In an embodiment, the region 38 has {HEAD ~ depth} greater than {TAIL ~ the region} 34 
greater than
In an embodiment , the region 38 has { HEAD ~ depth } greater than { TAIL ~ the region } 34
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH