(* (0x0b, 0x0e, 0x09, 0x0d) *)

Lemma rt2_equiv : forall n : nat,
(n < 256)%nat ->
let b := nth n inv_sbox Int.zero in
nth n RT2 Int.zero = word_to_int (ff_mult b (Int.repr 13), ff_mult b (Int.repr 11),
ff_mult b (Int.repr 14), ff_mult b (Int.repr 9)).