AlterQuery  t (children 2)
 ExpressionList (children 1)
  AlterCommand DELETE (children 1)
   Function in (children 1)
    ExpressionList (children 2)
     Identifier x
     Subquery (children 1)
      SelectWithUnionQuery (children 1)
       ExpressionList (children 1)
        SelectQuery (children 2)
         ExpressionList (children 1)
          Identifier y
         TablesInSelectQuery (children 1)
          TablesInSelectQueryElement (children 1)
           TableExpression (children 1)
            TableIdentifier t
 Identifier t
