;;; Michael Wollowski

(define (rl) (load "pascal.ss"))

(define pascal-triangle
  (lambda (n)
    (if (< n 0)
	()
	(pt n '((1))))))


(define pt
  (lambda (n accu)
    (if (= n 0)
	accu
	(pt (- n 1) (cons (cons 1 (make-row (car accu)))
			  accu)))))

(define make-row
  (lambda (row)
    (cond [(null? (cdr row)) '(1)]
	  [else (cons (+ (car row) (cadr row))
		      (make-row (cdr row)))])))