| Step |
Hyp |
Ref |
Expression |
| 1 |
|
simpll |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A A e. No ) |
| 2 |
|
simplr |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A B e. No ) |
| 3 |
|
sltso |
|- |
| 4 |
|
sonr |
|- ( ( -. A |
| 5 |
3 4
|
mpan |
|- ( A e. No -> -. A |
| 6 |
|
breq2 |
|- ( A = B -> ( A A |
| 7 |
6
|
notbid |
|- ( A = B -> ( -. A -. A |
| 8 |
5 7
|
syl5ibcom |
|- ( A e. No -> ( A = B -> -. A |
| 9 |
8
|
necon2ad |
|- ( A e. No -> ( A A =/= B ) ) |
| 10 |
9
|
imp |
|- ( ( A e. No /\ A A =/= B ) |
| 11 |
10
|
ad2ant2rl |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A A =/= B ) |
| 12 |
1 2 11
|
3jca |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A ( A e. No /\ B e. No /\ A =/= B ) ) |
| 13 |
|
nosepeq |
|- ( ( ( A e. No /\ B e. No /\ A =/= B ) /\ C e. |^| { a e. On | ( A ` a ) =/= ( B ` a ) } ) -> ( A ` C ) = ( B ` C ) ) |
| 14 |
12 13
|
sylan |
|- ( ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A ( A ` C ) = ( B ` C ) ) |
| 15 |
14
|
ex |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A ( C e. |^| { a e. On | ( A ` a ) =/= ( B ` a ) } -> ( A ` C ) = ( B ` C ) ) ) |