gistfile1.scm

#lang scheme

(letrec ([recur1 
             (lambda (x) 
               (cond 
                 [(< x 0) (display "Countdown complete.")]
                 [else      (printf "Counting ~s~n" x)
                            (recur2 (- x 1))]))]
         [recur2 
          (lambda (x) 
            (cond
              [(even? x) (printf "I saw an even number.~n") (recur1 x)]
              [(odd?  x) (printf "I saw an odd number.~n") (recur1 x)]))])
  (recur2 10))