Description: The unit interval is compact. (Contributed by Jeff Madsen, 2-Sep-2009) (Revised by Mario Carneiro, 13-Jun-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | iicmp | ⊢ II ∈ Comp |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0re | ⊢ 0 ∈ ℝ | |
2 | 1re | ⊢ 1 ∈ ℝ | |
3 | eqid | ⊢ ( topGen ‘ ran (,) ) = ( topGen ‘ ran (,) ) | |
4 | dfii2 | ⊢ II = ( ( topGen ‘ ran (,) ) ↾t ( 0 [,] 1 ) ) | |
5 | 3 4 | icccmp | ⊢ ( ( 0 ∈ ℝ ∧ 1 ∈ ℝ ) → II ∈ Comp ) |
6 | 1 2 5 | mp2an | ⊢ II ∈ Comp |