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63 ).
3.7.6 Pseudostate
3.7 The State Machine Diagram
FIGURE 3-63
Notation for initial and fi nal states.
stm Notation
Final state
Initial state
Defi nition
A pseudostate is a control element that influences the sequence of events in
a state machine. It is not a real state, and a pseudostate does not represent a
value combination either.
UML knows 10 different pseudostates. Each of them describes a special property
that controls state transitions. For example, the initial state discussed in Section
3.7.5 is a pseudostate. It is responsible for marking the initial state of a state
machine.
I ??™ ll briefl y describe the other nine states below:
?–  Shallow history
?–  Deep history
?–  Join
?–  Fork
?–  Junction
?–  Choice
?–  Exit point
?–  Entry point
?–  Terminate
200 CHAPTER 3 UML??”Unifi ed Modeling Language
There are two types of history state: shallow history and deep history . To better
understand history states, let ??™ s fi rst look at the state machine of a hairdryer
( Figure 3.64 ) 17 . Don ??™ t pay attention to the circle symbol with the letter ??? H ??? for
now.


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