(** Profs about [mem_obs_eq] and [weak_mem_obs_eq] *)

Lemma weak_obs_eq_restr :
forall (m m' : Mem.mem) (f : memren)
(weakObsEq: weak_mem_obs_eq f m m')
(pf: permMapLt (getCurPerm m) (getMaxPerm m))
(pf': permMapLt (getCurPerm m') (getMaxPerm (setMaxPerm m'))),
weak_mem_obs_eq f (restrPermMap pf) (restrPermMap pf').