SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 3)
    Function arrayJoin (alias x) (children 1)
     ExpressionList (children 1)
      Literal Array_[UInt64_0, UInt64_1, UInt64_3, NULL]
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier x
      Literal UInt64_0
    Function if (children 1)
     ExpressionList (children 3)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier x
        Literal UInt64_0
      Literal \'Definitely x = 0\'
      Literal \'We cannot say that x = 0\'