 Pairing function

A pairing function is a computable bijection from ${\mathbb{N}}_0^2$ to ${\mathbb{N}}_0$ whose inverse coordinate functions are also computable. Iterating it gives computable encodings of every fixed finite tuple of nonnegative integers.

A pairing function is a mathematical function that uniquely maps pairs of natural numbers (or non-negative integers) to a single natural number. This concept is particularly useful in various areas of mathematics and computer science, especially in combinatorics and theoretical computer science. Pairing functions can be used to encode two-dimensional data into one-dimensional data, making it easier to work with.