The performing the task corresponding to the first motion item may comprise, if the task corresponding to the first motion item is channel changing from among the second tasks, changing a current channel to one of {HEAD ~ a previous channel} and a next channel of {TAIL ~ the current channel} 
of
The performing the task corresponding to the first motion item may comprise , if the task corresponding to the first motion item is channel changing from among the second tasks , changing a current channel to one of { HEAD ~ a previous channel } and a next channel of { TAIL ~ the current channel }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL