| Step |
Hyp |
Ref |
Expression |
| 1 |
|
upgr1e.v |
|
| 2 |
|
upgr1e.a |
|
| 3 |
|
upgr1e.b |
|
| 4 |
|
upgr1e.c |
|
| 5 |
|
upgr1e.e |
|
| 6 |
|
prex |
|
| 7 |
6
|
snid |
|
| 8 |
7
|
a1i |
|
| 9 |
2 8
|
fsnd |
|
| 10 |
3 4
|
prssd |
|
| 11 |
10 1
|
sseqtrdi |
|
| 12 |
6
|
elpw |
|
| 13 |
11 12
|
sylibr |
|
| 14 |
13 3
|
upgr1elem |
|
| 15 |
9 14
|
fssd |
|
| 16 |
15
|
ffdmd |
|
| 17 |
5
|
dmeqd |
|
| 18 |
5 17
|
feq12d |
|
| 19 |
16 18
|
mpbird |
|
| 20 |
1
|
1vgrex |
|
| 21 |
|
eqid |
|
| 22 |
|
eqid |
|
| 23 |
21 22
|
isupgr |
|
| 24 |
3 20 23
|
3syl |
|
| 25 |
19 24
|
mpbird |
|