User Arno

19 votes

Probabilistic methods for undecidable problem

answered Oct 10, 2022 at 22:08

18 votes

Accepted

Detecting if three Turing Machines halt given a magic oracle that is only used twice

answered Jan 31, 2023 at 10:08

14 votes

Accepted

Do any decision problems exist outside NP and NP-Hard?

answered Dec 3, 2019 at 15:10

8 votes

Accepted

Assuming P != NP, what is the cardinality of the set of NP-Hard languages?

answered Dec 3, 2019 at 14:50

8 votes

Accepted

What is the "continuity" as a term in computable analysis?

answered Aug 23, 2020 at 8:46

8 votes

Accepted

Existence of a CFL $L$ such that $\sqrt{L}$ is not CFL

answered Apr 28, 2021 at 16:58

7 votes

Accepted

Given A to C, and B to C with known complexities, what can be said about A to B?

answered Jun 9, 2020 at 9:51

6 votes

Can a computer determine whether a mathematical statement is true or not?

answered Feb 11, 2021 at 11:55

5 votes

Accepted

Does the term "continuity" have a different meaning in maths and in CS?

answered Aug 24, 2020 at 8:56

5 votes

Accepted

CFG for the language {ω ∈ {a, b}*| in every prefix of ω, the number of a’s is greater than or equal to number of b’s}

answered Mar 24, 2019 at 15:47

5 votes

Are there problems in NP that would solve P vs NP, but are not NP complete

answered Oct 6, 2023 at 18:25

5 votes

Accepted

Proof that $NP \cap coNP = P$

answered Feb 9 at 9:24

4 votes

Accepted

Polynomial Hierarchy - the difference between $\Pi$ and $\Sigma$

answered Dec 7, 2023 at 23:29

4 votes

is there a constructive proof of the existence of a language which isn't recursive (without invoking infinities)?

answered Jan 25, 2021 at 17:47

4 votes

Is it possible that Co-NP = P but NP != P

answered May 27, 2020 at 21:40

4 votes

Accepted

Does godel's incompleteness theorem still hold if we have a TM that can do an infinity amount of computations?

answered Mar 17, 2018 at 9:04

4 votes

Why doesn't Godel's Second Incompleteness Theorem rule out a formalizable proof of P!=NP?

answered Jun 17, 2018 at 12:39

4 votes

Accepted

Proving FPT is strictly contained in XP

answered Aug 22, 2021 at 11:55

4 votes

Accepted

How does one define transcendental numbers (such as Pi) in theory of general recursive functions

answered Oct 10, 2022 at 16:39

3 votes

can you write a halting decider that is only wrong about itself by avoiding diagonalization?

answered Nov 19, 2022 at 12:10

3 votes

Is there a TM that halts iff P = NP?

answered Jul 24, 2021 at 17:38

3 votes

Accepted

If a computer can demonstrate singleton sets are closed, is the space Hausdorff?

answered Aug 22, 2021 at 7:48

3 votes

Cardinality of the set of algorithms

answered Aug 27, 2018 at 21:58

3 votes

Is there any other computation theory besides the one in automata theory?

answered Nov 28, 2018 at 14:28

3 votes

Accepted

Is Rice-Shapiro theorem bidirectional?

answered Jan 7, 2019 at 20:01

3 votes

Accepted

Is the set of language decidable by some Turing machine computing in some given computable time bound decidable

answered Feb 28, 2019 at 13:33

3 votes

Accepted

Why is this language Turing recognizable and not not-Turing recognizable

answered Jul 13, 2020 at 14:05

3 votes

What is wrong with the following $P$ problem?

answered Jan 9, 2020 at 16:51

2 votes

Analogue of the topology-computability correspondence for computational complexity

answered Jun 30, 2020 at 12:07

2 votes

Accepted

Proof for Turing Machines being able to simulate any algorithm in the same time complexity

answered Nov 3, 2018 at 15:15

Stack Exchange Network

87 Answers

Probabilistic methods for undecidable problem

Detecting if three Turing Machines halt given a magic oracle that is only used twice

Do any decision problems exist outside NP and NP-Hard?

Assuming P != NP, what is the cardinality of the set of NP-Hard languages?

What is the "continuity" as a term in computable analysis?

Existence of a CFL $L$ such that $\sqrt{L}$ is not CFL

Given A to C, and B to C with known complexities, what can be said about A to B?

Can a computer determine whether a mathematical statement is true or not?

Does the term "continuity" have a different meaning in maths and in CS?

CFG for the language {ω ∈ {a, b}*| in every prefix of ω, the number of a’s is greater than or equal to number of b’s}

Are there problems in NP that would solve P vs NP, but are not NP complete

Proof that $NP \cap coNP = P$

Polynomial Hierarchy - the difference between $\Pi$ and $\Sigma$

is there a constructive proof of the existence of a language which isn't recursive (without invoking infinities)?

Is it possible that Co-NP = P but NP != P

Does godel's incompleteness theorem still hold if we have a TM that can do an infinity amount of computations?

Why doesn't Godel's Second Incompleteness Theorem rule out a formalizable proof of P!=NP?

Proving FPT is strictly contained in XP

How does one define transcendental numbers (such as Pi) in theory of general recursive functions

can you write a halting decider that is only wrong about itself by avoiding diagonalization?

Is there a TM that halts iff P = NP?

If a computer can demonstrate singleton sets are closed, is the space Hausdorff?

Cardinality of the set of algorithms

Is there any other computation theory besides the one in automata theory?

Is Rice-Shapiro theorem bidirectional?

Is the set of language decidable by some Turing machine computing in some given computable time bound decidable

Why is this language Turing recognizable and not not-Turing recognizable

What is wrong with the following $P$ problem?

Analogue of the topology-computability correspondence for computational complexity

Proof for Turing Machines being able to simulate any algorithm in the same time complexity