[plt-scheme] Re: top-level error

However, why the code below works well??? I use odd? before its
definition, but no complaint from DrScheme. That's why I am confused?
So could someone talks more about the top-level in detail?


(define test (odd? 4))

(define even?
  (lambda (x)
    (if (= x 0)
        #t
        (odd? (- x 1)))))

(define odd?
  (lambda (x)
    (if (= x 0)
        #f
        (even? (- x 1)))))