Metamath Proof Explorer


Theorem 1fno

Description: Ordinal one maps to a surreal number. (Contributed by RP, 21-Sep-2023)

Ref Expression
Assertion 1fno ⊢ 1 𝑜 × 2 𝑜 ∈ No

Proof

Step Hyp Ref Expression
1 1on ⊢ 1 𝑜 ∈ On
2 1 onnoxpi ⊢ 1 𝑜 × 2 𝑜 ∈ No