Metamath Proof Explorer


Theorem kqf

Description: The Kolmogorov quotient is a topology on the quotient set. (Contributed by Mario Carneiro, 25-Aug-2015)

Ref Expression
Assertion kqf ⊢ KQ : Top ⟶ Kol2

Proof

Step Hyp Ref Expression
1 ovex ⊢ j qTop x ∈ ⋃ j ⟼ y ∈ j | x ∈ y ∈ V
2 df-kq ⊢ KQ = j ∈ Top ⟼ j qTop x ∈ ⋃ j ⟼ y ∈ j | x ∈ y
3 1 2 fnmpti ⊢ KQ Fn Top
4 kqt0 ⊢ x ∈ Top ↔ KQ ⁡ x ∈ Kol2
5 4 biimpi ⊢ x ∈ Top → KQ ⁡ x ∈ Kol2
6 5 rgen ⊢ ∀ x ∈ Top KQ ⁡ x ∈ Kol2
7 ffnfv ⊢ KQ : Top ⟶ Kol2 ↔ KQ Fn Top ∧ ∀ x ∈ Top KQ ⁡ x ∈ Kol2
8 3 6 7 mpbir2an ⊢ KQ : Top ⟶ Kol2