Description: The limit points of a perfect space. (Contributed by Mario Carneiro, 24-Dec-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | lpfval.1 | |- X = U. J | |
| Assertion | perflp | |- ( J e. Perf -> ( ( limPt ` J ) ` X ) = X ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | lpfval.1 | |- X = U. J | |
| 2 | 1 | isperf | |- ( J e. Perf <-> ( J e. Top /\ ( ( limPt ` J ) ` X ) = X ) ) | 
| 3 | 2 | simprbi | |- ( J e. Perf -> ( ( limPt ` J ) ` X ) = X ) |