The pair of stacks is connected by {TAIL ~ a length} of material which is folded on {HEAD ~ top} of the stacks 
The pair of stacks is connected by { TAIL ~ a length } of material which is folded on { HEAD ~ top } of the stacks
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH