The process Set is a container for other processes. Children can be added to it by using braces. Its children can be reached by their name through a dotted notation. Moreover, a Set has two special children named $added and $removed that contains a reference to the last child that has been, respectively, added or removed. These special children are reference properties. The additional size child, contains the number of children.


Set <id>


Activates all its children in an unspecified order.

Predefined children

$added, $removed and size.


Set mySet {
  Rectangle r1 (...)
  Rectangle r2 (...)
  Rectangle r3 (...)

frame.width => mySet.r1.width