Description: Ordinal zero maps to a surreal number. (Contributed by RP, 21-Sep-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | 0no | |- (/) e. No |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0xp | |- ( (/) X. { 2o } ) = (/) |
|
2 | 0elon | |- (/) e. On |
|
3 | 2 | onnoi | |- ( (/) X. { 2o } ) e. No |
4 | 1 3 | eqeltrri | |- (/) e. No |