Stack Overflow
Stack Overflow

Questions tagged [automata]

In theoretical computer science, automata theory is the study of abstract 'mathematical' machines or systems and the computational problems that can be solved using these machines. These abstract machines are called automata. ("Automata", Wikipedia)

From Wikipedia,

Automata, or automata theory, is the study of mathematical objects called abstract machines or automata and the computational problems that can be solved using them. Automata comes from the Greek word αὐτόματα meaning "self-acting".

692 questions
0
votes
1 answer

Some NFA & REGULAR LANGUAGE & Equivalences

I read some note about Automaton Course. i see this note, that following all is the same. but i think the L(g) is not equal to NFA and regular expression. anyone could help me with defining the language of this figures (nfa, regular expression and…
user4012783
0
votes
1 answer

Automata-Regular Expression

I'm having problem understanding regular expression. I was trying this exercise: Over the alphabet {a,b}, create a regular expression that: A) Accept all the words that contains at least one occurrence 'a' or 'b'. epsilon*(a U b ) B) Accept all the…
user3645265
  • 703
  • 1
  • 6
  • 11
0
votes
1 answer

Intersection of two DFA, how many states? Final States?

Consider the following languages over = {0, 1}, A = {2 : w contains 011 as a substring} B = the language matched by the regular expression 0(0 + 1)*1 Let M(B) be the DFA obtained by converting N(B) using the subset construction with all…
Braithe Warnock
  • 37
  • 1
  • 10
0
votes
1 answer

Some constraint on Language and CFG

I see one note about automaton theory: Consider the following language: L={xy : x,y in {a,b}*} and consider following constraint: 1) x=y 2) x != y 3) x=(y)reverse 4) number of x is not equal to number of y i read a language with constraint…
user3929084
0
votes
1 answer

BNF grammar for the set of rules

I have a problem (a) Give a grammar using BNF rules to construct a program in the language "witless". A witless program must follow the rules: The program must start and end with the word 'endstart' . There are three types of statements in the…
ProgrammingPanda
  • 143
  • 2
  • 11
0
votes
3 answers

Design a regular expression or Finite Automata for a language that consists of 01 or 010?

I have tried below question for designing automata but didn't success: The set of strings that consists of either 01 repeated one or more times or 010 repeated one or more times. where string contains binary characters only . Please read…
user3805652
  • 67
  • 9
0
votes
2 answers

How to recursive the authomata Strange Planet exercise?

The basic idea of this is that in a planet there is three diferent kinds of species, only two of the three species can came together to procreate, and the result is that this to species die a two new sobjects of the third species born, for example…
jaime_briones
  • 23
  • 1
  • 4
0
votes
1 answer

How can I fix the error in the Automata FSM?

I found a FSM called Automata that looks useful but there is one error that keeps me from using it. It might have something to do with the way the Node module exports? The FSM is available here: https://github.com/hyperandroid/Automata When I…
user3525949
  • 189
  • 1
  • 2
  • 10
0
votes
0 answers

Chomsky Normal Form Rules

In this old exam-question I need to convert a grammar to CNF, but I suspect the provided solution is wrong. Grammar: S -> aAB|a|aA|aB|AbB|b|Ab|bB A -> aA|a|cC|c B -> bB|b|dD|d C -> cC|c D -> dD|d In the first step I set variables for the four…
TheEagle
  • 117
  • 2
  • 8
0
votes
0 answers

Given a language a^n b^m such that n and m have some relation between them implies that the given language can not be regular.Am i correct?

I know what regular and context free language are and how regular language needs finite memory, and other related stuff. What concerns me is that I think if an bm such that n and m have some relation between them then they can not be regular, but I…
sandeep bisht
  • 111
  • 12
0
votes
1 answer

What are three dots in this DFA?

I need to understand this DFA? I have failed to understand it, especially three dots in the diagram. I am getting a vague idea of why is a transition pointing to where it is pointing. But I am still very confused. So it will be great if somebody can…
Solace
  • 8,612
  • 22
  • 95
  • 183
0
votes
1 answer

Can All States Be Final In A Deterministic Pushdown Automata?

When constructing deterministic pushdown automata, can every state be a final state? I'm having trouble, specifically, with constructing a DPDA that accepts the following language: L = { 0n 1m | n ≥ m } My approach is to make the initial state a…
Luke Godfrey
  • 67
  • 1
  • 6
0
votes
1 answer

Any algorithm to fix the ambiguity of a CFG?

Here is an ambiguous CFG: S -> aSb|bA|Ba A -> bA|B B -> aB|A|ε You can easily check the ambiguity of the grammar by parsing the string "ba". Are there any algorithms to fix the ambiguity of a CFG like the one above? Thanks for the help
coralcaves
  • 3
  • 1
0
votes
1 answer

Algorithm which decides whether L(M) = {a} or L(M) =/= {a}

I started learning about NFA's and DFA's and stumbled across this question online in one of the Berkley PDF's on DFA's, but the question did not have a solution attached. How would I be able to Show that there is an algorithm which receives as…
Tal Zamirly
  • 117
  • 1
  • 11
0
votes
3 answers

complement of regular expression how to find

Give a regular expression for the language L over the alphabet {0,1} whose complement is represented by the regular expression 0* i think that the answer is 1^+ but i cannot prove it please help
user2957741
  • 993
  • 2
  • 11
  • 11
1 2 3
…
46 47