anchor.diff:      ?f_debug("------------\nExplore ~p\n------------\n",
                [TraceTop#trace_state.i + 1]),
       case ordsets:subtract(Backtrack, Done) of
  -	[] ->
  +        [] ->
               ?f_debug("Backtrack set explored\n",[]),
               none;
           [SelectedLid|_RestLids] ->
  
positive.code:             end
      end.
  
  %% TODO: Maybe move into lid module.
  -spec lid_from_pid(pid()) -> concuerror_lid:lid() | 'not_found'.
  
  lid_from_pid(Pid) ->
  
negative.code:         {done, Ret} -> Ret;
          {cont, NewArg} -> dynamic_loop_acc(Fun, NewArg)
      end.
  
  update_lid_enabled(Lid, {_, Next, _}, Pollable, Enabled, Blocked) ->
      {NewEnabled, NewBlocked} =
          case is_enabled(Next) of
  