7 ;; check if not recursion
8 (let ([f (lambda (n) (print "not rec"))])
9 (let ([f (lambda (n) (if (= n 0)
14 (let ([f (lambda (n) (print "not rec"))])
15 (letrec ([f (lambda (n) (if (= n 0)
21 (letrec ([fact (lambda (n)
24 (* n (fact (- n 1)))))])
31 (* n (fact (- n 1)))))