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Related papers: Simulation of Two-Way Pushdown Automata Revisited

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Reward machines (RMs) are automata structures that encode (non-Markovian) reward functions for reinforcement learning (RL). RMs can reward any behaviour representable in regular languages and, when paired with RL algorithms that exploit RM…

Artificial Intelligence · Computer Science 2025-11-13 Giovanni Varricchione , Toryn Q. Klassen , Natasha Alechina , Mehdi Dastani , Brian Logan , Sheila A. McIlraith

We study decidability of verification problems for timed automata extended with unbounded discrete data structures. More detailed, we extend timed automata with a pushdown stack. In this way, we obtain a strong model that may for instance…

Logic in Computer Science · Computer Science 2017-01-11 Karin Quaas

In (Csuhaj-Varju et. al. 2000) Parallel Communicating Systems of Pushdown Automata (PCPA) were introduced and shown to be able to simulate nondeterministic one-way multi-head pushdown automata in returning mode, even if communication is…

Formal Languages and Automata Theory · Computer Science 2014-08-07 Holger Petersen

We show that deterministic collapsible pushdown automata of second order can recognize a language that is not recognizable by any deterministic higher-order pushdown automaton (without collapse) of any order. This implies that there exists…

Formal Languages and Automata Theory · Computer Science 2023-06-22 Paweł Parys

We introduce the notion of adaptive synchronisation for pushdown automata, in which there is an external observer who has no knowledge about the current state of the pushdown automaton, but can observe the contents of the stack. The…

Formal Languages and Automata Theory · Computer Science 2021-02-16 A. R. Balasubramanian , K. S. Thejaswini

A classical theorem states that the set of languages given by a pushdown automaton coincides with the set of languages given by a context-free grammar. In previous work, we proved the pendant of this theorem in a setting with interaction:…

Logic in Computer Science · Computer Science 2023-09-15 Jos C. M. Baeten , Bas Luttik

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

Time-space tradeoff has been studied in a variety of models, such as Turing machines, branching programs, and finite automata, etc. While communication complexity as a technique has been applied to study finite automata, it seems it has not…

Computational Complexity · Computer Science 2023-12-01 Shenggen Zheng , Yaqiao Li , Minghua Pan , Jozef Gruska , Lvzhou Li

In various models of one-way pushdown automata, the explicit use of two designated endmarkers on a read-once input tape has proven to be extremely useful for making a conscious, final decision on the acceptance/rejection of each input word…

Formal Languages and Automata Theory · Computer Science 2025-11-11 Tomoyuki Yamakami

Input-driven pushdown automata with translucent input letters are investigated. Here, the use of translucent input letters means that the input is processed in several sweeps and that, depending on the current state of the automaton, some…

Formal Languages and Automata Theory · Computer Science 2025-07-22 Martin Kutrib , Andreas Malcher , Matthias Wendlandt

Weighted pushdown automata (WPDAs) are at the core of many natural language processing tasks, like syntax-based statistical machine translation and transition-based dependency parsing. As most existing dynamic programming algorithms are…

Computation and Language · Computer Science 2025-03-25 Alexandra Butoi , Brian DuSell , Tim Vieira , Ryan Cotterell , David Chiang

A classical approach to formal policy synthesis in stochastic dynamical systems is to construct a finite-state abstraction, often represented as a Markov decision process (MDP). The correctness of these approaches hinges on a behavioural…

Systems and Control · Electrical Eng. & Systems 2025-08-08 Thom Badings , Alessandro Abate

Deterministic 2-head finite automata which are machines that process an input word from both ends are analyzed for their ability to perform reversible computations. This implies that the automata are backward deterministic, enabling unique…

Formal Languages and Automata Theory · Computer Science 2025-07-22 Benedek Nagy , Walaa Yasin

We study the relation between the standard two-way automata and more powerful devices, namely, two-way finite automata with an additional "pebble" movable along the input tape. Similarly as in the case of the classical two-way machines, it…

Formal Languages and Automata Theory · Computer Science 2009-07-30 Viliam Geffert , Lubomíra Ištoňová

The question if a deterministic finite automaton admits a software reset in the form of a so-called synchronizing word can be answered in polynomial time. In this paper, we extend this algorithmic question to deterministic automata beyond…

Formal Languages and Automata Theory · Computer Science 2020-12-23 Henning Fernau , Petra Wolf , Tomoyuki Yamakami

We present relaxed notions of simulation and bisimulation on Probabilistic Automata (PA), that allow some error epsilon. When epsilon is zero we retrieve the usual notions of bisimulation and simulation on PAs. We give logical…

Formal Languages and Automata Theory · Computer Science 2011-07-07 Mathieu Tracol , Josée Desharnais , Abir Zhioua

We investigate the possibility of a semantic account of the execution time (i.e. the number of beta-steps leading to the normal form, if any) for the shuffling calculus, an extension of Plotkin's call-by-value lambda-calculus. For this…

Logic in Computer Science · Computer Science 2019-04-25 Giulio Guerrieri

In this work, we introduce DeepDFA, a novel approach to identifying Deterministic Finite Automata (DFAs) from traces, harnessing a differentiable yet discrete model. Inspired by both the probabilistic relaxation of DFAs and Recurrent Neural…

Machine Learning · Computer Science 2024-08-19 Elena Umili , Roberto Capobianco

Probabilistic pushdown automata (pPDA) are a natural operational model for a variety of recursive discrete stochastic processes. In this paper, we study certificates - succinct and easily verifiable proofs - for upper and lower bounds on…

Formal Languages and Automata Theory · Computer Science 2023-04-25 Tobias Winkler , Joost-Pieter Katoen

Probabilistic pushdown automata (pPDA) are a standard operational model for programming languages involving discrete random choices and recursive procedures. Temporal properties are useful for specifying the chronological order of events…

Formal Languages and Automata Theory · Computer Science 2024-02-14 Tobias Winkler , Christina Gehnen , Joost-Pieter Katoen