Theorem nn0z

Description: A nonnegative integer is an integer. (Contributed by NM, 9-May-2004)

	Ref	Expression
Assertion	nn0z	⊢ ( 𝑁 ∈ ℕ0 → 𝑁 ∈ ℤ )

Proof

Step	Hyp	Ref	Expression
1		nn0ssz	⊢ ℕ0 ⊆ ℤ
2	1	sseli	⊢ ( 𝑁 ∈ ℕ0 → 𝑁 ∈ ℤ )