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Theorem hashgt23el 14067

Description: A set with more than two elements has at least three different elements. (Contributed by BTernaryTau, 21-Sep-2023.)

**Assertion**
Ref	Expression
hashgt23el	⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))

Distinct variable groups: 𝑊,𝑎 𝑉,𝑎,𝑏,𝑐 Allowed substitution hints: 𝑊(𝑏,𝑐)

**Proof of Theorem hashgt23el**
Step	Hyp	Ref	Expression
1		2pos 12006	. . . . . 6 ⊢ 0 < 2
2		0xr 10953	. . . . . . 7 ⊢ 0 ∈ ℝ^*
3		2re 11977	. . . . . . . 8 ⊢ 2 ∈ ℝ
4	3	rexri 10964	. . . . . . 7 ⊢ 2 ∈ ℝ^*
5		hashxrcl 14000	. . . . . . 7 ⊢ (𝑉 ∈ 𝑊 → (♯‘𝑉) ∈ ℝ^*)
6		xrlttr 12803	. . . . . . 7 ⊢ ((0 ∈ ℝ^* ∧ 2 ∈ ℝ^* ∧ (♯‘𝑉) ∈ ℝ^*) → ((0 < 2 ∧ 2 < (♯‘𝑉)) → 0 < (♯‘𝑉)))
7	2, 4, 5, 6	mp3an12i 1463	. . . . . 6 ⊢ (𝑉 ∈ 𝑊 → ((0 < 2 ∧ 2 < (♯‘𝑉)) → 0 < (♯‘𝑉)))
8	1, 7	mpani 692	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → 0 < (♯‘𝑉)))
9		hashgt0elex 14044	. . . . . 6 ⊢ ((𝑉 ∈ 𝑊 ∧ 0 < (♯‘𝑉)) → ∃𝑎 𝑎 ∈ 𝑉)
10	9	ex 412	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (0 < (♯‘𝑉) → ∃𝑎 𝑎 ∈ 𝑉))
11	8, 10	syld 47	. . . 4 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → ∃𝑎 𝑎 ∈ 𝑉))
12	11	imp 406	. . 3 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎 𝑎 ∈ 𝑉)
13		difexg 5246	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (𝑉 ∖ {𝑎}) ∈ V)
14		difsnid 4740	. . . . . . . . . . . 12 ⊢ (𝑎 ∈ 𝑉 → ((𝑉 ∖ {𝑎}) ∪ {𝑎}) = 𝑉)
15	14	fveq2d 6760	. . . . . . . . . . 11 ⊢ (𝑎 ∈ 𝑉 → (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) = (♯‘𝑉))
16	15	breq2d 5082	. . . . . . . . . 10 ⊢ (𝑎 ∈ 𝑉 → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ 2 < (♯‘𝑉)))
17	16	adantr 480	. . . . . . . . 9 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ 2 < (♯‘𝑉)))
18		df-2 11966	. . . . . . . . . . . . 13 ⊢ 2 = (1 + 1)
19	18	breq1i 5077	. . . . . . . . . . . 12 ⊢ (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})))
20		neldifsn 4722	. . . . . . . . . . . . . 14 ⊢ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})
21		1nn0 12179	. . . . . . . . . . . . . . . 16 ⊢ 1 ∈ ℕ₀
22		hashunsnggt 14037	. . . . . . . . . . . . . . . 16 ⊢ ((((𝑉 ∖ {𝑎}) ∈ V ∧ 𝑎 ∈ 𝑉 ∧ 1 ∈ ℕ₀) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
23	21, 22	mp3anl3 1455	. . . . . . . . . . . . . . 15 ⊢ ((((𝑉 ∖ {𝑎}) ∈ V ∧ 𝑎 ∈ 𝑉) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
24	13, 23	sylanl1 676	. . . . . . . . . . . . . 14 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
25	20, 24	mpan2 687	. . . . . . . . . . . . 13 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
26	25	biimp3ar 1468	. . . . . . . . . . . 12 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉 ∧ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))) → 1 < (♯‘(𝑉 ∖ {𝑎})))
27	19, 26	syl3an3b 1403	. . . . . . . . . . 11 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉 ∧ 2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))) → 1 < (♯‘(𝑉 ∖ {𝑎})))
28	27	3expia 1119	. . . . . . . . . 10 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
29	28	ancoms 458	. . . . . . . . 9 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
30	17, 29	sylbird 259	. . . . . . . 8 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘𝑉) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
31	30	3impia 1115	. . . . . . 7 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
32	31	3expib 1120	. . . . . 6 ⊢ (𝑎 ∈ 𝑉 → ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
33		1lt2 12074	. . . . . . . . . . 11 ⊢ 1 < 2
34		1xr 10965	. . . . . . . . . . . 12 ⊢ 1 ∈ ℝ^*
35		xrlttr 12803	. . . . . . . . . . . 12 ⊢ ((1 ∈ ℝ^* ∧ 2 ∈ ℝ^* ∧ (♯‘𝑉) ∈ ℝ^*) → ((1 < 2 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉)))
36	34, 4, 5, 35	mp3an12i 1463	. . . . . . . . . . 11 ⊢ (𝑉 ∈ 𝑊 → ((1 < 2 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉)))
37	33, 36	mpani 692	. . . . . . . . . 10 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → 1 < (♯‘𝑉)))
38	37	imp 406	. . . . . . . . 9 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉))
39	38	3adant1 1128	. . . . . . . 8 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉))
40		difsn 4728	. . . . . . . . . 10 ⊢ (¬ 𝑎 ∈ 𝑉 → (𝑉 ∖ {𝑎}) = 𝑉)
41	40	3ad2ant1 1131	. . . . . . . . 9 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → (𝑉 ∖ {𝑎}) = 𝑉)
42	41	fveq2d 6760	. . . . . . . 8 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → (♯‘(𝑉 ∖ {𝑎})) = (♯‘𝑉))
43	39, 42	breqtrrd 5098	. . . . . . 7 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
44	43	3expib 1120	. . . . . 6 ⊢ (¬ 𝑎 ∈ 𝑉 → ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
45	32, 44	pm2.61i 182	. . . . 5 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
46		hashgt12el 14065	. . . . 5 ⊢ (((𝑉 ∖ {𝑎}) ∈ V ∧ 1 < (♯‘(𝑉 ∖ {𝑎}))) → ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
47	13, 45, 46	syl2an2r 681	. . . 4 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
48	47	alrimiv 1931	. . 3 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∀𝑎∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
49		19.29r 1878	. . 3 ⊢ ((∃𝑎 𝑎 ∈ 𝑉 ∧ ∀𝑎∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐) → ∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐))
50	12, 48, 49	syl2anc 583	. 2 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐))
51		df-rex 3069	. . 3 ⊢ (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐))
52		eldifsn 4717	. . . . . . . . 9 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑏 ∈ 𝑉 ∧ 𝑏 ≠ 𝑎))
53		necom 2996	. . . . . . . . . 10 ⊢ (𝑏 ≠ 𝑎 ↔ 𝑎 ≠ 𝑏)
54	53	anbi2i 622	. . . . . . . . 9 ⊢ ((𝑏 ∈ 𝑉 ∧ 𝑏 ≠ 𝑎) ↔ (𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏))
55	52, 54	bitri 274	. . . . . . . 8 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏))
56		ax-5 1914	. . . . . . . . 9 ⊢ (𝑎 ≠ 𝑏 → ∀𝑐 𝑎 ≠ 𝑏)
57	56	anim2i 616	. . . . . . . 8 ⊢ ((𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏) → (𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏))
58	55, 57	sylbi 216	. . . . . . 7 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) → (𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏))
59		3anass 1093	. . . . . . . . . 10 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ (𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
60	59	exbii 1851	. . . . . . . . 9 ⊢ (∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
61		df-rex 3069	. . . . . . . . . 10 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐(𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐))
62		eldifsn 4717	. . . . . . . . . . . . . 14 ⊢ (𝑐 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑐 ∈ 𝑉 ∧ 𝑐 ≠ 𝑎))
63		necom 2996	. . . . . . . . . . . . . . 15 ⊢ (𝑐 ≠ 𝑎 ↔ 𝑎 ≠ 𝑐)
64	63	anbi2i 622	. . . . . . . . . . . . . 14 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑐 ≠ 𝑎) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐))
65	62, 64	bitri 274	. . . . . . . . . . . . 13 ⊢ (𝑐 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐))
66	65	anbi1i 623	. . . . . . . . . . . 12 ⊢ ((𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐) ∧ 𝑏 ≠ 𝑐))
67		df-3an 1087	. . . . . . . . . . . 12 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐) ∧ 𝑏 ≠ 𝑐))
68	66, 67	bitr4i 277	. . . . . . . . . . 11 ⊢ ((𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
69	68	exbii 1851	. . . . . . . . . 10 ⊢ (∃𝑐(𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
70	61, 69	bitri 274	. . . . . . . . 9 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
71		df-rex 3069	. . . . . . . . 9 ⊢ (∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
72	60, 70, 71	3bitr4i 302	. . . . . . . 8 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
73	72	biimpi 215	. . . . . . 7 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
74	58, 73	anim12i 612	. . . . . 6 ⊢ ((𝑏 ∈ (𝑉 ∖ {𝑎}) ∧ ∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐) → ((𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏) ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
75		alral 3079	. . . . . . . . . 10 ⊢ (∀𝑐 𝑎 ≠ 𝑏 → ∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏)
76	75	anim1i 614	. . . . . . . . 9 ⊢ ((∀𝑐 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → (∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
77		r19.29 3183	. . . . . . . . 9 ⊢ ((∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
78		3anass 1093	. . . . . . . . . . 11 ⊢ ((𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ (𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
79	78	biimpri 227	. . . . . . . . . 10 ⊢ ((𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
80	79	reximi 3174	. . . . . . . . 9 ⊢ (∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
81	76, 77, 80	3syl 18	. . . . . . . 8 ⊢ ((∀𝑐 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
82	81	anim2i 616	. . . . . . 7 ⊢ ((𝑏 ∈ 𝑉 ∧ (∀𝑐 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))) → (𝑏 ∈ 𝑉 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
83	82	anassrs 467	. . . . . 6 ⊢ (((𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏) ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → (𝑏 ∈ 𝑉 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
84	74, 83	syl 17	. . . . 5 ⊢ ((𝑏 ∈ (𝑉 ∖ {𝑎}) ∧ ∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐) → (𝑏 ∈ 𝑉 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
85	84	reximi2 3171	. . . 4 ⊢ (∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 → ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
86	85	reximi 3174	. . 3 ⊢ (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 → ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
87	51, 86	sylbir 234	. 2 ⊢ (∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐) → ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
88	50, 87	syl 17	1 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎 ∈ 𝑉 ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 395 ∧ w3a 1085 ∀wal 1537 = wceq 1539 ∃wex 1783 ∈ wcel 2108 ≠ wne 2942 ∀wral 3063 ∃wrex 3064 Vcvv 3422 ∖ cdif 3880 ∪ cun 3881 {csn 4558 class class class wbr 5070 ‘cfv 6418 (class class class)co 7255 0cc0 10802 1c1 10803 + caddc 10805 ℝ^*cxr 10939 < clt 10940 2c2 11958 ℕ₀cn0 12163 ♯chash 13972

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1799 ax-4 1813 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2110 ax-9 2118 ax-10 2139 ax-11 2156 ax-12 2173 ax-ext 2709 ax-sep 5218 ax-nul 5225 ax-pow 5283 ax-pr 5347 ax-un 7566 ax-cnex 10858 ax-resscn 10859 ax-1cn 10860 ax-icn 10861 ax-addcl 10862 ax-addrcl 10863 ax-mulcl 10864 ax-mulrcl 10865 ax-mulcom 10866 ax-addass 10867 ax-mulass 10868 ax-distr 10869 ax-i2m1 10870 ax-1ne0 10871 ax-1rid 10872 ax-rnegex 10873 ax-rrecex 10874 ax-cnre 10875 ax-pre-lttri 10876 ax-pre-lttrn 10877 ax-pre-ltadd 10878 ax-pre-mulgt0 10879

This theorem depends on definitions: df-bi 206 df-an 396 df-or 844 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1784 df-nf 1788 df-sb 2069 df-mo 2540 df-eu 2569 df-clab 2716 df-cleq 2730 df-clel 2817 df-nfc 2888 df-ne 2943 df-nel 3049 df-ral 3068 df-rex 3069 df-reu 3070 df-rab 3072 df-v 3424 df-sbc 3712 df-csb 3829 df-dif 3886 df-un 3888 df-in 3890 df-ss 3900 df-pss 3902 df-nul 4254 df-if 4457 df-pw 4532 df-sn 4559 df-pr 4561 df-tp 4563 df-op 4565 df-uni 4837 df-int 4877 df-iun 4923 df-br 5071 df-opab 5133 df-mpt 5154 df-tr 5188 df-id 5480 df-eprel 5486 df-po 5494 df-so 5495 df-fr 5535 df-we 5537 df-xp 5586 df-rel 5587 df-cnv 5588 df-co 5589 df-dm 5590 df-rn 5591 df-res 5592 df-ima 5593 df-pred 6191 df-ord 6254 df-on 6255 df-lim 6256 df-suc 6257 df-iota 6376 df-fun 6420 df-fn 6421 df-f 6422 df-f1 6423 df-fo 6424 df-f1o 6425 df-fv 6426 df-riota 7212 df-ov 7258 df-oprab 7259 df-mpo 7260 df-om 7688 df-1st 7804 df-2nd 7805 df-frecs 8068 df-wrecs 8099 df-recs 8173 df-rdg 8212 df-1o 8267 df-oadd 8271 df-er 8456 df-en 8692 df-dom 8693 df-sdom 8694 df-fin 8695 df-dju 9590 df-card 9628 df-pnf 10942 df-mnf 10943 df-xr 10944 df-ltxr 10945 df-le 10946 df-sub 11137 df-neg 11138 df-nn 11904 df-2 11966 df-n0 12164 df-xnn0 12236 df-z 12250 df-uz 12512 df-xneg 12777 df-xadd 12778 df-fz 13169 df-hash 13973

This theorem is referenced by: cusgr3cyclex 32998

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