Yasunori Ishihara, Kenji Hashimoto, Shougo Shimizu, Toru Fujiwara. XPath satisfiability with downward and sibling axes is tractable under most of real-world DTDs. In George H. L. Fletcher, Prasenjit Mitra, editors, Proceedings of the Twelfth International Workshop on Web Information and Data Management, WIDM 2012, Maui, HI, USA, November 02, 2012. pages 11-18, ACM, 2012. [doi]
Abstract is missing.