Metamath Proof Explorer


Theorem nnn0sd

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

Ref Expression
Hypothesis nnn0sd.1 ( 𝜑𝐴 ∈ ℕs )
Assertion nnn0sd ( 𝜑𝐴 ∈ ℕ0s )

Proof

Step Hyp Ref Expression
1 nnn0sd.1 ( 𝜑𝐴 ∈ ℕs )
2 nnssn0s s ⊆ ℕ0s
3 2 1 sselid ( 𝜑𝐴 ∈ ℕ0s )