Step |
Hyp |
Ref |
Expression |
1 |
|
bnj864.1 |
|- ( ph <-> ( f ` (/) ) = _pred ( X , A , R ) ) |
2 |
|
bnj864.2 |
|- ( ps <-> A. i e. _om ( suc i e. n -> ( f ` suc i ) = U_ y e. ( f ` i ) _pred ( y , A , R ) ) ) |
3 |
|
bnj864.3 |
|- D = ( _om \ { (/) } ) |
4 |
|
bnj864.4 |
|- ( ch <-> ( R _FrSe A /\ X e. A /\ n e. D ) ) |
5 |
|
bnj864.5 |
|- ( th <-> ( f Fn n /\ ph /\ ps ) ) |
6 |
1 2 3
|
bnj852 |
|- ( ( R _FrSe A /\ X e. A ) -> A. n e. D E! f ( f Fn n /\ ph /\ ps ) ) |
7 |
|
df-ral |
|- ( A. n e. D E! f ( f Fn n /\ ph /\ ps ) <-> A. n ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) |
8 |
7
|
imbi2i |
|- ( ( ( R _FrSe A /\ X e. A ) -> A. n e. D E! f ( f Fn n /\ ph /\ ps ) ) <-> ( ( R _FrSe A /\ X e. A ) -> A. n ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) ) |
9 |
|
19.21v |
|- ( A. n ( ( R _FrSe A /\ X e. A ) -> ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) <-> ( ( R _FrSe A /\ X e. A ) -> A. n ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) ) |
10 |
|
impexp |
|- ( ( ( ( R _FrSe A /\ X e. A ) /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) <-> ( ( R _FrSe A /\ X e. A ) -> ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) ) |
11 |
|
df-3an |
|- ( ( R _FrSe A /\ X e. A /\ n e. D ) <-> ( ( R _FrSe A /\ X e. A ) /\ n e. D ) ) |
12 |
11
|
bicomi |
|- ( ( ( R _FrSe A /\ X e. A ) /\ n e. D ) <-> ( R _FrSe A /\ X e. A /\ n e. D ) ) |
13 |
12
|
imbi1i |
|- ( ( ( ( R _FrSe A /\ X e. A ) /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) <-> ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) ) |
14 |
10 13
|
bitr3i |
|- ( ( ( R _FrSe A /\ X e. A ) -> ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) <-> ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) ) |
15 |
14
|
albii |
|- ( A. n ( ( R _FrSe A /\ X e. A ) -> ( n e. D -> E! f ( f Fn n /\ ph /\ ps ) ) ) <-> A. n ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) ) |
16 |
8 9 15
|
3bitr2i |
|- ( ( ( R _FrSe A /\ X e. A ) -> A. n e. D E! f ( f Fn n /\ ph /\ ps ) ) <-> A. n ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) ) |
17 |
6 16
|
mpbi |
|- A. n ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) |
18 |
17
|
spi |
|- ( ( R _FrSe A /\ X e. A /\ n e. D ) -> E! f ( f Fn n /\ ph /\ ps ) ) |
19 |
5
|
eubii |
|- ( E! f th <-> E! f ( f Fn n /\ ph /\ ps ) ) |
20 |
18 4 19
|
3imtr4i |
|- ( ch -> E! f th ) |