(************************************************  Reroot lemmas  ************************************************)

Lemma array_at_data_at''':
forall sh t gfs lo hi v p t0 n a,
nested_field_type t gfs = Tarray t0 n a ->
lo <= hi <= n ->
array_at sh t gfs lo hi v p =
data_at sh (nested_field_array_type t gfs lo hi) v
(field_address0 t (ArraySubsc lo::gfs) p).