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 e. ( Fil ` X ) /\ S e. F /\ S e. Fin ) -> |^| F =/= (/) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | filfbas | |- ( F e. ( Fil ` X ) -> F e. ( fBas ` X ) ) |
|
| 2 | fbfinnfr | |- ( ( F e. ( fBas ` X ) /\ S e. F /\ S e. Fin ) -> |^| F =/= (/) ) |
|
| 3 | 1 2 | syl3an1 | |- ( ( F e. ( Fil ` X ) /\ S e. F /\ S e. Fin ) -> |^| F =/= (/) ) |