text: Composite State [EA User Guide]
  Composite States are composed within the State Machine diagram by expanding a State element, adding Regions if applicable, and dragging further State elements, related elements and connectors within its boundaries. The internal State elements are then referred to as Sub-states.
  (You can also define a State element, as with many other types of element, as a composite element; this then has a hyperlink to a child diagram that can be another State Machine diagram or other type of diagram elsewhere in the model.)
  Composite States can be orthogonal, if Regions are created. If a Composite State is orthogonal, its entry denotes that a single Sub-state is concurrently active in all Regions. The hierarchical nesting of Composite States, coupled with Region use, generates a situation of multiple States concurrently active; this situation is referred to as the active State configuration.