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Such a machine is called queue machine and is Turing-complete. Tape memory: The inputs and outputs of automata are often described as input and output tapes. Some machines have additional working tapes, including the Turing machine, linear bounded automaton, and log-space transducer. Transition function
Classes of automata. (Clicking on each layer gets an article on that subject) A Turing machine is a mathematical model of computation describing an abstract machine [ 1 ] that manipulates symbols on a strip of tape according to a table of rules. [ 2 ] Despite the model's simplicity, it is capable of implementing any computer algorithm.
For these reasons, a universal Turing machine serves as a standard against which to compare computational systems, and a system that can simulate a universal Turing machine is called Turing complete. An abstract version of the universal Turing machine is the universal function , a computable function which can be used to calculate any other ...
In addition to the function Σ, Radó [1962] introduced another extreme function for Turing machines, the maximum shifts function, S, defined as follows: [4] s(M) = the number of shifts M makes before halting, for any M ∈ E n, S(n) = max{s(M) | M ∈ E n} = the largest number of shifts made by any halting n-state 2-symbol Turing machine.
A deterministic Turing machine has a transition function that, for a given state and symbol under the tape head, specifies three things: the symbol to be written to the tape (it may be the same as the symbol currently in that position, or not even write at all, resulting in no practical change),
Turing's a-machine model. Turing's a-machine (as he called it) was left-ended, right-end-infinite. He provided symbols əə to mark the left end. A finite number of tape symbols were permitted. The instructions (if a universal machine), and the "input" and "out" were written only on "F-squares", and markers were to appear on "E-squares".
A Turing machine that "solves" a problem is generally meant to mean one that decides the language. Turing machines enable intuitive notions of "time" and "space". The time complexity of a TM on a particular input is the number of elementary steps that the Turing machine takes to reach either an accept or reject state.
Similarly, in the Turing machine model of computation, a reversible Turing machine is one whose transition function is invertible, so that each machine state has at most one predecessor. Yves Lecerf proposed a reversible Turing machine in a 1963 paper, [ 10 ] but apparently unaware of Landauer's principle, did not pursue the subject further ...