Description: An element of a left set is a surreal. (Contributed by Scott Fenton, 27-Feb-2026)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | leftel.1 | |- ( ph -> A e. ( _Left ` B ) ) |
|
| Assertion | leftnod | |- ( ph -> A e. No ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | leftel.1 | |- ( ph -> A e. ( _Left ` B ) ) |
|
| 2 | leftno | |- ( A e. ( _Left ` B ) -> A e. No ) |
|
| 3 | 1 2 | syl | |- ( ph -> A e. No ) |