(* solve list equations *)
(* interpreted functions : Zlength app list_repeat / Zrepeat map sublist upd_Znth -> sublist Znth *)
Definition data_subsume {cs : compspecs} (t : type) (x y : reptype t) : Prop :=
forall sh p, data_at sh t x p |-- data_at sh t y p.
Ltac apply_list_ext :=
first
[ apply data_subsume_array_ext;
only 1, 2 : Zlength_solve
| match goal with |- @eq ?list_A _ _ =>
match eval compute in list_A with list ?A =>
apply (@Znth_eq_ext A ltac:(auto with typeclass_instances))
end
end;
only 1 : Zlength_solve
];
autorewrite with Zlength;
intros.

Lemma rangei_shift : forall (lo hi offset : Z) (P : Z -> Prop),
rangei lo hi P <-> rangei (lo + offset) (hi + offset) (fun i => P (i - offset)).