The performing {HEAD ~ the task} corresponding to {TAIL ~ 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 a previous channel and a next channel of the current channel 
corresponding to
The performing { HEAD ~ the task } corresponding to { TAIL ~ 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 a previous channel and a next channel of the current channel
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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 OTH