Metamath Proof Explorer


Theorem 0no

Description: Surreal zero is a surreal. (Contributed by Scott Fenton, 7-Aug-2024)

Ref Expression
Assertion 0no ⊢ 0 s ∈ No

Proof

Step Hyp Ref Expression
1 df-0s ⊢ 0 s = ∅ | s ∅
2 0elpw ⊢ ∅ ∈ 𝒫 No
3 nulsgts ⊢ ∅ ∈ 𝒫 No → ∅ ≪ s ∅
4 2 3 ax-mp ⊢ ∅ ≪ s ∅
5 cutscl ⊢ ∅ ≪ s ∅ → ∅ | s ∅ ∈ No
6 4 5 ax-mp ⊢ ∅ | s ∅ ∈ No
7 1 6 eqeltri ⊢ 0 s ∈ No