Well-Ordering Principle/Corollary

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Corollary to Well-Ordering Principle

Let $\le_1$ denote the restriction of the usual ordering $\le$ to the set $\N_{\ne 0}$ of natural numbers without zero.

The relational structure $\struct {\N_{\ne 0}, \le_1}$ forms a well-ordered set.


We have by the Well-Ordering Principle that $\struct {\N, \le}$ forms a well-ordered set.

We also have that $\N_{\ne 0}$ is a subset of $\N$.

The result follows from Subset of Well-Ordered Set is Well-Ordered.