(=> (Partly-Parallel-Plan ?Self)
(And (Minimum-Slot-Cardinality ?Self Plan-Direct-Successor 2)
(Exists (?Y ?Z)
(And (Generic-Plan ?Y)
(Generic-Plan ?Z)
(Co-Exist ?Y ?Z)
(Plan-Direct-Successor ?Self ?Y)
(Plan-Direct-Successor ?Self ?Z)))))