SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Literal UInt64_1
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias a) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_2 (alias x)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias b) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 2)
           Literal UInt64_1
           Literal UInt64_3 (alias y)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier y
        Identifier x