The notches hence cooperate with the pins to serve {TAIL ~ the above discussed functions} of {HEAD ~ the pins} 
The notches hence cooperate with the pins to serve { TAIL ~ the above discussed functions } of { HEAD ~ the pins }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD