Description: A cluster point of a filter. (Contributed by Mario Carneiro, 26-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | isfcls2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | topontop | |
|
2 | toponuni | |
|
3 | 2 | fveq2d | |
4 | 3 | eleq2d | |
5 | 4 | biimpa | |
6 | eqid | |
|
7 | 6 | isfcls | |
8 | df-3an | |
|
9 | 7 8 | bitri | |
10 | 9 | baib | |
11 | 1 5 10 | syl2an2r | |