Metamath Proof Explorer


Theorem reno

Description: A surreal real is a surreal number. (Contributed by Scott Fenton, 19-Feb-2026)

Ref Expression
Assertion reno ( 𝐴 ∈ ℝs𝐴 No )

Proof

Step Hyp Ref Expression
1 elreno ( 𝐴 ∈ ℝs ↔ ( 𝐴 No ∧ ( ∃ 𝑛 ∈ ℕs ( ( -us𝑛 ) <s 𝐴𝐴 <s 𝑛 ) ∧ 𝐴 = ( { 𝑥 ∣ ∃ 𝑛 ∈ ℕs 𝑥 = ( 𝐴 -s ( 1s /su 𝑛 ) ) } |s { 𝑥 ∣ ∃ 𝑛 ∈ ℕs 𝑥 = ( 𝐴 +s ( 1s /su 𝑛 ) ) } ) ) ) )
2 1 simplbi ( 𝐴 ∈ ℝs𝐴 No )