Metamath Proof Explorer


Theorem regtop

Description: A regular space is a topological space. (Contributed by Jeff Hankins, 1-Feb-2010)

Ref Expression
Assertion regtop ( 𝐽 ∈ Reg → 𝐽 ∈ Top )

Proof

Step Hyp Ref Expression
1 isreg ⊢ ( 𝐽 ∈ Reg ↔ ( 𝐽 ∈ Top ∧ ∀ 𝑥 ∈ 𝐽 ∀ 𝑦 ∈ 𝑥 ∃ 𝑧 ∈ 𝐽 ( 𝑦 ∈ 𝑧 ∧ ( ( cls ‘ 𝐽 ) ‘ 𝑧 ) ⊆ 𝑥 ) ) )
2 1 simplbi ⊢ ( 𝐽 ∈ Reg → 𝐽 ∈ Top )