Here, {TAIL ~ the first voltage source V1} is {HEAD ~ an output} from a constant voltage circuit 
Here , { TAIL ~ the first voltage source V1 } is { HEAD ~ an output } from a constant voltage circuit
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH