Specialization is a mechanism for refining the definition of members of an object class.
In this section we cover the relationship between state nets for generalizations and specializations. Since an object in a specialization class is also a member of the generalization class, we can say that an object in the specialization class exhibits the behavior common to the objects in the specialization class, as well as that common to the objects in the generalization class. The following example shows a state net for the Student object class. The state net declares that a Student object is initially in the idle state when a student comes into existence. When the time to finish classes condition becomes true, the Student object leaves the idle state, executes the transition, and enters the student responsibilities state.