This may sound odd, but when I type
C-h i m Emacs Lisp Intro -- it's not there. I'm on Ubuntu 19.10 with Emacs 26.3. I tried
apt-get install emacs-lisp-intro as the EmacsWiki said, but there's no such thing in the Ubuntu world. How can I get it installed?
I am not a Ubuntu user, on Debian this Elisp intro come from emacs-common-non-dfsg. I think that should do it : https://packages.ubuntu.com/search?lang=en&keywords=emacs-common-non-dfsg