Definition mem_ok (tp: dryThreadPool) m := 
   Smallstep.globals_not_fresh (Clight.genv_genv ge) m /\
   mem_wd2 m /\
  (forall i (CT: containsThread tp i),
      ctl_ok (Mem.nextblock m) (getThreadC CT)).

Lemma mem_ok_restr: forall tp m p Hlt, mem_ok tp m -> mem_ok tp (@restrPermMap p m Hlt).