;; Some inefficient arithmetic computations for benchmarking.

;; Unfortunately not yet available in tests of steps 4 and 5.

;; Compute n(n+1)/2 with a non tail-recursive call.
(def! sumdown
  (fn* [n]                              ; non-negative number
    (if (= n 0)
      0
      (+ n (sumdown  (- n 1))))))

;; Compute a Fibonacci number with two recursions.
(def! fib
  (fn* [n]                              ; non-negative number
    (if (<= n 1)
      n
      (+ (fib (- n 1)) (fib (- n 2))))))