MAUI thinks of user interfaces as finite state machines (FSMs).
An FSM is made up of a finite set of states and events. In MAUI, there are also a finite number of superstates and signs
An event can move the interface from one state to another state. Events describes a particular thing that could happen to the interface. This could be an external event, such as a button press or light conditions changing, or an internal event, such as a timer has reached a given limit. The move from one state to another caused by an event is called a transition
An event may have more than one transition for a given state. Such events are called non-deterministic, as are the models which contain them.
An event may not have any effect for a given state. Its transition may just return the interface to the same state. An event which always does this is called an identity event (written as [Id] or [Nothing]).
An event may not have a transition for a given state. The event is called guarded for that state.
Superstates are collections of states. Transitions for an event may be defined for a superstate, in which case all its member states have that transition.
Signs may also be on or off for superstates. If a sign is on for superstate, then it is on for all its member states.