Automata and Logics for Unranked and Unordered Trees

In this paper, we consider the monadic second order logic (MSO) and two of its extensions, namely Counting MSO (CMSO) and Presburger MSO (PMSO), interpreted over unranked and unordered trees. We survey classes of tree automata introduced for the logics PMSO and CMSO as well as other related formalisms; we gather results from the literature and sometimes clarify or fill the remaining gaps between those various formalisms. Finally, we complete our study by adapting these classes of automata for capturing precisely the expressiveness of the logic MSO.

• Type: Conference
• Year: 2005
• Where: RTA
• Authors: Iovka Boneva, Jean-Marc Talbot
• Keywords: Order Logic, Presburger MSO, RTA 2005, Theoretical Computer Science, Unordered Trees