Step |
Hyp |
Ref |
Expression |
1 |
|
simpll |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A A e. No ) |
2 |
|
nodenselem4 |
|- ( ( ( A e. No /\ B e. No ) /\ A |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On ) |
3 |
2
|
adantrl |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On ) |
4 |
|
noreson |
|- ( ( A e. No /\ |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On ) -> ( A |` |^| { a e. On | ( A ` a ) =/= ( B ` a ) } ) e. No ) |
5 |
1 3 4
|
syl2anc |
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A ( A |` |^| { a e. On | ( A ` a ) =/= ( B ` a ) } ) e. No ) |