Description: A perfect space is a topology. (Contributed by Mario Carneiro, 25-Dec-2016)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | perftop | ⊢ ( 𝐽 ∈ Perf → 𝐽 ∈ Top ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid | ⊢ ∪ 𝐽 = ∪ 𝐽 | |
| 2 | 1 | isperf | ⊢ ( 𝐽 ∈ Perf ↔ ( 𝐽 ∈ Top ∧ ( ( limPt ‘ 𝐽 ) ‘ ∪ 𝐽 ) = ∪ 𝐽 ) ) | 
| 3 | 2 | simplbi | ⊢ ( 𝐽 ∈ Perf → 𝐽 ∈ Top ) |