I am programming in Scheme, I am trying to make a function where you take a list of numbers, reverse the list, throw out the negative numbers and summantion the non$-$negatives. Here is my code:

$($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

$0))$

$($define $($JustDoIt lst$)$

$($if $($nonNegative $($ReverseEm $($sum lst$))))$

If I run $($JustDoIt $\text{'}(3-1460205))$ it says ill$-$formed special form: if

The correct output should be $(30216)$

Because summation of $3$ is $1+2+3=6,-14$ gets thrown out, $1+2+3+4+5+6=21,0=0,1+2=3,-5$ gets thrown out, the list gets: reversed: $(30216),$ I feel I am close, but I can't get the form right in scheme because I am unfimiliar with it$.$ Please understand that I don't want to sum all the non$-$negatives together, I want their SUMMATION, big difference, I explain it in great detail. I would also like to add that I only want to talk about scheme, not c$++,$ or python, or Algol $60,$ or Plankalkul, or intercal, or any other programming langauge, except for scheme, a dialect of Lisp. We are only to talk in terms of scheme. Another thing I would like to add is that I tested the three functions I made, they work as intended. ReverseEm reverses a list. nonNegative spits back the number at you, unless it's negative, it spits back a zero. And the sum functions works as intended. I am having trouble with the last part of the code. How do I fix $($define $($JustDoIt lst$)$

$($if $($nonNegative $($ReverseEm $($sum lst$)))),$ so it returns $(30216)?$