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 )