What is Turing Complete?
What does the expression Turing Complete means? Can you give a simple explanation, without going into too much theoretical details? ...
turing-machines
How do you apply Theoretical Computer Science?
Why is theory useful? Do you ever use it in your day-to-day coding? For example, we learned about the halting problem, Turing machines, reductions, etc... a lot of classmates are saying it's abstract and useless and there's no real point to knowning any of it (meaning, you can forget it once the course is over and not lose anything). ...
Multiple levels of infinity
Some programmers don't see much relevance in theoretical CS classes (especially my students). Here is something I find very relevant. Let me build it up in pieces for those that haven't seen it before... A) Programming problems can be reworded to be questions about languages. B) Turing machines recognize languages. C) Turing machines...
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 1's of exponent With my tape output being like 1's of base 0 1's of exponent 0 1's of...
Is computing theory useful for programmers?
Can learning subjects such as abstract machines and formal languages make you a better programmer? ...
How can I simulate a turing machine?
I don't quite understand the whole idea of a turing machine thing. I am currently tasked with making a busy beaver turing machine. But the thing I don't really get is it simulates input. So what kind of input do I simulate? For example, it's asking me how many 1s the 3 states busy beaver machines writes on tape? I'm sure I need to write...
Turing Machine Instruction Table
Hi! The definitions of Turing Machine say that it is prohibited for one to read/modify it's instruction table (program). Exactly, Turing Machine has no access to it's own program. What benefits can be achieved if one could weaken this restriction? If a machine could analise and/or modify it's program. Would that extend the class of tu...
How to argue that if we could solve the halting problem, then we could solve busy beaver?
This is one of the tasks of my assignment. I have a Turing machine simulation which can simulate a busy beaver function. I have done some research about proving this problem, but still don't get it so I guess maybe you can help me here. A good source for me to go to or example of how to argue this would be good. ...
Turing Machine Code Golf
Ok guys, today's goal is to build a Turing machine simulator. For those that don't know what it is, see the Wikipedia article. The state table we are using today is found at the end of the Formal Definition that's part of that page. The code will take a sequence of "0" and "1" string characters, an integer representing the character tha...
Turing machines of prime number
how to create a turing machine of prime number? ...
A Decidability Question
Can there be an NFA that decides on real numbers ? ...
Decidability of Machines
Hello, I cannot understand decidability really well. I have been reading from books and internet, but I am little bit confused. According to the book (as I understood), we can decide on decidability of a problem by constructing Turing Machines. Let us say that we want to decide whether an NFA is a decidable language. First, we need to c...
Turing machine adding two numbers
How can I create Turing Machine which will calculate sum of two binary digits separated by #, eg. 111#101B, where B is for blank? Result can be written at the end of the tape. ...
Designing a Turing Machine's state table
Are they any helpful guidelines to describing what a Turing machine does if you already have the pseudo code for the algorithm? I'm taking a course on complexity theory and it takes me a while to describe a Turing machine that decides or accepts some language (states, transitions, etc.) even though I know how I could code it in somethin...
Universal Turing Machine Problems
If I have a machine, call it machine 1, that is able to solve a problem: it's just a machine, not per se a Turing machine. It can solve one specific problem. If this exact same problem can be solved on a Universal Turing Machine, then is my original machine, 1, a Universal Turing Machine too? This does not hold for all problems, which i...
How does a non deterministic turing machine work?
I understand they aren't real and they seem to branch computation whenever there are 2 options, instead of picking one. But, for example, if I say this: "Non deterministically guess a bijection p of vertices from Graph G to Graph H" (context here is Graph Isomorphism) What is that supposed to mean? I understand the bijection, but it sa...
What are the useful limits of Linear Bounded Automata compared to Turing Machines?
There are languages that a Turing machine can handle that an LBA can't, but are there any useful, practical problems that LBAs can't solve but TMs can? An LBA is just a Turing machine with a finite tape, and actual computers have finite storage, so it would seem to me that there's nothing of practical importance that an LBA can't do. E...
A Turing Machine Question
Greetings, I have been struggling to find a question regarding this theoretical question, even tho it is not directly a programming question, I believe it is really related. Assume a type of Turing machine which cannot have more than 1000 squares. What would be the relationship between the set of such type of recognizable languages an...
Turing machine halting problem
Hi, I have a question about turing machines and halting problem. Suppose that we have Atm = {(M,w) where M is a turing machine and w is an input} and HALTtm = {(M,w) where M is a turing machine halts with an input w} I want to prove that HALTtm <=m Atm I've tried some methods but I think they're far from the solution. Anyone can gi...
What is the relationship between Turing Machine & Modern Computer ?
Possible Duplicate: What is the relationship between Turing Machine & Modern Computer ? I heard a lot that modern computers are based on Turing machine. I just cannot build a bridge from a conceptual Turing Machine to a real modern computer. Could someone help me build this bridge? Below is my current understanding. I thin...