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Questions tagged [turing-machines]

A Turing machine is an idealized model of computation consisting of a finite-state control, an infinite tape holding information, and a read head positioned somewhere over the tape. Turing machines are used in computability theory to reason about the limits of computation, to provide a formal definition for an algorithm, and to provide formal models for nondeterminism.

Wiki

A Turing machine is a device that manipulates symbols on a strip of tape according to a table of rules. Despite its simplicity, a Turing machine can be adapted to simulate the logic of any computer algorithm, and is particularly useful in explaining the functions of a CPU inside a computer.

Turing machines are not physical objects but mathematical ones. A Turing machine is a kind of state machine. At any time the machine is in any one of a finite number of states. Instructions for a Turing machine consist in specified conditions under which the machine will transition between one state and another.

The tape is used to store data. In addition, it can also store a series of transitions (a small programs) and thus, the head can run sub-programs. By analogy with modern computers, the tape is the memory and the head is the microprocessor.

Tag usage

The tag can be used for programming related problems in implementing features of a turing machine. The tag can also be used for algorithmic problems related to turing machine. Try to avoid theoretical and research based questions on Stack Overflow.

Please note https://cstheory.stackexchange.com is another stack exchange website which you can use to ask theoretical and conceptual problems with tag

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Turing machine to compare binary

I am trying to write, using a Turing simulation, so in the form: 0 1 * r 0 0 0 * r 0 0 # * * 3 0 x * r 0 0 y * r 0 ...a program that takes two binary values separated by a ">" e.g. 1010>111 which will halt-yes if left>right and…
CalEl
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M is a Turing machine that accepts string w and does not accept string ε

I need to prove whether this language is recognizable or not: { ⟨M, w⟩: M is a Turing machine that accepts string w and does not accept string ε } I figure I could do a reduction on ATM, but how do I handle the empty string?
Jerome Morrow
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binary universal turing machine code

In BINARY UNIVERSAL TURING MACHINE CODE how do we differentiate between the different turing machines..for example we can find the start and end of binary UTM code by '111' and we bifercate between two different states (q1,q2)with '11' but how do we…
SAURAV DUBEY
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What does the fancy R symbol mean as written here?

This is an assigned question I have, and I'm not sure how to interpret the R-like symbol in the exponent position. Does it mean the Turing machine should accept variable numbers of repetitions of w?
Austin
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what practical proofs are there about the Turing completeness of neural nets? what nns can execute code/algorithms?

I'm interested in the computational power of neural nets. It is generally accepted that recurrent neural nets are Turing complete. Now I was searching for some papers which proofs this. What I found so far: Turing computability with neural nets,…
Albert
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Running time of a program on deterministic and non-deterministic Turing machine

I've found the following statement: If a program P for Non Deterministic Turing Machine solves a decision problem in time limited by a polynomial p(S), where S-size of input, then it can be run on a Deterministic Turing Machine, and the solution…
user107986
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Is there a C++ code that compiles for infinite time?

I often hear about "C++ sources take a lot of time and memory to compile". I also hear about that C++ template is Turing complete, so it may suffer from Halting problem. I have also built a C++ project that costs 8 GiB of memory and 2 hours of…
Star Brilliant
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Is this language decidable, recognizable, or unrecognizable?

The language L that consists of all Turing Machine descriptions M, for which the language accepted by M is finite. I said L is a decidable language because I can just run M on a function D(M) that returns false if there exists a loop somewhere…
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how to calculate the turing machine running time?

I just review the computing theorem. And i met a question as follow. Consider a deterministic k-tape Turing machine with q states and σ alphabetic symbols. Suppose this Turing machine halts after using a maximum of h cells on each of the tapes. What…
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DPDA to Turing Machine?

Is there a way to convert a deterministic pushdown automata into a turing machine? I thought about putting the stack after the input on the tape, with '#' between them. But it seems kind of impossible to prove it formally. Do you have any…
pepper potts
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Testing a Turing Machine Simulation Program

I am trying to come up with large Test Cases for a Turing Machine Simulator program in Java. The program reads data from an input file and runs the simulation based on a testcase string and a list of Turing Machine rules. After executing the rules…
AnchovyLegend
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Memory leak in a Turing machine, compiled by Free Pascal

I programmed a Turing machine in Pascal using the Free Pascal compiler version 2.6.0 on a Windows Vista laptop. After compiling and testing the results, I used the 'heaptrc' unit to detect some memory leaks. Unfortunately, the program found several…
Petroglyph
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Finite automata, Pushdown automata and Turing machine examples

I'm looking for some good source of Finite automata, pushdown automata and Turing machine tasks examples (for solving manually, by hand). I was searching around but didn't find nothing special so I'm wondering if someone's got some good examples.…
dperitch
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Equivalence of models of computation

I'm seeking explanation on how one could prove that models of computation are equivalent. I have been reading books on the subject except that equivalence proves are omitted. I have a basic idea about what it means for two models of computation to…
mrk
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How to create a turing machine that serves as function calculator for x^y

I'm studying for a test on Turing machines, and I'm stuck with a problem in which I have to create a Turing Machine that serves as a function calculator for: f(x,y) = x ^ y I understand my tape input would come separated like this: 1's of base 0…
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