each of {HEAD ~ gate electrodes} of said third and fourth P channel MOS transistors is connected to {TAIL ~ a connection node} between said third P channel MOS transistor and said third N channel MOS transistor 
each of { HEAD ~ gate electrodes } of said third and fourth P channel MOS transistors is connected to { TAIL ~ a connection node } between said third P channel MOS transistor and said third N channel MOS transistor
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH