Description: Definition of a paracompact topology. A topology is said to be paracompact iff every open cover has an open refinement that is locally finite. The definition 6 of BourbakiTop1 p. I.69. also requires the topology to be Hausdorff, but this is dropped here. (Contributed by Thierry Arnoux, 7-Jan-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | df-pcmp | |- Paracomp = { j | j e. CovHasRef ( LocFin ` j ) } |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cpcmp | |- Paracomp |
|
1 | vj | |- j |
|
2 | 1 | cv | |- j |
3 | clocfin | |- LocFin |
|
4 | 2 3 | cfv | |- ( LocFin ` j ) |
5 | 4 | ccref | |- CovHasRef ( LocFin ` j ) |
6 | 2 5 | wcel | |- j e. CovHasRef ( LocFin ` j ) |
7 | 6 1 | cab | |- { j | j e. CovHasRef ( LocFin ` j ) } |
8 | 0 7 | wceq | |- Paracomp = { j | j e. CovHasRef ( LocFin ` j ) } |