*scratch1*.el

(defmacro in (list elem)
  " first macro nonsense"
  (let ((tempvar (make-symbol "is-in")))
    `(flet ((is-in (l e)
                   (if l (if (= (car l) e) t
                           (is-in (cdr l) e))
                     nil)))
       (is-in ,list ,elem))))