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0

votes

2

answers

118

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Is $MIN_{TM}$ not in $\overline{RE\cup coRE}$

turing-machines computability reductions

modified yesterday Community♦ 1

5

votes

4

answers

2k

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EQtm is not mapping reducible to its complement

computability turing-machines reductions undecidability

answered yesterday aozgaa 11

0

votes

1

answer

18

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Recognizability and complements

turing-machines undecidability

answered 2 days ago Steven 10k

0

votes

1

answer

17

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If two languages are decidable, can one be mapping reducible to the other?

formal-languages turing-machines reductions

answered 2 days ago Steven 10k

0

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0

answers

19

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Is there a decision problem in NP whose corresponding function problem is not in #P?

complexity-theory turing-machines time-complexity np nondeterminism

asked 2 days ago Ole 1

1

vote

0

answers

55

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How does a PDA compare two configurations of accepting histories?

complexity-theory turing-machines computability undecidability pushdown-automata

modified Oct 19 at 22:02 Mohamad Hussein Naim 11

0

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0

answers

20

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Is the set of recursive subsets of the set of natural numbers not r.e.?

turing-machines computability

asked Oct 18 at 20:20 holmes 101

2

votes

1

answer

118

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Proof of universality in the circuit model

turing-machines digital-circuits

modified Oct 18 at 18:09 plshelp 853

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1

answer

69

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What is the semantics of a Turing machine?

turing-machines operational-semantics denotational-semantics

modified Oct 16 at 13:29 Andrej Bauer 25.3k

0

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0

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31

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How would I prove that nondeterministic Turing machines are undecidable?

formal-languages turing-machines undecidability proof-techniques nondeterminism

asked Oct 16 at 1:18 Gareth Bradshaw 1

2

votes

1

answer

114

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Proving $E_{DFA}$ is decidable by running $A_{DFA}$ several times

turing-machines computability automata

modified Oct 13 at 18:05 Community♦ 1

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0

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15

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Multiple loops in a Turing Machine?

turing-machines

asked Oct 13 at 17:39 ShyPerson 763

3

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0

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60

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is it decidable whether a grammar in Chomsky normal form has useless rules?

formal-languages turing-machines context-free undecidability normal-forms

modified Oct 12 at 18:13 xdavidliu 517

4

votes

1

answer

278

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Undecidability of “is this CFG prefix-free?”

formal-languages turing-machines context-free undecidability

modified Oct 12 at 14:09 xdavidliu 517

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