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Metamath Proof Explorer

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 )