2. Do It, Do It Again, and Again, and Again ...

doit.clj

(defn atom? [x]
  (not (seq? x)))

(defn lat? [x]
  (loop [l x]
    (cond
      (empty? l) true
      (atom? (first l)) (recur (last l))
      :else false)))

(defn member? [atom lat]
  (loop [a atom l lat]
    (cond
      (empty? l) false
      :else (or (= (first l) a)
            (recur a (rest l))))))

Clojure functions for Chapter 2 of The Little Schemer.