Step |
Hyp |
Ref |
Expression |
1 |
|
axdc3.1 |
|
2 |
|
feq1 |
|
3 |
|
fveq1 |
|
4 |
3
|
eqeq1d |
|
5 |
|
fveq1 |
|
6 |
|
fveq1 |
|
7 |
6
|
fveq2d |
|
8 |
5 7
|
eleq12d |
|
9 |
8
|
ralbidv |
|
10 |
|
suceq |
|
11 |
10
|
fveq2d |
|
12 |
|
2fveq3 |
|
13 |
11 12
|
eleq12d |
|
14 |
13
|
cbvralvw |
|
15 |
9 14
|
bitrdi |
|
16 |
2 4 15
|
3anbi123d |
|
17 |
16
|
rexbidv |
|
18 |
17
|
cbvabv |
|
19 |
|
eqid |
|
20 |
1 18 19
|
axdc3lem4 |
|