Cancels wakeup requests for a specified process, including wakeup
    requests scheduled with either the RUN command or the $SCHDWK
    system service.
    Requires one of the following:
    o  Ownership of the process
    o  GROUP privilege to cancel scheduled wakeup requests for
       processes in the same group but not owned by you
    o  WORLD privilege to cancel scheduled wakeup requests for any
       process in the system
    Format
      CANCEL  [[node-name::]process-name]