Description: The cumulative hierarchy of a limit ordinal is closed under power set. (Contributed by Raph Levien, 29-May-2004) (Proof shortened by Mario Carneiro, 17-Nov-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | r1pwcl | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | r1elwf | |
|
2 | elfvdm | |
|
3 | 1 2 | jca | |
4 | 3 | a1i | |
5 | r1elwf | |
|
6 | pwwf | |
|
7 | 5 6 | sylibr | |
8 | elfvdm | |
|
9 | 7 8 | jca | |
10 | 9 | a1i | |
11 | limsuc | |
|
12 | 11 | adantr | |
13 | rankpwi | |
|
14 | 13 | ad2antrl | |
15 | 14 | eleq1d | |
16 | 12 15 | bitr4d | |
17 | rankr1ag | |
|
18 | 17 | adantl | |
19 | rankr1ag | |
|
20 | 6 19 | sylanb | |
21 | 20 | adantl | |
22 | 16 18 21 | 3bitr4d | |
23 | 22 | ex | |
24 | 4 10 23 | pm5.21ndd | |