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Mirrors > Home > MPE Home > Th. List > df-kq | Structured version Visualization version GIF version |
Description: Define the Kolmogorov quotient. This is a function on topologies which maps a topology to its quotient under the topological distinguishability map, which takes a point to the set of open sets that contain it. Two points are mapped to the same image under this function iff they are topologically indistinguishable. (Contributed by Mario Carneiro, 25-Aug-2015.) |
Ref | Expression |
---|---|
df-kq | ⊢ KQ = (𝑗 ∈ Top ↦ (𝑗 qTop (𝑥 ∈ ∪ 𝑗 ↦ {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦}))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ckq 23196 | . 2 class KQ | |
2 | vj | . . 3 setvar 𝑗 | |
3 | ctop 22394 | . . 3 class Top | |
4 | 2 | cv 1540 | . . . 4 class 𝑗 |
5 | vx | . . . . 5 setvar 𝑥 | |
6 | 4 | cuni 4908 | . . . . 5 class ∪ 𝑗 |
7 | vy | . . . . . . 7 setvar 𝑦 | |
8 | 5, 7 | wel 2107 | . . . . . 6 wff 𝑥 ∈ 𝑦 |
9 | 8, 7, 4 | crab 3432 | . . . . 5 class {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦} |
10 | 5, 6, 9 | cmpt 5231 | . . . 4 class (𝑥 ∈ ∪ 𝑗 ↦ {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦}) |
11 | cqtop 17448 | . . . 4 class qTop | |
12 | 4, 10, 11 | co 7408 | . . 3 class (𝑗 qTop (𝑥 ∈ ∪ 𝑗 ↦ {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦})) |
13 | 2, 3, 12 | cmpt 5231 | . 2 class (𝑗 ∈ Top ↦ (𝑗 qTop (𝑥 ∈ ∪ 𝑗 ↦ {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦}))) |
14 | 1, 13 | wceq 1541 | 1 wff KQ = (𝑗 ∈ Top ↦ (𝑗 qTop (𝑥 ∈ ∪ 𝑗 ↦ {𝑦 ∈ 𝑗 ∣ 𝑥 ∈ 𝑦}))) |
Colors of variables: wff setvar class |
This definition is referenced by: kqval 23229 kqtop 23248 kqf 23250 |
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