store/[org.clojure/clojure "1.6.0"] clj::clojure.core/disj

Official Documentation

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Arities
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   [set]
   [set key]
   [set key & ks]

Docstring
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  disj[oin]. Returns a new set of the same (hashed/sorted) type, that
  does not contain key(s).

Source

(defn disj
  "disj[oin]. Returns a new set of the same (hashed/sorted) type, that
  does not contain key(s)."
  {:added "1.0"
   :static true}
  ([set] set)
  ([^clojure.lang.IPersistentSet set key]
   (when set
     (. set (disjoin key))))
  ([set key & ks]
   (when set
     (let [ret (disj set key)]
       (if ks
         (recur ret (first ks) (next ks))
         ret)))))

Example 1

Edit
(disj #{1 2 3}) ; disjoin nothing 
;; => #{1 2 3} 

(disj #{1 2 3} 2) ; disjoin 2
;; => #{1 3} 

(disj #{1 2 3} 4) ; disjoin not existed item
;; => #{1 2 3} 

(disj #{1 2 3} 1 3) ; disjoin several items at once
;; => #{2}

Uses on crossclj