anchor.diff:          {ok, {false, EpochID3}} = WedgeStatus(hd(Ps)),
           %% The file we're assigned should be different with the epoch change.
           {ok, {_,_,File3}} = Append(hd(Ps), EpochID3),
  -        true = (File2 /= File3),
  +        true = (File1 /= File3),
   
           %% Confirm that 'a' is *not* wedged
           {ok, _} = Append(hd(Ps), EpochID3),
  
positive.code:         Proj_mCSum = Proj_m#projection_v1.epoch_csum,
          [{ok, {false, {Epoch_m, Proj_mCSum}}} = WedgeStatus(P) || % *not* wedged
               P <- Ps], 
          {ok, {false, EpochID2}} = WedgeStatus(hd(Ps)),
          [{ok,_} = Append(P, EpochID2) || P <- Ps],            % *not* wedged
          %% The file we're assigned should be different with the epoch change.
          {ok, {_,_,File2}} = Append(hd(Ps), EpochID2),
          true = (File1 /= File2),
          %% If we use the old epoch, then we're told that it's bad
          {error, bad_epoch} = Append(hd(Ps), EpochID1),
          %% If we use the current epoch again, then it's OK and given same File2
          {ok, {_,_,File2}} = Append(hd(Ps), EpochID2),
  
          %% Stop all but 'a'.
          [ok = machi_flu_psup:stop_flu_package(Name) || {Name,_} <- tl(Ps)],
  
negative.code:         true = (machi_projection:update_dbg2(Proj_m, []) ==
                      machi_projection:update_dbg2(Proj_m, [])),
          %% Confirm that 'a' is wedged
          {error, wedged} = Append(hd(Ps), EpochID1),
          {_, #p_srvr{address=Addr_a, port=TcpPort_a}} = hd(Ps),
          {error, wedged} = machi_flu1_client:read_chunk(
                              Addr_a, TcpPort_a, ?DUMMY_PV1_EPOCH,
  