(define add-5 '())
(define res 1)

(mutate! res (+ 2 (call/cc (lambda (cont) (set! add-5 cont) 1)) 3))
(assert (= res 6))

(add-5 100)
(assert (= res 105))

(add-5 10)
(assert (= res 15))


;; ----------- works until here ---------------


(set! res (+ 2 (call/cc (lambda (cont) (set! add-5 cont) 1)) 3))
;; (print)
;; (print res 6)
(assert (= res 6))

(add-5 100)
;; (print res 105)
(assert (= res 105))

(add-5 10)
(assert (= res 15))
;; (print res 15)

;; (define fun '())

;; (mutate! res (apply (call/cc (lambda (k) (set! fun k) +)) (list 1 2 3)))

;; (assert (= res 6))
;; (fun -)
;; (assert (= res -1))