anchor.diff:      MbrE = calc_nodes_mbr(PartE),
       MbrS = calc_nodes_mbr(PartS),
       MbrN = calc_nodes_mbr(PartN),
  -    MaxWE = max(length(PartW), length(PartE)),
  -    MaxSN = max(length(PartS), length(PartN)),
  +    MaxWE = erlang:max(length(PartW), length(PartE)),
  +    MaxSN = erlang:max(length(PartS), length(PartN)),
       if
           MaxWE < MaxSN ->
               [{MbrW, PartW}, {MbrE, PartE}];
  
positive.code:         not IsDisjoint ->
              {W1, S1, E1, N1} = Mbr1,
              {W2, S2, E2, N2} = Mbr2,
              {max(W1, W2), max(S1, S2), min(E1, E2), min(N1, N2)};
          true ->
              {0, 0, 0, 0}
      end.
  
negative.code: pos_to_data(Fd, [H|T], DataList) ->
      {ok, Data} = couch_file:pread_term(Fd, H),
      pos_to_data(Fd, T, DataList ++ [Data]).
  