Stop playing games with my funcs

fns.rkt

(define (pow1 x y)
  (if (zero? y)
      1
      (* x (pow1 x (- y 1)))))

(define pow2
  (lambda (x)
    (lambda (y)
      (if (zero? y)
          1
          (* x ((pow2 x) (- y 1)))))))

(define  three-to-the (pow2 3))

(define (sum xs)
  (if (null? xs)
      0
      (+ (car xs) (sum (cdr xs)))))

(define (my-append xs ys)
  (if (null? xs)
      ys
      (cons (car xs) (my-append (cdr xs) ys))))

(define (my-map f xs)
  (if (null? xs)
      null
      (cons (f (car xs))
            (my-map f (cdr xs)))))

(define (inc x) (+ x 1))

(define (fact n)
  (if (= n 1)
      1
      (* n (fact (- n 1)))))

(define (sum-of-all xs)
  (if (null? xs)
      0
      (if (number? (car xs))
          (+ (car xs) (sum-of-all (cdr xs)))
          (+ (sum-of-all (car xs)) (sum-of-all (cdr xs))))))

;; (sum-of-all '(1 (2 (3 (4) 5))))

(define (sum-of-all-nums xs)
  (if (null? xs)
      0
      (let [(head (car xs))
            (tail (cdr xs))]
        (cond [(number? head) (+ head (sum-of-all-nums tail))]
              [(list? head) (+ (sum-of-all-nums head) (sum-of-all-nums tail))]
              [#t (sum-of-all-nums tail)]))))

;; (sum-of-all-nums '(1 "hello" (2 ("world" (3 (4))))))

;; Everything is truthy except #f
(define (falses xs)
  (cond [(null? xs) 0]
        [(car xs) (falses (cdr xs))]
        [#t (+ 1 (falses (cdr xs)))]))

;; (falses (list "hello" #t "world" #f))