Metamath Proof Explorer


Theorem nodenselem7

Description: Lemma for nodense . A and B are equal at all elements of the abstraction. (Contributed by Scott Fenton, 17-Jun-2011)

Ref Expression
Assertion nodenselem7
|- ( ( ( A e. No /\ B e. No ) /\ ( ( bday ` A ) = ( bday ` B ) /\ A  ( C e. |^| { a e. On | ( A ` a ) =/= ( B ` a ) } -> ( A ` C ) = ( B ` C ) ) )

Proof

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 ) ) )