The lower portion is recessed relative to the upper portion in {TAIL ~ a direction} toward {HEAD ~ the opposite cutting edge} 
The lower portion is recessed relative to the upper portion in { TAIL ~ a direction } toward { HEAD ~ the opposite cutting edge }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD