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oai:drops-oai.dagstuhl.de:20793 2024-08-29T05:40:57Z ddc:004 open_access

Reversible Transducers over Infinite Words Dartois, Luc Gastin, Paul Germerie Guizouarn, Loïc Govind, R. Krishna, Shankaranarayanan Transducers Regular functions Reversibility Composition SSTs Deterministic two-way transducers capture the class of regular functions. The efficiency of composing two-way transducers has a direct implication in algorithmic problems related to synthesis, where transformation specifications are converted into equivalent transducers. These specifications are presented in a modular way, and composing the resultant machines simulates the full specification. An important result by Dartois et al. [Luc Dartois et al., 2017] shows that composition of two-way transducers enjoy a polynomial composition when the underlying transducer is reversible, that is, if they are both deterministic and co-deterministic. This is a major improvement over general deterministic two-way transducers, for which composition causes a doubly exponential blow-up in the size of the inputs in general. Moreover, they show that reversible two-way transducers have the same expressiveness as deterministic two-way transducers. However, the notion of reversible two-way transducers over infinite words as well as the question of their expressiveness were not studied yet. In this article, we introduce the class of reversible two-way transducers over infinite words and show that they enjoy the same expressive power as deterministic two-way transducers over infinite words. This is done through a non-trivial, effective construction inducing a single exponential blow-up in the set of states. Further, we also prove that composing two reversible two-way transducers over infinite words incurs only a polynomial complexity, thereby providing an efficient procedure for composition of transducers over infinite words. Schloss Dagstuhl – Leibniz-Zentrum für Informatik Luc Dartois and Paul Gastin and Loïc Germerie Guizouarn and R. Govind and Shankaranarayanan Krishna 2024 Is Part Of LIPIcs, Volume 311, 35th International Conference on Concurrency Theory (CONCUR 2024) InProceedings Text doc-type:ResearchArticle publishedVersion application/pdf doi:10.4230/LIPIcs.CONCUR.2024.21 urn:nbn:de:0030-drops-207932 https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CONCUR.2024.21 eng https://creativecommons.org/licenses/by/4.0/legalcode