Metamath Proof Explorer


Theorem hmphref

Description: "Is homeomorphic to" is reflexive. (Contributed by FL, 25-Feb-2007) (Proof shortened by Mario Carneiro, 23-Aug-2015)

Ref Expression
Assertion hmphref ⊢ J ∈ Top → J ≃ J

Proof

Step Hyp Ref Expression
1 toptopon2 ⊢ J ∈ Top ↔ J ∈ TopOn ⁡ ⋃ J
2 idhmeo ⊢ J ∈ TopOn ⁡ ⋃ J → I ↾ ⋃ J ∈ J Homeo J
3 1 2 sylbi ⊢ J ∈ Top → I ↾ ⋃ J ∈ J Homeo J
4 hmphi ⊢ I ↾ ⋃ J ∈ J Homeo J → J ≃ J
5 3 4 syl ⊢ J ∈ Top → J ≃ J