Description: In a closure system in which directed unions of closed sets are closed, closure commutes with directed unions. (Contributed by Stefan O'Rear, 2-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Hypothesis | acsdrscl.f | |
|
Assertion | isacs4lem | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | acsdrscl.f | |
|
2 | simpll | |
|
3 | elpwi | |
|
4 | 3 | ad2antrl | |
5 | 1 | mrcuni | |
6 | 2 4 5 | syl2anc | |
7 | 1 | mrcf | |
8 | 7 | ffnd | |
9 | 8 | adantr | |
10 | simpll | |
|
11 | simprl | |
|
12 | simprr | |
|
13 | 10 1 11 12 | mrcssd | |
14 | simprr | |
|
15 | 3 | ad2antrl | |
16 | 1 | fvexi | |
17 | 16 | imaex | |
18 | 17 | a1i | |
19 | 9 13 14 15 18 | ipodrsima | |
20 | 19 | adantlr | |
21 | fveq2 | |
|
22 | 21 | eleq1d | |
23 | unieq | |
|
24 | 23 | eleq1d | |
25 | 22 24 | imbi12d | |
26 | simplr | |
|
27 | imassrn | |
|
28 | 7 | frnd | |
29 | 27 28 | sstrid | |
30 | 17 | elpw | |
31 | 29 30 | sylibr | |
32 | 31 | ad2antrr | |
33 | 25 26 32 | rspcdva | |
34 | 20 33 | mpd | |
35 | 1 | mrcid | |
36 | 2 34 35 | syl2anc | |
37 | 6 36 | eqtrd | |
38 | 37 | exp32 | |
39 | 38 | ralrimiv | |
40 | 39 | ex | |
41 | 40 | imdistani | |