Global Notation "a # b" := (Maps.PMap.get b a) (at level 1).

Lemma mem_free_contents: forall m m2 lo hi b (Hfree: Mem.free m b lo hi = Some m2), forall b' ofs, Maps.ZMap.get ofs (Maps.PMap.get b' (Mem.mem_contents m)) = Maps.ZMap.get ofs (Maps.PMap.get b' (Mem.mem_contents m2)).