Metamath Proof Explorer

Theorem rightno

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

Ref Expression
Assertion rightno 
|- ( A e. ( _Right ` B ) -> A e. No )

Proof

Step Hyp Ref Expression
1 rightssno 
 |-  ( _Right ` B ) C_ No
2 1 sseli 
 |-  ( A e. ( _Right ` B ) -> A e. No )