Metamath Proof Explorer


Theorem t0hmph

Description: T_0 is a topological property. (Contributed by Mario Carneiro, 25-Aug-2015)

Ref Expression
Assertion t0hmph ⊢ J ≃ K → J ∈ Kol2 → K ∈ Kol2

Proof

Step Hyp Ref Expression
1 t0top ⊢ J ∈ Kol2 → J ∈ Top
2 cnt0 ⊢ J ∈ Kol2 ∧ f : ⋃ K ⟶ 1-1 ⋃ J ∧ f ∈ K Cn J → K ∈ Kol2
3 1 2 haushmphlem ⊢ J ≃ K → J ∈ Kol2 → K ∈ Kol2