| Step |
Hyp |
Ref |
Expression |
| 1 |
|
ax-his2 |
|
| 2 |
1
|
fveq2d |
|
| 3 |
|
hicl |
|
| 4 |
|
hicl |
|
| 5 |
|
cjadd |
|
| 6 |
3 4 5
|
syl2an |
|
| 7 |
6
|
3impdir |
|
| 8 |
2 7
|
eqtrd |
|
| 9 |
8
|
3comr |
|
| 10 |
|
hvaddcl |
|
| 11 |
|
ax-his1 |
|
| 12 |
10 11
|
sylan2 |
|
| 13 |
12
|
3impb |
|
| 14 |
|
ax-his1 |
|
| 15 |
14
|
3adant3 |
|
| 16 |
|
ax-his1 |
|
| 17 |
16
|
3adant2 |
|
| 18 |
15 17
|
oveq12d |
|
| 19 |
9 13 18
|
3eqtr4d |
|