Metamath Proof Explorer


Theorem hmphtop

Description: Reverse closure for the homeomorphic predicate. (Contributed by Mario Carneiro, 22-Aug-2015)

Ref Expression
Assertion hmphtop ( 𝐽 ≃ 𝐾 → ( 𝐽 ∈ Top ∧ 𝐾 ∈ Top ) )

Proof

Step Hyp Ref Expression
1 df-hmph ⊢ ≃ = ( ◡ Homeo “ ( V ∖ 1o ) )
2 cnvimass ⊢ ( ◡ Homeo “ ( V ∖ 1o ) ) ⊆ dom Homeo
3 hmeofn ⊢ Homeo Fn ( Top × Top )
4 fndm ⊢ ( Homeo Fn ( Top × Top ) → dom Homeo = ( Top × Top ) )
5 3 4 ax-mp ⊢ dom Homeo = ( Top × Top )
6 2 5 sseqtri ⊢ ( ◡ Homeo “ ( V ∖ 1o ) ) ⊆ ( Top × Top )
7 1 6 eqsstri ⊢ ≃ ⊆ ( Top × Top )
8 7 brel ⊢ ( 𝐽 ≃ 𝐾 → ( 𝐽 ∈ Top ∧ 𝐾 ∈ Top ) )