Metamath Proof Explorer


Theorem negsproplem2

Description: Lemma for surreal negation. Show that the cut that defines negation is legitimate. (Contributed by Scott Fenton, 2-Feb-2025)

Ref Expression
Hypotheses negsproplem.1 No typesetting found for |- ( 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 )
negsproplem2.1 φ A No
Assertion negsproplem2 Could not format assertion : No typesetting found for |- ( ph -> ( -us " ( _Right ` A ) ) <

Proof

Step Hyp Ref Expression
1 negsproplem.1 Could not format ( 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 ) 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 negsproplem2.1 φ A No
3 negsfn Could not format -us Fn No : No typesetting found for |- -us Fn No with typecode |-
4 fnfun Could not format ( -us Fn No -> Fun -us ) : No typesetting found for |- ( -us Fn No -> Fun -us ) with typecode |-
5 3 4 ax-mp Could not format Fun -us : No typesetting found for |- Fun -us with typecode |-
6 fvex Could not format ( _Right ` A ) e. _V : No typesetting found for |- ( _Right ` A ) e. _V with typecode |-
7 6 funimaex Could not format ( Fun -us -> ( -us " ( _Right ` A ) ) e. _V ) : No typesetting found for |- ( Fun -us -> ( -us " ( _Right ` A ) ) e. _V ) with typecode |-
8 5 7 mp1i Could not format ( ph -> ( -us " ( _Right ` A ) ) e. _V ) : No typesetting found for |- ( ph -> ( -us " ( _Right ` A ) ) e. _V ) with typecode |-
9 fvex Could not format ( _Left ` A ) e. _V : No typesetting found for |- ( _Left ` A ) e. _V with typecode |-
10 9 funimaex Could not format ( Fun -us -> ( -us " ( _Left ` A ) ) e. _V ) : No typesetting found for |- ( Fun -us -> ( -us " ( _Left ` A ) ) e. _V ) with typecode |-
11 5 10 mp1i Could not format ( ph -> ( -us " ( _Left ` A ) ) e. _V ) : No typesetting found for |- ( ph -> ( -us " ( _Left ` A ) ) e. _V ) with typecode |-
12 rightssold Could not format ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) : No typesetting found for |- ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) with typecode |-
13 imass2 Could not format ( ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) -> ( -us " ( _Right ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) ) : No typesetting found for |- ( ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) -> ( -us " ( _Right ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) ) with typecode |-
14 12 13 ax-mp Could not format ( -us " ( _Right ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( -us " ( _Right ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) with typecode |-
15 1 adantr Could not format ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> 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 ) 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 )
16 oldssno Old bday A No
17 16 sseli a Old bday A a No
18 17 adantl φ a Old bday A a No
19 0sno Could not format 0s e. No : No typesetting found for |- 0s e. No with typecode |-
20 19 a1i Could not format ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> 0s e. No ) : No typesetting found for |- ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> 0s e. No ) with typecode |-
21 bday0s Could not format ( bday ` 0s ) = (/) : No typesetting found for |- ( bday ` 0s ) = (/) with typecode |-
22 21 uneq2i Could not format ( ( bday ` a ) u. ( bday ` 0s ) ) = ( ( bday ` a ) u. (/) ) : No typesetting found for |- ( ( bday ` a ) u. ( bday ` 0s ) ) = ( ( bday ` a ) u. (/) ) with typecode |-
23 un0 bday a = bday a
24 22 23 eqtri Could not format ( ( bday ` a ) u. ( bday ` 0s ) ) = ( bday ` a ) : No typesetting found for |- ( ( bday ` a ) u. ( bday ` 0s ) ) = ( bday ` a ) with typecode |-
25 oldbdayim a Old bday A bday a bday A
26 25 adantl φ a Old bday A bday a bday A
27 elun1 bday a bday A bday a bday A bday B
28 26 27 syl φ a Old bday A bday a bday A bday B
29 24 28 eqeltrid Could not format ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> ( ( bday ` a ) u. ( bday ` 0s ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) : No typesetting found for |- ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> ( ( bday ` a ) u. ( bday ` 0s ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) with typecode |-
30 15 18 20 29 negsproplem1 Could not format ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> ( ( -us ` a ) e. No /\ ( a ( -us ` 0s ) ( ( -us ` a ) e. No /\ ( a ( -us ` 0s )
31 30 simpld Could not format ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> ( -us ` a ) e. No ) : No typesetting found for |- ( ( ph /\ a e. ( _Old ` ( bday ` A ) ) ) -> ( -us ` a ) e. No ) with typecode |-
32 31 ralrimiva Could not format ( ph -> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) : No typesetting found for |- ( ph -> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) with typecode |-
33 3 fndmi Could not format dom -us = No : No typesetting found for |- dom -us = No with typecode |-
34 16 33 sseqtrri Could not format ( _Old ` ( bday ` A ) ) C_ dom -us : No typesetting found for |- ( _Old ` ( bday ` A ) ) C_ dom -us with typecode |-
35 funimass4 Could not format ( ( Fun -us /\ ( _Old ` ( bday ` A ) ) C_ dom -us ) -> ( ( -us " ( _Old ` ( bday ` A ) ) ) C_ No <-> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) ) : No typesetting found for |- ( ( Fun -us /\ ( _Old ` ( bday ` A ) ) C_ dom -us ) -> ( ( -us " ( _Old ` ( bday ` A ) ) ) C_ No <-> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) ) with typecode |-
36 5 34 35 mp2an Could not format ( ( -us " ( _Old ` ( bday ` A ) ) ) C_ No <-> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) : No typesetting found for |- ( ( -us " ( _Old ` ( bday ` A ) ) ) C_ No <-> A. a e. ( _Old ` ( bday ` A ) ) ( -us ` a ) e. No ) with typecode |-
37 32 36 sylibr Could not format ( ph -> ( -us " ( _Old ` ( bday ` A ) ) ) C_ No ) : No typesetting found for |- ( ph -> ( -us " ( _Old ` ( bday ` A ) ) ) C_ No ) with typecode |-
38 14 37 sstrid Could not format ( ph -> ( -us " ( _Right ` A ) ) C_ No ) : No typesetting found for |- ( ph -> ( -us " ( _Right ` A ) ) C_ No ) with typecode |-
39 leftssold Could not format ( _Left ` A ) C_ ( _Old ` ( bday ` A ) ) : No typesetting found for |- ( _Left ` A ) C_ ( _Old ` ( bday ` A ) ) with typecode |-
40 imass2 Could not format ( ( _Left ` A ) C_ ( _Old ` ( bday ` A ) ) -> ( -us " ( _Left ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) ) : No typesetting found for |- ( ( _Left ` A ) C_ ( _Old ` ( bday ` A ) ) -> ( -us " ( _Left ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) ) with typecode |-
41 39 40 ax-mp Could not format ( -us " ( _Left ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( -us " ( _Left ` A ) ) C_ ( -us " ( _Old ` ( bday ` A ) ) ) with typecode |-
42 41 37 sstrid Could not format ( ph -> ( -us " ( _Left ` A ) ) C_ No ) : No typesetting found for |- ( ph -> ( -us " ( _Left ` A ) ) C_ No ) with typecode |-
43 rightssno Could not format ( _Right ` A ) C_ No : No typesetting found for |- ( _Right ` A ) C_ No with typecode |-
44 fvelimab Could not format ( ( -us Fn No /\ ( _Right ` A ) C_ No ) -> ( a e. ( -us " ( _Right ` A ) ) <-> E. xR e. ( _Right ` A ) ( -us ` xR ) = a ) ) : No typesetting found for |- ( ( -us Fn No /\ ( _Right ` A ) C_ No ) -> ( a e. ( -us " ( _Right ` A ) ) <-> E. xR e. ( _Right ` A ) ( -us ` xR ) = a ) ) with typecode |-
45 3 43 44 mp2an Could not format ( a e. ( -us " ( _Right ` A ) ) <-> E. xR e. ( _Right ` A ) ( -us ` xR ) = a ) : No typesetting found for |- ( a e. ( -us " ( _Right ` A ) ) <-> E. xR e. ( _Right ` A ) ( -us ` xR ) = a ) with typecode |-
46 leftssno Could not format ( _Left ` A ) C_ No : No typesetting found for |- ( _Left ` A ) C_ No with typecode |-
47 fvelimab Could not format ( ( -us Fn No /\ ( _Left ` A ) C_ No ) -> ( b e. ( -us " ( _Left ` A ) ) <-> E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) : No typesetting found for |- ( ( -us Fn No /\ ( _Left ` A ) C_ No ) -> ( b e. ( -us " ( _Left ` A ) ) <-> E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) with typecode |-
48 3 46 47 mp2an Could not format ( b e. ( -us " ( _Left ` A ) ) <-> E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) : No typesetting found for |- ( b e. ( -us " ( _Left ` A ) ) <-> E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) with typecode |-
49 45 48 anbi12i Could not format ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) <-> ( E. xR e. ( _Right ` A ) ( -us ` xR ) = a /\ E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) : No typesetting found for |- ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) <-> ( E. xR e. ( _Right ` A ) ( -us ` xR ) = a /\ E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) with typecode |-
50 reeanv Could not format ( E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) <-> ( E. xR e. ( _Right ` A ) ( -us ` xR ) = a /\ E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) : No typesetting found for |- ( E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) <-> ( E. xR e. ( _Right ` A ) ( -us ` xR ) = a /\ E. xL e. ( _Left ` A ) ( -us ` xL ) = b ) ) with typecode |-
51 49 50 bitr4i Could not format ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) <-> E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) ) : No typesetting found for |- ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) <-> E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) ) with typecode |-
52 lltropt Could not format ( _Left ` A ) <
53 52 a1i Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( _Left ` A ) < ( _Left ` A ) <
54 simprr Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. ( _Left ` A ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. ( _Left ` A ) ) with typecode |-
55 simprl Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. ( _Right ` A ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. ( _Right ` A ) ) with typecode |-
56 53 54 55 ssltsepcd Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL xL
57 1 adantr Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> 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 ) 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 )
58 46 sseli Could not format ( xL e. ( _Left ` A ) -> xL e. No ) : No typesetting found for |- ( xL e. ( _Left ` A ) -> xL e. No ) with typecode |-
59 58 ad2antll Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. No ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. No ) with typecode |-
60 43 sseli Could not format ( xR e. ( _Right ` A ) -> xR e. No ) : No typesetting found for |- ( xR e. ( _Right ` A ) -> xR e. No ) with typecode |-
61 60 adantr Could not format ( ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) -> xR e. No ) : No typesetting found for |- ( ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) -> xR e. No ) with typecode |-
62 61 adantl Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. No ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. No ) with typecode |-
63 39 sseli Could not format ( xL e. ( _Left ` A ) -> xL e. ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( xL e. ( _Left ` A ) -> xL e. ( _Old ` ( bday ` A ) ) ) with typecode |-
64 63 ad2antll Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xL e. ( _Old ` ( bday ` A ) ) ) with typecode |-
65 oldbdayim Could not format ( xL e. ( _Old ` ( bday ` A ) ) -> ( bday ` xL ) e. ( bday ` A ) ) : No typesetting found for |- ( xL e. ( _Old ` ( bday ` A ) ) -> ( bday ` xL ) e. ( bday ` A ) ) with typecode |-
66 64 65 syl Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( bday ` xL ) e. ( bday ` A ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( bday ` xL ) e. ( bday ` A ) ) with typecode |-
67 12 a1i Could not format ( ph -> ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( ph -> ( _Right ` A ) C_ ( _Old ` ( bday ` A ) ) ) with typecode |-
68 67 sselda Could not format ( ( ph /\ xR e. ( _Right ` A ) ) -> xR e. ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( ( ph /\ xR e. ( _Right ` A ) ) -> xR e. ( _Old ` ( bday ` A ) ) ) with typecode |-
69 68 adantrr Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. ( _Old ` ( bday ` A ) ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> xR e. ( _Old ` ( bday ` A ) ) ) with typecode |-
70 oldbdayim Could not format ( xR e. ( _Old ` ( bday ` A ) ) -> ( bday ` xR ) e. ( bday ` A ) ) : No typesetting found for |- ( xR e. ( _Old ` ( bday ` A ) ) -> ( bday ` xR ) e. ( bday ` A ) ) with typecode |-
71 69 70 syl Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( bday ` xR ) e. ( bday ` A ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( bday ` xR ) e. ( bday ` A ) ) with typecode |-
72 bdayelon Could not format ( bday ` xL ) e. On : No typesetting found for |- ( bday ` xL ) e. On with typecode |-
73 bdayelon Could not format ( bday ` xR ) e. On : No typesetting found for |- ( bday ` xR ) e. On with typecode |-
74 bdayelon bday A On
75 onunel Could not format ( ( ( bday ` xL ) e. On /\ ( bday ` xR ) e. On /\ ( bday ` A ) e. On ) -> ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) <-> ( ( bday ` xL ) e. ( bday ` A ) /\ ( bday ` xR ) e. ( bday ` A ) ) ) ) : No typesetting found for |- ( ( ( bday ` xL ) e. On /\ ( bday ` xR ) e. On /\ ( bday ` A ) e. On ) -> ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) <-> ( ( bday ` xL ) e. ( bday ` A ) /\ ( bday ` xR ) e. ( bday ` A ) ) ) ) with typecode |-
76 72 73 74 75 mp3an Could not format ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) <-> ( ( bday ` xL ) e. ( bday ` A ) /\ ( bday ` xR ) e. ( bday ` A ) ) ) : No typesetting found for |- ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) <-> ( ( bday ` xL ) e. ( bday ` A ) /\ ( bday ` xR ) e. ( bday ` A ) ) ) with typecode |-
77 66 71 76 sylanbrc Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) ) with typecode |-
78 elun1 Could not format ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) : No typesetting found for |- ( ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( bday ` A ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) with typecode |-
79 77 78 syl Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) : No typesetting found for |- ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( bday ` xL ) u. ( bday ` xR ) ) e. ( ( bday ` A ) u. ( bday ` B ) ) ) with typecode |-
80 57 59 62 79 negsproplem1 Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( -us ` xL ) e. No /\ ( xL ( -us ` xR ) ( ( -us ` xL ) e. No /\ ( xL ( -us ` xR )
81 80 simprd Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( xL ( -us ` xR ) ( xL ( -us ` xR )
82 56 81 mpd Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( -us ` xR ) ( -us ` xR )
83 breq12 Could not format ( ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) -> ( ( -us ` xR ) a ( ( -us ` xR ) a
84 82 83 syl5ibcom Could not format ( ( ph /\ ( xR e. ( _Right ` A ) /\ xL e. ( _Left ` A ) ) ) -> ( ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) -> a ( ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) -> a
85 84 rexlimdvva Could not format ( ph -> ( E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) -> a ( E. xR e. ( _Right ` A ) E. xL e. ( _Left ` A ) ( ( -us ` xR ) = a /\ ( -us ` xL ) = b ) -> a
86 51 85 biimtrid Could not format ( ph -> ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) -> a ( ( a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) -> a
87 86 3impib Could not format ( ( ph /\ a e. ( -us " ( _Right ` A ) ) /\ b e. ( -us " ( _Left ` A ) ) ) -> a a
88 8 11 38 42 87 ssltd Could not format ( ph -> ( -us " ( _Right ` A ) ) < ( -us " ( _Right ` A ) ) <