determining {TAIL ~ a total amount} of {HEAD ~ fuel} required to raise the temperature of exhaust above a regeneration temperature based on the determined flow rate and the determined temperature; and 
determining { TAIL ~ a total amount } of { HEAD ~ fuel } required to raise the temperature of exhaust above a regeneration temperature based on the determined flow rate and the determined temperature ; and
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH