anchor.diff:                                end
                         end, {MaxNum, []}, DB),
       %% see HINT in foldl/3
  -    lists:foldl(Fun, Acc, Data).
  +    lists:foldr(Fun, Acc, Data).
   
   %% @doc makes a foldr over the whole dataset.
   %%      Returns a potentially larger-than-memory dataset. Use with care.
  
positive.code:     %% HINT
      %% Fun can only be applied in a second pass. It could do a delete (or other
      %% write op) and toke can not handle writes whiles folding.
      %% It seems like toke_drv:fold is acting as foldr would in repect to the
      %% order of terms. So accumulating reverses it and we have the correct term
      %% order.
      lists:foldl(Fun, Acc, Data).
  
  %% @equiv foldl(DB, Fun, Acc0, Interval, get_load(DB))
  %% @doc   Returns a potentially larger-than-memory dataset. Use with care.
  
negative.code:                                  end
                           end, [], DB),
      %% see HINT in foldl/3
      lists:foldl(Fun, Acc, Data).
  
  %% @doc foldr iterates over DB and applies Fun(Entry, AccIn) to every element
  %%      encountered in Interval. On the first call AccIn == Acc0. The iteration
  