I'm trying to find out how I can do an "early return" in a scheme procedure without using a top-level if or cond like construct.

(define (win b)
 (let* ((test (first (first b)))
        (result (every (lambda (i) (= (list-ref (list-ref b i) i) test))
                       (enumerate (length b)))))
  (when (and (not (= test 0)) result) test))
 0)

For example, in the code above, I want win to return test if the when condition is met, otherwise return 0. However, what happens is that the procedure will always return 0, regardless of the result of the when condition.

The reason I am structuring my code this way is because in this procedure I need to do numerous complex checks (multiple blocks similar to the let* in the example) and putting everything in a big cond would be very unwieldy.