(Forall
(?Self ?Time)
(=> (Active ?Time 2d-Stream-Potential-Energy ?Self)
(= (Lambda (?T)
(If (= ?T ?Time)
(Value-At (Pe-Rate (2d-Stream-Involved ?Self))
?T)))
(* (Lambda (?T)
(If (= ?T ?Time)
(Value-At (Mass-Rate
(2d-Stream-Involved ?Self))
?T)))
(Lambda
(?T)
(If (= ?T ?Time)
(Value-At
(Stream-Elevation (2d-Stream-Involved ?Self))
?T)))
(Lambda (?T)
(If (= ?T ?Time)
(Value-At (Acceleration-Due-To-Gravity ?Self)
?T)))))))
(Forall (?Self ?Time)
(<=> (Active ?Time 2d-Stream-Potential-Energy ?Self)
(And (2d-Stream-Potential-Energy ?Self)
(Active ?Time 2d-Stream-Operating-Mode ?Self)
(Active ?Time Earth-Bound-Model ?Self))))