Metamath Proof Explorer


Definition df-hcmp

Description: Definition of the Hausdorff completion. In this definition, a structure w is a Hausdorff completion of a uniform structure u if w is a complete uniform space, in which u is dense, and which admits the same uniform structure. Theorem 3 of BourbakiTop1 p. II.21. states the existence and uniqueness of such a completion. (Contributed by Thierry Arnoux, 5-Mar-2018)

Ref Expression
Assertion df-hcmp ⊢ HCmp = u w | u ∈ ⋃ ran ⁡ UnifOn ∧ w ∈ CUnifSp ∧ UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u = u ∧ cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u = Base w

Detailed syntax breakdown

Step Hyp Ref Expression
0 chcmp class HCmp
1 vu setvar u
2 vw setvar w
3 1 cv setvar u
4 cust class UnifOn
5 4 crn class ran ⁡ UnifOn
6 5 cuni class ⋃ ran ⁡ UnifOn
7 3 6 wcel wff u ∈ ⋃ ran ⁡ UnifOn
8 2 cv setvar w
9 ccusp class CUnifSp
10 8 9 wcel wff w ∈ CUnifSp
11 7 10 wa wff u ∈ ⋃ ran ⁡ UnifOn ∧ w ∈ CUnifSp
12 cuss class UnifSt
13 8 12 cfv class UnifSt ⁡ w
14 crest class ↾ 𝑡
15 3 cuni class ⋃ u
16 15 cdm class dom ⁡ ⋃ u
17 13 16 14 co class UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u
18 17 3 wceq wff UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u = u
19 ccl class cls
20 ctopn class TopOpen
21 8 20 cfv class TopOpen ⁡ w
22 21 19 cfv class cls ⁡ TopOpen ⁡ w
23 16 22 cfv class cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u
24 cbs class Base
25 8 24 cfv class Base w
26 23 25 wceq wff cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u = Base w
27 11 18 26 w3a wff u ∈ ⋃ ran ⁡ UnifOn ∧ w ∈ CUnifSp ∧ UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u = u ∧ cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u = Base w
28 27 1 2 copab class u w | u ∈ ⋃ ran ⁡ UnifOn ∧ w ∈ CUnifSp ∧ UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u = u ∧ cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u = Base w
29 0 28 wceq wff HCmp = u w | u ∈ ⋃ ran ⁡ UnifOn ∧ w ∈ CUnifSp ∧ UnifSt ⁡ w ↾ 𝑡 dom ⁡ ⋃ u = u ∧ cls ⁡ TopOpen ⁡ w ⁡ dom ⁡ ⋃ u = Base w