SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 2)
    QualifiedAsterisk (children 1)
     Identifier t
    QualifiedAsterisk (children 1)
     Identifier s
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier t
    TablesInSelectQueryElement (children 2)
     TableExpression (children 1)
      TableIdentifier s
     TableJoin (children 1)
      Function and (children 1)
       ExpressionList (children 2)
        Function equals (children 1)
         ExpressionList (children 2)
          Identifier s.a
          Identifier t.a
        Function equals (children 1)
         ExpressionList (children 2)
          Identifier s.b
          Identifier t.b
   Set
