def inc (fn [x] (+ x 1))
def map (fn [f lst] (if (empty? lst) [] (cons (f (first lst)) (map f (rest lst)))))
def test (fn [name expr] (if expr (prn (str name " OK")) (prn (str name " FAILED"))))
test "map" (= [2 3 4] (map inc [1 2 3]))
test "double map" (= [3 4 5] (map inc (map inc [1 2 3])))