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May 18, 2015 · Hint 1: So your first step should be to determine whether a and b have, or can obtain, unrestricted access to unlimited memory. Hint 2: If yes, then try to emulate the missing pieces of your preferred Turing machine model. Hint 3: If no, then try to show that the halting problem (with empty tape as input) is decidable. Share.
Dec 18, 2016 · $\begingroup$ Part 1 is trivial because every standard Turing machine is also a modified Turing machine (argue why!). For part 2, it might help if you write down the formal definition of acceptance of a modified Turing machine and try to work from there (i.e. how to convert it so that you get the standard acceptance condition and then show that the two Turing machines accept the same language). $\endgroup$
Apr 23, 2017 · To simulate two tapes Turing machine by single tape encode locations 1,3,5,7... to encode the first tape and locations 2,4,6... to encode second tape and also use symbol for the encoding of head positions.
NDTM is one of many variants of turing mahcine. For example, the classical (deterministic) Turing machine can be equipped with multiple heads and tapes, randomness or quantum states. It can also be constrained by a limited alphabet, limited tape or pre-determined head-movements (see here).
1. The Turing machine is a theoretical computational model which is studied in undergraduate courses due to its simplicity and for historical reasons. Historically, the Turing machine was the first widely accepted definition of computation, and for many years, it was arguably the simplest definition to explain.
Nov 10, 2020 · I have the following Turing machine: A 2R-3L-TM is similar to a standard TM with the change in which the head can only move either 3 cells to the left or 2 cells to the right (those are the only possible moves). and I want to prove equivalence between 2R-3L-TM and standard TMs (one tape and the head can move single cell right or left only).
Turing machine with k-tape, tape of output. Consider a Turing machine with input alphabet {a, b} {a, b} that computes the following function: (w)> length (v), v otherwise. I wish to use a TM with two tapes, the first of which contains the input string, say encoded as ∗w ∗ v∗ ∗ w ∗ v ∗. I'm not sure, having read several books, which ...
May 5, 2015 · Turing machines are not a good model if you care about concrete efficiency. The more appropriate model is the RAM machine. RAM machines can probably simulate parallelism pretty efficiently, though you should not accept a running time any less that the combined running times of the individual threads in your parallel solution.
The language H0 = { M |M halts on empty input} H 0 = { M | M halts on empty input} is undecidable (this is the Empty-Input Halting Problem), but H0 H 0 can be recognized by the following procedure (call it RH R H): Simulate M M on empty input. If it ever halts, accept. Now we have a Turing machine whose language, L(RH) = H0 L (R H) = H 0, is ...
Oct 31, 2014 · These variants can effect the computational complexity, but usually don't change the Turing-completeness of the model. The Turing machine model is very primitive. The basic operations are very weak – the machine can read and write symbols, the head moves to the left or to the right, and that's all. Turing machines are also programmed differently.
