Description: Equality theorem for ordinal isomorphism. (Contributed by Mario Carneiro, 23-May-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | oieq1 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | weeq1 | |
|
2 | seeq1 | |
|
3 | 1 2 | anbi12d | |
4 | breq | |
|
5 | 4 | ralbidv | |
6 | 5 | rabbidv | |
7 | breq | |
|
8 | 7 | notbid | |
9 | 6 8 | raleqbidv | |
10 | 6 9 | riotaeqbidv | |
11 | 10 | mpteq2dv | |
12 | recseq | |
|
13 | 11 12 | syl | |
14 | 13 | imaeq1d | |
15 | breq | |
|
16 | 14 15 | raleqbidv | |
17 | 16 | rexbidv | |
18 | 17 | rabbidv | |
19 | 13 18 | reseq12d | |
20 | 3 19 | ifbieq1d | |
21 | df-oi | |
|
22 | df-oi | |
|
23 | 20 21 22 | 3eqtr4g | |