Metamath Proof Explorer


Theorem gpg5nbgrvtx03star

Description: In a generalized Petersen graph G(N,K) of order greater than 8 ( 3 < N ), every vertex of the first kind has exactly three (different) neighbors, and none of these neighbors are connected by an edge (i.e., the (closed) neighborhood of every vertex of the first kind induces a subgraph which is isomorphic to a 3-star). (Contributed by AV, 31-Aug-2025)

Ref Expression
Hypotheses gpgnbgr.j J = 1 ..^ N 2
gpgnbgr.g No typesetting found for |- G = ( N gPetersenGr K ) with typecode |-
gpgnbgr.v V = Vtx G
gpgnbgr.u U = G NeighbVtx X
gpgnbgr.e E = Edg G
Assertion gpg5nbgrvtx03star N 4 K J X V 1 st X = 0 U = 3 x U y U x y E

Proof

Step Hyp Ref Expression
1 gpgnbgr.j J = 1 ..^ N 2
2 gpgnbgr.g Could not format G = ( N gPetersenGr K ) : No typesetting found for |- G = ( N gPetersenGr K ) with typecode |-
3 gpgnbgr.v V = Vtx G
4 gpgnbgr.u U = G NeighbVtx X
5 gpgnbgr.e E = Edg G
6 eluz4eluz3 N 4 N 3
7 1 2 3 4 gpg3nbgrvtx0 N 3 K J X V 1 st X = 0 U = 3
8 6 7 sylanl1 N 4 K J X V 1 st X = 0 U = 3
9 eqid 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N
10 1 eleq2i K J K 1 ..^ N 2
11 10 biimpi K J K 1 ..^ N 2
12 gpgusgra Could not format ( ( N e. ( ZZ>= ` 3 ) /\ K e. ( 1 ..^ ( |^ ` ( N / 2 ) ) ) ) -> ( N gPetersenGr K ) e. USGraph ) : No typesetting found for |- ( ( N e. ( ZZ>= ` 3 ) /\ K e. ( 1 ..^ ( |^ ` ( N / 2 ) ) ) ) -> ( N gPetersenGr K ) e. USGraph ) with typecode |-
13 2 12 eqeltrid N 3 K 1 ..^ N 2 G USGraph
14 6 11 13 syl2an N 4 K J G USGraph
15 14 adantr N 4 K J X V 1 st X = 0 G USGraph
16 5 usgredgne G USGraph 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N
17 16 neneqd G USGraph 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E ¬ 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N
18 17 ex G USGraph 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E ¬ 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N
19 15 18 syl N 4 K J X V 1 st X = 0 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E ¬ 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N
20 9 19 mt2i N 4 K J X V 1 st X = 0 ¬ 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E
21 df-nel 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E ¬ 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E
22 20 21 sylibr N 4 K J X V 1 st X = 0 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E
23 6 adantr N 4 K J N 3
24 23 adantr N 4 K J X V 1 st X = 0 N 3
25 simplr N 4 K J X V 1 st X = 0 K J
26 6 anim1i N 4 K J N 3 K J
27 simpl X V 1 st X = 0 X V
28 26 27 anim12i N 4 K J X V 1 st X = 0 N 3 K J X V
29 eqid 0 ..^ N = 0 ..^ N
30 29 1 2 3 gpgvtxel2 N 3 K J X V 2 nd X 0 ..^ N
31 28 30 syl N 4 K J X V 1 st X = 0 2 nd X 0 ..^ N
32 1 2 3 5 gpg5nbgrvtx03starlem1 N 3 K J 2 nd X 0 ..^ N 0 2 nd X + 1 mod N 1 2 nd X E
33 24 25 31 32 syl3anc N 4 K J X V 1 st X = 0 0 2 nd X + 1 mod N 1 2 nd X E
34 simpll N 4 K J X V 1 st X = 0 N 4
35 elfzoelz 2 nd X 0 ..^ N 2 nd X
36 28 30 35 3syl N 4 K J X V 1 st X = 0 2 nd X
37 1 2 3 5 gpg5nbgrvtx03starlem2 N 4 K J 2 nd X 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
38 34 25 36 37 syl3anc N 4 K J X V 1 st X = 0 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
39 opex 0 2 nd X + 1 mod N V
40 opex 1 2 nd X V
41 opex 0 2 nd X 1 mod N V
42 preq2 y = 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N
43 neleq1 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E
44 42 43 syl y = 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E
45 preq2 y = 1 2 nd X 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 1 2 nd X
46 neleq1 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 1 2 nd X E
47 45 46 syl y = 1 2 nd X 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 1 2 nd X E
48 preq2 y = 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N
49 neleq1 0 2 nd X + 1 mod N y = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
50 48 49 syl y = 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
51 39 40 41 44 47 50 raltp y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E 0 2 nd X + 1 mod N 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 1 2 nd X E 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
52 22 33 38 51 syl3anbrc N 4 K J X V 1 st X = 0 y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E
53 prcom 1 2 nd X 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N 1 2 nd X
54 neleq1 1 2 nd X 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N 1 2 nd X 1 2 nd X 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 1 2 nd X E
55 53 54 ax-mp 1 2 nd X 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 1 2 nd X E
56 33 55 sylibr N 4 K J X V 1 st X = 0 1 2 nd X 0 2 nd X + 1 mod N E
57 eqid 1 2 nd X = 1 2 nd X
58 5 usgredgne G USGraph 1 2 nd X 1 2 nd X E 1 2 nd X 1 2 nd X
59 58 neneqd G USGraph 1 2 nd X 1 2 nd X E ¬ 1 2 nd X = 1 2 nd X
60 59 ex G USGraph 1 2 nd X 1 2 nd X E ¬ 1 2 nd X = 1 2 nd X
61 15 60 syl N 4 K J X V 1 st X = 0 1 2 nd X 1 2 nd X E ¬ 1 2 nd X = 1 2 nd X
62 57 61 mt2i N 4 K J X V 1 st X = 0 ¬ 1 2 nd X 1 2 nd X E
63 df-nel 1 2 nd X 1 2 nd X E ¬ 1 2 nd X 1 2 nd X E
64 62 63 sylibr N 4 K J X V 1 st X = 0 1 2 nd X 1 2 nd X E
65 1 2 3 5 gpg5nbgrvtx03starlem3 N 3 K J 2 nd X 0 ..^ N 1 2 nd X 0 2 nd X 1 mod N E
66 24 25 31 65 syl3anc N 4 K J X V 1 st X = 0 1 2 nd X 0 2 nd X 1 mod N E
67 preq2 y = 0 2 nd X + 1 mod N 1 2 nd X y = 1 2 nd X 0 2 nd X + 1 mod N
68 neleq1 1 2 nd X y = 1 2 nd X 0 2 nd X + 1 mod N 1 2 nd X y E 1 2 nd X 0 2 nd X + 1 mod N E
69 67 68 syl y = 0 2 nd X + 1 mod N 1 2 nd X y E 1 2 nd X 0 2 nd X + 1 mod N E
70 preq2 y = 1 2 nd X 1 2 nd X y = 1 2 nd X 1 2 nd X
71 neleq1 1 2 nd X y = 1 2 nd X 1 2 nd X 1 2 nd X y E 1 2 nd X 1 2 nd X E
72 70 71 syl y = 1 2 nd X 1 2 nd X y E 1 2 nd X 1 2 nd X E
73 preq2 y = 0 2 nd X 1 mod N 1 2 nd X y = 1 2 nd X 0 2 nd X 1 mod N
74 neleq1 1 2 nd X y = 1 2 nd X 0 2 nd X 1 mod N 1 2 nd X y E 1 2 nd X 0 2 nd X 1 mod N E
75 73 74 syl y = 0 2 nd X 1 mod N 1 2 nd X y E 1 2 nd X 0 2 nd X 1 mod N E
76 39 40 41 69 72 75 raltp y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 1 2 nd X y E 1 2 nd X 0 2 nd X + 1 mod N E 1 2 nd X 1 2 nd X E 1 2 nd X 0 2 nd X 1 mod N E
77 56 64 66 76 syl3anbrc N 4 K J X V 1 st X = 0 y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 1 2 nd X y E
78 prcom 0 2 nd X 1 mod N 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N
79 neleq1 0 2 nd X 1 mod N 0 2 nd X + 1 mod N = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
80 78 79 ax-mp 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E 0 2 nd X + 1 mod N 0 2 nd X 1 mod N E
81 38 80 sylibr N 4 K J X V 1 st X = 0 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E
82 prcom 0 2 nd X 1 mod N 1 2 nd X = 1 2 nd X 0 2 nd X 1 mod N
83 neleq1 0 2 nd X 1 mod N 1 2 nd X = 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X 1 mod N 1 2 nd X E 1 2 nd X 0 2 nd X 1 mod N E
84 82 83 ax-mp 0 2 nd X 1 mod N 1 2 nd X E 1 2 nd X 0 2 nd X 1 mod N E
85 66 84 sylibr N 4 K J X V 1 st X = 0 0 2 nd X 1 mod N 1 2 nd X E
86 eqid 0 2 nd X 1 mod N = 0 2 nd X 1 mod N
87 5 usgredgne G USGraph 0 2 nd X 1 mod N 0 2 nd X 1 mod N E 0 2 nd X 1 mod N 0 2 nd X 1 mod N
88 87 neneqd G USGraph 0 2 nd X 1 mod N 0 2 nd X 1 mod N E ¬ 0 2 nd X 1 mod N = 0 2 nd X 1 mod N
89 88 ex G USGraph 0 2 nd X 1 mod N 0 2 nd X 1 mod N E ¬ 0 2 nd X 1 mod N = 0 2 nd X 1 mod N
90 15 89 syl N 4 K J X V 1 st X = 0 0 2 nd X 1 mod N 0 2 nd X 1 mod N E ¬ 0 2 nd X 1 mod N = 0 2 nd X 1 mod N
91 86 90 mt2i N 4 K J X V 1 st X = 0 ¬ 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
92 df-nel 0 2 nd X 1 mod N 0 2 nd X 1 mod N E ¬ 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
93 91 92 sylibr N 4 K J X V 1 st X = 0 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
94 preq2 y = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 0 2 nd X + 1 mod N
95 neleq1 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 0 2 nd X + 1 mod N 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E
96 94 95 syl y = 0 2 nd X + 1 mod N 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E
97 preq2 y = 1 2 nd X 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 1 2 nd X
98 neleq1 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 1 2 nd X 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 1 2 nd X E
99 97 98 syl y = 1 2 nd X 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 1 2 nd X E
100 preq2 y = 0 2 nd X 1 mod N 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 0 2 nd X 1 mod N
101 neleq1 0 2 nd X 1 mod N y = 0 2 nd X 1 mod N 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
102 100 101 syl y = 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
103 39 40 41 96 99 102 raltp y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E 0 2 nd X 1 mod N 0 2 nd X + 1 mod N E 0 2 nd X 1 mod N 1 2 nd X E 0 2 nd X 1 mod N 0 2 nd X 1 mod N E
104 81 85 93 103 syl3anbrc N 4 K J X V 1 st X = 0 y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E
105 preq1 x = 0 2 nd X + 1 mod N x y = 0 2 nd X + 1 mod N y
106 neleq1 x y = 0 2 nd X + 1 mod N y x y E 0 2 nd X + 1 mod N y E
107 105 106 syl x = 0 2 nd X + 1 mod N x y E 0 2 nd X + 1 mod N y E
108 107 ralbidv x = 0 2 nd X + 1 mod N y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E
109 preq1 x = 1 2 nd X x y = 1 2 nd X y
110 neleq1 x y = 1 2 nd X y x y E 1 2 nd X y E
111 109 110 syl x = 1 2 nd X x y E 1 2 nd X y E
112 111 ralbidv x = 1 2 nd X y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 1 2 nd X y E
113 preq1 x = 0 2 nd X 1 mod N x y = 0 2 nd X 1 mod N y
114 neleq1 x y = 0 2 nd X 1 mod N y x y E 0 2 nd X 1 mod N y E
115 113 114 syl x = 0 2 nd X 1 mod N x y E 0 2 nd X 1 mod N y E
116 115 ralbidv x = 0 2 nd X 1 mod N y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E
117 39 40 41 108 112 116 raltp x 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X + 1 mod N y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 1 2 nd X y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N 0 2 nd X 1 mod N y E
118 52 77 104 117 syl3anbrc N 4 K J X V 1 st X = 0 x 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E
119 1 2 3 4 gpgnbgrvtx0 N 3 K J X V 1 st X = 0 U = 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N
120 6 119 sylanl1 N 4 K J X V 1 st X = 0 U = 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N
121 120 raleqdv N 4 K J X V 1 st X = 0 y U x y E y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E
122 120 121 raleqbidvv N 4 K J X V 1 st X = 0 x U y U x y E x 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N y 0 2 nd X + 1 mod N 1 2 nd X 0 2 nd X 1 mod N x y E
123 118 122 mpbird N 4 K J X V 1 st X = 0 x U y U x y E
124 8 123 jca N 4 K J X V 1 st X = 0 U = 3 x U y U x y E