a third set of {HEAD ~ coefficients} equal to −1 extending away from {TAIL ~ said direction} on said second side 
extending away from
a third set of { HEAD ~ coefficients } equal to −1 extending away from { TAIL ~ said direction } on said second side
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH