#lang racket
(define a 7)
(define b 'c)

(define length
  (lambda (ls)
    (if (eq? ls '())
        0
        (+ 1 (length (cdr ls))))))

(define member?
  (lambda (e ls)
    (if (eq? ls '())
        #f
        (if (eq? e (car ls))
            #t
            (member? e (cdr ls))))))