Metamath Proof Explorer


Theorem pibp16

Description: Property P000016 of pi-base. The class of compact topologies. A space X is compact if every open cover of X has a finite subcover. This theorem is just a relabeled copy of iscmp . (Contributed by ML, 8-Dec-2020)

Ref Expression
Hypothesis pibp16.x
|- X = U. J
Assertion pibp16
|- ( J e. Comp <-> ( J e. Top /\ A. y e. ~P J ( X = U. y -> E. z e. ( ~P y i^i Fin ) X = U. z ) ) )

Proof

Step Hyp Ref Expression
1 pibp16.x
 |-  X = U. J
2 1 iscmp
 |-  ( J e. Comp <-> ( J e. Top /\ A. y e. ~P J ( X = U. y -> E. z e. ( ~P y i^i Fin ) X = U. z ) ) )