Using racket/scheme I have to write a function, removeAll, which takes two lists, list-a and list-b and returns a list containing only the items in list-a that are not also in list-b. Example output: (remove-all '(a b b c c d) '(a c a)) -> '(b b d)

I am unsure how to work the recursion. I know you need to call the function recursively making list-b smaller and smaller each time.