Metamath Proof Explorer


Theorem filfinnfr

Description: No filter containing a finite element is free. (Contributed by Jeff Hankins, 5-Dec-2009) (Revised by Stefan O'Rear, 2-Aug-2015)

Ref Expression
Assertion filfinnfr F Fil X S F S Fin F

Proof

Step Hyp Ref Expression
1 filfbas F Fil X F fBas X
2 fbfinnfr F fBas X S F S Fin F
3 1 2 syl3an1 F Fil X S F S Fin F