anchor.diff:      end,
       {3 =< (1+entry_num_acks(E1)), entry_inc_num_acks(E1)}.
   
  --spec add_write_deny(entry(), prbr:r_with_id()) -> {boolean(), entry()}.
  -add_write_deny(Entry, Round) ->
  +-spec add_write_deny(entry(), prbr:r_with_id(), Consistency::boolean())
  +                    -> {boolean(), entry()}.
  +add_write_deny(Entry, Round, Cons) ->
       E1 =
           case Round > entry_latest_seen(Entry) of
               false -> Entry;
  
positive.code:             %% outdated as all replies run through the same process.
              State;
          _ ->
              {Done, NewEntry} = add_write_deny(Entry, NewerRound),
              case Done of
                  false -> set_entry(NewEntry, TableName),
                           State;
  
negative.code: -spec entry_num_newest(entry())    -> non_neg_integer().
  entry_num_newest(Entry)            -> element(13, Entry).
  
  -spec add_read_reply(entry(), prbr:r_with_id(), client_value(),
                       prbr:r_with_id(), Consistency::boolean())
                      -> {boolean() | write_through, entry()}.
  add_read_reply(Entry, AssignedRound, Val, AckRound, Cons) ->
      %% either decide on a majority of consistent replies, than we can
      %% just take the newest consistent value and do not need a
      %% write_through?
  
      %% Otherwise we decide on a consistent quorum (a majority agrees
      %% on the same version). We ensure this by write_through on odd
      %% cases.
      
      LatestSeen = entry_latest_seen(Entry),
      TmpEntry =
          if AckRound > LatestSeen ->
  