This assignment is intended to help you develop some experience in manipulating a formal model of a software architecture. In this case you will be using the formal model of event systems presented in class. Following the pattern of specialization in [GN91] you are to formally characterize as event systems the two architectural idioms described below. You may wish to consult the references [Spi89a, Spi89b, PST91] for additional help with the Z notation.