Metamath Proof Explorer


Theorem leftno

Description: An element of a left set is a surreal. (Contributed by Scott Fenton, 27-Feb-2026)

Ref Expression
Assertion leftno ( 𝐴 ∈ ( L ‘ 𝐵 ) → 𝐴 ∈ No )

Proof

Step Hyp Ref Expression
1 leftssno ⊢ ( L ‘ 𝐵 ) ⊆ No
2 1 sseli ⊢ ( 𝐴 ∈ ( L ‘ 𝐵 ) → 𝐴 ∈ No )