(+) (+ x) (+ x y) (+ x y & more)
Returns the sum of nums. (+) returns 0. Does not auto-promote longs, will throw on overflow. See also: +'
(+)
;;=> 0
(+ 1)
;;=> 1
(+ -10)
;;=> -10
(+ 1 2)
;;=> 3
(+ 1 2 3)
;;=> 6
(apply + (range 10000000000000 10000000001000))
;; ArithmeticException: integer overflow