I am programming in scheme

$($

define

$($

sum n

$)$

$$

$($

if

$($

eq

$?$

$$n

$0$

$)$

$$

$0$

$$

$($

$+$

$$n

$($

sum

$($

$-$

$$n

$1$

$)$

$)$

$)$

$$

$)$

$)$

$($

define

$($

ReverseEm elems

$)$

$$

$($

if

$($

null

$?$

$$elems

$)$

$$

$\text{'}$

$($

$)$

$$

$($

append

$($

ReverseEm

$($

cdr elems

$)$

$)$

$($

list

$($

car elems

$)$

$)$

$)$

$)$

$)$

$($

define

$($

nonNegative num

$)$

$$

$($

if

$($

$>$

$=$

$$num

$0$

$)$

$$ num

$$

$0$

$)$

$)$

Now want to make a function to use all three of these functions, with a list of numbers, summation the positive numbers, reverse the list.