Definition store_byte_list m b ofs lv :=
Mem.storebytes m b ofs (concat (map (encode_val Mint8unsigned) lv)).

Lemma age_rejoin : forall {Z} w1 w2 w w' (a a' z : Z) H (J : join w1 w2 w)
(Hc : joins (ghost_of w) [Some (ext_ref z, NoneP)])
(Hg1 : ghost_of w1 = [Some (ext_ghost a, NoneP)])
(Hl' : (level w' <= level w)%nat)
(Hr' : forall l, w' @ l = resource_fmap (approx (level w')) (approx (level w')) (w @ l))
(Hg' : ghost_of w' = Some (ext_ghost a', NoneP) :: own.ghost_approx (level w') (tl (ghost_of w))),
join (age_to.age_to (level w') (set_ghost w1 [Some (ext_ghost a', NoneP)] H)) (age_to.age_to (level w') w2) w'.