Description: The transitive closure of the empty set is the empty set. (Contributed by Matthew House, 6-Apr-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ttc0 | |- TC+ (/) = (/) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | tr0 | |- Tr (/) |
|
| 2 | ttctrid | |- ( Tr (/) -> TC+ (/) = (/) ) |
|
| 3 | 1 2 | ax-mp | |- TC+ (/) = (/) |