{HEAD ~ These extended end sections} constitute {TAIL ~ a leading end section} 12 and a trailing end section 14 
constitute
{ HEAD ~ These extended end sections } constitute { TAIL ~ a leading end section } 12 and a trailing end section 14
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH