Metamath Proof Explorer


Theorem hauslly

Description: A Hausdorff space is locally Hausdorff. (Contributed by Mario Carneiro, 2-Mar-2015)

Ref Expression
Assertion hauslly ( 𝐽 ∈ Haus → 𝐽 ∈ Locally Haus )

Proof

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 )