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 ) ) ) ) |