Metamath Proof Explorer


Theorem isubgr3stgrlem4

Description: Lemma 4 for isubgr3stgr . (Contributed by AV, 24-Sep-2025)

Ref Expression
Hypotheses isubgr3stgr.v ⊢ V = Vtx ⁡ G
isubgr3stgr.u ⊢ U = G NeighbVtx X
isubgr3stgr.c ⊢ C = G ClNeighbVtx X
isubgr3stgr.n ⊢ N ∈ ℕ 0
isubgr3stgr.s No typesetting found for |- S = ( StarGr ` N ) with typecode |-
isubgr3stgr.w ⊢ W = Vtx ⁡ S
isubgr3stgr.e ⊢ E = Edg ⁡ G
Assertion isubgr3stgrlem4 ⊢ A = X ∧ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ A ≠ B ∧ A ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F A B = 0 z

Proof

Step Hyp Ref Expression
1 isubgr3stgr.v ⊢ V = Vtx ⁡ G
2 isubgr3stgr.u ⊢ U = G NeighbVtx X
3 isubgr3stgr.c ⊢ C = G ClNeighbVtx X
4 isubgr3stgr.n ⊢ N ∈ ℕ 0
5 isubgr3stgr.s Could not format S = ( StarGr ` N ) : No typesetting found for |- S = ( StarGr ` N ) with typecode |-
6 isubgr3stgr.w ⊢ W = Vtx ⁡ S
7 isubgr3stgr.e ⊢ E = Edg ⁡ G
8 preq2 ⊢ z = F ⁡ B → 0 z = 0 F ⁡ B
9 8 eqeq2d ⊢ z = F ⁡ B → F X B = 0 z ↔ F X B = 0 F ⁡ B
10 f1of ⊢ F : C ⟶ 1-1 onto W → F : C ⟶ W
11 10 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → F : C ⟶ W
12 11 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F : C ⟶ W
13 simpr3 ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → B ∈ C
14 12 13 ffvelcdmd ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B ∈ W
15 5 fveq2i Could not format ( Vtx ` S ) = ( Vtx ` ( StarGr ` N ) ) : No typesetting found for |- ( Vtx ` S ) = ( Vtx ` ( StarGr ` N ) ) with typecode |-
16 stgrvtx Could not format ( N e. NN0 -> ( Vtx ` ( StarGr ` N ) ) = ( 0 ... N ) ) : No typesetting found for |- ( N e. NN0 -> ( Vtx ` ( StarGr ` N ) ) = ( 0 ... N ) ) with typecode |-
17 4 16 ax-mp Could not format ( Vtx ` ( StarGr ` N ) ) = ( 0 ... N ) : No typesetting found for |- ( Vtx ` ( StarGr ` N ) ) = ( 0 ... N ) with typecode |-
18 6 15 17 3eqtri ⊢ W = 0 … N
19 18 eleq2i ⊢ F ⁡ B ∈ W ↔ F ⁡ B ∈ 0 … N
20 fz0sn0fz1 ⊢ N ∈ ℕ 0 → 0 … N = 0 ∪ 1 … N
21 4 20 ax-mp ⊢ 0 … N = 0 ∪ 1 … N
22 21 eleq2i ⊢ F ⁡ B ∈ 0 … N ↔ F ⁡ B ∈ 0 ∪ 1 … N
23 elun ⊢ F ⁡ B ∈ 0 ∪ 1 … N ↔ F ⁡ B ∈ 0 ∨ F ⁡ B ∈ 1 … N
24 fvex ⊢ F ⁡ B ∈ V
25 24 elsn ⊢ F ⁡ B ∈ 0 ↔ F ⁡ B = 0
26 25 orbi1i ⊢ F ⁡ B ∈ 0 ∨ F ⁡ B ∈ 1 … N ↔ F ⁡ B = 0 ∨ F ⁡ B ∈ 1 … N
27 23 26 bitri ⊢ F ⁡ B ∈ 0 ∪ 1 … N ↔ F ⁡ B = 0 ∨ F ⁡ B ∈ 1 … N
28 19 22 27 3bitri ⊢ F ⁡ B ∈ W ↔ F ⁡ B = 0 ∨ F ⁡ B ∈ 1 … N
29 eqeq2 ⊢ F ⁡ X = 0 → F ⁡ B = F ⁡ X ↔ F ⁡ B = 0
30 29 adantl ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → F ⁡ B = F ⁡ X ↔ F ⁡ B = 0
31 30 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = F ⁡ X ↔ F ⁡ B = 0
32 f1of1 ⊢ F : C ⟶ 1-1 onto W → F : C ⟶ 1-1 W
33 dff14a ⊢ F : C ⟶ 1-1 W ↔ F : C ⟶ W ∧ ∀ a ∈ C ∀ b ∈ C a ≠ b → F ⁡ a ≠ F ⁡ b
34 simpl ⊢ a = X ∧ b = B → a = X
35 simpr ⊢ a = X ∧ b = B → b = B
36 34 35 neeq12d ⊢ a = X ∧ b = B → a ≠ b ↔ X ≠ B
37 fveq2 ⊢ a = X → F ⁡ a = F ⁡ X
38 37 adantr ⊢ a = X ∧ b = B → F ⁡ a = F ⁡ X
39 fveq2 ⊢ b = B → F ⁡ b = F ⁡ B
40 39 adantl ⊢ a = X ∧ b = B → F ⁡ b = F ⁡ B
41 38 40 neeq12d ⊢ a = X ∧ b = B → F ⁡ a ≠ F ⁡ b ↔ F ⁡ X ≠ F ⁡ B
42 36 41 imbi12d ⊢ a = X ∧ b = B → a ≠ b → F ⁡ a ≠ F ⁡ b ↔ X ≠ B → F ⁡ X ≠ F ⁡ B
43 42 rspc2gv ⊢ X ∈ C ∧ B ∈ C → ∀ a ∈ C ∀ b ∈ C a ≠ b → F ⁡ a ≠ F ⁡ b → X ≠ B → F ⁡ X ≠ F ⁡ B
44 43 3adant1 ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → ∀ a ∈ C ∀ b ∈ C a ≠ b → F ⁡ a ≠ F ⁡ b → X ≠ B → F ⁡ X ≠ F ⁡ B
45 id ⊢ X ≠ B → F ⁡ X ≠ F ⁡ B → X ≠ B → F ⁡ X ≠ F ⁡ B
46 eqneqall ⊢ F ⁡ X = F ⁡ B → F ⁡ X ≠ F ⁡ B → F ⁡ B ∈ 1 … N
47 46 eqcoms ⊢ F ⁡ B = F ⁡ X → F ⁡ X ≠ F ⁡ B → F ⁡ B ∈ 1 … N
48 47 com12 ⊢ F ⁡ X ≠ F ⁡ B → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
49 45 48 syl6com ⊢ X ≠ B → X ≠ B → F ⁡ X ≠ F ⁡ B → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
50 49 3ad2ant1 ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → X ≠ B → F ⁡ X ≠ F ⁡ B → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
51 44 50 syld ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → ∀ a ∈ C ∀ b ∈ C a ≠ b → F ⁡ a ≠ F ⁡ b → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
52 51 adantld ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → F : C ⟶ W ∧ ∀ a ∈ C ∀ b ∈ C a ≠ b → F ⁡ a ≠ F ⁡ b → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
53 33 52 biimtrid ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → F : C ⟶ 1-1 W → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
54 32 53 syl5com ⊢ F : C ⟶ 1-1 onto W → X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
55 54 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
56 55 imp ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = F ⁡ X → F ⁡ B ∈ 1 … N
57 31 56 sylbird ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = 0 → F ⁡ B ∈ 1 … N
58 idd ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B ∈ 1 … N → F ⁡ B ∈ 1 … N
59 57 58 jaod ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B = 0 ∨ F ⁡ B ∈ 1 … N → F ⁡ B ∈ 1 … N
60 28 59 biimtrid ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B ∈ W → F ⁡ B ∈ 1 … N
61 14 60 mpd ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ B ∈ 1 … N
62 f1ofn ⊢ F : C ⟶ 1-1 onto W → F Fn C
63 62 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → F Fn C
64 3simpc ⊢ X ≠ B ∧ X ∈ C ∧ B ∈ C → X ∈ C ∧ B ∈ C
65 63 64 anim12i ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F Fn C ∧ X ∈ C ∧ B ∈ C
66 3anass ⊢ F Fn C ∧ X ∈ C ∧ B ∈ C ↔ F Fn C ∧ X ∈ C ∧ B ∈ C
67 65 66 sylibr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F Fn C ∧ X ∈ C ∧ B ∈ C
68 fnimapr ⊢ F Fn C ∧ X ∈ C ∧ B ∈ C → F X B = F ⁡ X F ⁡ B
69 67 68 syl ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F X B = F ⁡ X F ⁡ B
70 simpr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → F ⁡ X = 0
71 70 adantr ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ X = 0
72 71 preq1d ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F ⁡ X F ⁡ B = 0 F ⁡ B
73 69 72 eqtrd ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → F X B = 0 F ⁡ B
74 9 61 73 rspcedvdw ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ X ≠ B ∧ X ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F X B = 0 z
75 74 ex ⊢ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → X ≠ B ∧ X ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F X B = 0 z
76 neeq1 ⊢ A = X → A ≠ B ↔ X ≠ B
77 eleq1 ⊢ A = X → A ∈ C ↔ X ∈ C
78 76 77 3anbi12d ⊢ A = X → A ≠ B ∧ A ∈ C ∧ B ∈ C ↔ X ≠ B ∧ X ∈ C ∧ B ∈ C
79 preq1 ⊢ A = X → A B = X B
80 79 imaeq2d ⊢ A = X → F A B = F X B
81 80 eqeq1d ⊢ A = X → F A B = 0 z ↔ F X B = 0 z
82 81 rexbidv ⊢ A = X → ∃ z ∈ 1 … N F A B = 0 z ↔ ∃ z ∈ 1 … N F X B = 0 z
83 78 82 imbi12d ⊢ A = X → A ≠ B ∧ A ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F A B = 0 z ↔ X ≠ B ∧ X ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F X B = 0 z
84 75 83 imbitrrid ⊢ A = X → F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 → A ≠ B ∧ A ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F A B = 0 z
85 84 3imp ⊢ A = X ∧ F : C ⟶ 1-1 onto W ∧ F ⁡ X = 0 ∧ A ≠ B ∧ A ∈ C ∧ B ∈ C → ∃ z ∈ 1 … N F A B = 0 z