Metamath Proof Explorer


Theorem nodenselem4

Description: Lemma for nodense . Show that a particular abstraction is an ordinal. (Contributed by Scott Fenton, 16-Jun-2011)

Ref Expression
Assertion nodenselem4
|- ( ( ( A e. No /\ B e. No ) /\ A  |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On )

Proof

Step Hyp Ref Expression
1 simpll
 |-  ( ( ( A e. No /\ B e. No ) /\ A  A e. No )
2 simplr
 |-  ( ( ( A e. No /\ B e. No ) /\ A  B e. No )
3 sltso
 |-  
4 sonr
 |-  ( (  -. A 
5 3 4 mpan
 |-  ( A e. No -> -. A 
6 5 adantr
 |-  ( ( A e. No /\ B e. No ) -> -. A 
7 breq2
 |-  ( A = B -> ( A  A 
8 7 notbid
 |-  ( A = B -> ( -. A  -. A 
9 6 8 syl5ibcom
 |-  ( ( A e. No /\ B e. No ) -> ( A = B -> -. A 
10 9 necon2ad
 |-  ( ( A e. No /\ B e. No ) -> ( A  A =/= B ) )
11 10 imp
 |-  ( ( ( A e. No /\ B e. No ) /\ A  A =/= B )
12 nosepon
 |-  ( ( A e. No /\ B e. No /\ A =/= B ) -> |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On )
13 1 2 11 12 syl3anc
 |-  ( ( ( A e. No /\ B e. No ) /\ A  |^| { a e. On | ( A ` a ) =/= ( B ` a ) } e. On )