In {TAIL ~ effect}, the flap and {HEAD ~ base member} define a receptacle within which the instrument can be retained 
In
In { TAIL ~ effect } , the flap and { HEAD ~ base member } define a receptacle within which the instrument can be retained
REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH