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 ) |