computability theory Computability theory, also known as recursion theory, is a branch of mathematical logic, computer science, and the theory of computation that originated in the 1930s with the study of computable functions and Turing degrees. The field has since ...

, a Friedberg numbering is a

numbering There are many different numbering schemes for assigning nominal numbers to entities. These generally require an agreed set of rules, or a central coordinator. The schemes can be considered to be examples of a primary key of a database management ...

(enumeration) of the set of all uniformly recursively enumerable sets that has no repetitions: each recursively enumerable set appears exactly once in the enumeration (Vereščagin and Shen 2003:30). The existence of such numberings was established by Richard M. Friedberg in 1958 (Cutland 1980:78).

References

* Nigel Cutland (1980), ''Computability: An Introduction to Recursive Function Theory'', Cambridge University Press. . * Richard M. Friedberg (1958), ''Three Theorems on Recursive Enumeration. I. Decomposition. II. Maximal Set. III. Enumeration Without Duplication'', ''Journal of Symbolic Logic'' 23:3, pp. 309–316. * Nikolaj K. Vereščagin and A. Shen (2003), ''Computable Functions'', American Mathematical Soc.

External links

Institute of Mathematics
{{Mathlogic-stub Computability theory