Hint Rewrite Znth_nthi using (auto; omega) : sublist.
Hint Resolve Zland_in_range.

Lemma  Sigma_0_eq: forall b_,
Sigma_0 b_ =
(Int.xor
(Int.xor
(Int.or (Int.shl b_ (Int.repr 30))
(Int.shru (Int.and b_ (Int.repr (-1)))
(Int.sub (Int.repr 32) (Int.repr 30))))
(Int.or (Int.shl b_ (Int.repr 19))
(Int.shru (Int.and b_ (Int.repr (-1)))
(Int.sub (Int.repr 32) (Int.repr 19)))))
(Int.or (Int.shl b_ (Int.repr 10))
(Int.shru (Int.and b_ (Int.repr (-1)))
(Int.sub (Int.repr 32) (Int.repr 10))))).