.ComplexLib.SinglePhase.Interfaces.TwoPort .ComplexLib.SinglePhase.Interfaces.TwoPortSuperclass of elements which have two ports i.e. four electrical pins of type ComplexPin. The identity of the phasor of the current flowing into pin p1 and the phasor of the current flowing out of pin n1 is forced by internal current balance. The same holds for the pins p2 and n2.