(*******Injectivity of pad_inc*************************)

Lemma pad_injective_aux (l1 l2: list byte) k
(K : k * Int.modulus + (BlockSize + Zlength l1) * 8 =
(BlockSize + Zlength l2) * 8)
(N : k <> 0):
- (BlockSize + Zlength l2 + 9) mod 64 = - (BlockSize + Zlength l1 + 9) mod 64.