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 ∧ 𝑥𝑗 ) → ( 𝑗t 𝑥 ) ∈ Haus )
2 1 adantl ( ( ⊤ ∧ ( 𝑗 ∈ Haus ∧ 𝑥𝑗 ) ) → ( 𝑗t 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 )