Description: Lemma for cnpfcf . If a function is continuous at a point, it respects clustering there. (Contributed by Jeff Hankins, 20-Nov-2009) (Revised by Stefan O'Rear, 9-Aug-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | cnpfcfi | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp2 | |
|
2 | eqid | |
|
3 | 2 | fclsfil | |
4 | 3 | 3ad2ant2 | |
5 | fclsfnflim | |
|
6 | 4 5 | syl | |
7 | 1 6 | mpbid | |
8 | simpl1 | |
|
9 | toptopon2 | |
|
10 | 8 9 | sylib | |
11 | simprl | |
|
12 | eqid | |
|
13 | 2 12 | cnpf | |
14 | 13 | 3ad2ant3 | |
15 | 14 | adantr | |
16 | flfssfcf | |
|
17 | 10 11 15 16 | syl3anc | |
18 | 12 | topopn | |
19 | 8 18 | syl | |
20 | 4 | adantr | |
21 | filfbas | |
|
22 | 20 21 | syl | |
23 | fmfil | |
|
24 | 19 22 15 23 | syl3anc | |
25 | filfbas | |
|
26 | 25 | ad2antrl | |
27 | simprrl | |
|
28 | fmss | |
|
29 | 19 22 26 15 27 28 | syl32anc | |
30 | fclsss2 | |
|
31 | 10 24 29 30 | syl3anc | |
32 | fcfval | |
|
33 | 10 11 15 32 | syl3anc | |
34 | fcfval | |
|
35 | 10 20 15 34 | syl3anc | |
36 | 31 33 35 | 3sstr4d | |
37 | 17 36 | sstrd | |
38 | simprrr | |
|
39 | simpl3 | |
|
40 | cnpflfi | |
|
41 | 38 39 40 | syl2anc | |
42 | 37 41 | sseldd | |
43 | 7 42 | rexlimddv | |