Use regions in state machine diagrams
You can easily insert regions into state machine diagrams and resize them. Depending on the kind of region already available in the diagram, you can insert either horizontal or vertical regions. To be able to insert a region of a different kind than the one currently in use, you must first delete the current regions from the container element.
In the Symbols bar, click Region (horizontal) or Region (vertical).
Move the mouse pointer to the border of the container element. A frame is shown, and a triangular arrow indicates the position for inserting the region.
Release the mouse button. The region is inserted at the position indicated by the triangular arrow, and the region's handles are displayed.
Click a handle of your choice and drag it in the required direction. The region is resized accordingly.
Inserting a region into a state machine diagram and resizing it is now complete.