/PREVIOUS="hot-key-defintion"

   This qualifier is used to define a hot-key sequence which causes PEEK
   to stop watching the current target and start watching the previous
   target.

   If there is no previous, matching target specification then PREVIOUS
   is equivalent to END_WATCH.

   The default hot-key value is taken from the logical WATCHER$PREVIOUS.

   Example:

         $ PEEK/PREVIOUS="<CTRL-P>P" GROUP1*
     or
         $ DEFINE WATCHER$PREVIOUS "<CTRL-P>P"
         $ PEEK GROUP1*

   In either case when the watcher presses Control-P followed by the
   letter P, PEEK will stop watching the current user and try to watch
   a previous user.

   For a complete description of the syntax used for specifying hot-key
   definitions, see the top-level PEEK Subtopic: Hot-Keys.