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Questions tagged [finite-automata]

A finite automaton (FA) is a mathematical description of an algorithm capable of parsing regular languages. FAs have no external memory, and as such can only take into account a fixed number of previous symbols when processing strings. A deterministic FA (DFAs) is one for which there is only ever one legal transition between states; nondeterministic FAs can be transformed into equivalent DFAs. FAs are the weakest of the commonly-defined automata.

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Need Regular Expression for Finite Automata: Even number of 1s and Even number of 0s

My problem may sounds different to you. I am a beginner and I am learning Finite Automata. I am googing over Internet to find the Regular Expression for Finite Automata of Given Machine Below. Can anyone help me to write "Regular Expression…
jyoti
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Python Finite Automata library

What would be the most complete finite automata library for Python, which is able to do the basic manipulations such as: Minimization, Determinization of Nondeterministic Finite automata Union, Intersection, and Product of the languages generated…
asker
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What is the fastest way to compute an epsilon closure?

I am working on a program to convert Non-deterministic finite state automata (NFAs) to Deterministic finite state automata (DFAs). To do this, I have to compute the epsilon closure of every state in the NFA that has an epsilon transition. I have…
Darkhydro
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Implementing A Nondeterminisic Finite Automaton(NFA)

I'm trying to a develop a simulation that executes a non deterministic finite automaton in Java. The first command line argument is a text file that defines the machine. The second argument is an input string. If it accepts the string, it prints to…
donth77
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How does "δ:Q×Σ→Q" read in the definition of a DFA (deterministic finite automaton)?

How do you say δ: Q × Σ → Q in English? Describing what × and → mean would also help.
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Real world uses of DFA,NFA,PDA and Turing machines

I am now taking a course on Theory of Computation. I can understand the concepts well. I can able to solve the problems. And, when I asked my instructor about the real world application, he told me these concepts will be surely useful and essential…
Muthu Ganapathy Nathan
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Levenshtein DFA in .NET

Good afternoon, Does anyone know of an "out-of-the-box" implementation of Levenshtein DFA (deterministic finite automata) in .NET (or easily translatable to it)? I have a very big dictionary with more than 160000 different words, and I want to,…
Miguel
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What are Finite State Automata and why should a programmer know about them?

Erm - what the question said. It's something I keep hearing about, but I've not got round to looking into it yet. (updated) I could look up the definition... but why not (as pointed out by @erikson) get insight into your real experiences and…
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How to find the intersection of two NFA

In DFA we can do the intersection of two automata by doing the cross product of the states of the two automata and accepting those states that are accepting in both the initial automata. Union is performed similarly. How ever although i can do union…
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What is the concatenation of this language with itself?

Given the following language: L1 = { (ab)n | n ≥ 0 } That is, L1 = { ε ab, abab, ababab, abababab, ... } The question is to find what language L12 is. My guess is that it's equal to { (ab)2n | n ≥ 0 }. Is that correct? If so, how do I prove it?…
Rouki
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How do I construct a function/type that observes each transition in this state machine?

The gist of my question is that I have a deterministic state automata that is transitioning according to a list of moves, and I want this sequence of transition to serve as a "computational context" for another function. This other function would…
xiaolingxiao
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How to get Ragel EOF actions working

I'm working with Ragel to evaluate FSAs, and I want to embed a user action that runs whenever my machine finishes testing the input. I need this action to run regardless of whether or not the machine ends in an accepting state or not. I have this…
Mark
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Building a lexer in C

I want to build a lexer in C and I am following the dragon book, I can understand the state transitions but how to implement them? Is there a better book? The fact that I have to parse a string through a number of states so that I can tell whether…
Hick
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Is there an efficient algorithm to decide whether the language accepted by one NFA is a superset of the language accepted by another?

Given two nondeterministic finite automata M1 and M2, is there an efficient algorithm to determine whether the language accepted by M1 is a superset of the language accepted by M2?
Daniel Trebbien
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What is the language of this deterministic finite automata?

Given: I have no idea what the accepted language is. From looking at it you can get several end results: 1.) bb 2.) ab(a,b) 3.) bbab(a, b) 4.) bbaaa
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