anchor.diff:             e = {}}}.
   
   %%%_* Bulk-loading a list into an empty B-tree =================================
  +%%%
   %%% Citing from Wikipedia's article on B-trees, section "Initial construction":
   %%%
   %%% "In applications, it is frequently useful to build a B-tree to represent a
  
positive.code: -type pageid() :: pos_integer() | ?NOPAGEID.
  
  %% An item is a pair of a key and a page reference.
  %% FIXME: inline as 2 consecutive elements in the page's E vector
  
  -type item() :: {K :: term(),
                   P :: pageid()}. % subtree with keys K' > K
  
negative.code:       Cache2
    end.
  
  %% Search and delete key X in B-tree A; if a page underflow is
  %% necessary, balance with adjacent page if possible, otherwise merge;
  %% return true if page A becomes undersize.
  delete(Cache, _N, _X, ?NOPAGEID) ->
    ?dbg("delete(~p, ~p)~n", [_X, ?NOPAGEID]),
    {Cache, false};
  