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Complexity of deciding if a DFA is counter-free

It is well-known that deciding whether an NFA or a regular expression define a counter-free/star-free language is PSPACE-complete. Does the problem become easier if I have a DFA as input? What's the ...
Nicola Gigante's user avatar
4 votes
1 answer
148 views

Building the minimal automaton from the syntactic monoid of a language

I'm studying the algebraic view of automata theory. One of the basic results is that the syntactic monoid of a language $L$ is the transition monoid $M(A)$ of the minimal automaton $A(L)$ accepting $L$...
Nicola Gigante's user avatar
2 votes
0 answers
39 views

Why are VFSMs not more commonly used?

For a job several years ago I worked with a team using technologies built around Virtual Finite State Machine models for system fault analysis and remediation. Since then, I've found it to be a ...
Bill's user avatar
  • 121
1 vote
1 answer
42 views

In which reference can I find a definition for the equivalence of DFAs?

How is the equivalence of DFA defined? I found the equivalence of states --- James Hein, section 5.3, page 301. But he doesn't define equivalence between entire automata. (Ullman and Hopcropft seem ...
R. Chopin's user avatar
  • 237
1 vote
1 answer
72 views

Simple property of DFAs

Do you know if this simple property of a DFA is stated as a property (or theorem) in some Automata theory book (possibly with a particular name)? Property: Given a DFA $A = \{ Q, \Sigma, \delta, q_0, ...
Vor's user avatar
  • 12.7k
2 votes
0 answers
84 views

Minimization of simple cyclic automata

Version 1 of the question: I am looking for any correct $O(n)$ algorithm in the literature which will solve the DFA minimization problem referred to in the quote below from [Almeida & Zeitoun 2008]...
ShyPerson's user avatar
  • 947
2 votes
0 answers
236 views

State of the Art in linear-time DFA minimization

What is the most complicated kind of deterministic finite-state automaton that can be minimized in $O(n)$ time? Here’s what I’ve been able to find so far: The acyclic case has been solved. So any ...
ShyPerson's user avatar
  • 947
6 votes
2 answers
457 views

How similar are two DFAs? -not just binary equivalence-

Are there any measures to compute similarity (or distance) between two DFAs? If yes, which are the main references? I need a measure of similarity, not only a (binary) equivalence test. "Similarity"...
Gabrer's user avatar
  • 165
5 votes
1 answer
755 views

space complexity of DFA intersection problem

the DFA-intersection computation problem, given two DFAs specified on the input, compute the intersection DFA, or the decision problem to determine its emptiness, turns out to have wider/ deeper ...
vzn's user avatar
  • 11.1k
11 votes
3 answers
2k views

Algorithms for minimizing Moore automata

Brzozowski's algorithm can be extended to Moore automata but its time complexity is exponential in general. Is there any other algorithm for minimization of Moore automata? What are the running times ...
Ajeet Singh's user avatar
6 votes
1 answer
388 views

Who invented the state elimination algorithm for converting finite automata into regular expressions?

The state elimination algorithm is an algorithm for converting finite automata into regular expressions. It's found in many textbooks, including Sipser's Introduction to the Theory of Computation. ...
templatetypedef's user avatar
0 votes
1 answer
84 views

LL(k) Prediction Techniques (and Insight on method applied)

I'm requesting references for LL(k) in situations where k > 1 for reasons described below. I'm looking for research/notes/...
Allen Clark Copeland Jr's user avatar
5 votes
0 answers
94 views

Languages recognized by finite state automata of polynomially growing size

In the course of my research (condensed matter physics stuff), I stumbled over the following concept: The class of regular languages can be defined via finite state machines (FSM): A language $L$ is ...
NcLang's user avatar
  • 91
10 votes
2 answers
296 views

Method for measuring the 'similarity' between FSA grammars?

I'm working with a pattern matching algorithm that generates an acyclic finite state automaton that accepts a given text string and all its substrings. The FSA algorithm is being run on a symbolic ...
flip's user avatar
  • 109
11 votes
2 answers
742 views

Is the reversal of a minimal DFA also minimal?

The question is pretty much in the title. Is there ever a time where some language $L$ can be accepted by a minimal DFA with $n$ states, but $L^R$, the reversal of $L$, can be accepted by a DFA with $...
Joey Eremondi's user avatar
2 votes
3 answers
1k views

Does there exist a proof of closure of regular languages under regular substitution by giving the corresponding DFA?

Every proof I can find of this result is by way of regular expressions. Is there any "constructive" proof that defines the corresponding DFA (probably NFA)? For instance the proof of concatenation ...
sjmc's user avatar
  • 630
5 votes
2 answers
143 views

What is Finite Automata Bowl?

I was trying to find info about this Finite Automata type FAB (Finite Automata Bowl) and wasn't able to find a lot. It is basically the rules that apply to PDA apply to FAB except you drop the ...
Jackie's user avatar
  • 51
4 votes
1 answer
368 views

C(++) library for DFAs - free for academic use

(I'm aware that software questions are better suited for stackoverflow, but since DFAs are not something that software developers usually care about, I hope it's alright if I ask here.) I'm currently ...
G. Bach's user avatar
  • 2,019
2 votes
1 answer
222 views

Mealy machines to model ciphers [closed]

Similar questions have occurred quite a number of times (1) (2) (3), but I have, say, a specific instance of one. I'm aware of a bunch of applications of finite automata, but would you provide an ...
Artem Pelenitsyn's user avatar
7 votes
1 answer
180 views

Results on the languages recognized by undirected DFAs

For my Bachelor's thesis, I consider the class of languages recognized by symmetrical DFAs, that is, deterministic (complete) finite automata satisfying the following condition: Let $A$ be a ...
Cornelius Brand's user avatar
13 votes
2 answers
2k views

What is the complexity of the emptiness problem for 2-way DFAs?

I'm wondering, what is the time-complexity of determining emptiness for 2-way DFAs? That is, finite automata which can move backwards on their read-only input tape. According to Wikipedia, they are ...
Joey Eremondi's user avatar
11 votes
1 answer
1k views

Difference between the languages accepted by two DFAs with different initial state/accepting states?

Recently, I asked a question on Math SE. No response yet. This question is related to that question, but more technical details toward computer science. Given two DFAs $A = (Q, \Sigma, \delta, q_1, ...
Nobody's user avatar
  • 440
8 votes
6 answers
13k views

Practical application of Finite State Machines

I am looking for practical applications of Finite State Machines like DFA, NFA, Moore, Mealy machines... It would be helpful if someone point to examples from Linux Kernel. I know that DFA is used in ...
user5507's user avatar
  • 2,221