Description: The empty set is greater than any set of surreals. (Contributed by Scott Fenton, 8-Dec-2021)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nulssgt | |- ( A e. ~P No -> A < | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | id | |- ( A e. ~P No -> A e. ~P No ) | |
| 2 | 0ex | |- (/) e. _V | |
| 3 | 2 | a1i | |- ( A e. ~P No -> (/) e. _V ) | 
| 4 | elpwi | |- ( A e. ~P No -> A C_ No ) | |
| 5 | 0ss | |- (/) C_ No | |
| 6 | 5 | a1i | |- ( A e. ~P No -> (/) C_ No ) | 
| 7 | noel | |- -. y e. (/) | |
| 8 | 7 | pm2.21i | |- ( y e. (/) -> x | 
| 9 | 8 | 3ad2ant3 | |- ( ( A e. ~P No /\ x e. A /\ y e. (/) ) -> x | 
| 10 | 1 3 4 6 9 | ssltd | |- ( A e. ~P No -> A < |