A pack containing {HEAD ~ an article} such as {TAIL ~ a bar} of soap consists of an inner tubular liner within an outer wrapper 
A pack containing { HEAD ~ an article } such as { TAIL ~ a bar } of soap consists of an inner tubular liner within an outer wrapper
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH