Seriously: Scheme is guaranteed to have tail-call replacement, the author should really take advantage of that. Here's one that does: (define (fib-tco n)

Seriously: Scheme is guaranteed to have tail-call replacement, the author should really take advantage of that. Here's one that does: (define (fib-tco n) (let loop ((x 0) (y 1) (num n)) (if (zero? n) x (loop y (+ x y) (- num 1))))) Try getting the 1000th Fibonacci number which each of these. Also, what's with the dangling parentheses?