Theorem 0xnn0

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

	Ref	Expression
Assertion	0xnn0	$$⊢0\in {\mathbb{N}}_0^{*}$$

Proof

Step	Hyp	Ref	Expression
1		nn0ssxnn0	$$⊢{\mathbb{N}}_0\subseteq {\mathbb{N}}_0^{*}$$
2		0nn0	$$⊢0\in {\mathbb{N}}_0$$
3	1 2	sselii	$$⊢0\in {\mathbb{N}}_0^{*}$$