a) providing {TAIL ~ a controller} operatively connected to each of {HEAD ~ the independently driven nip rollers} 
a ) providing { TAIL ~ a controller } operatively connected to each of { HEAD ~ the independently driven nip rollers }
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD