Recall the example from lecture, when we first saw accumulators:
;; bounced-a-check?: lon --> bool ;; given a list of bank transaction and an initial bank balance, ;; tell whether a check might bounce. ;; (A positive transaction means a deposit.) ;; (define bounced? (lambda (bal transacts) (cond [(empty? transacts) (negative? bal)] [else (or (negative? bal) (bounced? (+ bal (first transacts)) (rest transacts)))])))This example is a better accumulator example than sum-acc, because it doesn't have an easy non-accumulator version.