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 = { 𝑗𝑗 ∈ 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 ∈ CovHasRef ( LocFin ‘ 𝑗 )
7 6 1 cab { 𝑗𝑗 ∈ CovHasRef ( LocFin ‘ 𝑗 ) }
8 0 7 wceq Paracomp = { 𝑗𝑗 ∈ CovHasRef ( LocFin ‘ 𝑗 ) }