Corollary wf_table_upd_same : forall T k v i (Hwf : wf_table T) (HT : Zlength T = size)
  (Hi : fst (Znth i T) = k) (Hk : k <> 0), wf_table (upd_Znth i T (k, v)).

Lemma lock_struct_array : forall sh z (v : list val) p, data_at sh (tarray (tptr (Tstruct _lock_t noattr)) z) v p = data_at sh (tarray (tptr tlock) z) v p.