FOR YOU TO DO (IN PAIRS)

fill in the following, so that it returns
the indicated value

(letrec ((odd?
          (has-type
            (-> (number) boolean)
            (lambda (n)
              (if (zero? n)

                 (even? (- n 1))))))
         (even? 
           (has-type
             (-> (number) boolean)

	   

                 (odd? (- n 1))  )))
  (list (odd? 227) (even? 342)))

 ==>  (#t #t)