anchor.diff:  unbound_symb_error(Sym) ->
       eval_error({unbound_symb,Sym}).
   
  -unbound_func_error(Func) ->
  -    eval_error({unbound_func,Func}).
  +undefined_func_error(Func) ->
  +    eval_error({undefined_func,Func}).
   
   bad_form_error(Form) ->
       eval_error({bad_form,Form}).
  
positive.code: %% Copyright (c) 2008-2014 Robert Virding
  %%
  %% Licensed under the Apache License, Version 2.0 (the "License");
  %% you may not use this file except in compliance with the License.
  
negative.code:         {yes,_,_}=Yes -> Yes;                   %Imported function
          {yes,_}=Yes -> Yes;                     %Bound function
          no ->
              case lfe_internal:is_erl_bif(Name, Ar) of
                  true -> {yes,erlang,Name};      %Auto-imported Erlang BIF
                  false ->
                      case lfe_internal:is_lfe_bif(Name, Ar) of
                          true -> {yes,lfe,Name}; %Auto-imported LFE BIF
                          false -> no
                      end
              end
      end.
  
  eval_list(Es, Env) ->
  