Metamath Proof Explorer


Theorem fmfil

Description: A mapping filter is a filter. (Contributed by Jeff Hankins, 18-Sep-2009) (Revised by Stefan O'Rear, 6-Aug-2015)

Ref Expression
Assertion fmfil XABfBasYF:YXXFilMapFBFilX

Proof

Step Hyp Ref Expression
1 fmval XABfBasYF:YXXFilMapFB=XfilGenranyBFy
2 eqid ranyBFy=ranyBFy
3 2 fbasrn BfBasYF:YXXAranyBFyfBasX
4 3 3comr XABfBasYF:YXranyBFyfBasX
5 fgcl ranyBFyfBasXXfilGenranyBFyFilX
6 4 5 syl XABfBasYF:YXXfilGenranyBFyFilX
7 1 6 eqeltrd XABfBasYF:YXXFilMapFBFilX