Lazy version of evaluator and tests.

[sicp.git] / src / sicp / ex3_79.rkt

#lang racket

(define (solve-2nd f y0 dy0 dt)
  (define y (integral (delay dy) y0 dt))
  (define dy (integral (delay ddy) dy0 dt))
  (define ddy (stream-map f dy y))
  y)