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 app_eq_inv : forall {A} (l1 l2 l3 l4 : list A)
(Heq : l1 ++ l2 = l3 ++ l4) (Hlen : length l1 = length l3), l1 = l3 /\ l2 = l4.