SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Asterisk
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t1
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier t2
     TableJoin (children 1)
      Function or (children 1)
       ExpressionList (children 4)
        Function isNotDistinctFrom (children 1)
         ExpressionList (children 2)
          Identifier t1.x
          Identifier t2.x
        Function isNotDistinctFrom (children 1)
         ExpressionList (children 2)
          Identifier t1.y
          Identifier t2.y
        Function and (children 1)
         ExpressionList (children 2)
          Function isNull (children 1)
           ExpressionList (children 1)
            Identifier t1.x
          Function isNull (children 1)
           ExpressionList (children 1)
            Identifier t2.x
        Function and (children 1)
         ExpressionList (children 2)
          Function isNull (children 1)
           ExpressionList (children 1)
            Identifier t1.y
          Function isNull (children 1)
           ExpressionList (children 1)
            Identifier t2.y
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier t1.x
