this is an event, which is used to run dedicated code when the value of some variable changes.
this is an event, which is used to run dedicated code when the value of some variable changes. It can also impact on the value of other variable, although it is not recommended to implement invariants as events, because you cannot have the delta.
the variable whose change will trigger the execution of action
the action to execute when the variable changes.
the variables that could be modified by the Event