(define (pascal row col)
  (cond ((= col 0) 1)
        ((= col row) 1)
        (else (+ (pascal (- row 1) (- col 1))
                 (pascal (- row 1) col) ))))


(define (new-pascal row col)
  (nth col (pascal-row row)) )


(define (pascal-row row-num)
  (define (iter in out)
    (if (empty? (bf in))
        out
        (iter (bf in) (se (+ (first in) (first (bf in))) out)) ))
  (define (next-row old-row num)
    (if (= num 0)
        old-row
        (next-row (se 1 (iter old-row '(1))) (- num 1)) ))
  (next-row '(1) row-num) )