Step |
Hyp |
Ref |
Expression |
1 |
|
reu2eqd.1 |
|- ( x = B -> ( ps <-> ch ) ) |
2 |
|
reu2eqd.2 |
|- ( x = C -> ( ps <-> th ) ) |
3 |
|
reu2eqd.3 |
|- ( ph -> E! x e. A ps ) |
4 |
|
reu2eqd.4 |
|- ( ph -> B e. A ) |
5 |
|
reu2eqd.5 |
|- ( ph -> C e. A ) |
6 |
|
reu2eqd.6 |
|- ( ph -> ch ) |
7 |
|
reu2eqd.7 |
|- ( ph -> th ) |
8 |
|
reu2 |
|- ( E! x e. A ps <-> ( E. x e. A ps /\ A. x e. A A. y e. A ( ( ps /\ [ y / x ] ps ) -> x = y ) ) ) |
9 |
3 8
|
sylib |
|- ( ph -> ( E. x e. A ps /\ A. x e. A A. y e. A ( ( ps /\ [ y / x ] ps ) -> x = y ) ) ) |
10 |
9
|
simprd |
|- ( ph -> A. x e. A A. y e. A ( ( ps /\ [ y / x ] ps ) -> x = y ) ) |
11 |
|
nfv |
|- F/ x ch |
12 |
|
nfs1v |
|- F/ x [ y / x ] ps |
13 |
11 12
|
nfan |
|- F/ x ( ch /\ [ y / x ] ps ) |
14 |
|
nfv |
|- F/ x B = y |
15 |
13 14
|
nfim |
|- F/ x ( ( ch /\ [ y / x ] ps ) -> B = y ) |
16 |
|
nfv |
|- F/ y ( ( ch /\ th ) -> B = C ) |
17 |
1
|
anbi1d |
|- ( x = B -> ( ( ps /\ [ y / x ] ps ) <-> ( ch /\ [ y / x ] ps ) ) ) |
18 |
|
eqeq1 |
|- ( x = B -> ( x = y <-> B = y ) ) |
19 |
17 18
|
imbi12d |
|- ( x = B -> ( ( ( ps /\ [ y / x ] ps ) -> x = y ) <-> ( ( ch /\ [ y / x ] ps ) -> B = y ) ) ) |
20 |
|
nfv |
|- F/ x th |
21 |
20 2
|
sbhypf |
|- ( y = C -> ( [ y / x ] ps <-> th ) ) |
22 |
21
|
anbi2d |
|- ( y = C -> ( ( ch /\ [ y / x ] ps ) <-> ( ch /\ th ) ) ) |
23 |
|
eqeq2 |
|- ( y = C -> ( B = y <-> B = C ) ) |
24 |
22 23
|
imbi12d |
|- ( y = C -> ( ( ( ch /\ [ y / x ] ps ) -> B = y ) <-> ( ( ch /\ th ) -> B = C ) ) ) |
25 |
15 16 19 24
|
rspc2 |
|- ( ( B e. A /\ C e. A ) -> ( A. x e. A A. y e. A ( ( ps /\ [ y / x ] ps ) -> x = y ) -> ( ( ch /\ th ) -> B = C ) ) ) |
26 |
4 5 25
|
syl2anc |
|- ( ph -> ( A. x e. A A. y e. A ( ( ps /\ [ y / x ] ps ) -> x = y ) -> ( ( ch /\ th ) -> B = C ) ) ) |
27 |
10 26
|
mpd |
|- ( ph -> ( ( ch /\ th ) -> B = C ) ) |
28 |
6 7 27
|
mp2and |
|- ( ph -> B = C ) |