my Elisp probably introduced in Emacs 1.2

[Emanuel Berg]

(defun sort-lines-random (beg end)
  (interactive "r")
  (save-excursion
    (save-restriction
      (narrow-to-region beg end)
      (goto-char (point-min))
      (sort-subr nil
                 #'forward-line
                 #'end-of-line
                 nil nil
                 (lambda (_ __) (zerop (random 2)) )))))
(defalias 'r #'sort-lines-random)

But then I do C-h f r RET

  r is an alias for ‘sort-lines-random’ in ‘sort-incal.el’.

  (r BEG END)

  Not documented.

    Probably introduced at or before Emacs version 1.2.

Probably! I mean it's pretty good and I'm old-school and all ...

https://dataswamp.org/~incal/emacs-init/sort-incal.el

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