Lists, rationals, polynomials and intervals - Implementation (more functions) : Rat_poly_common.deriv

let rec deriv_poly = function

  p -> if is_null_poly (p)

         then null_poly ()

         else

           let

             (a, q) = inv_cons_poly (p)

           in

             add_poly (q, x_times (deriv_poly (q)))