Definition empty_rmap' : rmap' :=
  ((fun _: AV.address => NO Share.bot bot_unreadable), nil).Definition empty_rmap (n:nat) : rmap := R.squash (n, empty_rmap').

Lemma level_make_rmap: forall f g lev H Hg, @level rmap _ (proj1_sig (make_rmap f g lev H Hg)) = lev.