From these cases is determined a case of amounts supplemented in which the treating ability of {HEAD ~ chemical solution} is maintained at {TAIL ~ a required level} and the amounts supplemented are minimized 
From these cases is determined a case of amounts supplemented in which the treating ability of { HEAD ~ chemical solution } is maintained at { TAIL ~ a required level } and the amounts supplemented are minimized
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 TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH