In
computability theory, 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