;; guile: 10
;; (0 0)
;; mes: 10
;; (0 2)

(define (x)
  (define b 1)
  (define (y) b)

  (display b)
  (set! b 0)
  (display b)
  (newline)

  (list b
        (let ((b 2)) ;; b shadows previous b in mes
          (y))))     ;; guile: y captures shadowed b, mes: y runs in context new b

(display (x))
(newline)
""

;; guile: 10
;; (0 3)
;; mes: 10
;; (0 3)
(define (x)
  (define b 1)
  (define (y) b)   ;; var b is captured

  (display b)
  (set! b 0)
  (display b)
  (newline)

  (list b
        (let ((d 4))
          (set! b 3) ;; value b is changed
          (y))))

(display (x))
(newline)
""