Metamath Proof Explorer


Theorem rightge0

Description: A surreal is non-negative iff all its right options are positive. (Contributed by Scott Fenton, 1-Jan-2026)

Ref Expression
Hypotheses rightge0.1 φ A s B
rightge0.2 φ X = A | s B
Assertion rightge0 Could not format assertion : No typesetting found for |- ( ph -> ( 0s <_s X <-> A. xR e. B 0s

Proof

Step Hyp Ref Expression
1 rightge0.1 φ A s B
2 rightge0.2 φ X = A | s B
3 0elpw 𝒫 No
4 nulsgts 𝒫 No s
5 3 4 mp1i φ s
6 df-0s 0 s = | s
7 6 a1i φ 0 s = | s
8 5 1 7 2 lesrecd Could not format ( ph -> ( 0s <_s X <-> ( A. xR e. B 0s ( 0s <_s X <-> ( A. xR e. B 0s
9 ral0 Could not format A. xL e. (/) xL
10 9 biantru Could not format ( A. xR e. B 0s ( A. xR e. B 0s ( A. xR e. B 0s
11 8 10 bitr4di Could not format ( ph -> ( 0s <_s X <-> A. xR e. B 0s ( 0s <_s X <-> A. xR e. B 0s