Definition mod_after_alloc (phi: rmap) (lo hi: Z) (b: block) :=
proj1_sig (make_rmap (mod_after_alloc' phi lo hi b) (ghost_of phi)
_
(mod_after_alloc'_ok phi lo hi b) (ghost_of_approx phi)).
Transparent alloc.

Lemma alloc_dry_updated_on : forall m1 m2 lo hi b loc,
alloc m1 lo hi = (m2, b) ->
adr_range (b, lo) (hi - lo) loc ->
access_at m2 loc Cur=Some Freeable /\
contents_at m2 loc=Undef.