(define append1
  '(lambda-rec (append a b) (if (null? a) b (cons (car a) (append (cdr a) b)))))

(define map1
  '(lambda-rec (map proc args) (if (null? args)
                                  null
                                   (cons (proc (car args))
                                         (map proc (cdr args))))))

(define reverse1
  '(lambda (xs) ((lambda-rec (iter xs ys) (if (null? xs)
                                             ys
                                             (iter (cdr xs) (cons (car xs) ys)))) xs null)))