Metamath Proof Explorer


Theorem xrconn

Description: The topology of the extended reals is connected. (Contributed by Mario Carneiro, 9-Sep-2015)

Ref Expression
Assertion xrconn ( ordTop ‘ ≤ ) ∈ Conn

Proof

Step Hyp Ref Expression
1 xrhmph II ≃ ( ordTop ‘ ≤ )
2 iiconn II ∈ Conn
3 connhmph ( II ≃ ( ordTop ‘ ≤ ) → ( II ∈ Conn → ( ordTop ‘ ≤ ) ∈ Conn ) )
4 1 2 3 mp2 ( ordTop ‘ ≤ ) ∈ Conn