anchor.diff:      is_string(atom_to_list(A));
   is_string([H|T]) when is_integer(H), H < 256, H > -1 ->
       is_string(T);
  -is_string(<<H:8,T>>) when is_integer(H), H < 256, H > -1 ->
  +is_string(<<H:8,T/binary>>) when is_integer(H), H < 256, H > -1 ->
       is_string(T);
   is_string([]) -> true;
   is_string(<<>>) -> true;
  
positive.code:         true ->
              ?FAIL({Check,L})
      end;
  check_term1(Check, X, _Level, _DefTypes) ->
      %% io:format("~p isnot ~p~n", [Check, X]),
      %% exit({Y,isNotA, X}).
  
negative.code:     is_ascii(atom_to_list(A));
  is_ascii([H|T]) when is_integer(H), H < 128, H > -1 ->
      is_ascii(T);
  is_ascii(<<H:8,T/binary>>) when is_integer(H), H < 128, H > -1 ->
      is_ascii(T);
  is_ascii([]) -> true;
  is_ascii(<<>>) -> true;
  