Description: The closure of the union of any pair is equal to the union of closures if and only if the union of any pair belonging to the convergents of a point if equivalent to at least one of the pain belonging to the convergents of that point. (Contributed by RP, 19-Jun-2021)
Ref | Expression | ||
---|---|---|---|
Hypotheses | ntrnei.o | |
|
ntrnei.f | |
||
ntrnei.r | |
||
Assertion | ntrneix13 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ntrnei.o | |
|
2 | ntrnei.f | |
|
3 | ntrnei.r | |
|
4 | dfss3 | |
|
5 | 1 2 3 | ntrneiiex | |
6 | 5 | ad2antrr | |
7 | elmapi | |
|
8 | 6 7 | syl | |
9 | 1 2 3 | ntrneibex | |
10 | 9 | ad2antrr | |
11 | simplr | |
|
12 | 11 | elpwid | |
13 | simpr | |
|
14 | 13 | elpwid | |
15 | 12 14 | unssd | |
16 | 10 15 | sselpwd | |
17 | 8 16 | ffvelcdmd | |
18 | 17 | elpwid | |
19 | ralss | |
|
20 | 18 19 | syl | |
21 | 4 20 | bitrid | |
22 | dfss3 | |
|
23 | 8 11 | ffvelcdmd | |
24 | 23 | elpwid | |
25 | 8 13 | ffvelcdmd | |
26 | 25 | elpwid | |
27 | 24 26 | unssd | |
28 | ralss | |
|
29 | 27 28 | syl | |
30 | 22 29 | bitrid | |
31 | 21 30 | anbi12d | |
32 | eqss | |
|
33 | ralbiim | |
|
34 | 31 32 33 | 3bitr4g | |
35 | 3 | ad3antrrr | |
36 | simpr | |
|
37 | 9 | ad3antrrr | |
38 | simpllr | |
|
39 | 38 | elpwid | |
40 | simplr | |
|
41 | 40 | elpwid | |
42 | 39 41 | unssd | |
43 | 37 42 | sselpwd | |
44 | 1 2 35 36 43 | ntrneiel | |
45 | elun | |
|
46 | 1 2 35 36 38 | ntrneiel | |
47 | 1 2 35 36 40 | ntrneiel | |
48 | 46 47 | orbi12d | |
49 | 45 48 | bitrid | |
50 | 44 49 | bibi12d | |
51 | 50 | ralbidva | |
52 | 34 51 | bitrd | |
53 | 52 | ralbidva | |
54 | ralcom | |
|
55 | 53 54 | bitrdi | |
56 | 55 | ralbidva | |
57 | ralcom | |
|
58 | 56 57 | bitrdi | |