HerbM

(defn rducts
  ([f aseq]  (lazy-seq (rducts f (f (first aseq)) (rest aseq))))
  ([f accum aseq]
    (lazy-seq (cons accum (let [fs (first aseq) rs (rest aseq)]
      (if (not (seq rs))
        (list (f accum fs))
         (rducts f (f accum fs) rs)))))))

(take 5 (rducts + (range))) 
(rducts conj [1] [2 3 4]) 

HerbM

(defn tipe [s]
  (let [sym1  (gensym) sym2 (gensym) 
		sym3  (gensym) s12  (conj s {sym1 sym2}) 
        s1221 (conj (conj s {sym2 sym1}) s12)]
  (if (get s12 sym1) :map
      (if (get s12 {sym1 sym2}) :set      
          (if (= (first s1221) s12) :list :vector)))))

(= :map (tipe {:a 1, :b 2}))
(= :list (tipe (range (rand-int 20))))

HerbM

(ns clojure4.core)
;;; Re-implement Clojure "comp" for 4Clojure problem #58  (as "komp")

(defn komp 
  ([] (fn [n] (identity n)))
  ([fn1] (fn [& n] (apply fn1 n)) )
  ([fn1 fn2] (fn [& n]
               (fn1 ((fn [m] (apply fn2 m)) n))))
  ([fn1 fn2 & fns] (fn [& n]
               (fn1 ((fn [m] (apply (apply komp (conj fns fn2))  m )) n    )))))