Definition output_four_ints_as_bytes (s : four_ints) :=
  (put_uint32_le (col 0 s)) ++
  (put_uint32_le (col 1 s)) ++
  (put_uint32_le (col 2 s)) ++
  (put_uint32_le (col 3 s)).

Lemma output_four_ints_as_bytes_def: output_four_ints_as_bytes = fun (s : four_ints) => (put_uint32_le (col 0 s)) ++ (put_uint32_le (col 1 s)) ++ (put_uint32_le (col 2 s)) ++ (put_uint32_le (col 3 s)).