A stage performed to accomplish a branching or a synchronization contained in a plan that constitutes the method of the procedure at hand.
(=> (Planning-Stage ?Self)
(And (Exists (?A)
(And (Temporal-Part-Of ?Self ?A) (Procedure ?A)))
(Exists (?B)
(And (Method ?Self ?B)
(Or (Branching-Plan ?B) (Synchro-Plan ?B))))))