{HEAD ~ a pull up voltage supply circuit}, connected with the first power supply and {TAIL ~ the second power supply}, for supplying the pull up voltage 
connected with
{ HEAD ~ a pull up voltage supply circuit } , connected with the first power supply and { TAIL ~ the second power supply } , for supplying the pull up voltage
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH