Definition:Power (Algebra)/Natural Number

Definition
Let $\N$ denote the natural numbers.

For each $m \in \N$, let $e_m: \N \to \N$ be the mapping:
 * $e_m \left({n}\right) = \begin{cases}

1 & : n = 0 \\ m \times e_m \left({x}\right) & : n = x + 1 \end{cases}$ where:
 * $+$ denotes natural number addition.
 * $\times$ denotes natural number multiplication.

$e_m \left({n}\right)$ is then expressed as a binary operation in the form:
 * $m^n := e_m \left({n}\right)$