This is using MIT Scheme, coming from the infamous SICP. I just can't wrap my head around what is happening.
Here's a procedure to compute `N!`.

```
(define (factorial n)
     (if (= n 0)
          1
          (* n (factorial (- n 1)))))

```

Here's a procedure to compute Fibonacci

```
(define (fib n)
   (cond ((= n 0) 0)
         ((= n 1) 1)
   (else (+ (fib (- n 1))
            (fib (- n 2))))))

```