Theorem konigsberglem2 16935

Description: Lemma 2 for konigsberg 16939: Vertex 1 has degree three. (Contributed by Mario Carneiro, 11-Mar-2015.) (Revised by Mario Carneiro, 28-Feb-2016.) (Revised by AV, 4-Mar-2021.)

Hypotheses

Ref	Expression
konigsberg.v	⊢ 𝑉 = (0...3)
konigsberg.e	⊢ 𝐸 = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩
konigsberg.g	⊢ 𝐺 = ⟨𝑉, 𝐸⟩

Assertion

Ref	Expression
konigsberglem2	⊢ ((VtxDeg‘𝐺)‘1) = 3

Proof of Theorem konigsberglem2

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		0z 9666	. . . . . . 7 ⊢ 0 ∈ ℤ
2		3z 9684	. . . . . . 7 ⊢ 3 ∈ ℤ
3		fzfig 10888	. . . . . . 7 ⊢ ((0 ∈ ℤ ∧ 3 ∈ ℤ) → (0...3) ∈ Fin)
4	1, 2, 3	mp2an 430	. . . . . 6 ⊢ (0...3) ∈ Fin
5	4	elexi 2834	. . . . 5 ⊢ (0...3) ∈ V
6		0nn0 9589	. . . . . . . . . 10 ⊢ 0 ∈ ℕ0
7		1nn0 9590	. . . . . . . . . 10 ⊢ 1 ∈ ℕ0
8		prexg 4351	. . . . . . . . . 10 ⊢ ((0 ∈ ℕ0 ∧ 1 ∈ ℕ0) → {0, 1} ∈ V)
9	6, 7, 8	mp2an 430	. . . . . . . . 9 ⊢ {0, 1} ∈ V
10	9	a1i 9	. . . . . . . 8 ⊢ (⊤ → {0, 1} ∈ V)
11		2nn0 9591	. . . . . . . . . 10 ⊢ 2 ∈ ℕ0
12		prexg 4351	. . . . . . . . . 10 ⊢ ((0 ∈ ℕ0 ∧ 2 ∈ ℕ0) → {0, 2} ∈ V)
13	6, 11, 12	mp2an 430	. . . . . . . . 9 ⊢ {0, 2} ∈ V
14	13	a1i 9	. . . . . . . 8 ⊢ (⊤ → {0, 2} ∈ V)
15		3nn0 9592	. . . . . . . . . 10 ⊢ 3 ∈ ℕ0
16		prexg 4351	. . . . . . . . . 10 ⊢ ((0 ∈ ℕ0 ∧ 3 ∈ ℕ0) → {0, 3} ∈ V)
17	6, 15, 16	mp2an 430	. . . . . . . . 9 ⊢ {0, 3} ∈ V
18	17	a1i 9	. . . . . . . 8 ⊢ (⊤ → {0, 3} ∈ V)
19		prexg 4351	. . . . . . . . . 10 ⊢ ((1 ∈ ℕ0 ∧ 2 ∈ ℕ0) → {1, 2} ∈ V)
20	7, 11, 19	mp2an 430	. . . . . . . . 9 ⊢ {1, 2} ∈ V
21	20	a1i 9	. . . . . . . 8 ⊢ (⊤ → {1, 2} ∈ V)
22		prexg 4351	. . . . . . . . . 10 ⊢ ((2 ∈ ℕ0 ∧ 3 ∈ ℕ0) → {2, 3} ∈ V)
23	11, 15, 22	mp2an 430	. . . . . . . . 9 ⊢ {2, 3} ∈ V
24	23	a1i 9	. . . . . . . 8 ⊢ (⊤ → {2, 3} ∈ V)
25	10, 14, 18, 21, 21, 24	s6cld 11576	. . . . . . 7 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word V)
26	25	mptru 1411	. . . . . 6 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word V
27	26	elexi 2834	. . . . 5 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ V
28	5, 27	opvtxfvi 16473	. . . 4 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩) = (0...3)
29	28	eqcomi 2242	. . 3 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩)
30		1le3 9527	. . . . 5 ⊢ 1 ≤ 3
31		elfz2nn0 10536	. . . . 5 ⊢ (1 ∈ (0...3) ↔ (1 ∈ ℕ0 ∧ 3 ∈ ℕ0 ∧ 1 ≤ 3))
32	7, 15, 30, 31	mpbir3an 1210	. . . 4 ⊢ 1 ∈ (0...3)
33	32	a1i 9	. . 3 ⊢ (⊤ → 1 ∈ (0...3))
34	5, 27	opiedgfvi 16474	. . . 4 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩) = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩
35	34	eqcomi 2242	. . 3 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩)
36	24	s1cld 11412	. . . . . 6 ⊢ (⊤ → ⟨“{2, 3}”⟩ ∈ Word V)
37	36	mptru 1411	. . . . 5 ⊢ ⟨“{2, 3}”⟩ ∈ Word V
38		df-s7 11555	. . . . 5 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ++ ⟨“{2, 3}”⟩)
39		eqid 2238	. . . . . 6 ⊢ (0...3) = (0...3)
40		eqid 2238	. . . . . 6 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩
41		eqid 2238	. . . . . 6 ⊢ ⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩⟩ = ⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩⟩
42	39, 40, 41	konigsbergssiedgwen 16932	. . . . 5 ⊢ ((⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word V ∧ ⟨“{2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ++ ⟨“{2, 3}”⟩)) → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
43	26, 37, 38, 42	mp3an 1378	. . . 4 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)}
44	43	a1i 9	. . 3 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
45	10, 14, 18, 21, 21	s5cld 11575	. . . . . . . 8 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ Word V)
46	45	mptru 1411	. . . . . . 7 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ Word V
47	46	elexi 2834	. . . . . 6 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ V
48	5, 47	opvtxfvi 16473	. . . . 5 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩) = (0...3)
49	48	eqcomi 2242	. . . 4 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩)
50	5, 47	opiedgfvi 16474	. . . . 5 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩) = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩
51	50	eqcomi 2242	. . . 4 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩)
52	24, 24	s2cld 11572	. . . . 5 ⊢ (⊤ → ⟨“{2, 3} {2, 3}”⟩ ∈ Word V)
53	10, 14, 18, 21, 21, 24, 24	s5s2d 11599	. . . . 5 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ++ ⟨“{2, 3} {2, 3}”⟩))
54	39, 40, 41	konigsbergssiedgwen 16932	. . . . 5 ⊢ ((⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ Word V ∧ ⟨“{2, 3} {2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ++ ⟨“{2, 3} {2, 3}”⟩)) → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
55	45, 52, 53, 54	syl3anc 1278	. . . 4 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
56	10, 14, 18, 21	s4cld 11574	. . . . . . . . . 10 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ Word V)
57	56	mptru 1411	. . . . . . . . 9 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ Word V
58	57	elexi 2834	. . . . . . . 8 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ V
59	5, 58	opvtxfvi 16473	. . . . . . 7 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩) = (0...3)
60	59	eqcomi 2242	. . . . . 6 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩)
61	5, 58	opiedgfvi 16474	. . . . . . 7 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩) = ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩
62	61	eqcomi 2242	. . . . . 6 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩)
63	21, 24, 24	s3cld 11573	. . . . . . 7 ⊢ (⊤ → ⟨“{1, 2} {2, 3} {2, 3}”⟩ ∈ Word V)
64	10, 14, 18, 21, 21, 24, 24	s4s3d 11596	. . . . . . 7 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ++ ⟨“{1, 2} {2, 3} {2, 3}”⟩))
65	39, 40, 41	konigsbergssiedgwen 16932	. . . . . . 7 ⊢ ((⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ Word V ∧ ⟨“{1, 2} {2, 3} {2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ++ ⟨“{1, 2} {2, 3} {2, 3}”⟩)) → ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
66	56, 63, 64, 65	syl3anc 1278	. . . . . 6 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
67	10, 14, 18	s3cld 11573	. . . . . . . . . . . 12 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ Word V)
68	67	mptru 1411	. . . . . . . . . . 11 ⊢ ⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ Word V
69	68	elexi 2834	. . . . . . . . . 10 ⊢ ⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ V
70	5, 69	opvtxfvi 16473	. . . . . . . . 9 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩) = (0...3)
71	70	eqcomi 2242	. . . . . . . 8 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩)
72	5, 69	opiedgfvi 16474	. . . . . . . . 9 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩) = ⟨“{0, 1} {0, 2} {0, 3}”⟩
73	72	eqcomi 2242	. . . . . . . 8 ⊢ ⟨“{0, 1} {0, 2} {0, 3}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩)
74	21, 21, 24, 24	s4cld 11574	. . . . . . . . 9 ⊢ (⊤ → ⟨“{1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V)
75	10, 14, 18, 21, 21, 24, 24	s3s4d 11597	. . . . . . . . 9 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3}”⟩ ++ ⟨“{1, 2} {1, 2} {2, 3} {2, 3}”⟩))
76	39, 40, 41	konigsbergssiedgwen 16932	. . . . . . . . 9 ⊢ ((⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ Word V ∧ ⟨“{1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3}”⟩ ++ ⟨“{1, 2} {1, 2} {2, 3} {2, 3}”⟩)) → ⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
77	67, 74, 75, 76	syl3anc 1278	. . . . . . . 8 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
78	10, 14	s2cld 11572	. . . . . . . . . . . . 13 ⊢ (⊤ → ⟨“{0, 1} {0, 2}”⟩ ∈ Word V)
79	78	mptru 1411	. . . . . . . . . . . 12 ⊢ ⟨“{0, 1} {0, 2}”⟩ ∈ Word V
80	79	elexi 2834	. . . . . . . . . . 11 ⊢ ⟨“{0, 1} {0, 2}”⟩ ∈ V
81	5, 80	opvtxfvi 16473	. . . . . . . . . 10 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩) = (0...3)
82	81	eqcomi 2242	. . . . . . . . 9 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩)
83	5, 80	opiedgfvi 16474	. . . . . . . . . 10 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩) = ⟨“{0, 1} {0, 2}”⟩
84	83	eqcomi 2242	. . . . . . . . 9 ⊢ ⟨“{0, 1} {0, 2}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩)
85	18, 21, 21, 24, 24	s5cld 11575	. . . . . . . . . 10 ⊢ (⊤ → ⟨“{0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V)
86	10, 14, 18, 21, 21, 24, 24	s2s5d 11598	. . . . . . . . . 10 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2}”⟩ ++ ⟨“{0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩))
87	39, 40, 41	konigsbergssiedgwen 16932	. . . . . . . . . 10 ⊢ ((⟨“{0, 1} {0, 2}”⟩ ∈ Word V ∧ ⟨“{0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1} {0, 2}”⟩ ++ ⟨“{0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩)) → ⟨“{0, 1} {0, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
88	78, 85, 86, 87	syl3anc 1278	. . . . . . . . 9 ⊢ (⊤ → ⟨“{0, 1} {0, 2}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
89	10	s1cld 11412	. . . . . . . . . . . . . 14 ⊢ (⊤ → ⟨“{0, 1}”⟩ ∈ Word V)
90	89	mptru 1411	. . . . . . . . . . . . 13 ⊢ ⟨“{0, 1}”⟩ ∈ Word V
91	90	elexi 2834	. . . . . . . . . . . 12 ⊢ ⟨“{0, 1}”⟩ ∈ V
92	5, 91	opvtxfvi 16473	. . . . . . . . . . 11 ⊢ (Vtx‘⟨(0...3), ⟨“{0, 1}”⟩⟩) = (0...3)
93	92	eqcomi 2242	. . . . . . . . . 10 ⊢ (0...3) = (Vtx‘⟨(0...3), ⟨“{0, 1}”⟩⟩)
94	5, 91	opiedgfvi 16474	. . . . . . . . . . 11 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1}”⟩⟩) = ⟨“{0, 1}”⟩
95	94	eqcomi 2242	. . . . . . . . . 10 ⊢ ⟨“{0, 1}”⟩ = (iEdg‘⟨(0...3), ⟨“{0, 1}”⟩⟩)
96	14, 18, 21, 21, 24, 24	s6cld 11576	. . . . . . . . . . 11 ⊢ (⊤ → ⟨“{0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V)
97	10, 14, 18, 21, 21, 24, 24	s1s6d 11592	. . . . . . . . . . 11 ⊢ (⊤ → ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1}”⟩ ++ ⟨“{0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩))
98	39, 40, 41	konigsbergssiedgwen 16932	. . . . . . . . . . 11 ⊢ ((⟨“{0, 1}”⟩ ∈ Word V ∧ ⟨“{0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ ∈ Word V ∧ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩ = (⟨“{0, 1}”⟩ ++ ⟨“{0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩)) → ⟨“{0, 1}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
99	89, 96, 97, 98	syl3anc 1278	. . . . . . . . . 10 ⊢ (⊤ → ⟨“{0, 1}”⟩ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
100		0ex 4262	. . . . . . . . . . . . . 14 ⊢ ∅ ∈ V
101	5, 100	opvtxfvi 16473	. . . . . . . . . . . . 13 ⊢ (Vtx‘⟨(0...3), ∅⟩) = (0...3)
102	101	eqcomi 2242	. . . . . . . . . . . 12 ⊢ (0...3) = (Vtx‘⟨(0...3), ∅⟩)
103	5, 100	opiedgfvi 16474	. . . . . . . . . . . . 13 ⊢ (iEdg‘⟨(0...3), ∅⟩) = ∅
104	103	eqcomi 2242	. . . . . . . . . . . 12 ⊢ ∅ = (iEdg‘⟨(0...3), ∅⟩)
105		wrd0 11351	. . . . . . . . . . . . 13 ⊢ ∅ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)}
106	105	a1i 9	. . . . . . . . . . . 12 ⊢ (⊤ → ∅ ∈ Word {𝑥 ∈ 𝒫 (0...3) ∣ (𝑥 ≈ 1o ∨ 𝑥 ≈ 2o)})
107		eqidd 2239	. . . . . . . . . . . . 13 ⊢ (⊤ → ∅ = ∅)
108	4	a1i 9	. . . . . . . . . . . . 13 ⊢ (⊤ → (0...3) ∈ Fin)
109		upgr0eop 16568	. . . . . . . . . . . . . 14 ⊢ ((0...3) ∈ Fin → ⟨(0...3), ∅⟩ ∈ UPGraph)
110	4, 109	mp1i 10	. . . . . . . . . . . . 13 ⊢ (⊤ → ⟨(0...3), ∅⟩ ∈ UPGraph)
111	102, 104, 33, 107, 108, 110	vtxdgfi0e 16741	. . . . . . . . . . . 12 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ∅⟩)‘1) = 0)
112	92	a1i 9	. . . . . . . . . . . 12 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1}”⟩⟩) = (0...3))
113		0elfz 10542	. . . . . . . . . . . . 13 ⊢ (3 ∈ ℕ0 → 0 ∈ (0...3))
114	15, 113	mp1i 10	. . . . . . . . . . . 12 ⊢ (⊤ → 0 ∈ (0...3))
115		0ne1 9380	. . . . . . . . . . . . 13 ⊢ 0 ≠ 1
116	115	a1i 9	. . . . . . . . . . . 12 ⊢ (⊤ → 0 ≠ 1)
117		s1cl 11411	. . . . . . . . . . . . . . 15 ⊢ ({0, 1} ∈ V → ⟨“{0, 1}”⟩ ∈ Word V)
118		ccatlid 11396	. . . . . . . . . . . . . . 15 ⊢ (⟨“{0, 1}”⟩ ∈ Word V → (∅ ++ ⟨“{0, 1}”⟩) = ⟨“{0, 1}”⟩)
119	9, 117, 118	mp2b 8	. . . . . . . . . . . . . 14 ⊢ (∅ ++ ⟨“{0, 1}”⟩) = ⟨“{0, 1}”⟩
120	94, 119	eqtr4i 2262	. . . . . . . . . . . . 13 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1}”⟩⟩) = (∅ ++ ⟨“{0, 1}”⟩)
121	120	a1i 9	. . . . . . . . . . . 12 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1}”⟩⟩) = (∅ ++ ⟨“{0, 1}”⟩))
122	102, 33, 104, 106, 111, 112, 108, 114, 116, 121	vdegp1cid 16762	. . . . . . . . . . 11 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1}”⟩⟩)‘1) = (0 + 1))
123		0p1e1 9427	. . . . . . . . . . 11 ⊢ (0 + 1) = 1
124	122, 123	eqtrdi 2287	. . . . . . . . . 10 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1}”⟩⟩)‘1) = 1)
125	81	a1i 9	. . . . . . . . . 10 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩) = (0...3))
126		2re 9383	. . . . . . . . . . . . 13 ⊢ 2 ∈ ℝ
127		3re 9387	. . . . . . . . . . . . 13 ⊢ 3 ∈ ℝ
128		2lt3 9486	. . . . . . . . . . . . 13 ⊢ 2 < 3
129	126, 127, 128	ltleii 8435	. . . . . . . . . . . 12 ⊢ 2 ≤ 3
130		elfz2nn0 10536	. . . . . . . . . . . 12 ⊢ (2 ∈ (0...3) ↔ (2 ∈ ℕ0 ∧ 3 ∈ ℕ0 ∧ 2 ≤ 3))
131	11, 15, 129, 130	mpbir3an 1210	. . . . . . . . . . 11 ⊢ 2 ∈ (0...3)
132	131	a1i 9	. . . . . . . . . 10 ⊢ (⊤ → 2 ∈ (0...3))
133		1ne2 9522	. . . . . . . . . . . 12 ⊢ 1 ≠ 2
134	133	necomi 2505	. . . . . . . . . . 11 ⊢ 2 ≠ 1
135	134	a1i 9	. . . . . . . . . 10 ⊢ (⊤ → 2 ≠ 1)
136		0ne2 9521	. . . . . . . . . . 11 ⊢ 0 ≠ 2
137	136	a1i 9	. . . . . . . . . 10 ⊢ (⊤ → 0 ≠ 2)
138		df-s2 11550	. . . . . . . . . . . 12 ⊢ ⟨“{0, 1} {0, 2}”⟩ = (⟨“{0, 1}”⟩ ++ ⟨“{0, 2}”⟩)
139	83, 138	eqtri 2259	. . . . . . . . . . 11 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩) = (⟨“{0, 1}”⟩ ++ ⟨“{0, 2}”⟩)
140	139	a1i 9	. . . . . . . . . 10 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩) = (⟨“{0, 1}”⟩ ++ ⟨“{0, 2}”⟩))
141	93, 33, 95, 99, 124, 125, 108, 114, 116, 132, 135, 137, 140	vdegp1aid 16760	. . . . . . . . 9 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2}”⟩⟩)‘1) = 1)
142	70	a1i 9	. . . . . . . . 9 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩) = (0...3))
143		nn0fz0 10543	. . . . . . . . . . 11 ⊢ (3 ∈ ℕ0 ↔ 3 ∈ (0...3))
144	15, 143	mpbi 145	. . . . . . . . . 10 ⊢ 3 ∈ (0...3)
145	144	a1i 9	. . . . . . . . 9 ⊢ (⊤ → 3 ∈ (0...3))
146		1re 8331	. . . . . . . . . . 11 ⊢ 1 ∈ ℝ
147		1lt3 9487	. . . . . . . . . . 11 ⊢ 1 < 3
148	146, 147	gtneii 8428	. . . . . . . . . 10 ⊢ 3 ≠ 1
149	148	a1i 9	. . . . . . . . 9 ⊢ (⊤ → 3 ≠ 1)
150		3ne0 9408	. . . . . . . . . . 11 ⊢ 3 ≠ 0
151	150	necomi 2505	. . . . . . . . . 10 ⊢ 0 ≠ 3
152	151	a1i 9	. . . . . . . . 9 ⊢ (⊤ → 0 ≠ 3)
153		df-s3 11551	. . . . . . . . . . 11 ⊢ ⟨“{0, 1} {0, 2} {0, 3}”⟩ = (⟨“{0, 1} {0, 2}”⟩ ++ ⟨“{0, 3}”⟩)
154	72, 153	eqtri 2259	. . . . . . . . . 10 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩) = (⟨“{0, 1} {0, 2}”⟩ ++ ⟨“{0, 3}”⟩)
155	154	a1i 9	. . . . . . . . 9 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩) = (⟨“{0, 1} {0, 2}”⟩ ++ ⟨“{0, 3}”⟩))
156	82, 33, 84, 88, 141, 142, 108, 114, 116, 145, 149, 152, 155	vdegp1aid 16760	. . . . . . . 8 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3}”⟩⟩)‘1) = 1)
157	59	a1i 9	. . . . . . . 8 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩) = (0...3))
158		df-s4 11552	. . . . . . . . . 10 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ = (⟨“{0, 1} {0, 2} {0, 3}”⟩ ++ ⟨“{1, 2}”⟩)
159	61, 158	eqtri 2259	. . . . . . . . 9 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3}”⟩ ++ ⟨“{1, 2}”⟩)
160	159	a1i 9	. . . . . . . 8 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3}”⟩ ++ ⟨“{1, 2}”⟩))
161	71, 33, 73, 77, 156, 157, 108, 132, 135, 160	vdegp1bid 16761	. . . . . . 7 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩)‘1) = (1 + 1))
162		1p1e2 9430	. . . . . . 7 ⊢ (1 + 1) = 2
163	161, 162	eqtrdi 2287	. . . . . 6 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩⟩)‘1) = 2)
164	48	a1i 9	. . . . . 6 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩) = (0...3))
165		df-s5 11553	. . . . . . . 8 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ++ ⟨“{1, 2}”⟩)
166	50, 165	eqtri 2259	. . . . . . 7 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ++ ⟨“{1, 2}”⟩)
167	166	a1i 9	. . . . . 6 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2}”⟩ ++ ⟨“{1, 2}”⟩))
168	60, 33, 62, 66, 163, 164, 108, 132, 135, 167	vdegp1bid 16761	. . . . 5 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩)‘1) = (2 + 1))
169		2p1e3 9447	. . . . 5 ⊢ (2 + 1) = 3
170	168, 169	eqtrdi 2287	. . . 4 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩⟩)‘1) = 3)
171	28	a1i 9	. . . 4 ⊢ (⊤ → (Vtx‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩) = (0...3))
172	126, 128	ltneii 8429	. . . . 5 ⊢ 2 ≠ 3
173	172	a1i 9	. . . 4 ⊢ (⊤ → 2 ≠ 3)
174		df-s6 11554	. . . . . 6 ⊢ ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ++ ⟨“{2, 3}”⟩)
175	34, 174	eqtri 2259	. . . . 5 ⊢ (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ++ ⟨“{2, 3}”⟩)
176	175	a1i 9	. . . 4 ⊢ (⊤ → (iEdg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2}”⟩ ++ ⟨“{2, 3}”⟩))
177	49, 33, 51, 55, 170, 171, 108, 132, 135, 145, 149, 173, 176	vdegp1aid 16760	. . 3 ⊢ (⊤ → ((VtxDeg‘⟨(0...3), ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩⟩)‘1) = 3)
178		konigsberg.v	. . . . 5 ⊢ 𝑉 = (0...3)
179		konigsberg.e	. . . . 5 ⊢ 𝐸 = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩
180		konigsberg.g	. . . . 5 ⊢ 𝐺 = ⟨𝑉, 𝐸⟩
181	178, 179, 180	konigsbergvtx 16928	. . . 4 ⊢ (Vtx‘𝐺) = (0...3)
182	181	a1i 9	. . 3 ⊢ (⊤ → (Vtx‘𝐺) = (0...3))
183	178, 179, 180	konigsbergiedg 16929	. . . . 5 ⊢ (iEdg‘𝐺) = ⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3} {2, 3}”⟩
184	183, 38	eqtri 2259	. . . 4 ⊢ (iEdg‘𝐺) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ++ ⟨“{2, 3}”⟩)
185	184	a1i 9	. . 3 ⊢ (⊤ → (iEdg‘𝐺) = (⟨“{0, 1} {0, 2} {0, 3} {1, 2} {1, 2} {2, 3}”⟩ ++ ⟨“{2, 3}”⟩))
186	29, 33, 35, 44, 177, 182, 108, 132, 135, 145, 149, 173, 185	vdegp1aid 16760	. 2 ⊢ (⊤ → ((VtxDeg‘𝐺)‘1) = 3)
187	186	mptru 1411	1 ⊢ ((VtxDeg‘𝐺)‘1) = 3

This proof depends on syntax axioms:   ∨ wo 720   = wceq 1402  ⊤wtru 1403   ∈ wcel 2209   ≠ wne 2420  {crab 2532  Vcvv 2821  ∅c0 3520  𝒫 cpw 3688  {cpr 3710  ⟨cop 3712   class class class wbr 4131  ‘cfv 5380  (class class class)co 6088  1_oc1o 6684  2_oc2o 6685   ≈ cen 7024  Fincfn 7026  0cc0 8185  1c1 8186   + caddc 8188   ≤ cle 8367  2c2 9364  3c3 9365  ℕ₀cn0 9574  ℤcz 9655  ...cfz 10428  Word cword 11326   ++ cconcat 11380  ⟨“cs1 11405  ⟨“cs2 11543  ⟨“cs3 11544  ⟨“cs4 11545  ⟨“cs5 11546  ⟨“cs6 11547  ⟨“cs7 11548  Vtxcvtx 16458  iEdgciedg 16459  UPGraphcupgr 16537  VtxDegcvtxdg 16732

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-coll 4248  ax-sep 4251  ax-nul 4261  ax-pow 4313  ax-pr 4348  ax-un 4580  ax-setind 4686  ax-iinf 4737  ax-cnex 8276  ax-resscn 8277  ax-1cn 8278  ax-1re 8279  ax-icn 8280  ax-addcl 8281  ax-addrcl 8282  ax-mulcl 8283  ax-addcom 8285  ax-mulcom 8286  ax-addass 8287  ax-mulass 8288  ax-distr 8289  ax-i2m1 8290  ax-0lt1 8291  ax-1rid 8292  ax-0id 8293  ax-rnegex 8294  ax-cnre 8296  ax-pre-ltirr 8297  ax-pre-ltwlin 8298  ax-pre-lttrn 8299  ax-pre-apti 8300  ax-pre-ltadd 8301

This proof depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-reu 2535  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-if 3639  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-int 3971  df-iun 4014  df-br 4132  df-opab 4194  df-mpt 4195  df-tr 4232  df-id 4440  df-iord 4513  df-on 4515  df-ilim 4516  df-suc 4518  df-iom 4740  df-xp 4782  df-rel 4783  df-cnv 4784  df-co 4785  df-dm 4786  df-rn 4787  df-res 4788  df-ima 4789  df-iota 5340  df-fun 5382  df-fn 5383  df-f 5384  df-f1 5385  df-fo 5386  df-f1o 5387  df-fv 5388  df-riota 6041  df-ov 6091  df-oprab 6092  df-mpo 6093  df-1st 6378  df-2nd 6379  df-recs 6580  df-irdg 6645  df-frec 6666  df-1o 6691  df-2o 6692  df-oadd 6695  df-er 6811  df-en 7027  df-dom 7028  df-fin 7029  df-pnf 8368  df-mnf 8369  df-xr 8370  df-ltxr 8371  df-le 8372  df-sub 8506  df-neg 8507  df-inn 9314  df-2 9372  df-3 9373  df-4 9374  df-5 9375  df-6 9376  df-7 9377  df-8 9378  df-9 9379  df-n0 9575  df-z 9656  df-dec 9789  df-uz 9938  df-xadd 10192  df-fz 10429  df-fzo 10567  df-ihash 11237  df-word 11327  df-concat 11381  df-s1 11406  df-s2 11550  df-s3 11551  df-s4 11552  df-s5 11553  df-s6 11554  df-s7 11555  df-ndx 13413  df-slot 13414  df-base 13416  df-edgf 16451  df-vtx 16460  df-iedg 16461  df-upgren 16539  df-umgren 16540  df-vtxdg 16733

This theorem is used by:  konigsberglem4  16937