When editing or viewing long procedure definitions it is easy to forget which procedure you are looking at when the procedure statement itself is off the top of the screen. REDUCE mode can show in the mode line the name of the procedure (if any) that point is in. This facility is turned on and off by the command M-x reduce-show-proc-mode or via the REDUCE mode menu; it is on by default. (It is analogous to the standard Emacs “Which Function” mode – see Which Function in The Emacs Editor – but it is implemented independently.)
The procedure name is shown in the mode line near the end surrounded by square brackets. It provides a mouse menu as do most mode-line items; hover over it to see the options. Clicking mouse button 1 (usually the left button) on the procedure name jumps to the beginning of the procedure; clicking mouse button 2 (usually the right button) jumps to the end of the procedure; clicking mouse button 3 (usually the middle button) toggles hiding the buffer contents other than the procedure, i.e. it narrows to the procedure or widens the buffer if it is currently narrowed.
Toggle REDUCE Show Proc mode. REDUCE Show Proc mode displays the
current procedure name in the mode line and updates it after
idle-update-delay seconds of Emacs idle time.
This is a minor mode. If called interactively, toggle REDUCE Show Proc mode. If the prefix argument is positive, enable the mode, and if it is zero or negative, disable the mode.