the system consisting of a nozzle, an associated control-volume, and a throttling process.
the nozzle
the control volume associated with the nozzle in the nozzle-system
the throttling process
(Forall (?Self ?Time)
(<=> (Active ?Time Nozzle-System ?Self)
(And (Nozzle-System ?Self)
(Active ?Time System-Model ?Self))))
(=> (Nozzle-System ?Self)
(And (Cv-Component (Nzl-Cv ?Self) (Nzl ?Self))
(Component-Cv (Nzl ?Self) (Nzl-Cv ?Self))
(Process-Cv (Thrtlng-Prcs ?Self) (Nzl-Cv ?Self))))