| Step |
Hyp |
Ref |
Expression |
| 1 |
|
f1opw2.1 |
|- ( ph -> F : A -1-1-onto-> B ) |
| 2 |
|
f1opw2.2 |
|- ( ph -> ( `' F " a ) e. _V ) |
| 3 |
|
f1opw2.3 |
|- ( ph -> ( F " b ) e. _V ) |
| 4 |
|
eqid |
|- ( b e. ~P A |-> ( F " b ) ) = ( b e. ~P A |-> ( F " b ) ) |
| 5 |
|
imassrn |
|- ( F " b ) C_ ran F |
| 6 |
|
f1ofo |
|- ( F : A -1-1-onto-> B -> F : A -onto-> B ) |
| 7 |
1 6
|
syl |
|- ( ph -> F : A -onto-> B ) |
| 8 |
|
forn |
|- ( F : A -onto-> B -> ran F = B ) |
| 9 |
7 8
|
syl |
|- ( ph -> ran F = B ) |
| 10 |
5 9
|
sseqtrid |
|- ( ph -> ( F " b ) C_ B ) |
| 11 |
3 10
|
elpwd |
|- ( ph -> ( F " b ) e. ~P B ) |
| 12 |
11
|
adantr |
|- ( ( ph /\ b e. ~P A ) -> ( F " b ) e. ~P B ) |
| 13 |
|
imassrn |
|- ( `' F " a ) C_ ran `' F |
| 14 |
|
dfdm4 |
|- dom F = ran `' F |
| 15 |
|
f1odm |
|- ( F : A -1-1-onto-> B -> dom F = A ) |
| 16 |
1 15
|
syl |
|- ( ph -> dom F = A ) |
| 17 |
14 16
|
eqtr3id |
|- ( ph -> ran `' F = A ) |
| 18 |
13 17
|
sseqtrid |
|- ( ph -> ( `' F " a ) C_ A ) |
| 19 |
2 18
|
elpwd |
|- ( ph -> ( `' F " a ) e. ~P A ) |
| 20 |
19
|
adantr |
|- ( ( ph /\ a e. ~P B ) -> ( `' F " a ) e. ~P A ) |
| 21 |
|
elpwi |
|- ( a e. ~P B -> a C_ B ) |
| 22 |
21
|
adantl |
|- ( ( b e. ~P A /\ a e. ~P B ) -> a C_ B ) |
| 23 |
|
foimacnv |
|- ( ( F : A -onto-> B /\ a C_ B ) -> ( F " ( `' F " a ) ) = a ) |
| 24 |
7 22 23
|
syl2an |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> ( F " ( `' F " a ) ) = a ) |
| 25 |
24
|
eqcomd |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> a = ( F " ( `' F " a ) ) ) |
| 26 |
|
imaeq2 |
|- ( b = ( `' F " a ) -> ( F " b ) = ( F " ( `' F " a ) ) ) |
| 27 |
26
|
eqeq2d |
|- ( b = ( `' F " a ) -> ( a = ( F " b ) <-> a = ( F " ( `' F " a ) ) ) ) |
| 28 |
25 27
|
syl5ibrcom |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> ( b = ( `' F " a ) -> a = ( F " b ) ) ) |
| 29 |
|
f1of1 |
|- ( F : A -1-1-onto-> B -> F : A -1-1-> B ) |
| 30 |
1 29
|
syl |
|- ( ph -> F : A -1-1-> B ) |
| 31 |
|
elpwi |
|- ( b e. ~P A -> b C_ A ) |
| 32 |
31
|
adantr |
|- ( ( b e. ~P A /\ a e. ~P B ) -> b C_ A ) |
| 33 |
|
f1imacnv |
|- ( ( F : A -1-1-> B /\ b C_ A ) -> ( `' F " ( F " b ) ) = b ) |
| 34 |
30 32 33
|
syl2an |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> ( `' F " ( F " b ) ) = b ) |
| 35 |
34
|
eqcomd |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> b = ( `' F " ( F " b ) ) ) |
| 36 |
|
imaeq2 |
|- ( a = ( F " b ) -> ( `' F " a ) = ( `' F " ( F " b ) ) ) |
| 37 |
36
|
eqeq2d |
|- ( a = ( F " b ) -> ( b = ( `' F " a ) <-> b = ( `' F " ( F " b ) ) ) ) |
| 38 |
35 37
|
syl5ibrcom |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> ( a = ( F " b ) -> b = ( `' F " a ) ) ) |
| 39 |
28 38
|
impbid |
|- ( ( ph /\ ( b e. ~P A /\ a e. ~P B ) ) -> ( b = ( `' F " a ) <-> a = ( F " b ) ) ) |
| 40 |
4 12 20 39
|
f1o2d |
|- ( ph -> ( b e. ~P A |-> ( F " b ) ) : ~P A -1-1-onto-> ~P B ) |