Ltac coinductive_case CIH :=
    apply W_tl; simpl in *; auto;
    apply CIH; simpl in *; auto.

Lemma Unlock_in_network_eventually_MsgUnlock : forall c s, lb_step_execution lb_step_async s -> weak_fairness lb_step_async label_silent s -> In (mkPacket c Server Unlock) (nwPackets (evt_a (hd s))) -> eventually (now (occurred MsgUnlock)) s.