Theorem piord

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

	Ref	Expression
Assertion	piord	⊢ ( 𝐴 ∈ N → Ord 𝐴 )

Proof

Step	Hyp	Ref	Expression
1		pinn	⊢ ( 𝐴 ∈ N → 𝐴 ∈ ω )
2		nnord	⊢ ( 𝐴 ∈ ω → Ord 𝐴 )
3	1 2	syl	⊢ ( 𝐴 ∈ N → Ord 𝐴 )