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Theorem frgr3vlem1 27137
Description: Lemma 1 for frgr3v 27139. (Contributed by Alexander van der Vekens, 4-Oct-2017.) (Revised by AV, 29-Mar-2021.)
Hypotheses
Ref Expression
frgr3v.v  |-  V  =  (Vtx `  G )
frgr3v.e  |-  E  =  (Edg `  G )
Assertion
Ref Expression
frgr3vlem1  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A. x A. y
( ( ( x  e.  { A ,  B ,  C }  /\  { { x ,  A } ,  {
x ,  B } }  C_  E )  /\  ( y  e.  { A ,  B ,  C }  /\  { {
y ,  A } ,  { y ,  B } }  C_  E ) )  ->  x  =  y ) )
Distinct variable groups:    x, A, y    x, B, y    x, C, y    x, E, y   
x, G, y    x, V, y    x, X, y   
x, Y, y    x, Z, y

Proof of Theorem frgr3vlem1
StepHypRef Expression
1 vex 3203 . . . . . 6  |-  x  e. 
_V
21eltp 4230 . . . . 5  |-  ( x  e.  { A ,  B ,  C }  <->  ( x  =  A  \/  x  =  B  \/  x  =  C )
)
3 vex 3203 . . . . . . . . 9  |-  y  e. 
_V
43eltp 4230 . . . . . . . 8  |-  ( y  e.  { A ,  B ,  C }  <->  ( y  =  A  \/  y  =  B  \/  y  =  C )
)
5 eqidd 2623 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  A )
65a1i 11 . . . . . . . . . . . . . 14  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  A ) )
76a1i13 27 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  A ) ) ) )
8 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  A  ->  { y ,  A }  =  { A ,  A }
)
9 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  A  ->  { y ,  B }  =  { A ,  B }
)
108, 9preq12d 4276 . . . . . . . . . . . . . 14  |-  ( y  =  A  ->  { {
y ,  A } ,  { y ,  B } }  =  { { A ,  A } ,  { A ,  B } } )
1110sseq1d 3632 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E 
<->  { { A ,  A } ,  { A ,  B } }  C_  E ) )
12 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  A  ->  ( A  =  y  <->  A  =  A ) )
1312imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  A  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  A ) ) )
1413imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  (
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) )  <->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  A ) ) ) )
157, 11, 143imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  A  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) )
16 prex 4909 . . . . . . . . . . . . . . . . . . 19  |-  { A ,  A }  e.  _V
17 prex 4909 . . . . . . . . . . . . . . . . . . 19  |-  { A ,  B }  e.  _V
1816, 17prss 4351 . . . . . . . . . . . . . . . . . 18  |-  ( ( { A ,  A }  e.  E  /\  { A ,  B }  e.  E )  <->  { { A ,  A } ,  { A ,  B } }  C_  E )
19 frgr3v.e . . . . . . . . . . . . . . . . . . . . . . 23  |-  E  =  (Edg `  G )
2019usgredgne 26098 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( ( G  e. USGraph  /\  { A ,  A }  e.  E
)  ->  A  =/=  A )
2120adantll 750 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { A ,  A }  e.  E
)  ->  A  =/=  A )
22 df-ne 2795 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( A  =/=  A  <->  -.  A  =  A )
23 eqid 2622 . . . . . . . . . . . . . . . . . . . . . . 23  |-  A  =  A
2423pm2.24i 146 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( -.  A  =  A  ->  A  =  B )
2522, 24sylbi 207 . . . . . . . . . . . . . . . . . . . . 21  |-  ( A  =/=  A  ->  A  =  B )
2621, 25syl 17 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { A ,  A }  e.  E
)  ->  A  =  B )
2726expcom 451 . . . . . . . . . . . . . . . . . . 19  |-  ( { A ,  A }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  B )
)
2827adantr 481 . . . . . . . . . . . . . . . . . 18  |-  ( ( { A ,  A }  e.  E  /\  { A ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  B ) )
2918, 28sylbir 225 . . . . . . . . . . . . . . . . 17  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  B )
)
3029com12 32 . . . . . . . . . . . . . . . 16  |-  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  A  =  B ) )
31303ad2ant3 1084 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  A  =  B )
)
3231com12 32 . . . . . . . . . . . . . 14  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  B ) )
33322a1i 12 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  B ) ) ) )
34 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  B  ->  { y ,  A }  =  { B ,  A }
)
35 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  B  ->  { y ,  B }  =  { B ,  B }
)
3634, 35preq12d 4276 . . . . . . . . . . . . . 14  |-  ( y  =  B  ->  { {
y ,  A } ,  { y ,  B } }  =  { { B ,  A } ,  { B ,  B } } )
3736sseq1d 3632 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E 
<->  { { B ,  A } ,  { B ,  B } }  C_  E ) )
38 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  B  ->  ( A  =  y  <->  A  =  B ) )
3938imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  B  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  B ) ) )
4039imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  (
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) )  <->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  B ) ) ) )
4133, 37, 403imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  B  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) )
4223pm2.24i 146 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( -.  A  =  A  ->  A  =  C )
4322, 42sylbi 207 . . . . . . . . . . . . . . . . . . . . 21  |-  ( A  =/=  A  ->  A  =  C )
4421, 43syl 17 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { A ,  A }  e.  E
)  ->  A  =  C )
4544expcom 451 . . . . . . . . . . . . . . . . . . 19  |-  ( { A ,  A }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  C )
)
4645adantr 481 . . . . . . . . . . . . . . . . . 18  |-  ( ( { A ,  A }  e.  E  /\  { A ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  C ) )
4718, 46sylbir 225 . . . . . . . . . . . . . . . . 17  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  A  =  C )
)
4847com12 32 . . . . . . . . . . . . . . . 16  |-  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  A  =  C ) )
49483ad2ant3 1084 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  A  =  C )
)
5049com12 32 . . . . . . . . . . . . . 14  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  C ) )
51502a1i 12 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  C ) ) ) )
52 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  C  ->  { y ,  A }  =  { C ,  A }
)
53 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( y  =  C  ->  { y ,  B }  =  { C ,  B }
)
5452, 53preq12d 4276 . . . . . . . . . . . . . 14  |-  ( y  =  C  ->  { {
y ,  A } ,  { y ,  B } }  =  { { C ,  A } ,  { C ,  B } } )
5554sseq1d 3632 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E 
<->  { { C ,  A } ,  { C ,  B } }  C_  E ) )
56 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  C  ->  ( A  =  y  <->  A  =  C ) )
5756imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  C  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  C ) ) )
5857imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  (
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) )  <->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  C ) ) ) )
5951, 55, 583imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  C  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) )
6015, 41, 593jaoi 1391 . . . . . . . . . . 11  |-  ( ( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) )
61 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  A  ->  { x ,  A }  =  { A ,  A }
)
62 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  A  ->  { x ,  B }  =  { A ,  B }
)
6361, 62preq12d 4276 . . . . . . . . . . . . . 14  |-  ( x  =  A  ->  { {
x ,  A } ,  { x ,  B } }  =  { { A ,  A } ,  { A ,  B } } )
6463sseq1d 3632 . . . . . . . . . . . . 13  |-  ( x  =  A  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E 
<->  { { A ,  A } ,  { A ,  B } }  C_  E ) )
65 eqeq1 2626 . . . . . . . . . . . . . 14  |-  ( x  =  A  ->  (
x  =  y  <->  A  =  y ) )
6665imbi2d 330 . . . . . . . . . . . . 13  |-  ( x  =  A  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) )
6764, 66imbi12d 334 . . . . . . . . . . . 12  |-  ( x  =  A  ->  (
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) )  <->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) )
6867imbi2d 330 . . . . . . . . . . 11  |-  ( x  =  A  ->  (
( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) )  <->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A  =  y ) ) ) ) )
6960, 68syl5ibr 236 . . . . . . . . . 10  |-  ( x  =  A  ->  (
( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { {
x ,  A } ,  { x ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
70 prex 4909 . . . . . . . . . . . . . . . . . . 19  |-  { B ,  A }  e.  _V
71 prex 4909 . . . . . . . . . . . . . . . . . . 19  |-  { B ,  B }  e.  _V
7270, 71prss 4351 . . . . . . . . . . . . . . . . . 18  |-  ( ( { B ,  A }  e.  E  /\  { B ,  B }  e.  E )  <->  { { B ,  A } ,  { B ,  B } }  C_  E )
7319usgredgne 26098 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( ( G  e. USGraph  /\  { B ,  B }  e.  E
)  ->  B  =/=  B )
7473adantll 750 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { B ,  B }  e.  E
)  ->  B  =/=  B )
75 df-ne 2795 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( B  =/=  B  <->  -.  B  =  B )
76 eqid 2622 . . . . . . . . . . . . . . . . . . . . . . 23  |-  B  =  B
7776pm2.24i 146 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( -.  B  =  B  ->  B  =  A )
7875, 77sylbi 207 . . . . . . . . . . . . . . . . . . . . 21  |-  ( B  =/=  B  ->  B  =  A )
7974, 78syl 17 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { B ,  B }  e.  E
)  ->  B  =  A )
8079expcom 451 . . . . . . . . . . . . . . . . . . 19  |-  ( { B ,  B }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  A )
)
8180adantl 482 . . . . . . . . . . . . . . . . . 18  |-  ( ( { B ,  A }  e.  E  /\  { B ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  A ) )
8272, 81sylbir 225 . . . . . . . . . . . . . . . . 17  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  A )
)
8382com12 32 . . . . . . . . . . . . . . . 16  |-  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  B  =  A ) )
84833ad2ant3 1084 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  B  =  A )
)
8584com12 32 . . . . . . . . . . . . . 14  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  A ) )
86852a1i 12 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  A ) ) ) )
87 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  A  ->  ( B  =  y  <->  B  =  A ) )
8887imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  A  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  A ) ) )
8988imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  (
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) )  <->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  A ) ) ) )
9086, 11, 893imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  A  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) )
91 eqidd 2623 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  B )
9291a1i 11 . . . . . . . . . . . . . 14  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  B ) )
9392a1i13 27 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  B ) ) ) )
94 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  B  ->  ( B  =  y  <->  B  =  B ) )
9594imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  B  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  B ) ) )
9695imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  (
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) )  <->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  B ) ) ) )
9793, 37, 963imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  B  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) )
9876pm2.24i 146 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( -.  B  =  B  ->  B  =  C )
9975, 98sylbi 207 . . . . . . . . . . . . . . . . . . . . 21  |-  ( B  =/=  B  ->  B  =  C )
10074, 99syl 17 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { B ,  B }  e.  E
)  ->  B  =  C )
101100expcom 451 . . . . . . . . . . . . . . . . . . 19  |-  ( { B ,  B }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  C )
)
102101adantl 482 . . . . . . . . . . . . . . . . . 18  |-  ( ( { B ,  A }  e.  E  /\  { B ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  C ) )
10372, 102sylbir 225 . . . . . . . . . . . . . . . . 17  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  B  =  C )
)
104103com12 32 . . . . . . . . . . . . . . . 16  |-  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  B  =  C ) )
1051043ad2ant3 1084 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  B  =  C )
)
106105com12 32 . . . . . . . . . . . . . 14  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  C ) )
1071062a1i 12 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  C ) ) ) )
108 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  C  ->  ( B  =  y  <->  B  =  C ) )
109108imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  C  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  C ) ) )
110109imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  (
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) )  <->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  C ) ) ) )
111107, 55, 1103imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  C  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) )
11290, 97, 1113jaoi 1391 . . . . . . . . . . 11  |-  ( ( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) )
113 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  B  ->  { x ,  A }  =  { B ,  A }
)
114 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  B  ->  { x ,  B }  =  { B ,  B }
)
115113, 114preq12d 4276 . . . . . . . . . . . . . 14  |-  ( x  =  B  ->  { {
x ,  A } ,  { x ,  B } }  =  { { B ,  A } ,  { B ,  B } } )
116115sseq1d 3632 . . . . . . . . . . . . 13  |-  ( x  =  B  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E 
<->  { { B ,  A } ,  { B ,  B } }  C_  E ) )
117 eqeq1 2626 . . . . . . . . . . . . . 14  |-  ( x  =  B  ->  (
x  =  y  <->  B  =  y ) )
118117imbi2d 330 . . . . . . . . . . . . 13  |-  ( x  =  B  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) )
119116, 118imbi12d 334 . . . . . . . . . . . 12  |-  ( x  =  B  ->  (
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) )  <->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) )
120119imbi2d 330 . . . . . . . . . . 11  |-  ( x  =  B  ->  (
( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) )  <->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  B  =  y ) ) ) ) )
121112, 120syl5ibr 236 . . . . . . . . . 10  |-  ( x  =  B  ->  (
( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { {
x ,  A } ,  { x ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
12223pm2.24i 146 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( -.  A  =  A  ->  C  =  A )
12322, 122sylbi 207 . . . . . . . . . . . . . . . . . . . . 21  |-  ( A  =/=  A  ->  C  =  A )
12421, 123syl 17 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { A ,  A }  e.  E
)  ->  C  =  A )
125124expcom 451 . . . . . . . . . . . . . . . . . . 19  |-  ( { A ,  A }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  C  =  A )
)
126125adantr 481 . . . . . . . . . . . . . . . . . 18  |-  ( ( { A ,  A }  e.  E  /\  { A ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  C  =  A ) )
12718, 126sylbir 225 . . . . . . . . . . . . . . . . 17  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  C  =  A )
)
128127com12 32 . . . . . . . . . . . . . . . 16  |-  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { A ,  A } ,  { A ,  B } }  C_  E  ->  C  =  A ) )
1291283ad2ant3 1084 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  C  =  A )
)
130129com12 32 . . . . . . . . . . . . . 14  |-  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  A ) )
131130a1i13 27 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  ( { { A ,  A } ,  { A ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  A ) ) ) )
132 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  A  ->  ( C  =  y  <->  C  =  A ) )
133132imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  A  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  A ) ) )
134133imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  A  ->  (
( { { C ,  A } ,  { C ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) )  <->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  A ) ) ) )
135131, 11, 1343imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  A  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) )
136 pm2.21 120 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( -.  B  =  B  -> 
( B  =  B  ->  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  C  =  B ) ) )
13775, 136sylbi 207 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( B  =/=  B  ->  ( B  =  B  ->  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  ->  C  =  B ) ) )
13874, 76, 137mpisyl 21 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  /\  { B ,  B }  e.  E
)  ->  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  C  =  B ) )
139138expcom 451 . . . . . . . . . . . . . . . . . . . 20  |-  ( { B ,  B }  e.  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  C  =  B ) ) )
140139adantl 482 . . . . . . . . . . . . . . . . . . 19  |-  ( ( { B ,  A }  e.  E  /\  { B ,  B }  e.  E )  ->  (
( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  C  =  B ) ) )
14172, 140sylbir 225 . . . . . . . . . . . . . . . . . 18  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  C  =  B ) ) )
142141com13 88 . . . . . . . . . . . . . . . . 17  |-  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  C  =  B )
) )
143142a1d 25 . . . . . . . . . . . . . . . 16  |-  ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  ->  ( ( A  =/= 
B  /\  A  =/=  C  /\  B  =/=  C
)  ->  ( ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  )  -> 
( { { B ,  A } ,  { B ,  B } }  C_  E  ->  C  =  B ) ) ) )
1441433imp 1256 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  C  =  B )
)
145144com12 32 . . . . . . . . . . . . . 14  |-  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  B ) )
146145a1i13 27 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  ( { { B ,  A } ,  { B ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  B ) ) ) )
147 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  B  ->  ( C  =  y  <->  C  =  B ) )
148147imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  B  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  B ) ) )
149148imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  B  ->  (
( { { C ,  A } ,  { C ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) )  <->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  B ) ) ) )
150146, 37, 1493imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  B  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) )
151 eqidd 2623 . . . . . . . . . . . . . . 15  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  C )
152151a1i 11 . . . . . . . . . . . . . 14  |-  ( { { C ,  A } ,  { C ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  C ) )
153152a1i13 27 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  C ) ) ) )
154 eqeq2 2633 . . . . . . . . . . . . . . 15  |-  ( y  =  C  ->  ( C  =  y  <->  C  =  C ) )
155154imbi2d 330 . . . . . . . . . . . . . 14  |-  ( y  =  C  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  C ) ) )
156155imbi2d 330 . . . . . . . . . . . . 13  |-  ( y  =  C  ->  (
( { { C ,  A } ,  { C ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) )  <->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  C ) ) ) )
157153, 55, 1563imtr4d 283 . . . . . . . . . . . 12  |-  ( y  =  C  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) )
158135, 150, 1573jaoi 1391 . . . . . . . . . . 11  |-  ( ( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { C ,  A } ,  { C ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) )
159 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  C  ->  { x ,  A }  =  { C ,  A }
)
160 preq1 4268 . . . . . . . . . . . . . . 15  |-  ( x  =  C  ->  { x ,  B }  =  { C ,  B }
)
161159, 160preq12d 4276 . . . . . . . . . . . . . 14  |-  ( x  =  C  ->  { {
x ,  A } ,  { x ,  B } }  =  { { C ,  A } ,  { C ,  B } } )
162161sseq1d 3632 . . . . . . . . . . . . 13  |-  ( x  =  C  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E 
<->  { { C ,  A } ,  { C ,  B } }  C_  E ) )
163 eqeq1 2626 . . . . . . . . . . . . . 14  |-  ( x  =  C  ->  (
x  =  y  <->  C  =  y ) )
164163imbi2d 330 . . . . . . . . . . . . 13  |-  ( x  =  C  ->  (
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y )  <->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) )
165162, 164imbi12d 334 . . . . . . . . . . . 12  |-  ( x  =  C  ->  (
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) )  <->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) )
166165imbi2d 330 . . . . . . . . . . 11  |-  ( x  =  C  ->  (
( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) )  <->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { { C ,  A } ,  { C ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  C  =  y ) ) ) ) )
167158, 166syl5ibr 236 . . . . . . . . . 10  |-  ( x  =  C  ->  (
( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { {
x ,  A } ,  { x ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
16869, 121, 1673jaoi 1391 . . . . . . . . 9  |-  ( ( x  =  A  \/  x  =  B  \/  x  =  C )  ->  ( ( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  ->  ( { {
x ,  A } ,  { x ,  B } }  C_  E  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
169168com3l 89 . . . . . . . 8  |-  ( ( y  =  A  \/  y  =  B  \/  y  =  C )  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( ( x  =  A  \/  x  =  B  \/  x  =  C )  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
1704, 169sylbi 207 . . . . . . 7  |-  ( y  e.  { A ,  B ,  C }  ->  ( { { y ,  A } ,  { y ,  B } }  C_  E  -> 
( ( x  =  A  \/  x  =  B  \/  x  =  C )  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) ) )
171170imp 445 . . . . . 6  |-  ( ( y  e.  { A ,  B ,  C }  /\  { { y ,  A } ,  {
y ,  B } }  C_  E )  -> 
( ( x  =  A  \/  x  =  B  \/  x  =  C )  ->  ( { { x ,  A } ,  { x ,  B } }  C_  E  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) )
172171com3l 89 . . . . 5  |-  ( ( x  =  A  \/  x  =  B  \/  x  =  C )  ->  ( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( y  e.  { A ,  B ,  C }  /\  { {
y ,  A } ,  { y ,  B } }  C_  E )  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) )
1732, 172sylbi 207 . . . 4  |-  ( x  e.  { A ,  B ,  C }  ->  ( { { x ,  A } ,  {
x ,  B } }  C_  E  ->  (
( y  e.  { A ,  B ,  C }  /\  { {
y ,  A } ,  { y ,  B } }  C_  E )  ->  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/=  C
)  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) ) ) )
174173imp31 448 . . 3  |-  ( ( ( x  e.  { A ,  B ,  C }  /\  { {
x ,  A } ,  { x ,  B } }  C_  E )  /\  ( y  e. 
{ A ,  B ,  C }  /\  { { y ,  A } ,  { y ,  B } }  C_  E ) )  -> 
( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z )  /\  ( A  =/=  B  /\  A  =/=  C  /\  B  =/= 
C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  x  =  y ) )
175174com12 32 . 2  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  ( ( ( x  e.  { A ,  B ,  C }  /\  { { x ,  A } ,  {
x ,  B } }  C_  E )  /\  ( y  e.  { A ,  B ,  C }  /\  { {
y ,  A } ,  { y ,  B } }  C_  E ) )  ->  x  =  y ) )
176175alrimivv 1856 1  |-  ( ( ( A  e.  X  /\  B  e.  Y  /\  C  e.  Z
)  /\  ( A  =/=  B  /\  A  =/= 
C  /\  B  =/=  C )  /\  ( V  =  { A ,  B ,  C }  /\  G  e. USGraph  ) )  ->  A. x A. y
( ( ( x  e.  { A ,  B ,  C }  /\  { { x ,  A } ,  {
x ,  B } }  C_  E )  /\  ( y  e.  { A ,  B ,  C }  /\  { {
y ,  A } ,  { y ,  B } }  C_  E ) )  ->  x  =  y ) )
Colors of variables: wff setvar class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 384    \/ w3o 1036    /\ w3a 1037   A.wal 1481    = wceq 1483    e. wcel 1990    =/= wne 2794    C_ wss 3574   {cpr 4179   {ctp 4181   ` cfv 5888  Vtxcvtx 25874  Edgcedg 25939   USGraph cusgr 26044
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949  ax-cnex 9992  ax-resscn 9993  ax-1cn 9994  ax-icn 9995  ax-addcl 9996  ax-addrcl 9997  ax-mulcl 9998  ax-mulrcl 9999  ax-mulcom 10000  ax-addass 10001  ax-mulass 10002  ax-distr 10003  ax-i2m1 10004  ax-1ne0 10005  ax-1rid 10006  ax-rnegex 10007  ax-rrecex 10008  ax-cnre 10009  ax-pre-lttri 10010  ax-pre-lttrn 10011  ax-pre-ltadd 10012  ax-pre-mulgt0 10013
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-nel 2898  df-ral 2917  df-rex 2918  df-reu 2919  df-rmo 2920  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-pss 3590  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-tp 4182  df-op 4184  df-uni 4437  df-int 4476  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-tr 4753  df-id 5024  df-eprel 5029  df-po 5035  df-so 5036  df-fr 5073  df-we 5075  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-pred 5680  df-ord 5726  df-on 5727  df-lim 5728  df-suc 5729  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-riota 6611  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-om 7066  df-1st 7168  df-2nd 7169  df-wrecs 7407  df-recs 7468  df-rdg 7506  df-1o 7560  df-oadd 7564  df-er 7742  df-en 7956  df-dom 7957  df-sdom 7958  df-fin 7959  df-card 8765  df-cda 8990  df-pnf 10076  df-mnf 10077  df-xr 10078  df-ltxr 10079  df-le 10080  df-sub 10268  df-neg 10269  df-nn 11021  df-2 11079  df-n0 11293  df-z 11378  df-uz 11688  df-fz 12327  df-hash 13118  df-edg 25940  df-umgr 25978  df-usgr 26046
This theorem is referenced by:  frgr3vlem2  27138
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