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 corestep_containsThread: forall (tp : t) c c' m m' p i j ev (Hcnti : containsThread tp i) (Hcntj: containsThread tp j) (Hcorestep: ev_step semSem c m ev c' m') (Hcode: getThreadC Hcnti = Krun c), containsThread (updThread Hcnti (Krun c') p) j.