SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 3)
          ExpressionList (children 1)
           Identifier y
          TablesInSelectQuery (children 1)
           TablesInSelectQueryElement (children 1)
            TableExpression (children 1)
             Function VALUES (children 1)
              ExpressionList (children 2)
               Literal \'y UInt16\'
               Literal UInt64_2
          Function equals (children 1)
           ExpressionList (children 2)
            Literal UInt64_1 (alias x)
            Identifier y
