Install emacs25-el by entering the following commands in the terminal:
sudo apt update sudo apt install emacs25-el
Description:
GNU Emacs LISP (.el) files
GNU Emacs is the extensible self-documenting text editor. This package contains the elisp sources for the convenience of users, saving space in the main package for small systems.
Homepage: http://www.gnu.org/software/emacs/
Version: 25.2+1-6
Section: editors