When {HEAD ~ execution} of {TAIL ~ the communication task} can be extended, the communication apparatus extends execution of the communication task to a later time 
of
When { HEAD ~ execution } of { TAIL ~ the communication task } can be extended , the communication apparatus extends execution of the communication task to a later time
OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH