anchor.diff:  mapl(_, []) ->
   	[].
   
  -%% normalise(AbsTerm)
  -%% abstract(Term)
   %%  Convert between the abstract form of a term and a term.
   
  +-spec normalise(AbsTerm) -> Data when
  +      AbsTerm :: abstract_expr(),
  +      Data :: term().
   normalise({char,_,C}) -> C;
   normalise({integer,_,I}) -> I;
   normalise({float,_,F}) -> F;
  
positive.code: abstract_list([], _Line) ->
      [].
  
  %% tokens(AbsTerm) -> [Token]
  %% tokens(AbsTerm, More) -> [Token]
  %%  Generate a list of tokens representing the abstract term.
  
  tokens(Abs) ->
      tokens(Abs, []).
  
  tokens({char,L,C}, More) -> [{char,L,C}|More];
  tokens({integer,L,N}, More) -> [{integer,L,N}|More];
  tokens({float,L,F}, More) -> [{float,L,F}|More];
  
negative.code: %%
  %% %CopyrightBegin%
  %%
  %% Copyright Ericsson AB 1996-2011. All Rights Reserved.
  %%
  %% The contents of this file are subject to the Erlang Public License,
  %% Version 1.1, (the "License"); you may not use this file except in
  