Definition ev_step_det:
        forall (m m' m'' : mem) (c c' c'' : semC) ev ev',
          ev_step semSem c m ev c' m' ->
          ev_step semSem c m ev' c'' m'' -> c' = c'' /\ m' = m'' /\ ev = ev'.

Lemma decay_disjoint: forall m m' p (Hdecay: decay m m') (Hlt: permMapLt p (getMaxPerm m)) (Hdisjoint: permMapsDisjoint (getCurPerm m) p), permMapsDisjoint (getCurPerm m') p.