Providing signal conductors which serve only to interconnect the programmable logic elements in each group avoids tying up much longer conductors just to make {HEAD ~ short interconnections} between {TAIL ~ adjacent programmable logic elements} 
between
Providing signal conductors which serve only to interconnect the programmable logic elements in each group avoids tying up much longer conductors just to make { HEAD ~ short interconnections } between { TAIL ~ adjacent programmable logic elements }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL