Definition mem_wd2 m := forall b ofs, memval_inject (Mem.flat_inj (Mem.nextblock m))
    (ZMap.get ofs (PMap.get b (Mem.mem_contents m))) (ZMap.get ofs (PMap.get b (Mem.mem_contents m))).

Lemma mem_wd2_store: forall m b ofs v m' chunk (WDm: mem_wd2 m) (ST: Mem.store chunk m b ofs v = Some m') (V: val_valid v m), mem_wd2 m'.