Metamath Proof Explorer


Theorem conntop

Description: A connected topology is a topology. (Contributed by FL, 22-Dec-2008) (Revised by Mario Carneiro, 14-Dec-2013)

Ref Expression
Assertion conntop ⊢ J ∈ Conn → J ∈ Top

Proof

Step Hyp Ref Expression
1 eqid ⊢ ⋃ J = ⋃ J
2 1 isconn ⊢ J ∈ Conn ↔ J ∈ Top ∧ J ∩ Clsd ⁡ J = ∅ ⋃ J
3 2 simplbi ⊢ J ∈ Conn → J ∈ Top