CL from Emacs Lisp
- https://stackoverflow.com/questions/8433474/what-are-the-major-differences-between-emacs-lisp-and-common-lisp
- https://www.emacswiki.org/emacs/CommonLisp
- https://www.emacswiki.org/emacs/EmacsLispLimitations
- https://copyprogramming.com/howto/what-are-the-major-differences-between-emacs-lisp-and-common-lisp
- https://yoo2080.wordpress.com/2013/08/16/differences-between-common-lisp-and-emacs-lisp/ Public Domain