In one example, the two cores have adjacent ends which are contiguous, and in other cases {HEAD ~ the adjacent core ends} are separated by {TAIL ~ a space} 
are separated by
In one example , the two cores have adjacent ends which are contiguous , and in other cases { HEAD ~ the adjacent core ends } are separated by { TAIL ~ a space }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL