The operational amplifiers 40 and 42 operate in conjunction such that the voltage level appearing on line 15 will be {HEAD ~ the minimum} of the potentials appearing on {TAIL ~ lines} 23 and 25 
The operational amplifiers 40 and 42 operate in conjunction such that the voltage level appearing on line 15 will be { HEAD ~ the minimum } of the potentials appearing on { TAIL ~ lines } 23 and 25
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH