User rici

7 votes

Maximum number of path for acyclic graph with start and end node

answered Jan 23, 2013 at 4:37

4 votes

Accepted

square-free word

answered Sep 14, 2018 at 18:40

3 votes

Accepted

How does the following Non Deterministic Automata accept the language A every time?

answered Jun 12, 2017 at 2:10

3 votes

Do lookahead and lookbehind in regex come from some type of formal languages?

answered Jun 22, 2020 at 21:26

3 votes

Accepted

Describe the language of $S\to0S0\,\,|\,\,1S0\,\,|\,\,\varepsilon$

answered Dec 31, 2022 at 18:02

2 votes

Accepted

Is $L_2=\{w^*\,:\,w\in L_1\}$ where $L_1$ is regular, a regular language?

answered Jun 18, 2022 at 23:04

2 votes

If $L_1L_2$ is regular language, is $L_2L_1$ regular as well?

answered Dec 19, 2022 at 0:30

2 votes

Accepted

Can we find grammar for every CFL without $ε $ with these productions

answered Apr 27, 2021 at 18:21

2 votes

Is $L = \{ a^p : \text{$p$ is prime} \}$ a context-sensitive language?

answered Jul 13, 2021 at 20:42

2 votes

Accepted

CFG: Translate English sentence to math basic logic

answered Aug 29, 2021 at 6:50

2 votes

If $𝐿$ is regular, will $L' = \{v\in L:\,\exists w\in L: w = v^R\}$ be regular also?

answered Oct 18, 2021 at 22:30

2 votes

Accepted

CFG for $a^ib^jc^k : j <= i + k$

answered Jul 6, 2019 at 2:07

2 votes

Accepted

“Two-dimensional” Catalan numbers?

answered Feb 18, 2020 at 21:49

2 votes

Accepted

How to connect DFA state which had no transitions after minimizing it?

answered Nov 24, 2018 at 14:58

2 votes

How many essentially different strings are there of length $\leq n$ and over an alphabet of size $|\Sigma| = m$?

answered Feb 11, 2019 at 17:16

1 vote

Describing max(L) using a regular expression - proper prefix

answered May 11, 2019 at 23:48

1 vote

Accepted

Adding trigonometric operations and other operations to context free grammar

answered Jun 24, 2019 at 19:48

1 vote

What would be the complement of $L =\{a^{n}b^{m}a^{n}b^{m} | n,m \geq 1\}$

answered Dec 16, 2018 at 22:54

1 vote

Accepted

On left recursive context-free grammars

answered Dec 7, 2018 at 16:24

1 vote

Accepted

If $R^(R+S)\equiv S^(R+S)$, then $R^\equiv S^$

answered Jul 9, 2017 at 5:46

1 vote

Proof that $\textit{INFINITE}_{\text{DFA}}$ is decidable.(Sipser Q.4.10)

answered Mar 25, 2018 at 6:10

1 vote

Expected number of 1s for a random integer

answered Mar 8, 2013 at 4:26

1 vote

Is this language Regular or non regular

answered Oct 18, 2018 at 15:11

1 vote

Regular expressions match not "abc"

answered Oct 19, 2018 at 3:08

1 vote

Automata q0 ∈ F but no transitions to itself.

answered Oct 20, 2018 at 3:02

1 vote

Accepted

Which symbols in the following grammar $G$ are generating?

answered Apr 1, 2020 at 16:13

1 vote

Are programming languages generally CFLs or deterministic CFLs?

answered Jun 14, 2020 at 20:51

1 vote

Accepted

What are the critera for a family of languages to qualify as a type of language in Chomsky hierarchy?

answered Jun 21, 2020 at 18:58

1 vote

derived tree from cfg

answered Jul 9, 2019 at 17:32

1 vote

Give a grammar complement to a non-CFL language

answered Dec 11, 2019 at 16:06

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55 Answers

Maximum number of path for acyclic graph with start and end node

square-free word

How does the following Non Deterministic Automata accept the language A every time?

Do lookahead and lookbehind in regex come from some type of formal languages?

Describe the language of $S\to0S0\,\,|\,\,1S0\,\,|\,\,\varepsilon$

Is $L_2=\{w^*\,:\,w\in L_1\}$ where $L_1$ is regular, a regular language?

If $L_1L_2$ is regular language, is $L_2L_1$ regular as well?

Can we find grammar for every CFL without $ε $ with these productions

Is $L = \{ a^p : \text{$p$ is prime} \}$ a context-sensitive language?

CFG: Translate English sentence to math basic logic

If $𝐿$ is regular, will $L' = \{v\in L:\,\exists w\in L: w = v^R\}$ be regular also?

CFG for $a^ib^jc^k : j <= i + k$

“Two-dimensional” Catalan numbers?

How to connect DFA state which had no transitions after minimizing it?

How many essentially different strings are there of length $\leq n$ and over an alphabet of size $|\Sigma| = m$?

Describing max(L) using a regular expression - proper prefix

Adding trigonometric operations and other operations to context free grammar

What would be the complement of $L =\{a^{n}b^{m}a^{n}b^{m} | n,m \geq 1\}$

On left recursive context-free grammars

If $R^(R+S)\equiv S^(R+S)$, then $R^\equiv S^$

Proof that $\textit{INFINITE}_{\text{DFA}}$ is decidable.(Sipser Q.4.10)

Expected number of 1s for a random integer

Is this language Regular or non regular

Regular expressions match not "abc"

Automata q0 ∈ F but no transitions to itself.

Which symbols in the following grammar $G$ are generating?

Are programming languages generally CFLs or deterministic CFLs?

What are the critera for a family of languages to qualify as a type of language in Chomsky hierarchy?

derived tree from cfg

Give a grammar complement to a non-CFL language