Description: A Hausdorff space is locally Hausdorff. (Contributed by Mario Carneiro, 2-Mar-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | hauslly | ⊢ ( 𝐽 ∈ Haus → 𝐽 ∈ Locally Haus ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resthaus | ⊢ ( ( 𝑗 ∈ Haus ∧ 𝑥 ∈ 𝑗 ) → ( 𝑗 ↾t 𝑥 ) ∈ Haus ) | |
| 2 | 1 | adantl | ⊢ ( ( ⊤ ∧ ( 𝑗 ∈ Haus ∧ 𝑥 ∈ 𝑗 ) ) → ( 𝑗 ↾t 𝑥 ) ∈ Haus ) |
| 3 | haustop | ⊢ ( 𝑗 ∈ Haus → 𝑗 ∈ Top ) | |
| 4 | 3 | ssriv | ⊢ Haus ⊆ Top |
| 5 | 4 | a1i | ⊢ ( ⊤ → Haus ⊆ Top ) |
| 6 | 2 5 | restlly | ⊢ ( ⊤ → Haus ⊆ Locally Haus ) |
| 7 | 6 | mptru | ⊢ Haus ⊆ Locally Haus |
| 8 | 7 | sseli | ⊢ ( 𝐽 ∈ Haus → 𝐽 ∈ Locally Haus ) |