wherein said means for pushing is {HEAD ~ at least one source transistor} and said means for pulling is {TAIL ~ at least one sink transistor} 
wherein said means for pushing is { HEAD ~ at least one source transistor } and said means for pulling is { TAIL ~ at least one sink transistor }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL