Theorem nnord

Description: A natural number is ordinal. (Contributed by NM, 17-Oct-1995)

	Ref	Expression
Assertion	nnord	$$⊢A\in \mathrm{\omega }\to \mathrm{Ord}A$$

Proof

Step	Hyp	Ref	Expression
1		nnon	$$⊢A\in \mathrm{\omega }\to A\in \mathrm{On}$$
2		eloni	$$⊢A\in \mathrm{On}\to \mathrm{Ord}A$$
3	1 2	syl	$$⊢A\in \mathrm{\omega }\to \mathrm{Ord}A$$