In {HEAD ~ some cases} {TAIL ~ protection} of certain reactive functionalities may be necessary to achieve some of the above transformations 
In { HEAD ~ some cases } { TAIL ~ protection } of certain reactive functionalities may be necessary to achieve some of the above transformations
OTH HEAD HEAD HEAD HEAD HEAD HEAD TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH