Metamath Proof Explorer


Theorem uffcfflf

Description: If the domain filter is an ultrafilter, the cluster points of the function are the limit points. (Contributed by Jeff Hankins, 12-Dec-2009) (Revised by Stefan O'Rear, 9-Aug-2015)

Ref Expression
Assertion uffcfflf J TopOn X L UFil Y F : Y X J fClusf L F = J fLimf L F

Proof

Step Hyp Ref Expression
1 toponmax J TopOn X X J
2 fmufil X J L UFil Y F : Y X X FilMap F L UFil X
3 1 2 syl3an1 J TopOn X L UFil Y F : Y X X FilMap F L UFil X
4 uffclsflim X FilMap F L UFil X J fClus X FilMap F L = J fLim X FilMap F L
5 3 4 syl J TopOn X L UFil Y F : Y X J fClus X FilMap F L = J fLim X FilMap F L
6 ufilfil L UFil Y L Fil Y
7 fcfval J TopOn X L Fil Y F : Y X J fClusf L F = J fClus X FilMap F L
8 6 7 syl3an2 J TopOn X L UFil Y F : Y X J fClusf L F = J fClus X FilMap F L
9 flfval J TopOn X L Fil Y F : Y X J fLimf L F = J fLim X FilMap F L
10 6 9 syl3an2 J TopOn X L UFil Y F : Y X J fLimf L F = J fLim X FilMap F L
11 5 8 10 3eqtr4d J TopOn X L UFil Y F : Y X J fClusf L F = J fLimf L F