remove-duplicates in clojure based on the distinct function

remove-duplicates

(defn remove-duplicates
  "Returns a lazy sequence of the elements of coll with duplicates removed using a predicate"
  [coll pred]
    (let [step (fn step [xs seen]
                   (lazy-seq
                    ((fn [[f :as xs] seen]
                      (when-let [s (seq xs)]
                        (if (some #(pred f %) seen)
                          (recur (rest s) seen)
                          (cons f (step (rest s) (conj seen f))))))
                     xs seen)))]
      (step coll #{})))