Require Export VST.msl.iter_sepcon.
Require Export VST.concurrency.semax_conc_pred.
Require Export VST.concurrency.semax_conc.
Require Export VST.floyd.proofauto.
Require Export VST.floyd.sublist.
(* general list lemmas *)
Notation vint z := (Vint (Int.repr z)).
Notation vptrofs z := (Vptrofs (Ptrofs.repr z)).
Hint Resolve repable_0.
Definition complete MAX l := l ++ repeat (vptrofs 0) (Z.to_nat MAX - length l).
Definition remove_at {A} i (l : list A) := firstn i l ++ skipn (S i) l.
Open Scope logic.
Definition rotate {A} (l : list A) n m := sublist (m - n) (Zlength l) l ++
sublist 0 (m - n) l.

Lemma rotate_1 : forall v l n m, 0 <= n < m -> Zlength l < m ->
rotate (upd_Znth 0 (complete m (v :: l)) (vptrofs 0)) n m =
rotate (complete m l) ((n + 1) mod m) m.