anchor.diff:                  react_to_env_A10(S)
           end
       catch
  -        throw:{zerf,_} ->
  +        throw:{zerf,_}=_Throw ->
               Proj = S#ch_mgr.proj,
  +io:format(user, "\n\nzerf ~p throw ~p\n", [S#ch_mgr.name, _Throw]),
               {{no_change, [], Proj#projection_v1.epoch_number}, S}
       end.
   
  
positive.code:                                             MembersDict),
                      machi_projection:update_checksum(
                        P#projection_v1{epoch_number=OldEpochNum});
                  _ ->
                      %% TODO: This corner case needs more thought.
                      %%
                      %% Easy case: epoch 1, All=[a,b,c], UPI=[a,b],
  
negative.code:                                     end,
                               Rel2;
                           {error, not_written} ->
  io:format(user, "fold ~p ~p not_written\n", [E, FLU]),
                               Rel
                       end
               end, Relation, [{E, FLU} || E <- NowEpochs, FLU <- Up]),
      SortedRel = lists:reverse(lists:sort(Rel2)),
  io:format(user, "zerf_find_last_common rel ~p\n", [SortedRel]),
      case [T || T={{E, OorI, Proj}, WrittenFLUs} <- SortedRel,
                 lists:sort(Proj#projection_v1.upi) == lists:sort(WrittenFLUs)
                 andalso
  