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 ctl_ok_updThreadC: forall nextb (ms: dryThreadPool) tid c (H: containsThread ms tid), ctl_ok nextb c -> (forall i (CT: containsThread ms i), ctl_ok nextb (getThreadC CT)) -> (forall i (CT: containsThread (updThreadC H c) i), ctl_ok nextb (getThreadC CT)).