Description: Define the unit interval with the Euclidean topology. (Contributed by Jeff Madsen, 2-Sep-2009) (Revised by Mario Carneiro, 3-Sep-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | df-ii | ⊢ II = ( MetOpen ‘ ( ( abs ∘ − ) ↾ ( ( 0 [,] 1 ) × ( 0 [,] 1 ) ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 0 | cii | ⊢ II | |
| 1 | cmopn | ⊢ MetOpen | |
| 2 | cabs | ⊢ abs | |
| 3 | cmin | ⊢ − | |
| 4 | 2 3 | ccom | ⊢ ( abs ∘ − ) |
| 5 | cc0 | ⊢ 0 | |
| 6 | cicc | ⊢ [,] | |
| 7 | c1 | ⊢ 1 | |
| 8 | 5 7 6 | co | ⊢ ( 0 [,] 1 ) |
| 9 | 8 8 | cxp | ⊢ ( ( 0 [,] 1 ) × ( 0 [,] 1 ) ) |
| 10 | 4 9 | cres | ⊢ ( ( abs ∘ − ) ↾ ( ( 0 [,] 1 ) × ( 0 [,] 1 ) ) ) |
| 11 | 10 1 | cfv | ⊢ ( MetOpen ‘ ( ( abs ∘ − ) ↾ ( ( 0 [,] 1 ) × ( 0 [,] 1 ) ) ) ) |
| 12 | 0 11 | wceq | ⊢ II = ( MetOpen ‘ ( ( abs ∘ − ) ↾ ( ( 0 [,] 1 ) × ( 0 [,] 1 ) ) ) ) |