Tree Automata with Memory, Visibility and Structural Constraints

  • Hubert Comon-Lundh
  • Florent Jacquemard
  • Nicolas Perrin
Conference paper

DOI: 10.1007/978-3-540-71389-0_13

Part of the Lecture Notes in Computer Science book series (LNCS, volume 4423)
Cite this paper as:
Comon-Lundh H., Jacquemard F., Perrin N. (2007) Tree Automata with Memory, Visibility and Structural Constraints. In: Seidl H. (eds) Foundations of Software Science and Computational Structures. FoSSaCS 2007. Lecture Notes in Computer Science, vol 4423. Springer, Berlin, Heidelberg


Tree automata with one memory have been introduced in 2001. They generalize both pushdown (word) automata and the tree automata with constraints of equality between brothers of Bogaert and Tison. Though it has a decidable emptiness problem, the main weakness of this model is its lack of good closure properties.

We propose a generalization of the visibly pushdown automata of Alur and Madhusudan to a family of tree recognizers which carry along their (bottom-up) computation an auxiliary unbounded memory with a tree structure (instead of a symbol stack). In other words, these recognizers, called visibly Tree Automata with Memory (VTAM) define a subclass of tree automata with one memory enjoying Boolean closure properties. We show in particular that they can be determinized and the problems like emptiness, inclusion and universality are decidable for VTAM. Moreover, we propose an extension of VTAM whose transitions may be constrained by structural equality and disequality tests between memories, and show that this extension preserves the good closure and decidability properties.

Copyright information

© Springer Berlin Heidelberg 2007

Authors and Affiliations

  • Hubert Comon-Lundh
    • 1
  • Florent Jacquemard
    • 2
  • Nicolas Perrin
    • 3
  1. 1.LSV & ENS Cachan 
  2. 2.INRIA Futurs & LSV 
  3. 3.ENS Lyon 

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