A Playful Glance at Hierarchical Questions for Two-Way Alternating Automata

Two-way alternating automata were introduced by Vardi in order to study the satisfiability problem for the modal µ-calculus extended with backwards modalities. In this paper, we present a very simple proof by way of Wadge games of the strictness of the hierarchy of Motowski indices of two-way alternating automata over trees. Keywords : µ-calculus, backward modalities, Wadge games, topological complexity, parity games, two-way alternating tree automata, descriptive set theory.

• Type: Conference
• Year: 2007
• Where: ILC
• Authors: Jacques Duparc, Alessandro Facchini
• Keywords: Alternating Tree Automata, Artificial Intelligence, ILC 2007, Two-way Alternating Automata, Wadge Games