Definition Wcopyspec (t0 t1 t2 t3: int):=
(Int.xor t0
        (Int.rol
           (Int.add
              (Int.xor t3
                 (Int.rol
                    (Int.add
                       (Int.xor t2
                          (Int.rol
                             (Int.add
                                (Int.xor t1
                                   (Int.rol (Int.add t0 t3) (Int.repr 7))) t0)
                             (Int.repr 9)))
                       (Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7))))
                    (Int.repr 13)))
              (Int.xor t2
                 (Int.rol
                    (Int.add
                       (Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7))) t0)
                    (Int.repr 9)))) (Int.repr 18)),
  Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7)),
  Int.xor t2
       (Int.rol
          (Int.add (Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7))) t0)
          (Int.repr 9)),
  Int.xor t3
       (Int.rol
          (Int.add
             (Int.xor t2
                (Int.rol
                   (Int.add
                      (Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7))) t0)
                   (Int.repr 9)))
             (Int.xor t1 (Int.rol (Int.add t0 t3) (Int.repr 7))))
          (Int.repr 13))).

(* Specifications: *)
Lemma SixteenWR_Znth_int' s i: 0 <= i < 16 -> exists ii : int, Znth i (SixteenWordRep s) = Vint ii.