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Metamath Proof Explorer

Theorem 0xnn0

Description: Zero is an extended nonnegative integer. (Contributed by AV, 10-Dec-2020)

		Ref	Expression
	Assertion	0xnn0	⊢ 0 ∈ ℕ₀^*

Step	Hyp	Ref	Expression
1		nn0ssxnn0	⊢ ℕ₀ ⊆ ℕ₀^*
2		0nn0	⊢ 0 ∈ ℕ₀
3	1 2	sselii	⊢ 0 ∈ ℕ₀^*