+(define-minor-mode winner-mode
+ "Toggle Winner mode on or off.
+With a prefix argument ARG, enable Winner mode if ARG is
+positive, and disable it otherwise. If called from Lisp, enable
+the mode if ARG is omitted or nil, and toggle it if ARG is ‘toggle’.
+
+Winner mode is a global minor mode that records the changes in
+the window configuration (i.e. how the frames are partitioned
+into windows) so that the changes can be \"undone\" using the
+command `winner-undo'. By default this one is bound to the key
+sequence `C-c <left>'. If you change your mind (while undoing),
+you can press `C-c <right>' (calling `winner-redo')."
+ :global t