Description: A Hausdorff space is a topology. (Contributed by NM, 5-Mar-2007)
Ref | Expression | ||
---|---|---|---|
Assertion | haustop | ⊢ ( 𝐽 ∈ Haus → 𝐽 ∈ Top ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid | ⊢ ∪ 𝐽 = ∪ 𝐽 | |
2 | 1 | ishaus | ⊢ ( 𝐽 ∈ Haus ↔ ( 𝐽 ∈ Top ∧ ∀ 𝑥 ∈ ∪ 𝐽 ∀ 𝑦 ∈ ∪ 𝐽 ( 𝑥 ≠ 𝑦 → ∃ 𝑛 ∈ 𝐽 ∃ 𝑚 ∈ 𝐽 ( 𝑥 ∈ 𝑛 ∧ 𝑦 ∈ 𝑚 ∧ ( 𝑛 ∩ 𝑚 ) = ∅ ) ) ) ) |
3 | 2 | simplbi | ⊢ ( 𝐽 ∈ Haus → 𝐽 ∈ Top ) |