Theorem 7nn0

Description: 7 is a nonnegative integer. (Contributed by Mario Carneiro, 19-Apr-2015)

	Ref	Expression
Assertion	7nn0	⊢ 7 ∈ ℕ0

Proof

Step	Hyp	Ref	Expression
1		7nn	⊢ 7 ∈ ℕ
2	1	nnnn0i	⊢ 7 ∈ ℕ0