- `(defvar x 10)` - `(setq x 20)` - `(let ((x 10) (y 20))` - `(let* ((x 10) (y (+ x 20 30)))`
(defvar x 10)(setq x 20)(let ((x 10) (y 20))(let* ((x 10) (y (+ x 20 30)))