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 |
|