the class of thermal components with two inlets and one outlet
(Forall (?Self ?Time) (<=> (Active ?Time 2-1-Port-Thermal-Component ?Self) (And (2-1-Port-Thermal-Component ?Self) (Active ?Time 2-Input-Thermal-Component ?Self) (Active ?Time 1-Output-Thermal-Component ?Self))))
(Forall (?Self ?Time) (<=> (Active ?Time 2-1-Port-Thermal-Component ?Self) (And (2-1-Port-Thermal-Component ?Self) (Active ?Time 2-Input-Thermal-Component ?Self) (Active ?Time 1-Output-Thermal-Component ?Self)))) (Forall (?Self ?Time) (<=> (Active ?Time 2-1-Open-Feedwater-Heater ?Self) (And (2-1-Open-Feedwater-Heater ?Self) (Active ?Time 2-1-Port-Thermal-Component ?Self) (Active ?Time Open-Feedwater-Heater ?Self))))