anchor.diff:  is_lfe_bif(sublis, 2) -> true;
   is_lfe_bif(eval, 1) -> true;
   is_lfe_bif(eval, 2) -> true;
  +is_lfe_bif('macro-function', 1) -> true;
  +is_lfe_bif('macro-function', 2) -> true;
   is_lfe_bif(macroexpand, 1) -> true;
   is_lfe_bif(macroexpand, 2) -> true;
   is_lfe_bif('macroexpand-1', 1) -> true;
  
positive.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,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]).
  
negative.code: %% subst-if-not(New, Test, Tree) -> Tree.
  %% sublis(Alist, Tree) -> Tree.
  %% eval(Sexpr) -> Value.
  %% 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;
  