Metamath Proof Explorer


Theorem negsproplem5

Description: Lemma for surreal negation. Show the second half of the inductive hypothesis when B is simpler than A . (Contributed by Scott Fenton, 3-Feb-2025)

Ref Expression
Hypotheses negsproplem.1
|- ( ph -> A. x e. No A. y e. No ( ( ( bday ` x ) u. ( bday ` y ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) -> ( ( -us ` x ) e. No /\ ( x  ( -us ` y ) 
negsproplem4.1
|- ( ph -> A e. No )
negsproplem4.2
|- ( ph -> B e. No )
negsproplem4.3
|- ( ph -> A 
negsproplem5.4
|- ( ph -> ( bday ` B ) e. ( bday ` A ) )
Assertion negsproplem5
|- ( ph -> ( -us ` B ) 

Proof

Step Hyp Ref Expression
1 negsproplem.1
 |-  ( ph -> A. x e. No A. y e. No ( ( ( bday ` x ) u. ( bday ` y ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) -> ( ( -us ` x ) e. No /\ ( x  ( -us ` y ) 
2 negsproplem4.1
 |-  ( ph -> A e. No )
3 negsproplem4.2
 |-  ( ph -> B e. No )
4 negsproplem4.3
 |-  ( ph -> A 
5 negsproplem5.4
 |-  ( ph -> ( bday ` B ) e. ( bday ` A ) )
6 1 2 negsproplem3
 |-  ( ph -> ( ( -us ` A ) e. No /\ ( -us " ( _Right ` A ) ) <
7 6 simp2d
 |-  ( ph -> ( -us " ( _Right ` A ) ) <
8 negsfn
 |-  -us Fn No
9 rightssno
 |-  ( _Right ` A ) C_ No
10 bdayelon
 |-  ( bday ` A ) e. On
11 oldbday
 |-  ( ( ( bday ` A ) e. On /\ B e. No ) -> ( B e. ( _Old ` ( bday ` A ) ) <-> ( bday ` B ) e. ( bday ` A ) ) )
12 10 3 11 sylancr
 |-  ( ph -> ( B e. ( _Old ` ( bday ` A ) ) <-> ( bday ` B ) e. ( bday ` A ) ) )
13 5 12 mpbird
 |-  ( ph -> B e. ( _Old ` ( bday ` A ) ) )
14 breq2
 |-  ( b = B -> ( A  A 
15 rightval
 |-  ( _Right ` A ) = { b e. ( _Old ` ( bday ` A ) ) | A 
16 14 15 elrab2
 |-  ( B e. ( _Right ` A ) <-> ( B e. ( _Old ` ( bday ` A ) ) /\ A 
17 13 4 16 sylanbrc
 |-  ( ph -> B e. ( _Right ` A ) )
18 fnfvima
 |-  ( ( -us Fn No /\ ( _Right ` A ) C_ No /\ B e. ( _Right ` A ) ) -> ( -us ` B ) e. ( -us " ( _Right ` A ) ) )
19 8 9 17 18 mp3an12i
 |-  ( ph -> ( -us ` B ) e. ( -us " ( _Right ` A ) ) )
20 fvex
 |-  ( -us ` A ) e. _V
21 20 snid
 |-  ( -us ` A ) e. { ( -us ` A ) }
22 21 a1i
 |-  ( ph -> ( -us ` A ) e. { ( -us ` A ) } )
23 7 19 22 ssltsepcd
 |-  ( ph -> ( -us ` B )