| Step |
Hyp |
Ref |
Expression |
| 1 |
|
elex |
|
| 2 |
1
|
adantr |
|
| 3 |
|
elex |
|
| 4 |
3
|
adantl |
|
| 5 |
|
funmpt |
|
| 6 |
5
|
a1i |
|
| 7 |
|
dftpos4 |
|
| 8 |
|
tposexg |
|
| 9 |
8
|
adantr |
|
| 10 |
7 9
|
eqeltrrid |
|
| 11 |
|
dftpos4 |
|
| 12 |
|
tposexg |
|
| 13 |
12
|
adantl |
|
| 14 |
11 13
|
eqeltrrid |
|
| 15 |
|
ofco2 |
|
| 16 |
2 4 6 10 14 15
|
syl23anc |
|
| 17 |
|
dftpos4 |
|
| 18 |
7 11
|
oveq12i |
|
| 19 |
16 17 18
|
3eqtr4g |
|