Lexical Scope _and_ Dynamic Scope

gistfile1.el

;;; http://jutememo.blogspot.com/2012/03/blog-post.html
;;; in Emacs Scratch Buffer

(setq x 7)
7

(defun g () x)
g

(defun f ()
  (let ((x 9))
    (g)))
f
(f)
9