anchor.diff:  bad_form_error(L, F, St) ->
       add_error(L, {bad_form,F}, St).
   
  -bad_gform_error(L, F, St) ->
  -    add_error(L, {bad_gform,F}, St).
  +bad_guard_form_error(L, F, St) ->
  +    add_error(L, {bad_guard_form,F}, St).
   
   -ifdef(HAS_MAPS).
   illegal_mapkey_error(L, K, St) ->
  
positive.code:         check_foldl(fun (Seg, Bvs, St) ->
                              pat_bitseg(Seg, Bvs, Pvs, Env, L, St)
                      end,
                      fun (St) -> bad_pat_error(L, binary, St) end,
                      Bvs0, St0, Segs),
      {union(Bvs1, Pvs),St1}.                     %Add bitvars to patvars
  
  
negative.code: check_import([from,Mod|Fs], L, St) when is_atom(Mod) ->
      Check = fun ([F,A], Imps, S) when is_atom(F), is_integer(A) ->
                      {orddict:store({F,A}, F, Imps),S};
                  (_, Imps, S) -> {Imps,bad_module_error(L, <<"import from">>, S)}
              end,
      check_import(Check, Mod, L, St, Fs);
  check_import([rename,Mod|Rs], L, St) when is_atom(Mod) ->
  