The main unit includes a display and {HEAD ~ the keyboard unit} includes {TAIL ~ a full alphabet keyboard} 
includes
The main unit includes a display and { HEAD ~ the keyboard unit } includes { TAIL ~ a full alphabet keyboard }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL