Theorem nn0xnn0

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

	Ref	Expression
Assertion	nn0xnn0	$$⊢A\in {\mathbb{N}}_0\to A\in {\mathbb{N}}_0^{*}$$

Proof

Step	Hyp	Ref	Expression
1		nn0ssxnn0	$$⊢{\mathbb{N}}_0\subseteq {\mathbb{N}}_0^{*}$$
2	1	sseli	$$⊢A\in {\mathbb{N}}_0\to A\in {\mathbb{N}}_0^{*}$$