A plan branched to a set of plans not executable in parallel.
(=> (Case-Plan ?Self)
(And (Minimum-Slot-Cardinality ?Self Plan-Direct-Successor 2)
(Exists (?A) (And (Method-Of ?Self ?A) (Case-Stage ?A)))
(Exists (?B) (And (Represented-By ?Self ?B) (Fork-Node ?B)))))