English
Related papers

Related papers: New Size Hierarchies for Two Way Automata

200 papers

We consider a class of finite state three-tape transducers which models the operation of shuffling and splitting words. We present them as automata over the so-called Shuffling Monoid. These automata can be seen as either shufflers or…

Formal Languages and Automata Theory · Computer Science 2024-07-04 Ignacio Mollo Cunningham

Single-tape nondeterministic Turing machines that are allowed to replace the symbol in each tape cell only when it is scanned for the first time are also known as 1-limited automata. These devices characterize, exactly as finite automata,…

Formal Languages and Automata Theory · Computer Science 2023-09-07 Giovanni Pighizzini , Luca Prigioniero

Lately, there have been intensive studies on strengths and limitations of nonuniform families of promise decision problems solvable by various types of polynomial-size finite automata families, where ``polynomial-size'' refers to the…

Computational Complexity · Computer Science 2025-11-19 Tomoyuki Yamakami

The question of the state-size cost for simulation of two-way nondeterministic automata (2NFAs) by two-way deterministic automata (2DFAs) was raised in 1978 and, despite many attempts, it is still open. Subsequently, the problem was…

Formal Languages and Automata Theory · Computer Science 2011-10-07 Viliam Geffert , Bruno Guillon , Giovanni Pighizzini

We define a model of advised computation by finite automata where the advice is provided on a separate tape. We consider several variants of the model where the advice is deterministic or randomized, the input tape head is allowed…

Formal Languages and Automata Theory · Computer Science 2016-03-27 Uğur Küçük , A. C. Cem Say , Abuzer Yakaryılmaz

Every language recognized by a non-deterministic finite automaton can be recognized by a deterministic automaton, at the cost of a potential increase of the number of states, which in the worst case can go from $n$ states to $2^n$ states.…

Formal Languages and Automata Theory · Computer Science 2025-02-05 Arnaud Carayol , Philippe Duchon , Florent Koechlin , Cyril Nicaud

A typewriter automaton is a special variant of a two-dimensional automaton that receives two-dimensional words as input and is only capable of moving its input head through its input word in three directions: downward, leftward, and…

Formal Languages and Automata Theory · Computer Science 2022-07-21 Taylor J. Smith

We extensively investigate two-step shape invariance in the framework of N-fold supersymmetry. We first show that any two-step shape-invariant system possesses type A 2-fold supersymmetry with an intermediate Hamiltonian and thus has…

Mathematical Physics · Physics 2015-02-10 Barnana Roy , Toshiaki Tanaka

We examine different generalizations of checking stack automata by allowing multiple input heads and multiple stacks, and characterize their computing power in terms of two-way multi-head finite automata and space-bounded Turing machines.…

Formal Languages and Automata Theory · Computer Science 2022-12-05 Oscar H. Ibarra , Ian McQuillan

We study three levels in a hierarchy of nondeterminism: A nondeterministic automaton $\mathcal{A}$ is determinizable by pruning (DBP) if we can obtain a deterministic automaton equivalent to $\mathcal{A}$ by removing some of its…

Formal Languages and Automata Theory · Computer Science 2025-10-29 Bader Abu Radi , Orna Kupferman , Ofer Leshkowitz

Deterministic and nondeterministic finite automata with translucent letters were introduced by Nagy and Otto more than a decade ago as Cooperative Distributed systems of a kind of stateless restarting automata with window size one. These…

Formal Languages and Automata Theory · Computer Science 2023-09-07 Benedek Nagy

Deterministic timed automata are strictly less expressive than their non-deterministic counterparts, which are again less expressive than those with silent transitions. As a consequence, timed automata are in general non-determinizable.…

Formal Languages and Automata Theory · Computer Science 2015-08-17 Florian Lorber , Amnon Rosenmann , Dejan Nickovic , Bernhard Aichernig

The present paper introduces and studies an alternative concept of two-way finite automata called input-erasing two-way finite automata. Like the original model, these new automata can also move the reading head freely left or right on the…

Formal Languages and Automata Theory · Computer Science 2025-04-03 Alexander Meduna , Dominik Nejedlý , Zbyněk Křivka

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

Finite state transducers, multitape automata and weighted automata have a lot in common. By studying their universal foundations, one can discover some new insights into all of them. The main result presented here is the introduction of…

Formal Languages and Automata Theory · Computer Science 2020-09-23 Aleksander Mendoza-Drosik

A new class of automata networks is defined. Their evolution rules are determined by a probability measure p on the set of all integers Z and an indicator function I_A on the interval [0,1]. It is shown that any cellular automaton rule can…

chao-dyn · Physics 2009-10-28 N. Boccara , H. Fuks , S. Geurten

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

An algebraic representation of the Turing machines is given, where the configurations of Turing machines are represented by 4 order tensors, and the transition functions by 8 order tensors. Two types of tensor product are defined, one is to…

Computational Complexity · Computer Science 2016-07-14 Yue Liu

We characterize complete deterministic finite automata with two input letters in which every non-empty set of states occurs as the image of the whole state set under the action of a suitable input word. The characterization leads to a…

Formal Languages and Automata Theory · Computer Science 2022-08-23 David Casas , Mikhail V. Volkov

We prove that, paying a polynomial increase in size only, every unrestricted two-way nondeterministic finite automaton (2NFA) can be complemented by a 1-limited automaton (1-LA), a nondeterministic extension of 2NFAs still characterizing…

Formal Languages and Automata Theory · Computer Science 2025-07-16 Bruno Guillon , Luca Prigioniero , Javad Taheri