MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  4cycl4dv4e Structured version   Unicode version

Theorem 4cycl4dv4e 24372
Description: If there is a cycle of length 4 in a graph, there are four (different) vertices in the graph which are mutually connected by edges. (Contributed by Alexander van der Vekens, 9-Nov-2017.)
Assertion
Ref Expression
4cycl4dv4e  |-  ( ( V USGrph  E  /\  F ( V Cycles  E ) P  /\  ( # `  F
)  =  4 )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) )
Distinct variable groups:    E, a,
b, c, d    P, a, b, c, d    V, a, b, c, d
Allowed substitution hints:    F( a, b, c, d)

Proof of Theorem 4cycl4dv4e
Dummy variable  k is distinct from all other variables.
StepHypRef Expression
1 cycliswlk 24336 . . . . 5  |-  ( F ( V Cycles  E ) P  ->  F ( V Walks  E ) P )
2 wlkbprop 24227 . . . . 5  |-  ( F ( V Walks  E ) P  ->  ( ( # `
 F )  e. 
NN0  /\  ( V  e.  _V  /\  E  e. 
_V )  /\  ( F  e.  _V  /\  P  e.  _V ) ) )
31, 2syl 16 . . . 4  |-  ( F ( V Cycles  E ) P  ->  ( ( # `
 F )  e. 
NN0  /\  ( V  e.  _V  /\  E  e. 
_V )  /\  ( F  e.  _V  /\  P  e.  _V ) ) )
4 iscycl 24329 . . . . . 6  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Cycles  E ) P 
<->  ( F ( V Paths 
E ) P  /\  ( P `  0 )  =  ( P `  ( # `  F ) ) ) ) )
5 ispth 24274 . . . . . . . 8  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Paths  E ) P 
<->  ( F ( V Trails  E ) P  /\  Fun  `' ( P  |`  ( 1..^ ( # `  F
) ) )  /\  ( ( P " { 0 ,  (
# `  F ) } )  i^i  ( P " ( 1..^ (
# `  F )
) ) )  =  (/) ) ) )
6 istrl 24243 . . . . . . . . . 10  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Trails  E ) P 
<->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... ( # `  F
) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F
) ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } ) ) )
7 fzo0to42pr 11869 . . . . . . . . . . . . . . . . . . . 20  |-  ( 0..^ 4 )  =  ( { 0 ,  1 }  u.  { 2 ,  3 } )
87raleqi 3062 . . . . . . . . . . . . . . . . . . 19  |-  ( A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  A. k  e.  ( { 0 ,  1 }  u.  { 2 ,  3 } ) ( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )
9 ralunb 3685 . . . . . . . . . . . . . . . . . . 19  |-  ( A. k  e.  ( {
0 ,  1 }  u.  { 2 ,  3 } ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) }  <->  ( A. k  e.  { 0 ,  1 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  /\  A. k  e.  { 2 ,  3 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } ) )
10 0z 10875 . . . . . . . . . . . . . . . . . . . . 21  |-  0  e.  ZZ
11 1z 10894 . . . . . . . . . . . . . . . . . . . . 21  |-  1  e.  ZZ
12 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  0  ->  ( F `  k )  =  ( F ` 
0 ) )
1312fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  0  ->  ( E `  ( F `  k ) )  =  ( E `  ( F `  0 )
) )
14 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  0  ->  ( P `  k )  =  ( P ` 
0 ) )
15 oveq1 6291 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( k  =  0  ->  (
k  +  1 )  =  ( 0  +  1 ) )
16 0p1e1 10647 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( 0  +  1 )  =  1
1715, 16syl6eq 2524 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( k  =  0  ->  (
k  +  1 )  =  1 )
1817fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  0  ->  ( P `  ( k  +  1 ) )  =  ( P ` 
1 ) )
1914, 18preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  0  ->  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  =  { ( P ` 
0 ) ,  ( P `  1 ) } )
2013, 19eqeq12d 2489 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( k  =  0  ->  (
( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( E `  ( F `  0
) )  =  {
( P `  0
) ,  ( P `
 1 ) } ) )
21 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  1  ->  ( F `  k )  =  ( F ` 
1 ) )
2221fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  1  ->  ( E `  ( F `  k ) )  =  ( E `  ( F `  1 )
) )
23 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  1  ->  ( P `  k )  =  ( P ` 
1 ) )
24 oveq1 6291 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( k  =  1  ->  (
k  +  1 )  =  ( 1  +  1 ) )
25 1p1e2 10649 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( 1  +  1 )  =  2
2624, 25syl6eq 2524 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( k  =  1  ->  (
k  +  1 )  =  2 )
2726fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  1  ->  ( P `  ( k  +  1 ) )  =  ( P ` 
2 ) )
2823, 27preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  1  ->  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  =  { ( P ` 
1 ) ,  ( P `  2 ) } )
2922, 28eqeq12d 2489 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( k  =  1  ->  (
( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( E `  ( F `  1
) )  =  {
( P `  1
) ,  ( P `
 2 ) } ) )
3020, 29ralprg 4076 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( 0  e.  ZZ  /\  1  e.  ZZ )  ->  ( A. k  e. 
{ 0 ,  1 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( ( E `  ( F `  0 ) )  =  { ( P `
 0 ) ,  ( P `  1
) }  /\  ( E `  ( F `  1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } ) ) )
3110, 11, 30mp2an 672 . . . . . . . . . . . . . . . . . . . 20  |-  ( A. k  e.  { 0 ,  1 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( ( E `
 ( F ` 
0 ) )  =  { ( P ` 
0 ) ,  ( P `  1 ) }  /\  ( E `
 ( F ` 
1 ) )  =  { ( P ` 
1 ) ,  ( P `  2 ) } ) )
32 2z 10896 . . . . . . . . . . . . . . . . . . . . 21  |-  2  e.  ZZ
33 3z 10897 . . . . . . . . . . . . . . . . . . . . 21  |-  3  e.  ZZ
34 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  2  ->  ( F `  k )  =  ( F ` 
2 ) )
3534fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  2  ->  ( E `  ( F `  k ) )  =  ( E `  ( F `  2 )
) )
36 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  2  ->  ( P `  k )  =  ( P ` 
2 ) )
37 oveq1 6291 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( k  =  2  ->  (
k  +  1 )  =  ( 2  +  1 ) )
38 2p1e3 10659 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( 2  +  1 )  =  3
3937, 38syl6eq 2524 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( k  =  2  ->  (
k  +  1 )  =  3 )
4039fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  2  ->  ( P `  ( k  +  1 ) )  =  ( P ` 
3 ) )
4136, 40preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  2  ->  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  =  { ( P ` 
2 ) ,  ( P `  3 ) } )
4235, 41eqeq12d 2489 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( k  =  2  ->  (
( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( E `  ( F `  2
) )  =  {
( P `  2
) ,  ( P `
 3 ) } ) )
43 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  3  ->  ( F `  k )  =  ( F ` 
3 ) )
4443fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  3  ->  ( E `  ( F `  k ) )  =  ( E `  ( F `  3 )
) )
45 fveq2 5866 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  3  ->  ( P `  k )  =  ( P ` 
3 ) )
46 oveq1 6291 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( k  =  3  ->  (
k  +  1 )  =  ( 3  +  1 ) )
47 3p1e4 10661 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( 3  +  1 )  =  4
4846, 47syl6eq 2524 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( k  =  3  ->  (
k  +  1 )  =  4 )
4948fveq2d 5870 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( k  =  3  ->  ( P `  ( k  +  1 ) )  =  ( P ` 
4 ) )
5045, 49preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( k  =  3  ->  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  =  { ( P ` 
3 ) ,  ( P `  4 ) } )
5144, 50eqeq12d 2489 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( k  =  3  ->  (
( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( E `  ( F `  3
) )  =  {
( P `  3
) ,  ( P `
 4 ) } ) )
5242, 51ralprg 4076 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( 2  e.  ZZ  /\  3  e.  ZZ )  ->  ( A. k  e. 
{ 2 ,  3 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( ( E `  ( F `  2 ) )  =  { ( P `
 2 ) ,  ( P `  3
) }  /\  ( E `  ( F `  3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) ) )
5332, 33, 52mp2an 672 . . . . . . . . . . . . . . . . . . . 20  |-  ( A. k  e.  { 2 ,  3 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( ( E `
 ( F ` 
2 ) )  =  { ( P ` 
2 ) ,  ( P `  3 ) }  /\  ( E `
 ( F ` 
3 ) )  =  { ( P ` 
3 ) ,  ( P `  4 ) } ) )
5431, 53anbi12i 697 . . . . . . . . . . . . . . . . . . 19  |-  ( ( A. k  e.  {
0 ,  1 }  ( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  /\  A. k  e.  { 2 ,  3 }  ( E `  ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  <->  ( (
( E `  ( F `  0 )
)  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) ) )
558, 9, 543bitri 271 . . . . . . . . . . . . . . . . . 18  |-  ( A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  ( ( ( E `  ( F `
 0 ) )  =  { ( P `
 0 ) ,  ( P `  1
) }  /\  ( E `  ( F `  1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) ) )
56 preq2 4107 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( ( P `  4 )  =  ( P ` 
0 )  ->  { ( P `  3 ) ,  ( P ` 
4 ) }  =  { ( P ` 
3 ) ,  ( P `  0 ) } )
5756eqcoms 2479 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( ( P `  0 )  =  ( P ` 
4 )  ->  { ( P `  3 ) ,  ( P ` 
4 ) }  =  { ( P ` 
3 ) ,  ( P `  0 ) } )
5857eqeq2d 2481 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( ( P `  0 )  =  ( P ` 
4 )  ->  (
( E `  ( F `  3 )
)  =  { ( P `  3 ) ,  ( P ` 
4 ) }  <->  ( E `  ( F `  3
) )  =  {
( P `  3
) ,  ( P `
 0 ) } ) )
5958anbi2d 703 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( ( P `  0 )  =  ( P ` 
4 )  ->  (
( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } )  <->  ( ( E `  ( F `  2 ) )  =  { ( P `
 2 ) ,  ( P `  3
) }  /\  ( E `  ( F `  3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) ) )
6059anbi2d 703 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( P `  0 )  =  ( P ` 
4 )  ->  (
( ( ( E `
 ( F ` 
0 ) )  =  { ( P ` 
0 ) ,  ( P `  1 ) }  /\  ( E `
 ( F ` 
1 ) )  =  { ( P ` 
1 ) ,  ( P `  2 ) } )  /\  (
( E `  ( F `  2 )
)  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) )  <-> 
( ( ( E `
 ( F ` 
0 ) )  =  { ( P ` 
0 ) ,  ( P `  1 ) }  /\  ( E `
 ( F ` 
1 ) )  =  { ( P ` 
1 ) ,  ( P `  2 ) } )  /\  (
( E `  ( F `  2 )
)  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) ) ) )
61 simpll 753 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F ) )  /\  ( # `  F )  =  4 )  ->  V USGrph  E )
62 simplrl 759 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F ) )  /\  ( # `  F )  =  4 )  ->  F  e. Word  dom 
E )
63 simplrr 760 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F ) )  /\  ( # `  F )  =  4 )  ->  Fun  `' F
)
64 simpr 461 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F ) )  /\  ( # `  F )  =  4 )  ->  ( # `  F
)  =  4 )
65 4cycl4dv 24371 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F  /\  ( # `
 F )  =  4 ) )  -> 
( ( ( ( E `  ( F `
 0 ) )  =  { ( P `
 0 ) ,  ( P `  1
) }  /\  ( E `  ( F `  1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) )  ->  ( ( ( { ( P ` 
0 ) ,  ( P `  1 ) }  e.  ran  E  /\  { ( P ` 
1 ) ,  ( P `  2 ) }  e.  ran  E
)  /\  ( {
( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E ) )  /\  ( ( ( P `  0
)  =/=  ( P `
 1 )  /\  ( P `  0 )  =/=  ( P ` 
2 )  /\  ( P `  0 )  =/=  ( P `  3
) )  /\  (
( P `  1
)  =/=  ( P `
 2 )  /\  ( P `  1 )  =/=  ( P ` 
3 )  /\  ( P `  2 )  =/=  ( P `  3
) ) ) ) ) )
6661, 62, 63, 64, 65syl13anc 1230 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F ) )  /\  ( # `  F )  =  4 )  ->  ( (
( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) )  ->  ( ( ( { ( P ` 
0 ) ,  ( P `  1 ) }  e.  ran  E  /\  { ( P ` 
1 ) ,  ( P `  2 ) }  e.  ran  E
)  /\  ( {
( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E ) )  /\  ( ( ( P `  0
)  =/=  ( P `
 1 )  /\  ( P `  0 )  =/=  ( P ` 
2 )  /\  ( P `  0 )  =/=  ( P `  3
) )  /\  (
( P `  1
)  =/=  ( P `
 2 )  /\  ( P `  1 )  =/=  ( P ` 
3 )  /\  ( P `  2 )  =/=  ( P `  3
) ) ) ) ) )
6766imp 429 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F
) )  /\  ( # `
 F )  =  4 )  /\  (
( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) ) )  ->  ( (
( { ( P `
 0 ) ,  ( P `  1
) }  e.  ran  E  /\  { ( P `
 1 ) ,  ( P `  2
) }  e.  ran  E )  /\  ( { ( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E ) )  /\  ( ( ( P `  0
)  =/=  ( P `
 1 )  /\  ( P `  0 )  =/=  ( P ` 
2 )  /\  ( P `  0 )  =/=  ( P `  3
) )  /\  (
( P `  1
)  =/=  ( P `
 2 )  /\  ( P `  1 )  =/=  ( P ` 
3 )  /\  ( P `  2 )  =/=  ( P `  3
) ) ) ) )
68 4nn0 10814 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  |-  4  e.  NN0
6968nn0zi 10889 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  4  e.  ZZ
70 3re 10609 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  |-  3  e.  RR
71 4re 10612 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  |-  4  e.  RR
72 3lt4 10705 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  |-  3  <  4
7370, 71, 72ltleii 9707 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  3  <_  4
74 eluz2 11088 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( 4  e.  ( ZZ>= `  3
)  <->  ( 3  e.  ZZ  /\  4  e.  ZZ  /\  3  <_ 
4 ) )
7533, 69, 73, 74mpbir3an 1178 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  4  e.  ( ZZ>= `  3 )
76 4fvwrd4 11790 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( ( 4  e.  ( ZZ>= ` 
3 )  /\  P : ( 0 ... 4 ) --> V )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( P `
 0 )  =  a  /\  ( P `
 1 )  =  b )  /\  (
( P `  2
)  =  c  /\  ( P `  3 )  =  d ) ) )
7775, 76mpan 670 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( P : ( 0 ... 4 ) --> V  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( P `
 0 )  =  a  /\  ( P `
 1 )  =  b )  /\  (
( P `  2
)  =  c  /\  ( P `  3 )  =  d ) ) )
78 preq12 4108 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( P `  0
)  =  a  /\  ( P `  1 )  =  b )  ->  { ( P ` 
0 ) ,  ( P `  1 ) }  =  { a ,  b } )
7978adantr 465 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  { ( P `
 0 ) ,  ( P `  1
) }  =  {
a ,  b } )
8079eleq1d 2536 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  <->  { a ,  b }  e.  ran  E
) )
81 simplr 754 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( P ` 
1 )  =  b )
82 simprl 755 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( P ` 
2 )  =  c )
8381, 82preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  { ( P `
 1 ) ,  ( P `  2
) }  =  {
b ,  c } )
8483eleq1d 2536 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E  <->  { b ,  c }  e.  ran  E
) )
8580, 84anbi12d 710 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( { ( P `  0
) ,  ( P `
 1 ) }  e.  ran  E  /\  { ( P `  1
) ,  ( P `
 2 ) }  e.  ran  E )  <-> 
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E ) ) )
86 preq12 4108 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( P `  2
)  =  c  /\  ( P `  3 )  =  d )  ->  { ( P ` 
2 ) ,  ( P `  3 ) }  =  { c ,  d } )
8786adantl 466 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  { ( P `
 2 ) ,  ( P `  3
) }  =  {
c ,  d } )
8887eleq1d 2536 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( { ( P `  2 ) ,  ( P ` 
3 ) }  e.  ran  E  <->  { c ,  d }  e.  ran  E
) )
89 simprr 756 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( P ` 
3 )  =  d )
90 simpll 753 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( P ` 
0 )  =  a )
9189, 90preq12d 4114 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  { ( P `
 3 ) ,  ( P `  0
) }  =  {
d ,  a } )
9291eleq1d 2536 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( { ( P `  3 ) ,  ( P ` 
0 ) }  e.  ran  E  <->  { d ,  a }  e.  ran  E
) )
9388, 92anbi12d 710 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( { ( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E )  <-> 
( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) ) )
9485, 93anbi12d 710 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( { ( P ` 
0 ) ,  ( P `  1 ) }  e.  ran  E  /\  { ( P ` 
1 ) ,  ( P `  2 ) }  e.  ran  E
)  /\  ( {
( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E ) )  <->  ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) ) ) )
9590, 81neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 0 )  =/=  ( P `  1
)  <->  a  =/=  b
) )
9690, 82neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 0 )  =/=  ( P `  2
)  <->  a  =/=  c
) )
9790, 89neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 0 )  =/=  ( P `  3
)  <->  a  =/=  d
) )
9895, 96, 973anbi123d 1299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( P `  0 )  =/=  ( P ` 
1 )  /\  ( P `  0 )  =/=  ( P `  2
)  /\  ( P `  0 )  =/=  ( P `  3
) )  <->  ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d ) ) )
9981, 82neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 1 )  =/=  ( P `  2
)  <->  b  =/=  c
) )
10081, 89neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 1 )  =/=  ( P `  3
)  <->  b  =/=  d
) )
101 simpl 457 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( P `  2
)  =  c  /\  ( P `  3 )  =  d )  -> 
( P `  2
)  =  c )
102 simpr 461 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35  |-  ( ( ( P `  2
)  =  c  /\  ( P `  3 )  =  d )  -> 
( P `  3
)  =  d )
103101, 102neeq12d 2746 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34  |-  ( ( ( P `  2
)  =  c  /\  ( P `  3 )  =  d )  -> 
( ( P ` 
2 )  =/=  ( P `  3 )  <->  c  =/=  d ) )
104103adantl 466 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( P `
 2 )  =/=  ( P `  3
)  <->  c  =/=  d
) )
10599, 100, 1043anbi123d 1299 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( P `  1 )  =/=  ( P ` 
2 )  /\  ( P `  1 )  =/=  ( P `  3
)  /\  ( P `  2 )  =/=  ( P `  3
) )  <->  ( b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) )
10698, 105anbi12d 710 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( ( P `  0
)  =/=  ( P `
 1 )  /\  ( P `  0 )  =/=  ( P ` 
2 )  /\  ( P `  0 )  =/=  ( P `  3
) )  /\  (
( P `  1
)  =/=  ( P `
 2 )  /\  ( P `  1 )  =/=  ( P ` 
3 )  /\  ( P `  2 )  =/=  ( P `  3
) ) )  <->  ( (
a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) )
10794, 106anbi12d 710 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30  |-  ( ( ( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( ( { ( P `
 0 ) ,  ( P `  1
) }  e.  ran  E  /\  { ( P `
 1 ) ,  ( P `  2
) }  e.  ran  E )  /\  ( { ( P `  2
) ,  ( P `
 3 ) }  e.  ran  E  /\  { ( P `  3
) ,  ( P `
 0 ) }  e.  ran  E ) )  /\  ( ( ( P `  0
)  =/=  ( P `
 1 )  /\  ( P `  0 )  =/=  ( P ` 
2 )  /\  ( P `  0 )  =/=  ( P `  3
) )  /\  (
( P `  1
)  =/=  ( P `
 2 )  /\  ( P `  1 )  =/=  ( P ` 
3 )  /\  ( P `  2 )  =/=  ( P `  3
) ) ) )  <-> 
( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
108107biimpcd 224 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  |-  ( ( ( ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  /\  { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E )  /\  ( { ( P ` 
2 ) ,  ( P `  3 ) }  e.  ran  E  /\  { ( P ` 
3 ) ,  ( P `  0 ) }  e.  ran  E
) )  /\  (
( ( P ` 
0 )  =/=  ( P `  1 )  /\  ( P `  0
)  =/=  ( P `
 2 )  /\  ( P `  0 )  =/=  ( P ` 
3 ) )  /\  ( ( P ` 
1 )  =/=  ( P `  2 )  /\  ( P `  1
)  =/=  ( P `
 3 )  /\  ( P `  2 )  =/=  ( P ` 
3 ) ) ) )  ->  ( (
( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E
)  /\  ( {
c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
109108reximdv 2937 . . . . . . . . . . . . . . . . . . . . . . . . . . . 28  |-  ( ( ( ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  /\  { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E )  /\  ( { ( P ` 
2 ) ,  ( P `  3 ) }  e.  ran  E  /\  { ( P ` 
3 ) ,  ( P `  0 ) }  e.  ran  E
) )  /\  (
( ( P ` 
0 )  =/=  ( P `  1 )  /\  ( P `  0
)  =/=  ( P `
 2 )  /\  ( P `  0 )  =/=  ( P ` 
3 ) )  /\  ( ( P ` 
1 )  =/=  ( P `  2 )  /\  ( P `  1
)  =/=  ( P `
 3 )  /\  ( P `  2 )  =/=  ( P ` 
3 ) ) ) )  ->  ( E. d  e.  V  (
( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
110109reximdv 2937 . . . . . . . . . . . . . . . . . . . . . . . . . . 27  |-  ( ( ( ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  /\  { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E )  /\  ( { ( P ` 
2 ) ,  ( P `  3 ) }  e.  ran  E  /\  { ( P ` 
3 ) ,  ( P `  0 ) }  e.  ran  E
) )  /\  (
( ( P ` 
0 )  =/=  ( P `  1 )  /\  ( P `  0
)  =/=  ( P `
 2 )  /\  ( P `  0 )  =/=  ( P ` 
3 ) )  /\  ( ( P ` 
1 )  =/=  ( P `  2 )  /\  ( P `  1
)  =/=  ( P `
 3 )  /\  ( P `  2 )  =/=  ( P ` 
3 ) ) ) )  ->  ( E. c  e.  V  E. d  e.  V  (
( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
111110reximdv 2937 . . . . . . . . . . . . . . . . . . . . . . . . . 26  |-  ( ( ( ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  /\  { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E )  /\  ( { ( P ` 
2 ) ,  ( P `  3 ) }  e.  ran  E  /\  { ( P ` 
3 ) ,  ( P `  0 ) }  e.  ran  E
) )  /\  (
( ( P ` 
0 )  =/=  ( P `  1 )  /\  ( P `  0
)  =/=  ( P `
 2 )  /\  ( P `  0 )  =/=  ( P ` 
3 ) )  /\  ( ( P ` 
1 )  =/=  ( P `  2 )  /\  ( P `  1
)  =/=  ( P `
 3 )  /\  ( P `  2 )  =/=  ( P ` 
3 ) ) ) )  ->  ( E. b  e.  V  E. c  e.  V  E. d  e.  V  (
( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
112111reximdv 2937 . . . . . . . . . . . . . . . . . . . . . . . . 25  |-  ( ( ( ( { ( P `  0 ) ,  ( P ` 
1 ) }  e.  ran  E  /\  { ( P `  1 ) ,  ( P ` 
2 ) }  e.  ran  E )  /\  ( { ( P ` 
2 ) ,  ( P `  3 ) }  e.  ran  E  /\  { ( P ` 
3 ) ,  ( P `  0 ) }  e.  ran  E
) )  /\  (
( ( P ` 
0 )  =/=  ( P `  1 )  /\  ( P `  0
)  =/=  ( P `
 2 )  /\  ( P `  0 )  =/=  ( P ` 
3 ) )  /\  ( ( P ` 
1 )  =/=  ( P `  2 )  /\  ( P `  1
)  =/=  ( P `
 3 )  /\  ( P `  2 )  =/=  ( P ` 
3 ) ) ) )  ->  ( E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  (
( ( P ` 
0 )  =  a  /\  ( P ` 
1 )  =  b )  /\  ( ( P `  2 )  =  c  /\  ( P `  3 )  =  d ) )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
11367, 77, 112syl2im 38 . . . . . . . . . . . . . . . . . . . . . . . 24  |-  ( ( ( ( V USGrph  E  /\  ( F  e. Word  dom  E  /\  Fun  `' F
) )  /\  ( # `
 F )  =  4 )  /\  (
( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) ) )  ->  ( P : ( 0 ... 4 ) --> V  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )
114113exp41 610 . . . . . . . . . . . . . . . . . . . . . . 23  |-  ( V USGrph  E  ->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  (
( # `  F )  =  4  ->  (
( ( ( E `
 ( F ` 
0 ) )  =  { ( P ` 
0 ) ,  ( P `  1 ) }  /\  ( E `
 ( F ` 
1 ) )  =  { ( P ` 
1 ) ,  ( P `  2 ) } )  /\  (
( E `  ( F `  2 )
)  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) )  ->  ( P :
( 0 ... 4
) --> V  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
115114com14 88 . . . . . . . . . . . . . . . . . . . . . 22  |-  ( ( ( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) )  ->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  (
( # `  F )  =  4  ->  ( V USGrph  E  ->  ( P : ( 0 ... 4 ) --> V  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
116115com35 90 . . . . . . . . . . . . . . . . . . . . 21  |-  ( ( ( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  0
) } ) )  ->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  ( P : ( 0 ... 4 ) --> V  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
11760, 116syl6bi 228 . . . . . . . . . . . . . . . . . . . 20  |-  ( ( P `  0 )  =  ( P ` 
4 )  ->  (
( ( ( E `
 ( F ` 
0 ) )  =  { ( P ` 
0 ) ,  ( P `  1 ) }  /\  ( E `
 ( F ` 
1 ) )  =  { ( P ` 
1 ) ,  ( P `  2 ) } )  /\  (
( E `  ( F `  2 )
)  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) )  ->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  ( P : ( 0 ... 4 ) --> V  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
118117com12 31 . . . . . . . . . . . . . . . . . . 19  |-  ( ( ( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) )  ->  ( ( P `
 0 )  =  ( P `  4
)  ->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  ( P : ( 0 ... 4 ) --> V  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
119118com24 87 . . . . . . . . . . . . . . . . . 18  |-  ( ( ( ( E `  ( F `  0 ) )  =  { ( P `  0 ) ,  ( P ` 
1 ) }  /\  ( E `  ( F `
 1 ) )  =  { ( P `
 1 ) ,  ( P `  2
) } )  /\  ( ( E `  ( F `  2 ) )  =  { ( P `  2 ) ,  ( P ` 
3 ) }  /\  ( E `  ( F `
 3 ) )  =  { ( P `
 3 ) ,  ( P `  4
) } ) )  ->  ( P :
( 0 ... 4
) --> V  ->  (
( F  e. Word  dom  E  /\  Fun  `' F
)  ->  ( ( P `  0 )  =  ( P ` 
4 )  ->  ( V USGrph  E  ->  ( ( # `
 F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
12055, 119sylbi 195 . . . . . . . . . . . . . . . . 17  |-  ( A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  ->  ( P : ( 0 ... 4 ) --> V  -> 
( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  (
( P `  0
)  =  ( P `
 4 )  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
121120com13 80 . . . . . . . . . . . . . . . 16  |-  ( ( F  e. Word  dom  E  /\  Fun  `' F )  ->  ( P :
( 0 ... 4
) --> V  ->  ( A. k  e.  (
0..^ 4 ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) }  ->  (
( P `  0
)  =  ( P `
 4 )  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
1221213imp 1190 . . . . . . . . . . . . . . 15  |-  ( ( ( F  e. Word  dom  E  /\  Fun  `' F
)  /\  P :
( 0 ... 4
) --> V  /\  A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  (
( P `  0
)  =  ( P `
 4 )  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
123122com14 88 . . . . . . . . . . . . . 14  |-  ( (
# `  F )  =  4  ->  (
( P `  0
)  =  ( P `
 4 )  -> 
( V USGrph  E  ->  ( ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... 4 ) --> V  /\  A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
124 fveq2 5866 . . . . . . . . . . . . . . 15  |-  ( (
# `  F )  =  4  ->  ( P `  ( # `  F
) )  =  ( P `  4 ) )
125124eqeq2d 2481 . . . . . . . . . . . . . 14  |-  ( (
# `  F )  =  4  ->  (
( P `  0
)  =  ( P `
 ( # `  F
) )  <->  ( P `  0 )  =  ( P `  4
) ) )
126 oveq2 6292 . . . . . . . . . . . . . . . . . 18  |-  ( (
# `  F )  =  4  ->  (
0 ... ( # `  F
) )  =  ( 0 ... 4 ) )
127126feq2d 5718 . . . . . . . . . . . . . . . . 17  |-  ( (
# `  F )  =  4  ->  ( P : ( 0 ... ( # `  F
) ) --> V  <->  P :
( 0 ... 4
) --> V ) )
128 oveq2 6292 . . . . . . . . . . . . . . . . . 18  |-  ( (
# `  F )  =  4  ->  (
0..^ ( # `  F
) )  =  ( 0..^ 4 ) )
129128raleqdv 3064 . . . . . . . . . . . . . . . . 17  |-  ( (
# `  F )  =  4  ->  ( A. k  e.  (
0..^ ( # `  F
) ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) }  <->  A. k  e.  ( 0..^ 4 ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) } ) )
130127, 1293anbi23d 1302 . . . . . . . . . . . . . . . 16  |-  ( (
# `  F )  =  4  ->  (
( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... ( # `  F
) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F
) ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  <->  ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... 4 ) --> V  /\  A. k  e.  ( 0..^ 4 ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } ) ) )
131130imbi1d 317 . . . . . . . . . . . . . . 15  |-  ( (
# `  F )  =  4  ->  (
( ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... ( # `  F
) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F
) ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) )  <->  ( ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... 4 ) --> V  /\  A. k  e.  ( 0..^ 4 ) ( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) )
132131imbi2d 316 . . . . . . . . . . . . . 14  |-  ( (
# `  F )  =  4  ->  (
( V USGrph  E  ->  ( ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... ( # `  F
) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F
) ) ( E `
 ( F `  k ) )  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) )  <->  ( V USGrph  E  ->  ( ( ( F  e. Word  dom  E  /\  Fun  `' F )  /\  P : ( 0 ... 4 ) --> V  /\  A. k  e.  ( 0..^ 4 ) ( E `  ( F `  k )
)  =  { ( P `  k ) ,  ( P `  ( k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
133123, 125, 1323imtr4d 268 . . . . . . . . . . . . 13  |-  ( (
# `  F )  =  4  ->  (
( P `  0
)  =  ( P `
 ( # `  F
) )  ->  ( V USGrph  E  ->  ( (
( F  e. Word  dom  E  /\  Fun  `' F
)  /\  P :
( 0 ... ( # `
 F ) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F ) ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) } )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
134133com14 88 . . . . . . . . . . . 12  |-  ( ( ( F  e. Word  dom  E  /\  Fun  `' F
)  /\  P :
( 0 ... ( # `
 F ) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F ) ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) } )  -> 
( ( P ` 
0 )  =  ( P `  ( # `  F ) )  -> 
( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
135134a1d 25 . . . . . . . . . . 11  |-  ( ( ( F  e. Word  dom  E  /\  Fun  `' F
)  /\  P :
( 0 ... ( # `
 F ) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F ) ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) } )  -> 
( ( ( P
" { 0 ,  ( # `  F
) } )  i^i  ( P " (
1..^ ( # `  F
) ) ) )  =  (/)  ->  ( ( P `  0 )  =  ( P `  ( # `  F ) )  ->  ( V USGrph  E  ->  ( ( # `  F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
136135a1d 25 . . . . . . . . . 10  |-  ( ( ( F  e. Word  dom  E  /\  Fun  `' F
)  /\  P :
( 0 ... ( # `
 F ) ) --> V  /\  A. k  e.  ( 0..^ ( # `  F ) ) ( E `  ( F `
 k ) )  =  { ( P `
 k ) ,  ( P `  (
k  +  1 ) ) } )  -> 
( Fun  `' ( P  |`  ( 1..^ (
# `  F )
) )  ->  (
( ( P " { 0 ,  (
# `  F ) } )  i^i  ( P " ( 1..^ (
# `  F )
) ) )  =  (/)  ->  ( ( P `
 0 )  =  ( P `  ( # `
 F ) )  ->  ( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) )
1376, 136syl6bi 228 . . . . . . . . 9  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Trails  E ) P  ->  ( Fun  `' ( P  |`  ( 1..^ ( # `  F
) ) )  -> 
( ( ( P
" { 0 ,  ( # `  F
) } )  i^i  ( P " (
1..^ ( # `  F
) ) ) )  =  (/)  ->  ( ( P `  0 )  =  ( P `  ( # `  F ) )  ->  ( V USGrph  E  ->  ( ( # `  F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) ) ) )
1381373impd 1210 . . . . . . . 8  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( ( F ( V Trails  E
) P  /\  Fun  `' ( P  |`  (
1..^ ( # `  F
) ) )  /\  ( ( P " { 0 ,  (
# `  F ) } )  i^i  ( P " ( 1..^ (
# `  F )
) ) )  =  (/) )  ->  ( ( P `  0 )  =  ( P `  ( # `  F ) )  ->  ( V USGrph  E  ->  ( ( # `  F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
1395, 138sylbid 215 . . . . . . 7  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Paths  E ) P  ->  ( ( P `
 0 )  =  ( P `  ( # `
 F ) )  ->  ( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) ) )
140139impd 431 . . . . . 6  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( ( F ( V Paths  E
) P  /\  ( P `  0 )  =  ( P `  ( # `  F ) ) )  ->  ( V USGrph  E  ->  ( ( # `
 F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( (
( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
1414, 140sylbid 215 . . . . 5  |-  ( ( ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Cycles  E ) P  ->  ( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
1421413adant1 1014 . . . 4  |-  ( ( ( # `  F
)  e.  NN0  /\  ( V  e.  _V  /\  E  e.  _V )  /\  ( F  e.  _V  /\  P  e.  _V )
)  ->  ( F
( V Cycles  E ) P  ->  ( V USGrph  E  ->  ( ( # `  F
)  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) ) )
1433, 142mpcom 36 . . 3  |-  ( F ( V Cycles  E ) P  ->  ( V USGrph  E  ->  ( ( # `  F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) )
144143com12 31 . 2  |-  ( V USGrph  E  ->  ( F ( V Cycles  E ) P  ->  ( ( # `  F )  =  4  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) ) ) )
1451443imp 1190 1  |-  ( ( V USGrph  E  /\  F ( V Cycles  E ) P  /\  ( # `  F
)  =  4 )  ->  E. a  e.  V  E. b  e.  V  E. c  e.  V  E. d  e.  V  ( ( ( { a ,  b }  e.  ran  E  /\  { b ,  c }  e.  ran  E )  /\  ( { c ,  d }  e.  ran  E  /\  { d ,  a }  e.  ran  E ) )  /\  ( ( a  =/=  b  /\  a  =/=  c  /\  a  =/=  d )  /\  (
b  =/=  c  /\  b  =/=  d  /\  c  =/=  d ) ) ) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    <-> wb 184    /\ wa 369    /\ w3a 973    = wceq 1379    e. wcel 1767    =/= wne 2662   A.wral 2814   E.wrex 2815   _Vcvv 3113    u. cun 3474    i^i cin 3475   (/)c0 3785   {cpr 4029   class class class wbr 4447   `'ccnv 4998   dom cdm 4999   ran crn 5000    |` cres 5001   "cima 5002   Fun wfun 5582   -->wf 5584   ` cfv 5588  (class class class)co 6284   0cc0 9492   1c1 9493    + caddc 9495    <_ cle 9629   2c2 10585   3c3 10586   4c4 10587   NN0cn0 10795   ZZcz 10864   ZZ>=cuz 11082   ...cfz 11672  ..^cfzo 11792   #chash 12373  Word cword 12500   USGrph cusg 24034   Walks cwalk 24202   Trails ctrail 24203   Paths cpath 24204   Cycles ccycl 24211
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1601  ax-4 1612  ax-5 1680  ax-6 1719  ax-7 1739  ax-8 1769  ax-9 1771  ax-10 1786  ax-11 1791  ax-12 1803  ax-13 1968  ax-ext 2445  ax-rep 4558  ax-sep 4568  ax-nul 4576  ax-pow 4625  ax-pr 4686  ax-un 6576  ax-cnex 9548  ax-resscn 9549  ax-1cn 9550  ax-icn 9551  ax-addcl 9552  ax-addrcl 9553  ax-mulcl 9554  ax-mulrcl 9555  ax-mulcom 9556  ax-addass 9557  ax-mulass 9558  ax-distr 9559  ax-i2m1 9560  ax-1ne0 9561  ax-1rid 9562  ax-rnegex 9563  ax-rrecex 9564  ax-cnre 9565  ax-pre-lttri 9566  ax-pre-lttrn 9567  ax-pre-ltadd 9568  ax-pre-mulgt0 9569
This theorem depends on definitions:  df-bi 185  df-or 370  df-an 371  df-3or 974  df-3an 975  df-tru 1382  df-ex 1597  df-nf 1600  df-sb 1712  df-eu 2279  df-mo 2280  df-clab 2453  df-cleq 2459  df-clel 2462  df-nfc 2617  df-ne 2664  df-nel 2665  df-ral 2819  df-rex 2820  df-reu 2821  df-rmo 2822  df-rab 2823  df-v 3115  df-sbc 3332  df-csb 3436  df-dif 3479  df-un 3481  df-in 3483  df-ss 3490  df-pss 3492  df-nul 3786  df-if 3940  df-pw 4012  df-sn 4028  df-pr 4030  df-tp 4032  df-op 4034  df-uni 4246  df-int 4283  df-iun 4327  df-br 4448  df-opab 4506  df-mpt 4507  df-tr 4541  df-eprel 4791  df-id 4795  df-po 4800  df-so 4801  df-fr 4838  df-we 4840  df-ord 4881  df-on 4882  df-lim 4883  df-suc 4884  df-xp 5005  df-rel 5006  df-cnv 5007  df-co 5008  df-dm 5009  df-rn 5010  df-res 5011  df-ima 5012  df-iota 5551  df-fun 5590  df-fn 5591  df-f 5592  df-f1 5593  df-fo 5594  df-f1o 5595  df-fv 5596  df-riota 6245  df-ov 6287  df-oprab 6288  df-mpt2 6289  df-om 6685  df-1st 6784  df-2nd 6785  df-recs 7042  df-rdg 7076  df-1o 7130  df-oadd 7134  df-er 7311  df-map 7422  df-pm 7423  df-en 7517  df-dom 7518  df-sdom 7519  df-fin 7520  df-card 8320  df-cda 8548  df-pnf 9630  df-mnf 9631  df-xr 9632  df-ltxr 9633  df-le 9634  df-sub 9807  df-neg 9808  df-nn 10537  df-2 10594  df-3 10595  df-4 10596  df-n0 10796  df-z 10865  df-uz 11083  df-fz 11673  df-fzo 11793  df-hash 12374  df-word 12508  df-usgra 24037  df-wlk 24212  df-trail 24213  df-pth 24214  df-cycl 24217
This theorem is referenced by:  n4cyclfrgra  24722
  Copyright terms: Public domain W3C validator