Notation nodes1 := (cs1 ++ cls1).Notation nodes2 := (cs2 ++ cls2).(* Protocol I'm a server in *)
Notation cal1 := (cal_with_inv l1 f prec cs1 cls1).Notation cal2 := (cal_with_inv l2 f prec cs2 cls2).Notation W1 := (mkWorld cal1).Notation W2 := (mkWorld cal2).

Lemma validV : valid V.