Admissible numbering

Admissible numbering is a concept from recursion theory and mathematical logic, particularly in the study of computability and computable structures. An admissible numbering is a way of assigning natural numbers to objects in such a way that the properties and relationships of these objects can be effectively worked with or analyzed. More specifically, an admissible numbering is a type of coding that provides a systematic method to index or enumerate certain sets or classes of objects, typically in recursion theory or the theory of computable functions.