SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias t1) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 4)
           Function count (children 1)
            ExpressionList (children 1)
             Literal \'a\'
           Function count (children 1)
            ExpressionList (children 1)
             Literal \'b\'
           Function count (children 1)
            ExpressionList (children 1)
             Literal \'c\'
           Literal UInt64_2 (alias x)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias t2) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 3)
           Function count (children 1)
            ExpressionList (children 1)
             Literal \'x\'
           Function count (children 1)
            ExpressionList (children 1)
             Literal \'y\'
           Literal UInt64_0 (alias x)
     TableJoin (children 1)
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t1.x
        Identifier t2.x
