Step |
Hyp |
Ref |
Expression |
1 |
|
elex |
|- ( A e. V -> A e. _V ) |
2 |
|
issetft |
|- ( F/_ x A -> ( A e. _V <-> E. x x = A ) ) |
3 |
1 2
|
imbitrid |
|- ( F/_ x A -> ( A e. V -> E. x x = A ) ) |
4 |
3
|
ad2antrr |
|- ( ( ( F/_ x A /\ F/ x ps ) /\ ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) ) -> ( A e. V -> E. x x = A ) ) |
5 |
4
|
3impia |
|- ( ( ( F/_ x A /\ F/ x ps ) /\ ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) /\ A e. V ) -> E. x x = A ) |
6 |
|
biimp |
|- ( ( ph <-> ps ) -> ( ph -> ps ) ) |
7 |
6
|
imim2i |
|- ( ( x = A -> ( ph <-> ps ) ) -> ( x = A -> ( ph -> ps ) ) ) |
8 |
7
|
com23 |
|- ( ( x = A -> ( ph <-> ps ) ) -> ( ph -> ( x = A -> ps ) ) ) |
9 |
8
|
imp |
|- ( ( ( x = A -> ( ph <-> ps ) ) /\ ph ) -> ( x = A -> ps ) ) |
10 |
9
|
alanimi |
|- ( ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) -> A. x ( x = A -> ps ) ) |
11 |
|
19.23t |
|- ( F/ x ps -> ( A. x ( x = A -> ps ) <-> ( E. x x = A -> ps ) ) ) |
12 |
11
|
adantl |
|- ( ( F/_ x A /\ F/ x ps ) -> ( A. x ( x = A -> ps ) <-> ( E. x x = A -> ps ) ) ) |
13 |
10 12
|
imbitrid |
|- ( ( F/_ x A /\ F/ x ps ) -> ( ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) -> ( E. x x = A -> ps ) ) ) |
14 |
13
|
imp |
|- ( ( ( F/_ x A /\ F/ x ps ) /\ ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) ) -> ( E. x x = A -> ps ) ) |
15 |
14
|
3adant3 |
|- ( ( ( F/_ x A /\ F/ x ps ) /\ ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) /\ A e. V ) -> ( E. x x = A -> ps ) ) |
16 |
5 15
|
mpd |
|- ( ( ( F/_ x A /\ F/ x ps ) /\ ( A. x ( x = A -> ( ph <-> ps ) ) /\ A. x ph ) /\ A e. V ) -> ps ) |