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Related papers: On Indexing and Compressing Finite Automata

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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

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

Many natural language processing systems operate over tokenizations of text to address the open-vocabulary problem. In this paper, we give and analyze an algorithm for the efficient construction of deterministic finite automata (DFA)…

Formal Languages and Automata Theory · Computer Science 2025-05-27 Martin Berglund , Willeke Martens , Brink van der Merwe

A deterministic finite-state automaton (FSA) is an abstract sequential machine that reads the symbols comprising an input word one at a time. An FSA is symmetric if its output is independent of the order in which the input symbols are read,…

Formal Languages and Automata Theory · Computer Science 2010-08-06 David Pritchard

Weighted finite-state automata (WSFAs) are commonly used in NLP. Failure transitions are a useful extension for compactly representing backoffs or interpolation in $n$-gram models and CRFs, which are special cases of WFSAs. The pathsum in…

Data Structures and Algorithms · Computer Science 2023-07-12 Anej Svete , Benjamin Dayan , Tim Vieira , Ryan Cotterell , Jason Eisner

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

The ambiguity of a nondeterministic finite automaton (NFA) N for input size n is the maximal number of accepting computations of N for an input of size n. For all k, r 2 N we construct languages Lr,k which can be recognized by NFA's with…

Formal Languages and Automata Theory · Computer Science 2009-03-02 Juraj Hromkovic , Georg Schnitger

The compressed indexing problem is to preprocess a string $S$ of length $n$ into a compressed representation that supports pattern matching queries. That is, given a string $P$ of length $m$ report all occurrences of $P$ in $S$. We present…

Data Structures and Algorithms · Computer Science 2018-04-12 Anders Roy Christiansen , Mikko Berggren Ettienne

In this paper, a compressed membership problem for finite automata, both deterministic and non-deterministic, with compressed transition labels is studied. The compression is represented by straight-line programs (SLPs), i.e. context-free…

Formal Languages and Automata Theory · Computer Science 2013-10-28 Artur Jeż

We consider two natural problems about nondeterministic finite automata. First, given such an automaton M of n states, and a length l, does M accept a word of length l? We show that the classic problem of triangle-free graph recognition…

Formal Languages and Automata Theory · Computer Science 2018-02-14 Aaron Potechin , Jeffrey Shallit

A \emph{data automaton} is a finite automaton equipped with variables (counters or registers) ranging over infinite data domains. A trace of a data automaton is an alternating sequence of alphabet symbols and values taken by the counters…

Logic in Computer Science · Computer Science 2015-10-22 Radu Iosif , Adam Rogalewicz , Tomas Vojnar

We present efficient algorithms to reduce the size of nondeterministic B\"uchi word automata (NBA) and nondeterministic finite word automata (NFA), while retaining their languages. Additionally, we describe methods to solve PSPACE-complete…

Formal Languages and Automata Theory · Computer Science 2023-06-22 Lorenzo Clemente , Richard Mayr

The fundamental question considered in algorithms on strings is that of indexing, that is, preprocessing a given string for specific queries. By now we have a number of efficient solutions for this problem when the queries ask for an exact…

Data Structures and Algorithms · Computer Science 2023-04-04 Paweł Gawrychowski , Garance Gourdel , Tatiana Starikovskaya , Teresa Anna Steiner

The rapid growth of symbolic data in areas like internet, biological, and financial data has increased the demand for efficient pattern matching and regular expression processing. Non-deterministic Finite Automata (NFA) are used for these…

Distributed, Parallel, and Cluster Computing · Computer Science 2024-10-29 Ryan Karbowniczak Rasha Karakchi

This paper establishes a lower bound on the number of states necessary in the worst case to simulate an $n$-state two-way nondeterministic finite automaton (2NFA) by a one-way unambiguous finite automaton (UFA). It is proved that for every…

Formal Languages and Automata Theory · Computer Science 2024-12-10 Semyon Petrov , Alexander Okhotin

The problem of constructing optimal factoring automata arises in the context of unification factoring for the efficient execution of logic programs. Given an ordered set of $n$ strings of length $m$, the problem is to construct a trie-like…

Data Structures and Algorithms · Computer Science 2024-04-04 Thomas Erlebach , Kleitos Papadopoulos

The work presents some new algorithms realized recently in the package TESTAS. They decide whether or not deterministic finite automaton (DFA) is synchronizing, several procedures find relatively short synchronizing words and a…

Formal Languages and Automata Theory · Computer Science 2020-11-12 Avraham N. Trahtman

Affine finite automata (AfA) can be more succinct than probabilistic and quantum finite automata when recognizing some regular languages with bounded-error. In this paper, we improve previously known constructions given for the succinctness…

Formal Languages and Automata Theory · Computer Science 2021-07-01 Abuzer Yakaryılmaz

Indexed languages are a classical notion in formal language theory, which has attracted attention in recent decades due to its role in higher-order model checking: They are precisely the languages accepted by order-2 pushdown automata. The…

Formal Languages and Automata Theory · Computer Science 2026-05-28 Richard Mandel , Corto Mascle , Georg Zetzsche

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