(define (rl) (load "cartesian-proper.ss"))

(define list-recur
  (lambda (f init)
    (letrec ([helper
	      (lambda (l)
		(if (null? l)
		    init
		    (f (car l) (helper (cdr l)))))])
      helper)))

;;; Let's start off easy, we'll go through the second list

(define cart1
  (lambda (l1 l2)
    ((list-recur (lambda (x y) (cons (cons x l1) y)) ()) l2)))


(define cart2
  (lambda (l1 l2)
    ((list-recur (lambda (x y) (append ((list-recur (lambda (k m) (cons (list x k) m)) ()) l2) y)) ()) l1)))

(define cart4
  (lambda (l1 l2)
    (let* ([helper2 (lambda (x) (list-recur (lambda (k m) (cons (list x k) m)) ()))]
	   [helper (list-recur (lambda (x y) (append ((helper2 x) l2) y)) ())])
    (helper l1))))