Definition inj_offset_aligned (delta: Z) (size: Z) : Prop :=
forall chunk, size_chunk chunk <= size -> (align_chunk chunk | delta).

Axiom free_inject:
forall f m1 l m1' m2 b lo hi m2',
inject f m1 m2 ->
free_list m1 l = Some m1' ->
free m2 b lo hi = Some m2' ->
(forall b1 delta ofs k p,
f b1 = Some(b, delta) -> perm m1 b1 ofs k p -> lo <= ofs + delta < hi ->
exists lo1, exists hi1, In (b1, lo1, hi1) l /\ lo1 <= ofs < hi1) ->
inject f m1' m2'.