#lang racket

(define snlist-recur
  (lambda (flist fatom init)
    (letrec ([helper (lambda (l)
		       (cond [(null? l) init]
			     [(or (pair? (car l))
			          (null? (car l)))
			      (flist (helper (car l))
				     (helper (cdr l)))]
			     [else (fatom (car l) (helper (cdr l)))]))])
      helper)))