Description: The topology of the extended reals is connected. (Contributed by Mario Carneiro, 9-Sep-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | xrconn | ⊢ ( ordTop ‘ ≤ ) ∈ Conn |
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 |