anchor.diff:  
   random_re_prop({M0, F0}, {M1, F1}) ->
       ?FORALL({Str,RE,Opts},
  -            {oneof(?STRINGS), oneof(?REGEXES), oneof(?REGEXOPTS)},
  +            {elements(?STRINGS), elements(?REGEXES), elements(?REGEXOPTS)},
               M0:F0(Str, RE, Opts) =:= M1:F1(Str, RE, Opts)).
   
   prop_random_re2() ->
  
positive.code:     ?FORALL(Byte, byte(),
              match =:= re2:match([Byte], "^.*", [{capture, none}])).
  
  valid_string() -> non_empty(list(oneof([unicode_char(), unicode_binary()]))).
  
  binary_str(Str) -> unicode:characters_to_binary(Str).
  
  prop_char() ->
  
negative.code:             end).
  
  prop_string() ->
      ?FORALL(Str, ?LET(Size, choose(1,64), unicode_string(Size)),
              begin
                  S = binary_str(Str),
                  match =:= re2:match(S, "^.+$", [{capture, none}])
  