Corollary mem_obs_eq_domain_ren:
    forall f m m',
      mem_obs_eq f m m' ->
      domain_memren f m.

Lemma valid_access_obs_eq': forall f m1 m2 b1 b2 chunk ofs p, strong_mem_obs_eq f m1 m2 -> f b1 = Some b2 -> Mem.valid_access m2 chunk b2 ofs p -> Mem.valid_access m1 chunk b1 ofs p.