SimpleAttribute TriState {}
SimpleAttribute String {}
SimpleAttribute Boolean {}

Class State {
    name : String
    isInitial : Boolean
}
Class ErrorState : State {}
Class NormalState : State {}

Association Transition (State, State) {
    objPresent : TriState
}
Association OnUp : Transition (State, State) {}
Association OnDown : Transition (State, State) {}
Association OnNeutral : Transition (State, State) {}