Theorem nnnn0i

Description: A positive integer is a nonnegative integer. (Contributed by NM, 20-Jun-2005)

	Ref	Expression
Hypothesis	nnnn0i.1	⊢ 𝑁 ∈ ℕ
Assertion	nnnn0i	⊢ 𝑁 ∈ ℕ0

Proof

Step	Hyp	Ref	Expression
1		nnnn0i.1	⊢ 𝑁 ∈ ℕ
2		nnnn0	⊢ ( 𝑁 ∈ ℕ → 𝑁 ∈ ℕ0 )
3	1 2	ax-mp	⊢ 𝑁 ∈ ℕ0