Where used: State Change And Event Model

State Change

Read First: State

A state change is a change in the relation instances (tuples) that an
object participates in, in such a way that its changes state.  For
example, if Mary loses her job, it would affect her Employed state, but
if she changes Employers, it would not.  In each case, the tuple she
participates in changes, but in one case the state rule for Employed is
violated, but not in the other.

The states before and after a state change are given by
isPrestateFor/hasPrestate and hasPostState/isPostStateFor respectively.


Attributes: None

Operations: None