Description: The limit of all preimage maps by the "less than or equal to" relation is the universe. (Contributed by Thierry Arnoux, 12-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypotheses | dstfrv.1 | |
|
dstfrv.2 | |
||
Assertion | dstfrvunirn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dstfrv.1 | |
|
2 | dstfrv.2 | |
|
3 | 1red | |
|
4 | 1 2 | rrvvf | |
5 | 4 | ffvelcdmda | |
6 | 3 5 | ifcld | |
7 | breq2 | |
|
8 | breq2 | |
|
9 | 1le1 | |
|
10 | 9 | a1i | |
11 | 3 5 | lenltd | |
12 | 11 | biimpar | |
13 | 7 8 10 12 | ifbothda | |
14 | flge1nn | |
|
15 | 6 13 14 | syl2anc | |
16 | 15 | peano2nnd | |
17 | 1 | adantr | |
18 | 2 | adantr | |
19 | 16 | nnred | |
20 | simpr | |
|
21 | breq2 | |
|
22 | breq2 | |
|
23 | 5 | adantr | |
24 | 1red | |
|
25 | simpr | |
|
26 | 23 24 25 | ltled | |
27 | 5 | leidd | |
28 | 27 | adantr | |
29 | 21 22 26 28 | ifbothda | |
30 | fllep1 | |
|
31 | 6 30 | syl | |
32 | 5 6 19 29 31 | letrd | |
33 | 17 18 19 20 32 | dstfrvel | |
34 | oveq2 | |
|
35 | 34 | eleq2d | |
36 | 35 | rspcev | |
37 | 16 33 36 | syl2anc | |
38 | 37 | ex | |
39 | 1 | adantr | |
40 | 2 | adantr | |
41 | simpr | |
|
42 | 41 | nnred | |
43 | 39 40 42 | orvclteel | |
44 | elunii | |
|
45 | 44 | expcom | |
46 | 43 45 | syl | |
47 | 46 | rexlimdva | |
48 | 38 47 | impbid | |
49 | eliun | |
|
50 | 48 49 | bitr4di | |
51 | 50 | eqrdv | |
52 | ovex | |
|
53 | 52 | dfiun3 | |
54 | 51 53 | eqtr2di | |