A Note on Partially Ordered Tree Automata

Pierre-Cyrille Héam (1)

1 CASSIS - Combination of approaches to the security of infinite states systems

A recent paper by Bouajjani, Muscholl and Touili shows that the class of languages accepted by partially ordered word automata (or equivalently accepted by Sigma2-formulae) is closed under semi-commutation and it suggested the following open question: can we extend this result to tree languages? This problem can be addressed by proving 1) that the class of tree regular languages accepted by Sigma2 formulae is strictly included in the class of languages accepted by partially ordered automata, and 2) that Bouajjani and the others results can't be extended to tree.

Domaines: Génie logiciel [cs.SE]; Modélisation et simulation

Pierre-Cyrille Héam. A Note on Partially Ordered Tree Automata. Information Processing Letters, 2008, 108 (4), pp.242--246. ⟨10.1016/j.ipl.2008.05.012⟩. ⟨hal-00561271⟩