cps.scm

(define (plus3 x y)
  (+ (+ x y) 3))

(define (plus3&co x y co)
  (let ((plus&co (lambda (x y co) 
		   (co (+ x y)))))
    (plus&co x y (lambda (z)
		   (co (+ z 3))))))

(plus3&co 1 2 (lambda (x) x))

(define (x^2_plus_y^2 x y)
  (+ (* x x) (* y y)))

(define (x^2_plus_y^2&co x y co)
  (let ((p2&co
	 (lambda (x co0) (co0 (* x x)))))
    (p2&co x (lambda (x^2)
	       (p2&co y (lambda (y^2)
			  (co (+ x^2 y^2))))))))