# Definition:Initial Segment of Natural Numbers/One-Based

## Definition

Let $n \in \N$ be a natural number.

The initial segment of the non-zero natural numbers determined by $n$:

$\set {1, 2, 3, \ldots, n}$

is denoted $\N^*_{\le n}$.

## Also denoted as

The usual notation for this is $\N^*_n$, but the notation $\N^*_{\le n}$ is less ambiguous.

Some sources use the notation of integers, and denote $\set {1, 2, 3, \ldots, n}$ as $\map \Z n$.

There does not seem to be any notation for this concept which is neither ambiguous nor cumbersome, so on $\mathsf{Pr} \infty \mathsf{fWiki}$ it is commonplace to select a simple notation and define it at point of use.