Description: Rewrite df-oi with abbreviations. (Contributed by Mario Carneiro, 24-Jun-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | dfoi.1 | |
|
dfoi.2 | |
||
dfoi.3 | |
||
Assertion | dfoi | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfoi.1 | |
|
2 | dfoi.2 | |
|
3 | dfoi.3 | |
|
4 | df-oi | |
|
5 | 1 | a1i | |
6 | 5 | raleqdv | |
7 | 5 6 | riotaeqbidv | |
8 | 7 | mpteq2ia | |
9 | 2 8 | eqtri | |
10 | recseq | |
|
11 | 9 10 | ax-mp | |
12 | 3 11 | eqtri | |
13 | 12 | imaeq1i | |
14 | 13 | raleqi | |
15 | 14 | rexbii | |
16 | 15 | rabbii | |
17 | 12 16 | reseq12i | |
18 | ifeq1 | |
|
19 | 17 18 | ax-mp | |
20 | 4 19 | eqtr4i | |