Do you program any elisp, at all, ever?
;; Elisp go-to-definition with M-. and back again with M-, (autoload 'elisp-slime-nav-mode "elisp-slime-nav") (add-hook 'emacs-lisp-mode-hook (lambda () (elisp-slime-nav-mode t))) (eval-after-load 'elisp-slime-nav '(diminish 'elisp-slime-nav-mode))
Then you need to M-x
It lets you jump to the definition of a function with M-., and back again afterwards with M-,.
That last line says that we want elisp-slime-nav-mode to continue doing its work for us, but we no longer want to be reminded of it.