An Activity is a predecsessor of another activity if the activity begins after the predecessor activity completes and no other activities occur between them.
(Inherited-Facet-Value Minimum-Slot-Cardinality Epml-Activity Epml-Activity-Predecessor 0) (Inherited-Facet-Value Slot-Value-Type Epml-Activity Epml-Activity-Predecessor Epml-Activity)