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Determine in which class $L=\big\{\langle M_1,M_2,w\rangle\mid M_1,M_2\text{ are TM and }L(M_1)\cap L(M_2)=\{w\}\big\}$

turing-machines

answered 2 days ago user3563894 71

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How to simulate a bidirectional TM on a regular one with time factor four?

turing-machines simulation computation-models

modified Aug 12 at 13:02 Community♦ 1

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Prove {0^n OR 1^2n OR 2^3n | n >= 0} is not context free

turing-machines regular-languages context-free pumping-lemma

answered Aug 10 at 12:27 VashTheStampede 81

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SAT Solving + Turing Machines

turing-machines np-complete heuristics probabilistic-algorithms backtracking

answered Aug 3 at 17:22 Juho 14.7k

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If $L=\big\{\langle M_1,M_2\rangle\mid M_1, M_2\text{ are TM and } L(M_1)\cup L(M_1)=\Sigma^* \big\}$ is in $RE$ or $coRE$ or not in $RE\cup coRE$?

turing-machines reductions

answered Aug 3 at 13:29 Daniel Mroz 226

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How would a Turing Machine recognize n consecutive characters

formal-languages turing-machines

modified Aug 2 at 19:02 Community♦ 1

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Turing machine that accepts L = {a^nb^2n : n ≥ 0}

turing-machines

answered Aug 2 at 13:34 David Richerby 59.9k

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Turing machine different accepting states

turing-machines turing

answered Aug 1 at 17:32 David Richerby 59.9k

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How to start solving this type of exercise: Determine if $L$ is in $RE\setminus coRE$ or $coRE\setminus RE$ or $R$ or not in $RE\cup coRE$?

turing-machines reductions undecidability

answered Jul 31 at 13:48 Yuval Filmus 180k

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Prove that the TM which would go over the leftmost position is not decidable

turing-machines reductions

modified Jul 30 at 23:01 Community♦ 1

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Prove or disprove if $L_{1}$ is undecidable and $L_{2}$ is finite language then $L_{1} \cup L_{2}$ is undecidable

turing-machines undecidability halting-problem

answered Jul 29 at 14:36 Asaf 26

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Prove or disprove if $L_{1}$ is Turing-recognizable and $L_{2}$ is co-Turing-recognizable then $L_{1}\cap L_{2}$ is decidable

turing-machines computability

modified Jul 27 at 10:02 xskxzr 2,551

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Understanding proof for Busy Beaver being uncomputable

computability turing-machines halting-problem busy-beaver

modified Jul 24 at 13:44 James Parker 21

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Reduce ATM to the language of TM encodings concatenated by a string where the TM accepts both the string and its reverse

turing-machines reductions undecidability

modified Jul 23 at 19:09 Community♦ 1

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Determine in which class $L=\big\{\langle M_1,M_2,w\rangle\mid M_1,M_2\text{ are TM and }L(M_1)\cap L(M_2)=\{w\}\big\}$

How to simulate a bidirectional TM on a regular one with time factor four?

Prove {0^n OR 1^2n OR 2^3n | n >= 0} is not context free

SAT Solving + Turing Machines

If $L=\big\{\langle M_1,M_2\rangle\mid M_1, M_2\text{ are TM and } L(M_1)\cup L(M_1)=\Sigma^* \big\}$ is in $RE$ or $coRE$ or not in $RE\cup coRE$?

How would a Turing Machine recognize n consecutive characters

Turing machine that accepts L = {a^nb^2n : n ≥ 0}

Turing machine different accepting states

How to start solving this type of exercise: Determine if $L$ is in $RE\setminus coRE$ or $coRE\setminus RE$ or $R$ or not in $RE\cup coRE$?

Prove that the TM which would go over the leftmost position is not decidable

Prove or disprove if $L_{1}$ is undecidable and $L_{2}$ is finite language then $L_{1} \cup L_{2}$ is undecidable

Prove or disprove if $L_{1}$ is Turing-recognizable and $L_{2}$ is co-Turing-recognizable then $L_{1}\cap L_{2}$ is decidable

Understanding proof for Busy Beaver being uncomputable

Reduce ATM to the language of TM encodings concatenated by a string where the TM accepts both the string and its reverse

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