Definition meminj_no_overlap (f: meminj) (m: mem) : Prop :=
forall b1 b1' delta1 b2 b2' delta2 ofs1 ofs2,
b1 <> b2 ->
f b1 = Some (b1', delta1) ->
f b2 = Some (b2', delta2) ->
perm m b1 ofs1 Max Nonempty ->
perm m b2 ofs2 Max Nonempty ->
b1' <> b2' \/ ofs1 + delta1 <> ofs2 + delta2.

Lemma store_outside_inj:
forall f m1 m2 chunk b ofs v m2',
mem_inj f m1 m2 ->
(forall b' delta ofs',
f b' = Some(b, delta) ->
perm m1 b' ofs' Cur Readable ->
ofs <= ofs' + delta < ofs + size_chunk chunk -> False) ->
store chunk m2 b ofs v = Some m2' ->
mem_inj f m1 m2'.