Bottom-up automata on data trees and vertical XPath

Diego Figueira (1) , Luc Segoufin (1)

1 LSV - Laboratoire Spécification et Vérification [Cachan]

A data tree is a tree whose every node carries a label from a finite alphabet and a datum from some infinite domain. We introduce a new model of automata over unranked data trees with a decidable emptiness problem. It is essentially a bottom-up alternating automaton with one register, enriched with epsilon-transitions that perform tests on the data values of the subtree. We show that it captures the expressive power of the vertical fragment of XPath —containing the child, descendant, parent and ancestor axes— obtaining thus a decision procedure for its satisfiability problem.

Mots clés: XPath; Data trees; Bottom-up tree automata; Decidability

Domaines: Complexité [cs.CC]; Algorithme et structure de données [cs.DS]

Diego Figueira, Luc Segoufin. Bottom-up automata on data trees and vertical XPath. Symposium on Theoretical Aspects of Computer Science (STACS), Mar 2011, Dortmund, Germany. pp.93-104. ⟨hal-00573596⟩