| Step |
Hyp |
Ref |
Expression |
| 1 |
|
phplem2OLD.1 |
|- A e. _V |
| 2 |
|
phplem2OLD.2 |
|- B e. _V |
| 3 |
|
bren |
|- ( suc A ~~ suc B <-> E. f f : suc A -1-1-onto-> suc B ) |
| 4 |
|
f1of1 |
|- ( f : suc A -1-1-onto-> suc B -> f : suc A -1-1-> suc B ) |
| 5 |
4
|
adantl |
|- ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) -> f : suc A -1-1-> suc B ) |
| 6 |
2
|
sucex |
|- suc B e. _V |
| 7 |
|
sssucid |
|- A C_ suc A |
| 8 |
|
f1imaen2g |
|- ( ( ( f : suc A -1-1-> suc B /\ suc B e. _V ) /\ ( A C_ suc A /\ A e. _V ) ) -> ( f " A ) ~~ A ) |
| 9 |
7 1 8
|
mpanr12 |
|- ( ( f : suc A -1-1-> suc B /\ suc B e. _V ) -> ( f " A ) ~~ A ) |
| 10 |
5 6 9
|
sylancl |
|- ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) -> ( f " A ) ~~ A ) |
| 11 |
10
|
ensymd |
|- ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) -> A ~~ ( f " A ) ) |
| 12 |
|
nnord |
|- ( A e. _om -> Ord A ) |
| 13 |
|
orddif |
|- ( Ord A -> A = ( suc A \ { A } ) ) |
| 14 |
12 13
|
syl |
|- ( A e. _om -> A = ( suc A \ { A } ) ) |
| 15 |
14
|
imaeq2d |
|- ( A e. _om -> ( f " A ) = ( f " ( suc A \ { A } ) ) ) |
| 16 |
|
f1ofn |
|- ( f : suc A -1-1-onto-> suc B -> f Fn suc A ) |
| 17 |
1
|
sucid |
|- A e. suc A |
| 18 |
|
fnsnfv |
|- ( ( f Fn suc A /\ A e. suc A ) -> { ( f ` A ) } = ( f " { A } ) ) |
| 19 |
16 17 18
|
sylancl |
|- ( f : suc A -1-1-onto-> suc B -> { ( f ` A ) } = ( f " { A } ) ) |
| 20 |
19
|
difeq2d |
|- ( f : suc A -1-1-onto-> suc B -> ( ( f " suc A ) \ { ( f ` A ) } ) = ( ( f " suc A ) \ ( f " { A } ) ) ) |
| 21 |
|
imadmrn |
|- ( f " dom f ) = ran f |
| 22 |
21
|
eqcomi |
|- ran f = ( f " dom f ) |
| 23 |
|
f1ofo |
|- ( f : suc A -1-1-onto-> suc B -> f : suc A -onto-> suc B ) |
| 24 |
|
forn |
|- ( f : suc A -onto-> suc B -> ran f = suc B ) |
| 25 |
23 24
|
syl |
|- ( f : suc A -1-1-onto-> suc B -> ran f = suc B ) |
| 26 |
|
f1odm |
|- ( f : suc A -1-1-onto-> suc B -> dom f = suc A ) |
| 27 |
26
|
imaeq2d |
|- ( f : suc A -1-1-onto-> suc B -> ( f " dom f ) = ( f " suc A ) ) |
| 28 |
22 25 27
|
3eqtr3a |
|- ( f : suc A -1-1-onto-> suc B -> suc B = ( f " suc A ) ) |
| 29 |
28
|
difeq1d |
|- ( f : suc A -1-1-onto-> suc B -> ( suc B \ { ( f ` A ) } ) = ( ( f " suc A ) \ { ( f ` A ) } ) ) |
| 30 |
|
dff1o3 |
|- ( f : suc A -1-1-onto-> suc B <-> ( f : suc A -onto-> suc B /\ Fun `' f ) ) |
| 31 |
|
imadif |
|- ( Fun `' f -> ( f " ( suc A \ { A } ) ) = ( ( f " suc A ) \ ( f " { A } ) ) ) |
| 32 |
30 31
|
simplbiim |
|- ( f : suc A -1-1-onto-> suc B -> ( f " ( suc A \ { A } ) ) = ( ( f " suc A ) \ ( f " { A } ) ) ) |
| 33 |
20 29 32
|
3eqtr4rd |
|- ( f : suc A -1-1-onto-> suc B -> ( f " ( suc A \ { A } ) ) = ( suc B \ { ( f ` A ) } ) ) |
| 34 |
15 33
|
sylan9eq |
|- ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) -> ( f " A ) = ( suc B \ { ( f ` A ) } ) ) |
| 35 |
11 34
|
breqtrd |
|- ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) -> A ~~ ( suc B \ { ( f ` A ) } ) ) |
| 36 |
|
fnfvelrn |
|- ( ( f Fn suc A /\ A e. suc A ) -> ( f ` A ) e. ran f ) |
| 37 |
16 17 36
|
sylancl |
|- ( f : suc A -1-1-onto-> suc B -> ( f ` A ) e. ran f ) |
| 38 |
24
|
eleq2d |
|- ( f : suc A -onto-> suc B -> ( ( f ` A ) e. ran f <-> ( f ` A ) e. suc B ) ) |
| 39 |
23 38
|
syl |
|- ( f : suc A -1-1-onto-> suc B -> ( ( f ` A ) e. ran f <-> ( f ` A ) e. suc B ) ) |
| 40 |
37 39
|
mpbid |
|- ( f : suc A -1-1-onto-> suc B -> ( f ` A ) e. suc B ) |
| 41 |
|
fvex |
|- ( f ` A ) e. _V |
| 42 |
2 41
|
phplem3OLD |
|- ( ( B e. _om /\ ( f ` A ) e. suc B ) -> B ~~ ( suc B \ { ( f ` A ) } ) ) |
| 43 |
40 42
|
sylan2 |
|- ( ( B e. _om /\ f : suc A -1-1-onto-> suc B ) -> B ~~ ( suc B \ { ( f ` A ) } ) ) |
| 44 |
43
|
ensymd |
|- ( ( B e. _om /\ f : suc A -1-1-onto-> suc B ) -> ( suc B \ { ( f ` A ) } ) ~~ B ) |
| 45 |
|
entr |
|- ( ( A ~~ ( suc B \ { ( f ` A ) } ) /\ ( suc B \ { ( f ` A ) } ) ~~ B ) -> A ~~ B ) |
| 46 |
35 44 45
|
syl2an |
|- ( ( ( A e. _om /\ f : suc A -1-1-onto-> suc B ) /\ ( B e. _om /\ f : suc A -1-1-onto-> suc B ) ) -> A ~~ B ) |
| 47 |
46
|
anandirs |
|- ( ( ( A e. _om /\ B e. _om ) /\ f : suc A -1-1-onto-> suc B ) -> A ~~ B ) |
| 48 |
47
|
ex |
|- ( ( A e. _om /\ B e. _om ) -> ( f : suc A -1-1-onto-> suc B -> A ~~ B ) ) |
| 49 |
48
|
exlimdv |
|- ( ( A e. _om /\ B e. _om ) -> ( E. f f : suc A -1-1-onto-> suc B -> A ~~ B ) ) |
| 50 |
3 49
|
biimtrid |
|- ( ( A e. _om /\ B e. _om ) -> ( suc A ~~ suc B -> A ~~ B ) ) |