{HEAD ~ The region} is encoded to generate {TAIL ~ a temporary encoded region} and the temporary encoded region is then decoded to generate a decoded region 
is encoded to generate
{ HEAD ~ The region } is encoded to generate { TAIL ~ a temporary encoded region } and the temporary encoded region is then decoded to generate a decoded region
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH