anchor.diff:  
   check_elements(_IO, _N, E, I, LowerBound) when I > size(E) -> LowerBound;
   check_elements(IO, N, E, I, LowerBound) ->
  -  #item{k = K, p = P} = element(I, E),
  +  ?item(K, P) = element(I, E),
     check_key(K, LowerBound),
     LowerBound2 = {ok, K},
     LowerBound3 = check_pageid(IO, N, P, LowerBound2, false),
  
positive.code: 
  print_page(IO, #page{p0 = P0, e = E}, L) ->
    [io:format("     ") || _I <- lists:seq(1, L)],
    [io:format(" ~4w", [(element(I, E))#item.k]) || I <- lists:seq(1, size(E))],
    io:format("~n"),
    print_pageid(IO, P0, L + 1),
    [print_pageid(IO, (element(I, E))#item.p, L + 1) || I <- lists:seq(1, size(E))],
    ok.
  
  %%%_* Emacs ====================================================================
  
negative.code:     {not_found, R} ->
        QPageId =
          if R =:= 0 -> AP0;
             true -> item_p(element(R, AE))
          end,
        case delete(Cache2, N, X, QPageId) of
          {Cache3, true} ->
  