Description: Define surreal one. This is the simplest number greater than surreal zero. Definition from Conway p. 18. (Contributed by Scott Fenton, 7-Aug-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-1s | |- 1s = ( { 0s } |s (/) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | c1s | |- 1s |
|
| 1 | c0s | |- 0s |
|
| 2 | 1 | csn | |- { 0s } |
| 3 | cscut | |- |s |
|
| 4 | c0 | |- (/) |
|
| 5 | 2 4 3 | co | |- ( { 0s } |s (/) ) |
| 6 | 0 5 | wceq | |- 1s = ( { 0s } |s (/) ) |