Abstract. Given a subset S of N, filtering a word a0a1 · · · an by S consists in deleting the letters ai such that i is not in S. By a natural generalization, denote by L[S], w...
Jean Berstel, Luc Boasson, Olivier Carton, Bruno P...
Formal power series are an extension of formal languages. Recognizable formal power series can be captured by the so-called weighted finite automata, generalizing finite state ma...
We show that it is equivalent, for certain sets of finite graphs, to be definable in CMS (counting monadic second-order, a natural extension of monoadic second-order logic), and t...
This paper proposes an alternative approach to the standard notion of rational (or regular) expression for tree languages. The main difference is that in the new notion we have on...
We show that the family of tree languages recognized by weak alternating automata is closed by three set theoretic operations that correspond to sum, multiplication by ordinals <...