SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Identifier b.id
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias a) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Function toLowCardinality (alias id) (children 1)
            ExpressionList (children 1)
             Function CAST (children 1)
              ExpressionList (children 2)
               Literal \'0\'
               Literal \'UInt32\'
          ExpressionList (children 1)
           Function array (children 1)
            ExpressionList
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias b) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function toLowCardinality (alias id) (children 1)
            ExpressionList (children 1)
             Function CAST (children 1)
              ExpressionList (children 2)
               Literal \'1\'
               Literal \'UInt64\'
     TableJoin (children 1)
      ExpressionList (children 1)
       Identifier id
