Consider the system outlined in It consists of three processes: Line, Producer, and Consumer. Line represents the external environment of the system. It writes single characters into Port, from which Producer gets them. The two are synchronized through a monitor. Producer puts the character into Buffer through another monitor, from which Consumer gets packets of n 5 size (Buffer) characters. Consumer does not have to wait until the buffer is full. Formalize a correct behavior of this system by means of an appropriate invariant assertion.