@conference {420, title = {Saturation, Definability, and Separation for XPath on Data Trees}, booktitle = {9th Alberto Mendelzon International Workshop on Foundations of Data Management}, year = {2015}, url = {http://ceur-ws.org/Vol-1378/AMW_2015_paper_21.pdf}, author = {Sergio Abriola and Mar{\'\i}a Emilia Descotte and Santiago Figueira} }