Theorem funtopon

Description: The class TopOn is a function. (Contributed by BJ, 29-Apr-2021)

	Ref	Expression
Assertion	funtopon	⊢ Fun TopOn

Proof

Step	Hyp	Ref	Expression
1		df-topon	⊢ TopOn = ( 𝑦 ∈ V ↦ { 𝑥 ∈ Top ∣ 𝑦 = ∪ 𝑥 } )
2	1	funmpt2	⊢ Fun TopOn