(assert= 8 ([2 6 2 8 9] 3))
(assert= 9 ([[3 6] [9 2]] 1 0))

($ a ['a' [[2 true] 2.3]])

(assert= 'a' (a 0))
(assert= 2 (a 1 0 0))

($ (second arr)
   (arr 1))

(assert= 6 (second [2 6]))

($ (produce)
   [2 4 6])

(assert= 4 (second (produce)))

($ arr [2 'bim' produce false])
(assert= 6 (((arr 2)) 2))