SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 1)
         ExpressionList (children 1)
          Literal UInt64_1 (alias a)
    WithElement (children 1)
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 2)
         ExpressionList (children 1)
          Function plus (alias a) (children 1)
           ExpressionList (children 2)
            Literal UInt64_1
            Identifier subquery_1.a
         TablesInSelectQuery (children 1)
          TablesInSelectQueryElement (children 1)
           TableExpression (children 1)
            TableIdentifier subquery_1
   ExpressionList (children 1)
    Identifier subquery_2.a
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier subquery_2