Metamath Proof Explorer


Theorem ssltss1

Description: The first argument of surreal set is a set of surreals. (Contributed by Scott Fenton, 8-Dec-2021)

Ref Expression
Assertion ssltss1
|- ( A < A C_ No )

Proof

Step Hyp Ref Expression
1 brsslt
 |-  ( A < ( ( A e. _V /\ B e. _V ) /\ ( A C_ No /\ B C_ No /\ A. x e. A A. y e. B x 
2 simpr1
 |-  ( ( ( A e. _V /\ B e. _V ) /\ ( A C_ No /\ B C_ No /\ A. x e. A A. y e. B x  A C_ No )
3 1 2 sylbi
 |-  ( A < A C_ No )