(define (fib n ac1 ac2)
  (if (zero? n)
    ac1
    (fib (- n 1) ac2 (+ ac1 ac2))))

(define (build-fib-list ubound)
  (map (lambda (n) (fib n 0 1)) (iota 100 1)))

(apply +
  (filter
    (lambda (n)
      (and (even? n) (< n 4000000)))
    (build-fib-list 100)))