Theorem 1zs

Description: One is a surreal integer. (Contributed by Scott Fenton, 24-Jul-2025)

	Ref	Expression
Assertion	1zs	$$⊢1_s\in {\mathbb{Z}}_s$$

Proof

Step	Hyp	Ref	Expression
1		1n0s	$$⊢1_s\in {\mathbb{N}}_{\mathrm{0s}}$$
2		n0zs	$$⊢1_s\in {\mathbb{N}}_{\mathrm{0s}}\to 1_s\in {\mathbb{Z}}_s$$
3	1 2	ax-mp	$$⊢1_s\in {\mathbb{Z}}_s$$