1
2(define reduce
3  (lambda (op base l)
4    (if (null? l)
5        (begin (browse-environment) base)
6        (op (car l) (reduce op base (cdr l))))))
7
8(reduce + 0 '(2 3 4))
9
10(define factit
11  (lambda (n)
12    (letrec
13        ((fit
14          (lambda (n acc)
15            (if (= n 0)
16                (begin
17                  (browse-environment) acc)
18                (fit (- n 1) (* n acc))))))
19      (fit n 1))))
20
21(factit 6)
22
23(define rec
24  (lambda (n stop)
25    (display n) (newline)
26    (if (= n 0)
27        (begin
28          (browse-environment)
29          (stop 0))
30        (begin
31          (rec (- n 1) stop)
32          (display n) (newline)))))
33
34(rec 6 (lambda (x) '()))
35