{HEAD ~ The user input interface}, in turn, can comprise {TAIL ~ any} of a number of devices allowing the entity to receive data from a user, such as a keypad , a touch display, a joystick or other input device 
{ HEAD ~ The user input interface } , in turn , can comprise { TAIL ~ any } of a number of devices allowing the entity to receive data from a user , such as a keypad , a touch display , a joystick or other input device
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH