fibonacci.scm

; Заяц
(define fib (lambda (n fib-1 fib-2)
                (if (<= n 1)
                    (+ fib-1 fib-2)
                    (fib (- n 1) (+ fib-1 fib-2) fib-1)))
  )

; Черепаха
(define slow-fib (lambda (n)
                     (if (equal? n 0)
                         0
                         (if (equal? n 1)
                             1
                             (+ (slow-fib (- n 1)) (slow-fib (- n 2)))
                             )
                         )
                     )
    )