anchor.diff:  %% subst-if-not(New, Test, Tree) -> Tree.
   %% sublis(Alist, Tree) -> Tree.
   %% eval(Sexpr) -> Value.
  -%% macroexpand(Form [,Environment]) -> {yes,Expansion} | no.
  -%% macroexpand-1(Form [,Environment]) -> {yes,Expansion} | no.
  -%% macroexpand-all(Form [,Environment]) -> {yes,Expansion} | no.
  +%% macro-function(Name [,Environment]) -> Macro | [].
  +%% macroexpand(Form [,Environment]) -> Expansion | Form.
  +%% macroexpand-1(Form [,Environment]) -> Expansion | Form.
  +%% macroexpand-all(Form [,Environment]) -> Expansion | Form.
   
   is_lfe_bif(acons, 3) -> true;
   is_lfe_bif(pairlis, 2) -> true;
  
positive.code: is_lfe_bif(sublis, 2) -> true;
  is_lfe_bif(eval, 1) -> true;
  is_lfe_bif(eval, 2) -> true;
  is_lfe_bif(macroexpand, 1) -> true;
  is_lfe_bif(macroexpand, 2) -> true;
  is_lfe_bif('macroexpand-1', 1) -> true;
  
negative.code: 
  %% Standard lisp library.
  -export([is_lfe_bif/2,
           acons/3,pairlis/2,pairlis/3,
           assoc/2,'assoc-if'/2,'assoc-if-not'/2,
           rassoc/2,'rassoc-if'/2,'rassoc-if-not'/2,
           subst/3,'subst-if'/3,'subst-if-not'/3,sublis/2,
           eval/1,eval/2,
           'macro-function'/1,'macro-function'/2,
           macroexpand/1,macroexpand/2,
           'macroexpand-1'/1,'macroexpand-1'/2,
           'macroexpand-all'/1,'macroexpand-all'/2]).
  
  %% Miscellaneous useful LFE functions.
  -export([format_exception/6,format_stacktrace/3]).
  