Metamath Proof Explorer


Definition df-pcmp

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 ) }

Detailed syntax breakdown

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 ) }