(Forall
(?Self ?Time)
(=> (Active ?Time 2d-Stream-Mass-Flow-Rate ?Self)
(= (* (Lambda (?T)
(If (= ?T ?Time)
(Value-At (Mass-Rate
(2d-Stream-Involved ?Self))
?T)))
(Lambda
(?T)
(If (= ?T ?Time)
(Value-At
(Specific-Volume (2d-Stream-Involved ?Self))
?T))))
(* (Lambda (?T)
(If (= ?T ?Time)
(Value-At
(Stream-Area (2d-Stream-Involved ?Self))
?T)))
(Lambda (?T)
(If (= ?T ?Time)
(Value-At (Velocity (2d-Stream-Involved ?Self))
?T)))))))
(Forall (?Self ?Time)
(<=> (Active ?Time 2d-Stream-Mass-Flow-Rate ?Self)
(And (2d-Stream-Mass-Flow-Rate ?Self)
(Active ?Time 2d-Stream-Operating-Mode ?Self))))