In the closed position a portion of the display is obstructed by the keyboard unit, and in the open position {HEAD ~ the display} is unobstructed by {TAIL ~ the keyboard unit} 
is unobstructed by
In the closed position a portion of the display is obstructed by the keyboard unit , and in the open position { HEAD ~ the display } is unobstructed by { TAIL ~ the keyboard unit }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL