Matt Bowcock // mbowcock.com

Had a little time and got it done quicker than I expected. Problem 1.12 was to write a procedure to calculate elements of pascals triangle. I took that to mean calculate the value at position n of a given row. Take a look -

(define (pascal row n)
  (cond ((> n row) 0)
        ((or (= n 1) (= n row)) 1)
        (else (+ (pascal (- row 1) n) (pascal (- row 1) (- n 1))))))