Description: Surreal zero is a surreal. (Contributed by Scott Fenton, 7-Aug-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0sno | |- 0s e. No |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-0s | |- 0s = ( (/) |s (/) ) |
|
| 2 | 0elpw | |- (/) e. ~P No |
|
| 3 | nulssgt | |- ( (/) e. ~P No -> (/) < |
|
| 4 | 2 3 | ax-mp | |- (/) < |
| 5 | scutcl | |- ( (/) < |
|
| 6 | 4 5 | ax-mp | |- ( (/) |s (/) ) e. No |
| 7 | 1 6 | eqeltri | |- 0s e. No |