Of course, optionally, {TAIL ~ non commercial or fewer repetition zero clearance cutting operations} also may be provided by {HEAD ~ the invention} 
Of course , optionally , { TAIL ~ non commercial or fewer repetition zero clearance cutting operations } also may be provided by { HEAD ~ the invention }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD