Metamath Proof Explorer


Theorem pgnbgreunbgrlem3

Description: Lemma 3 for pgnbgreunbgr . (Contributed by AV, 18-Nov-2025)

Ref Expression
Hypotheses pgnbgreunbgr.g No typesetting found for |- G = ( 5 gPetersenGr 2 ) with typecode |-
pgnbgreunbgr.v ⊢ V = Vtx ⁡ G
pgnbgreunbgr.e ⊢ E = Edg ⁡ G
pgnbgreunbgr.n ⊢ N = G NeighbVtx X
Assertion pgnbgreunbgrlem3 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b

Proof

Step Hyp Ref Expression
1 pgnbgreunbgr.g Could not format G = ( 5 gPetersenGr 2 ) : No typesetting found for |- G = ( 5 gPetersenGr 2 ) with typecode |-
2 pgnbgreunbgr.v ⊢ V = Vtx ⁡ G
3 pgnbgreunbgr.e ⊢ E = Edg ⁡ G
4 pgnbgreunbgr.n ⊢ N = G NeighbVtx X
5 2 nbgrcl ⊢ K ∈ G NeighbVtx X → X ∈ V
6 5 4 eleq2s ⊢ K ∈ N → X ∈ V
7 6 3ad2ant1 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L → X ∈ V
8 5eluz3 ⊢ 5 ∈ ℤ ≥ 3
9 pglem ⊢ 2 ∈ 1 ..^ 5 2
10 eqid ⊢ 0 ..^ 5 = 0 ..^ 5
11 eqid ⊢ 1 ..^ 5 2 = 1 ..^ 5 2
12 10 11 1 2 gpgvtxel ⊢ 5 ∈ ℤ ≥ 3 ∧ 2 ∈ 1 ..^ 5 2 → X ∈ V ↔ ∃ x ∈ 0 1 ∃ y ∈ 0 ..^ 5 X = x y
13 8 9 12 mp2an ⊢ X ∈ V ↔ ∃ x ∈ 0 1 ∃ y ∈ 0 ..^ 5 X = x y
14 13 biimpi ⊢ X ∈ V → ∃ x ∈ 0 1 ∃ y ∈ 0 ..^ 5 X = x y
15 14 adantl ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → ∃ x ∈ 0 1 ∃ y ∈ 0 ..^ 5 X = x y
16 vex ⊢ x ∈ V
17 16 elpr ⊢ x ∈ 0 1 ↔ x = 0 ∨ x = 1
18 opeq1 ⊢ x = 0 → x y = 0 y
19 18 eqeq2d ⊢ x = 0 → X = x y ↔ X = 0 y
20 19 adantr ⊢ x = 0 ∧ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y ↔ X = 0 y
21 8 9 pm3.2i ⊢ 5 ∈ ℤ ≥ 3 ∧ 2 ∈ 1 ..^ 5 2
22 2 eleq2i ⊢ X ∈ V ↔ X ∈ Vtx ⁡ G
23 22 biimpi ⊢ X ∈ V → X ∈ Vtx ⁡ G
24 c0ex ⊢ 0 ∈ V
25 vex ⊢ y ∈ V
26 24 25 op1std ⊢ X = 0 y → 1 st ⁡ X = 0
27 23 26 anim12i ⊢ X ∈ V ∧ X = 0 y → X ∈ Vtx ⁡ G ∧ 1 st ⁡ X = 0
28 eqid ⊢ Vtx ⁡ G = Vtx ⁡ G
29 11 1 28 4 gpgnbgrvtx0 ⊢ 5 ∈ ℤ ≥ 3 ∧ 2 ∈ 1 ..^ 5 2 ∧ X ∈ Vtx ⁡ G ∧ 1 st ⁡ X = 0 → N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
30 21 27 29 sylancr ⊢ X ∈ V ∧ X = 0 y → N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
31 eleq2 ⊢ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ∈ N ↔ K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
32 eleq2 ⊢ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → L ∈ N ↔ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
33 31 32 anbi12d ⊢ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ∈ N ∧ L ∈ N ↔ K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 ∧ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
34 33 adantl ⊢ X ∈ V ∧ X = 0 y ∧ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ∈ N ∧ L ∈ N ↔ K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 ∧ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5
35 eltpi ⊢ K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K = 0 2 nd ⁡ X + 1 mod 5 ∨ K = 1 2 nd ⁡ X ∨ K = 0 2 nd ⁡ X − 1 mod 5
36 eltpi ⊢ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → L = 0 2 nd ⁡ X + 1 mod 5 ∨ L = 1 2 nd ⁡ X ∨ L = 0 2 nd ⁡ X − 1 mod 5
37 1 2 3 4 pgnbgreunbgrlem1 ⊢ L = 0 2 nd ⁡ X + 1 mod 5 ∨ L = 1 2 nd ⁡ X ∨ L = 0 2 nd ⁡ X − 1 mod 5 → K = 0 2 nd ⁡ X + 1 mod 5 ∨ K = 1 2 nd ⁡ X ∨ K = 0 2 nd ⁡ X − 1 mod 5 → X ∈ V ∧ X = 0 y → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
38 36 37 syl ⊢ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K = 0 2 nd ⁡ X + 1 mod 5 ∨ K = 1 2 nd ⁡ X ∨ K = 0 2 nd ⁡ X − 1 mod 5 → X ∈ V ∧ X = 0 y → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
39 35 38 mpan9 ⊢ K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 ∧ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → X ∈ V ∧ X = 0 y → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
40 39 com12 ⊢ X ∈ V ∧ X = 0 y → K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 ∧ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
41 40 adantr ⊢ X ∈ V ∧ X = 0 y ∧ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 ∧ L ∈ 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
42 34 41 sylbid ⊢ X ∈ V ∧ X = 0 y ∧ N = 0 2 nd ⁡ X + 1 mod 5 1 2 nd ⁡ X 0 2 nd ⁡ X − 1 mod 5 → K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
43 30 42 mpdan ⊢ X ∈ V ∧ X = 0 y → K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
44 43 com12 ⊢ K ∈ N ∧ L ∈ N → X ∈ V ∧ X = 0 y → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
45 44 expd ⊢ K ∈ N ∧ L ∈ N → X ∈ V → X = 0 y → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
46 45 com23 ⊢ K ∈ N ∧ L ∈ N → X = 0 y → X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
47 46 com24 ⊢ K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
48 47 expd ⊢ K ∈ N ∧ L ∈ N → K ≠ L → b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
49 48 3impia ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L → b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
50 49 expdimp ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → y ∈ 0 ..^ 5 → X ∈ V → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
51 50 com23 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → X ∈ V → y ∈ 0 ..^ 5 → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
52 51 imp31 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
53 52 adantl ⊢ x = 0 ∧ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = 0 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
54 20 53 sylbid ⊢ x = 0 ∧ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
55 54 ex ⊢ x = 0 → K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
56 1ex ⊢ 1 ∈ V
57 56 25 op1std ⊢ X = 1 y → 1 st ⁡ X = 1
58 57 anim1ci ⊢ X = 1 y ∧ X ∈ V → X ∈ V ∧ 1 st ⁡ X = 1
59 11 1 2 4 gpgnbgrvtx1 ⊢ 5 ∈ ℤ ≥ 3 ∧ 2 ∈ 1 ..^ 5 2 ∧ X ∈ V ∧ 1 st ⁡ X = 1 → N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
60 21 58 59 sylancr ⊢ X = 1 y ∧ X ∈ V → N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
61 eleq2 ⊢ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ∈ N ↔ K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
62 eleq2 ⊢ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → L ∈ N ↔ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
63 61 62 anbi12d ⊢ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ∈ N ∧ L ∈ N ↔ K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 ∧ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
64 63 adantl ⊢ X = 1 y ∧ X ∈ V ∧ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ∈ N ∧ L ∈ N ↔ K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 ∧ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5
65 eltpi ⊢ K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K = 1 2 nd ⁡ X + 2 mod 5 ∨ K = 0 2 nd ⁡ X ∨ K = 1 2 nd ⁡ X − 2 mod 5
66 eltpi ⊢ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → L = 1 2 nd ⁡ X + 2 mod 5 ∨ L = 0 2 nd ⁡ X ∨ L = 1 2 nd ⁡ X − 2 mod 5
67 1 2 3 4 pgnbgreunbgrlem2 ⊢ L = 1 2 nd ⁡ X + 2 mod 5 ∨ L = 0 2 nd ⁡ X ∨ L = 1 2 nd ⁡ X − 2 mod 5 → K = 1 2 nd ⁡ X + 2 mod 5 ∨ K = 0 2 nd ⁡ X ∨ K = 1 2 nd ⁡ X − 2 mod 5 → X = 1 y ∧ X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
68 66 67 syl ⊢ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K = 1 2 nd ⁡ X + 2 mod 5 ∨ K = 0 2 nd ⁡ X ∨ K = 1 2 nd ⁡ X − 2 mod 5 → X = 1 y ∧ X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
69 65 68 mpan9 ⊢ K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 ∧ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → X = 1 y ∧ X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
70 69 com12 ⊢ X = 1 y ∧ X ∈ V → K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 ∧ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
71 70 adantr ⊢ X = 1 y ∧ X ∈ V ∧ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 ∧ L ∈ 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
72 64 71 sylbid ⊢ X = 1 y ∧ X ∈ V ∧ N = 1 2 nd ⁡ X + 2 mod 5 0 2 nd ⁡ X 1 2 nd ⁡ X − 2 mod 5 → K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
73 60 72 mpdan ⊢ X = 1 y ∧ X ∈ V → K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
74 73 com12 ⊢ K ∈ N ∧ L ∈ N → X = 1 y ∧ X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
75 74 expd ⊢ K ∈ N ∧ L ∈ N → X = 1 y → X ∈ V → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
76 75 com24 ⊢ K ∈ N ∧ L ∈ N → K ≠ L ∧ b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
77 76 expd ⊢ K ∈ N ∧ L ∈ N → K ≠ L → b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
78 77 3impia ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L → b ∈ 0 ..^ 5 ∧ y ∈ 0 ..^ 5 → X ∈ V → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
79 78 expdimp ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → y ∈ 0 ..^ 5 → X ∈ V → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
80 79 com23 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → X ∈ V → y ∈ 0 ..^ 5 → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
81 80 imp31 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
82 opeq1 ⊢ x = 1 → x y = 1 y
83 82 eqeq2d ⊢ x = 1 → X = x y ↔ X = 1 y
84 83 imbi1d ⊢ x = 1 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b ↔ X = 1 y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
85 81 84 imbitrrid ⊢ x = 1 → K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
86 55 85 jaoi ⊢ x = 0 ∨ x = 1 → K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
87 17 86 sylbi ⊢ x ∈ 0 1 → K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
88 87 expd ⊢ x ∈ 0 1 → K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
89 88 com12 ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → x ∈ 0 1 → y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
90 89 impd ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → x ∈ 0 1 ∧ y ∈ 0 ..^ 5 → X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
91 90 rexlimdvv ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → ∃ x ∈ 0 1 ∃ y ∈ 0 ..^ 5 X = x y → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
92 15 91 mpd ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 ∧ X ∈ V → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b
93 7 92 mpidan ⊢ K ∈ N ∧ L ∈ N ∧ K ≠ L ∧ b ∈ 0 ..^ 5 → K 0 b ∈ E ∧ 0 b L ∈ E → X = 0 b