Примери коришћења Computable functions на Енглеском и њихови преводи на Српски
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R is equal to the set of all total computable functions.
Computable functions are the basic objects of study in computability theory.
Numberings can be partial-recursive although some of its members are total recursive,that is, computable functions.
Computable functions are used to discuss computability without referring to any concrete model of computation such as Turing machines or register machines.
THEOREM XXX: The following classes of partial functions… have the same members:(a)the partial recursive functions,(b) the computable functions…"p.
Note however that the partial computable functions(those that need not be defined for all arguments) can be explicitly enumerated, for instance by enumerating Turing machine encodings.
Theorem XXX: The following classes of partial functions are coextensive, i.e. have the same members:(a)the partial recursive functions,(b) the computable functions.
Equivalently, computable functions can be formalized as functions which can be calculated by an idealized computing agent such as a Turing machine or a register machine.
Is it possible to change the definition of a Turing machine so that a particular class of total Turing machines,computing all the total computable functions, can be found?
According to the Church-Turing thesis, computable functions are exactly the functions that can be calculated using a mechanical calculation device given unlimited amounts of time and storage space.
The second question asks, in essence, whether there is another reasonable model of computation which computes only total functions andcomputes all the total computable functions.
For example, one can formalize computable functions as μ-recursive functions, which are partial functions that take finite tuples of natural numbers and return a single natural number(just as above).
Recursion theory- Recursion theory, also called computability theory,is a branch of mathematical logic that originated in the 1930s with the study of computable functions and Turing degrees.
Although the Church-Turing thesis states that the computable functions include all functions with algorithms, it is possible to consider broader classes of functions that relax the requirements that algorithms must possess.
The following theorem shows that the functions computable by machines that always halt do not include extensions of all partial computable functions, which implies the first question above has a negative answer.
Computable functions are the formalized analogue of the intuitive notion of algorithm, in the sense that a function is computable if there exists an algorithm that can do the job of the function, i.e. given an input of the function domain it can return the corresponding output.
Computability theory, also called recursion theory, is a branch of mathematical logic, of computer science, andof the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees.
The answer to each of these questions is no. The following theorem shows that the functions computable by machines that always halt do not include extensions of all partial computable functions, which implies the first question above has a negative answer.
Enderton[1977] gives the following characteristics of a procedure for computing a computable function;
Not every total computable function is provably total in Peano arithmetic, however;
This argument provides a computable function which is not primitive recursive.
That reduction function must be a computable function.
Many equivalent models of computation are known, andthey all give the same definition of computable function(or a weaker version, in some instances).
Before the precise definition of computable function mathematicians often used the informal term effectively calculable to describe functions that are computable by paper-- pencil methods.
There are Turing computable partial functions that have no extension to a total Turing computable function.
Not every total computable function is provably total in Peano arithmetic, however; an example of such a function is provided by Goodstein's theorem.
If g were a total computable function extending f then g would be computable by some Turing machine;