Metamath Proof Explorer


Theorem hmeofn

Description: The set of homeomorphisms is a function on topologies. (Contributed by Mario Carneiro, 23-Aug-2015)

Ref Expression
Assertion hmeofn ⊢ Homeo Fn Top × Top

Proof

Step Hyp Ref Expression
1 df-hmeo ⊢ Homeo = j ∈ Top , k ∈ Top ⟼ f ∈ j Cn k | f -1 ∈ k Cn j
2 ovex ⊢ j Cn k ∈ V
3 2 rabex ⊢ f ∈ j Cn k | f -1 ∈ k Cn j ∈ V
4 1 3 fnmpoi ⊢ Homeo Fn Top × Top