Theorem divs1d

Description: A surreal divided by one is itself. Deduction version. (Contributed by Scott Fenton, 27-Feb-2026)

	Ref	Expression
Hypothesis	divs1d.1	⊢ ( 𝜑 → 𝐴 ∈ No )
Assertion	divs1d	⊢ ( 𝜑 → ( 𝐴 /su 1s ) = 𝐴 )

Proof

Step	Hyp	Ref	Expression
1		divs1d.1	⊢ ( 𝜑 → 𝐴 ∈ No )
2		divs1	⊢ ( 𝐴 ∈ No → ( 𝐴 /su 1s ) = 𝐴 )
3	1 2	syl	⊢ ( 𝜑 → ( 𝐴 /su 1s ) = 𝐴 )