Dyadic union

Set union is a dyadic verb. Rеturns all vаlues from both arguments once.

Syntax: <x> union <y>; union[<x>; <y>]

o)1 2 3 4 union 4 0
1 2 3 4 0
o)distinct 10 12 31 31 65, 12 14 65 81      // same as distinct on join
10 12 31 65 14 81
o)