       ?CLASSIC ->
                           Candidates = ordsets:subtract(Enabled, Sleepers),
  
positive.code:                         case Predecessor of
                              [] ->
                                  ?debug("    All sleeping...\n"),
                                  NewClockVector =
                                      lookup_clock(ProcSI, ClockMap),
                                  MaxClockVector =
                                      max_cv(NewClockVector, ClockVector),
                                  {continue_source, ProcSI, MaxClockVector};
                              [P] ->
                                  Intersection =
                                      ordsets:intersection(BacktrackSet, Initial),
  
negative.code:                              Trace, [StateI|Acc], Rest);
  add_all_backtracks_trace(Transition, Lid, ClockVector, PreBound, Flavor,
                           [StateI,PreSI|Rest], Acc, AccRest) ->
      #trace_state{i = I, last = {ProcSI, _, _} = SI} = StateI,
      Clock = lookup_clock_value(ProcSI, ClockVector),
      Action =
          case I > Clock andalso concuerror_deps:dependent(Transition, SI) of
  