| Step |
Hyp |
Ref |
Expression |
| 1 |
|
axc16i.1 |
|- ( x = z -> ( ph <-> ps ) ) |
| 2 |
|
axc16i.2 |
|- ( ps -> A. x ps ) |
| 3 |
|
nfv |
|- F/ z x = y |
| 4 |
|
nfv |
|- F/ x z = y |
| 5 |
|
ax7 |
|- ( x = z -> ( x = y -> z = y ) ) |
| 6 |
3 4 5
|
cbv3 |
|- ( A. x x = y -> A. z z = y ) |
| 7 |
|
ax7 |
|- ( z = x -> ( z = y -> x = y ) ) |
| 8 |
7
|
spimvw |
|- ( A. z z = y -> x = y ) |
| 9 |
|
equcomi |
|- ( x = y -> y = x ) |
| 10 |
|
equcomi |
|- ( z = y -> y = z ) |
| 11 |
|
ax7 |
|- ( y = z -> ( y = x -> z = x ) ) |
| 12 |
10 11
|
syl |
|- ( z = y -> ( y = x -> z = x ) ) |
| 13 |
9 12
|
syl5com |
|- ( x = y -> ( z = y -> z = x ) ) |
| 14 |
13
|
alimdv |
|- ( x = y -> ( A. z z = y -> A. z z = x ) ) |
| 15 |
8 14
|
mpcom |
|- ( A. z z = y -> A. z z = x ) |
| 16 |
|
equcomi |
|- ( z = x -> x = z ) |
| 17 |
16
|
alimi |
|- ( A. z z = x -> A. z x = z ) |
| 18 |
15 17
|
syl |
|- ( A. z z = y -> A. z x = z ) |
| 19 |
1
|
biimpcd |
|- ( ph -> ( x = z -> ps ) ) |
| 20 |
19
|
alimdv |
|- ( ph -> ( A. z x = z -> A. z ps ) ) |
| 21 |
2
|
nf5i |
|- F/ x ps |
| 22 |
|
nfv |
|- F/ z ph |
| 23 |
1
|
biimprd |
|- ( x = z -> ( ps -> ph ) ) |
| 24 |
16 23
|
syl |
|- ( z = x -> ( ps -> ph ) ) |
| 25 |
21 22 24
|
cbv3 |
|- ( A. z ps -> A. x ph ) |
| 26 |
20 25
|
syl6com |
|- ( A. z x = z -> ( ph -> A. x ph ) ) |
| 27 |
6 18 26
|
3syl |
|- ( A. x x = y -> ( ph -> A. x ph ) ) |