[racket-dev] feature request: gcd, lcm for rationals

It would be nice if gcd and lcm were extended to rational numbers, which 
seems in-line with Scheme's philosophy (but not standards) on numbers.

(define (gcd-rational . rs)
   (/ (apply gcd (map numerator rs))
      (apply lcm (map denominator rs))))

(define (lcm-rational . rs)
   (/ (abs (apply * rs))
      (apply gcd-rational rs)))

David