;;; -*- Mode:LISP; Package:USER; Readtable:CL; Base:10 -*-

(defvar a 3 "foo")

(defun foo (&optional (a a))
  (bar))

(defun bar ()
  (1+ a))

(defun baz ()
  (let ((a 6))
    (bar)))

(defun yow ()
  (+ (let ((a 9))
       (bar))
     a))