Tree automata based algorithms are essential in many fields in computer science such as verification, specification, program analysis. They become also essential for databases with the development of standards such as XML. In this paper, we define new classes of non deterministic tree automata, namely residual finite tree automata (RFTA). In the bottom-up case, we obtain a new characterization ...

A new tree automata framework, called equational tree automata, is presented. In the newly introduced setting, congruence closures of recognizable tree languages are recognizable. Furthermore, we prove that in certain useful cases, recognizable tree languages are closed under union and intersection. To compare with early related work, e.g. [7], we discuss the relationship between linear bounded...

We introduce symbolic tree automata as a generalization of finite tree automata with a parametric alphabet over any given background theory. We show that symbolic tree automata are closed under Boolean operations, and that the operations are effectively uniform in the given alphabet theory. This generalizes the corresponding classical properties known for finite tree automata.

We introduce various types of w-automata, top-down automata and bottom-up automata on infinite trees. We study the power of deterministic and nondeter-ministic tree automata and prove that deterministic and non-deterministic bottom-up tree automata accept the same intinite tree sets. We establish a relationship between tree automata, Logic programs, recursive program schemes, and the monadic se...

Tree-walking automata are a natural sequential model for recognizing languages of finite trees. Such automata walk around the tree and may decide in the end to accept it. It is shown that deterministic tree-walking automata are weaker than nondeterministic tree-walking automata.

Encoding unranked trees to binary trees, henceforth called binarization, is an important method to deal with unranked trees. For each of three binarizations we show that weighted (ranked) tree automata together with the binarization are equivalent to weighted unranked tree automata; even in the probabilistic case. This allows to easily adapt training methods for weighted (ranked) tree automata ...

Connections between Tree Automata and Term Rewriting are now well known. Whereas treeautomata can be viewed as a subclass of ground rewrite systems, tree automata are successfullyused as decision tools in rewriting theory. Furthermore, applications, including rewriting theory,have influenced the definition of new classes of tree automata. In this talk, we will first presenta sho...

Connections between Tree Automata and Term Rewriting are now well known. Whereas tree automata can be viewed as a subclass of ground rewrite systems, tree automata are successfully used as decision tools in rewriting theory. Furthermore, applications, including rewriting theory, have influenced the definition of new classes of tree automata. In this talk, we will first present a short and not e...

Abstract We show the decidability of finite sequentiality problem for unambiguous max-plus tree automata. A automaton is called if there at most one accepting run on every tree. The asks whether a given automaton, exist finitely many deterministic automata whose pointwise maximum equivalent to automaton.

We consider finite and polynomial ambiguity of weighted tree automata. Concerning finite ambiguity, we show that a finitely ambiguous weighted tree automaton can be decomposed into a sum of unambiguous automata. For polynomial ambiguity, we show how to decompose a polynomially ambiguous weighted tree automaton into simpler polynomially ambiguous automata and then analyze the structure of these ...