a plurality of window system processing means, one of which can refresh a graphic display by producing graphic display data based on {HEAD ~ original data} for {TAIL ~ the graphic display} 
for
a plurality of window system processing means , one of which can refresh a graphic display by producing graphic display data based on { HEAD ~ original data } for { TAIL ~ the graphic display }
OTH OTH 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 TAIL TAIL TAIL TAIL TAIL TAIL TAIL