Metamath Proof Explorer


Theorem n0zsd

Description: A non-negative surreal integer is a surreal integer. (Contributed by Scott Fenton, 26-May-2025)

Ref Expression
Hypothesis n0zsd.1 ⊢ φ → A ∈ ℕ 0s
Assertion n0zsd ⊢ φ → A ∈ ℤ s

Proof

Step Hyp Ref Expression
1 n0zsd.1 ⊢ φ → A ∈ ℕ 0s
2 n0zs ⊢ A ∈ ℕ 0s → A ∈ ℤ s
3 1 2 syl ⊢ φ → A ∈ ℤ s