Theorem piord

Description: A positive integer is ordinal. (Contributed by NM, 29-Jan-1996) (New usage is discouraged.)

	Ref	Expression
Assertion	piord	$$⊢A\in 𝑵\to \mathrm{Ord}A$$

Proof

Step	Hyp	Ref	Expression
1		pinn	$$⊢A\in 𝑵\to A\in \mathrm{\omega }$$
2		nnord	$$⊢A\in \mathrm{\omega }\to \mathrm{Ord}A$$
3	1 2	syl	$$⊢A\in 𝑵\to \mathrm{Ord}A$$