SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 2)
    Identifier c
    Identifier a (alias c)
   TablesInSelectQuery (children 3)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (alias X) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_1 (alias a)
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias Y) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 2)
          ExpressionList (children 1)
           Literal UInt64_1
          Function equals (children 1)
           ExpressionList (children 2)
            Identifier c
            Literal UInt64_1
     TableJoin
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      Subquery (alias Z) (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Literal UInt64_1 (alias c)
     TableJoin
