#lang racket

; downward funarg
(define (a x y) ; x is a natural number, y is a list of functions with no args
  (define z x)
  (define (f)
    z)
  (define (g l) ; evaluates each list element as a function with no args, along with summing
    (if (empty? l)
        0
        (+ ((car l)) (g (cdr l)))))
  (define (b)
    (define (c)
      (define (d)
        (define (e)   ; builds list of function references or evaluates list
          (if (= x 0)
              (g y)   ; evaluate the list
              (a (sub1 x) (cons f y))))  ; 
        (e))
      (d))
    (c))
 (b))

; upward funarg
(define (h x y) ; x is a natural number, y is a list of functions with no args
  (define z x)
  (define (f)
    z)
  (define (g l) ; evaluates each list element as a function with no args, along with summing
    (if (empty? l)
        0
        (+ ((car l)) (g (cdr l)))))
  (define (b)
    (define (c)
      (define (d)
        (define (e)   ; builds list of function references or evaluates list
          (if (= x 0)
              (lambda () (g y))   ; return function to evaluate the list
              (h (sub1 x) (cons f y))))  ; 
        (e))
      (d))
    (c))
 (b))

(a 5 '())

(h 5 '())

((h 5 '()))