{HEAD ~ The other ends} of the cores are spaced on {TAIL ~ either side} of the adjacent ends 
{ HEAD ~ The other ends } of the cores are spaced on { TAIL ~ either side } of the adjacent ends
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH