Clojure

Calc

(defn calc [op v1 v2] (cond (= "+" op) (+ v1 v2) (= "-" op) (- v1 v2) (= "*" op) (* v1 v2) (= "/" op) (/ v1 v2)))

Set - Intersection

user=> (clojure.core/refer 'clojure.set)user=> (def s #{1 2 3 4 })user=> (def s2 #{3 4 5 6 7}) user=> (intersection s)#{1 2 3 4}user=> (intersection s s2)#{3 4}user=> (def s3 #{2 3 9 0})user=> (intersection s s2 s3)#{3}

Set - Difference

user=> (difference s)

#{1 2 3 4}

user=> (difference s s2)

#{1 2}

user=> (difference s s2 s3)

#{1}

Set - Union

user=> (union s)

#{1 2 3 4}

user=> (union s s2)

#{1 2 3 4 5 6 7}

user=> (union s s2 s3)

#{0 1 2 3 4 5 6 7 9}