(let
  (
    (a 1)
    (b 2))
  (let
    (
      (
        c 3))
    (format #t "a: ~A, b: ~A, c: ~A"
                 a      b      c)))

((a))

(define (hello)
  (display "hello"))

(let
  ((a 1)
    (b 2))
  (format #t "a: ~A, b: ~A"
               a      b))