English
Related papers

Related papers: Completely reachable automata: a quadratic decisio…

200 papers

Threshold automata are a formalism for modeling and analyzing fault-tolerant distributed algorithms, recently introduced by Konnov, Veith, and Widder, describing protocols executed by a fixed but arbitrary number of processes. We conduct…

Logic in Computer Science · Computer Science 2025-12-02 A. R. Balasubramanian , Javier Esparza , Marijana Lazic

A word is called carefully synchronising for a partial deterministic finite semi-automaton if it maps all states to the same state. Equivalently, it is a composition of partial transformations equal to a constant total transformation. There…

Discrete Mathematics · Computer Science 2025-06-18 Andrew Ryzhikov

Most slowly synchronizing automata over binary alphabets are circular, i.e., containing a letter permuting the states in a single cycle, and their set of synchronizing words has maximal state complexity, which also implies complete…

Formal Languages and Automata Theory · Computer Science 2020-12-01 Stefan Hoffmann

We answer two open questions by (Gruber, Holzer, Kutrib, 2009) on the state-complexity of representing sub- or superword closures of context-free grammars (CFGs): (1) We prove a (tight) upper bound of $2^{\mathcal{O}(n)}$ on the size of…

Formal Languages and Automata Theory · Computer Science 2014-10-24 Georg Bachmeier , Michael Luttenberger , Maximilian Schlund

We define a quantum computational model over infinite words, called Measure-Many Quantum B\"uchi Automata (MMQBA), which extends Measure-many Quantum Finite automata (MMQFA) to the infinite word setting with B\"uchi acceptance condition. In…

Formal Languages and Automata Theory · Computer Science 2026-05-11 Abhisek Midya , A Baskar

A goal of this paper is to introduce the new construction of an automaton with shortest synchronizing word of length $O(d^{\frac{n}{d}})$, where $d \in \mathbb{N}$ and $n$ is the number of states for that automaton. Additionally we…

Formal Languages and Automata Theory · Computer Science 2020-06-23 Jakub Ruszil

Weighted timed automata have been defined in the early 2000's for modelling resource-consumption or -allocation problems in real-time systems. Optimal reachability is decidable in weighted timed automata, and a symbolic forward algorithm…

Logic in Computer Science · Computer Science 2016-02-02 Patricia Bouyer , Maximilien Colange , Nicolas Markey

Probabilistic automata are an extension of nondeterministic finite automata in which transitions are annotated with probabilities. Despite its simplicity, this model is very expressive and many of the associated algorithmic questions are…

Formal Languages and Automata Theory · Computer Science 2022-05-20 Nathanaël Fijalkow , Cristian Riveros , James Worrell

This paper is about reachability analysis in a restricted subclass of multi-pushdown automata. We assume that the control states of an automaton are partially ordered, and all transitions of an automaton go downwards with respect to the…

Logic in Computer Science · Computer Science 2015-07-01 Wojciech Czerwiński , Piotr Hofman , SŁawomir Lasota

We introduce the model of communicating timed automata (CTA) that extends the classical models of finite-state processes communicating through FIFO perfect channels and timed automata, in the sense that the finite-state processes are…

Formal Languages and Automata Theory · Computer Science 2018-03-20 Parosh Aziz Abdulla , Mohamed Faouzi Atig , S. Krishna

Families of deterministic finite automata (FDFA) represent regular $\omega$-languages through their ultimately periodic words (UP-words). An FDFA accepts pairs of words, where the first component corresponds to a prefix of the UP-word, and…

Formal Languages and Automata Theory · Computer Science 2025-06-17 León Bohn , Yong Li , Christof Löding , Sven Schewe

In the field of computational logic, two classes of finite automata are considered fundamental: deterministic and nondeterministic automata (DFAs and NFAs). In a more fine-grained approach three natural intermediate classes were introduced,…

Formal Languages and Automata Theory · Computer Science 2025-07-22 Karolina Drabik , Anita Dürr , Fabian Frei , Filip Mazowiecki , Karol Węgrzycki

History-deterministic automata are those in which nondeterministic choices can be correctly resolved stepwise: there is a strategy to select a continuation of a run given the next input letter so that if the overall input word admits some…

Formal Languages and Automata Theory · Computer Science 2026-04-01 Soumyajit Paul , David Purser , Sven Schewe , Qiyi Tang , Patrick Totzke , Di-De Yen

We present new results on realtime alternating, private alternating, and quantum alternating automaton models. Firstly, we show that the emptiness problem for alternating one-counter automata on unary alphabets is undecidable. Then, we…

Formal Languages and Automata Theory · Computer Science 2023-06-22 Gökalp Demirci , Mika Hirvensalo , Klaus Reinhardt , A. C. Cem Say , Abuzer Yakaryılmaz

We prove that two-way probabilistic and quantum finite automata (2PFA's and 2QFA's) can be considerably more concise than both their one-way versions (1PFA's and 1QFA's), and two-way nondeterministic finite automata (2NFA's). For this…

Computational Complexity · Computer Science 2014-01-29 Abuzer Yakaryilmaz , A. C. Cem Say

The problem of k-minimisation for a DFA M is the computation of a smallest DFA N (where the size |M| of a DFA M is the size of the domain of the transition function) such that their recognized languages differ only on words of length less…

Formal Languages and Automata Theory · Computer Science 2011-03-01 Paweł Gawrychowski , Artur Jeż , Andreas Maletti

We introduce deterministic suffix-reading automata (DSA), a new automaton model over finite words. Transitions in a DSA are labeled with words. From a state, a DSA triggers an outgoing transition on seeing a word ending with the…

Formal Languages and Automata Theory · Computer Science 2024-10-31 R Keerthan , B Srivathsan , R Venkatesh , Sagar Verma

We discuss the problem of learning a deterministic finite automaton (DFA) from a confidence oracle. That is, we are given access to an oracle $Q$ with incomplete knowledge of some target language $L$ over an alphabet $\Sigma$; the oracle…

Formal Languages and Automata Theory · Computer Science 2023-11-21 Wilson Wu

Let $NFA_b(q)$ denote the set of languages accepted by nondeterministic finite automata with $q$ states over an alphabet with $b$ letters. Let $B_n$ denote the set of words of length $n$. We give a quadratic lower bound on the VC dimension…

Formal Languages and Automata Theory · Computer Science 2021-08-06 Bjørn Kjos-Hanssen , Clyde James Felix , Sun Young Kim , Ethan Lamb , Davin Takahashi

Hybrid automata are a natural framework for modeling and analyzing systems which exhibit a mixed discrete continuous behaviour. However, the standard operational semantics defined over such models implicitly assume perfect knowledge of the…

Systems and Control · Computer Science 2013-08-27 Alberto Casagrande , Tommaso Dreossi , Carla Piazza