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

Lemma val_at_alloc_3: forall m m' lo hi nb b ofs (Halloc: Mem.alloc m lo hi = (m', nb)) (Hvalid: b <> nb), Maps.ZMap.get ofs (Maps.PMap.get b (Mem.mem_contents m)) = Maps.ZMap.get ofs (Maps.PMap.get b (Mem.mem_contents m')).