Thus, one aspect of {HEAD ~ the invention} is a portable device having a main unit and {TAIL ~ a keyboard unit} 
Thus , one aspect of { HEAD ~ the invention } is a portable device having a main unit and { TAIL ~ a keyboard unit }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL