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