Metamath Proof Explorer


Theorem hmeoclda

Description: Homeomorphisms preserve closedness. (Contributed by Jeff Hankins, 3-Jul-2009) (Revised by Mario Carneiro, 3-Jun-2014)

Ref Expression
Assertion hmeoclda ⊢ J ∈ Top ∧ K ∈ Top ∧ F ∈ J Homeo K ∧ S ∈ Clsd ⁡ J → F S ∈ Clsd ⁡ K

Proof

Step Hyp Ref Expression
1 hmeocnvcn ⊢ F ∈ J Homeo K → F -1 ∈ K Cn J
2 1 3ad2ant3 ⊢ J ∈ Top ∧ K ∈ Top ∧ F ∈ J Homeo K → F -1 ∈ K Cn J
3 imacnvcnv ⊢ F -1 -1 S = F S
4 cnclima ⊢ F -1 ∈ K Cn J ∧ S ∈ Clsd ⁡ J → F -1 -1 S ∈ Clsd ⁡ K
5 3 4 eqeltrrid ⊢ F -1 ∈ K Cn J ∧ S ∈ Clsd ⁡ J → F S ∈ Clsd ⁡ K
6 2 5 sylan ⊢ J ∈ Top ∧ K ∈ Top ∧ F ∈ J Homeo K ∧ S ∈ Clsd ⁡ J → F S ∈ Clsd ⁡ K