Metamath Proof Explorer


Theorem hmpher

Description: "Is homeomorphic to" is an equivalence relation. (Contributed by FL, 22-Mar-2007) (Revised by Mario Carneiro, 23-Aug-2015)

Ref Expression
Assertion hmpher ⊢ ≃ Er Top

Proof

Step Hyp Ref Expression
1 df-hmph ⊢ ≃ = Homeo -1 V ∖ 1 𝑜
2 cnvimass ⊢ Homeo -1 V ∖ 1 𝑜 ⊆ dom ⁡ Homeo
3 hmeofn ⊢ Homeo Fn Top × Top
4 3 fndmi ⊢ dom ⁡ Homeo = Top × Top
5 2 4 sseqtri ⊢ Homeo -1 V ∖ 1 𝑜 ⊆ Top × Top
6 1 5 eqsstri ⊢ ≃ ⊆ Top × Top
7 relxp ⊢ Rel ⁡ Top × Top
8 relss ⊢ ≃ ⊆ Top × Top → Rel ⁡ Top × Top → Rel ⁡ ≃
9 6 7 8 mp2 ⊢ Rel ⁡ ≃
10 hmphsym ⊢ x ≃ y → y ≃ x
11 hmphtr ⊢ x ≃ y ∧ y ≃ z → x ≃ z
12 hmphref ⊢ x ∈ Top → x ≃ x
13 hmphtop1 ⊢ x ≃ x → x ∈ Top
14 12 13 impbii ⊢ x ∈ Top ↔ x ≃ x
15 9 10 11 14 iseri ⊢ ≃ Er Top