Theorem 12nn0

Description: 12 is a nonnegative integer. (Contributed by Umit Teoman Dogan, 10-Jun-2026)

	Ref	Expression
Assertion	12nn0	$$⊢12\in {\mathbb{N}}_0$$

Proof

Step	Hyp	Ref	Expression
1		1nn0	$$⊢1\in {\mathbb{N}}_0$$
2		2nn0	$$⊢2\in {\mathbb{N}}_0$$
3	1 2	deccl	$$⊢12\in {\mathbb{N}}_0$$