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Theorem hashgt23el 13786

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 11741	. . . . . 6 ⊢ 0 < 2
2		0xr 10688	. . . . . . 7 ⊢ 0 ∈ ℝ^*
3		2re 11712	. . . . . . . 8 ⊢ 2 ∈ ℝ
4	3	rexri 10699	. . . . . . 7 ⊢ 2 ∈ ℝ^*
5		hashxrcl 13719	. . . . . . 7 ⊢ (𝑉 ∈ 𝑊 → (♯‘𝑉) ∈ ℝ^*)
6		xrlttr 12534	. . . . . . 7 ⊢ ((0 ∈ ℝ^* ∧ 2 ∈ ℝ^* ∧ (♯‘𝑉) ∈ ℝ^*) → ((0 < 2 ∧ 2 < (♯‘𝑉)) → 0 < (♯‘𝑉)))
7	2, 4, 5, 6	mp3an12i 1461	. . . . . 6 ⊢ (𝑉 ∈ 𝑊 → ((0 < 2 ∧ 2 < (♯‘𝑉)) → 0 < (♯‘𝑉)))
8	1, 7	mpani 694	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → 0 < (♯‘𝑉)))
9		hashgt0elex 13763	. . . . . 6 ⊢ ((𝑉 ∈ 𝑊 ∧ 0 < (♯‘𝑉)) → ∃𝑎 𝑎 ∈ 𝑉)
10	9	ex 415	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (0 < (♯‘𝑉) → ∃𝑎 𝑎 ∈ 𝑉))
11	8, 10	syld 47	. . . 4 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → ∃𝑎 𝑎 ∈ 𝑉))
12	11	imp 409	. . 3 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎 𝑎 ∈ 𝑉)
13		difexg 5231	. . . . 5 ⊢ (𝑉 ∈ 𝑊 → (𝑉 ∖ {𝑎}) ∈ V)
14		difsnid 4743	. . . . . . . . . . . 12 ⊢ (𝑎 ∈ 𝑉 → ((𝑉 ∖ {𝑎}) ∪ {𝑎}) = 𝑉)
15	14	fveq2d 6674	. . . . . . . . . . 11 ⊢ (𝑎 ∈ 𝑉 → (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) = (♯‘𝑉))
16	15	breq2d 5078	. . . . . . . . . 10 ⊢ (𝑎 ∈ 𝑉 → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ 2 < (♯‘𝑉)))
17	16	adantr 483	. . . . . . . . 9 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ 2 < (♯‘𝑉)))
18		df-2 11701	. . . . . . . . . . . . 13 ⊢ 2 = (1 + 1)
19	18	breq1i 5073	. . . . . . . . . . . 12 ⊢ (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})))
20		neldifsn 4725	. . . . . . . . . . . . . 14 ⊢ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})
21		1nn0 11914	. . . . . . . . . . . . . . . 16 ⊢ 1 ∈ ℕ₀
22		hashunsnggt 13756	. . . . . . . . . . . . . . . 16 ⊢ ((((𝑉 ∖ {𝑎}) ∈ V ∧ 𝑎 ∈ 𝑉 ∧ 1 ∈ ℕ₀) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
23	21, 22	mp3anl3 1453	. . . . . . . . . . . . . . 15 ⊢ ((((𝑉 ∖ {𝑎}) ∈ V ∧ 𝑎 ∈ 𝑉) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
24	13, 23	sylanl1 678	. . . . . . . . . . . . . 14 ⊢ (((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) ∧ ¬ 𝑎 ∈ (𝑉 ∖ {𝑎})) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
25	20, 24	mpan2 689	. . . . . . . . . . . . 13 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) → (1 < (♯‘(𝑉 ∖ {𝑎})) ↔ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))))
26	25	biimp3ar 1466	. . . . . . . . . . . 12 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉 ∧ (1 + 1) < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))) → 1 < (♯‘(𝑉 ∖ {𝑎})))
27	19, 26	syl3an3b 1401	. . . . . . . . . . 11 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉 ∧ 2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎}))) → 1 < (♯‘(𝑉 ∖ {𝑎})))
28	27	3expia 1117	. . . . . . . . . 10 ⊢ ((𝑉 ∈ 𝑊 ∧ 𝑎 ∈ 𝑉) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
29	28	ancoms 461	. . . . . . . . 9 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘((𝑉 ∖ {𝑎}) ∪ {𝑎})) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
30	17, 29	sylbird 262	. . . . . . . 8 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊) → (2 < (♯‘𝑉) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
31	30	3impia 1113	. . . . . . 7 ⊢ ((𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
32	31	3expib 1118	. . . . . 6 ⊢ (𝑎 ∈ 𝑉 → ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
33		1lt2 11809	. . . . . . . . . . 11 ⊢ 1 < 2
34		1xr 10700	. . . . . . . . . . . 12 ⊢ 1 ∈ ℝ^*
35		xrlttr 12534	. . . . . . . . . . . 12 ⊢ ((1 ∈ ℝ^* ∧ 2 ∈ ℝ^* ∧ (♯‘𝑉) ∈ ℝ^*) → ((1 < 2 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉)))
36	34, 4, 5, 35	mp3an12i 1461	. . . . . . . . . . 11 ⊢ (𝑉 ∈ 𝑊 → ((1 < 2 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉)))
37	33, 36	mpani 694	. . . . . . . . . 10 ⊢ (𝑉 ∈ 𝑊 → (2 < (♯‘𝑉) → 1 < (♯‘𝑉)))
38	37	imp 409	. . . . . . . . 9 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉))
39	38	3adant1 1126	. . . . . . . 8 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘𝑉))
40		difsn 4731	. . . . . . . . . 10 ⊢ (¬ 𝑎 ∈ 𝑉 → (𝑉 ∖ {𝑎}) = 𝑉)
41	40	3ad2ant1 1129	. . . . . . . . 9 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → (𝑉 ∖ {𝑎}) = 𝑉)
42	41	fveq2d 6674	. . . . . . . 8 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → (♯‘(𝑉 ∖ {𝑎})) = (♯‘𝑉))
43	39, 42	breqtrrd 5094	. . . . . . 7 ⊢ ((¬ 𝑎 ∈ 𝑉 ∧ 𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
44	43	3expib 1118	. . . . . 6 ⊢ (¬ 𝑎 ∈ 𝑉 → ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎}))))
45	32, 44	pm2.61i 184	. . . . 5 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → 1 < (♯‘(𝑉 ∖ {𝑎})))
46		hashgt12el 13784	. . . . 5 ⊢ (((𝑉 ∖ {𝑎}) ∈ V ∧ 1 < (♯‘(𝑉 ∖ {𝑎}))) → ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
47	13, 45, 46	syl2an2r 683	. . . 4 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
48	47	alrimiv 1928	. . 3 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∀𝑎∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐)
49		19.29r 1875	. . 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 586	. 2 ⊢ ((𝑉 ∈ 𝑊 ∧ 2 < (♯‘𝑉)) → ∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐))
51		df-rex 3144	. . 3 ⊢ (∃𝑎 ∈ 𝑉 ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑎(𝑎 ∈ 𝑉 ∧ ∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐))
52		eldifsn 4719	. . . . . . . . 9 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑏 ∈ 𝑉 ∧ 𝑏 ≠ 𝑎))
53		necom 3069	. . . . . . . . . 10 ⊢ (𝑏 ≠ 𝑎 ↔ 𝑎 ≠ 𝑏)
54	53	anbi2i 624	. . . . . . . . 9 ⊢ ((𝑏 ∈ 𝑉 ∧ 𝑏 ≠ 𝑎) ↔ (𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏))
55	52, 54	bitri 277	. . . . . . . 8 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏))
56		ax-5 1911	. . . . . . . . 9 ⊢ (𝑎 ≠ 𝑏 → ∀𝑐 𝑎 ≠ 𝑏)
57	56	anim2i 618	. . . . . . . 8 ⊢ ((𝑏 ∈ 𝑉 ∧ 𝑎 ≠ 𝑏) → (𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏))
58	55, 57	sylbi 219	. . . . . . 7 ⊢ (𝑏 ∈ (𝑉 ∖ {𝑎}) → (𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏))
59		3anass 1091	. . . . . . . . . 10 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ (𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
60	59	exbii 1848	. . . . . . . . 9 ⊢ (∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
61		df-rex 3144	. . . . . . . . . 10 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐(𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐))
62		eldifsn 4719	. . . . . . . . . . . . . 14 ⊢ (𝑐 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑐 ∈ 𝑉 ∧ 𝑐 ≠ 𝑎))
63		necom 3069	. . . . . . . . . . . . . . 15 ⊢ (𝑐 ≠ 𝑎 ↔ 𝑎 ≠ 𝑐)
64	63	anbi2i 624	. . . . . . . . . . . . . 14 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑐 ≠ 𝑎) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐))
65	62, 64	bitri 277	. . . . . . . . . . . . 13 ⊢ (𝑐 ∈ (𝑉 ∖ {𝑎}) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐))
66	65	anbi1i 625	. . . . . . . . . . . 12 ⊢ ((𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐) ∧ 𝑏 ≠ 𝑐))
67		df-3an 1085	. . . . . . . . . . . 12 ⊢ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ((𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐) ∧ 𝑏 ≠ 𝑐))
68	66, 67	bitr4i 280	. . . . . . . . . . 11 ⊢ ((𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ (𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
69	68	exbii 1848	. . . . . . . . . 10 ⊢ (∃𝑐(𝑐 ∈ (𝑉 ∖ {𝑎}) ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
70	61, 69	bitri 277	. . . . . . . . 9 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
71		df-rex 3144	. . . . . . . . 9 ⊢ (∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ ∃𝑐(𝑐 ∈ 𝑉 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
72	60, 70, 71	3bitr4i 305	. . . . . . . 8 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 ↔ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
73	72	biimpi 218	. . . . . . 7 ⊢ (∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
74	58, 73	anim12i 614	. . . . . 6 ⊢ ((𝑏 ∈ (𝑉 ∖ {𝑎}) ∧ ∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐) → ((𝑏 ∈ 𝑉 ∧ ∀𝑐 𝑎 ≠ 𝑏) ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
75		alral 3154	. . . . . . . . . 10 ⊢ (∀𝑐 𝑎 ≠ 𝑏 → ∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏)
76	75	anim1i 616	. . . . . . . . 9 ⊢ ((∀𝑐 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → (∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
77		r19.29 3254	. . . . . . . . 9 ⊢ ((∀𝑐 ∈ 𝑉 𝑎 ≠ 𝑏 ∧ ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
78		3anass 1091	. . . . . . . . . . 11 ⊢ ((𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐) ↔ (𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)))
79	78	biimpri 230	. . . . . . . . . 10 ⊢ ((𝑎 ≠ 𝑏 ∧ (𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐)) → (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
80	79	reximi 3243	. . . . . . . . 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 618	. . . . . . 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 470	. . . . . 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 3244	. . . 4 ⊢ (∃𝑏 ∈ (𝑉 ∖ {𝑎})∃𝑐 ∈ (𝑉 ∖ {𝑎})𝑏 ≠ 𝑐 → ∃𝑏 ∈ 𝑉 ∃𝑐 ∈ 𝑉 (𝑎 ≠ 𝑏 ∧ 𝑎 ≠ 𝑐 ∧ 𝑏 ≠ 𝑐))
86	85	reximi 3243	. . 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 237	. 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 208 ∧ wa 398 ∧ w3a 1083 ∀wal 1535 = wceq 1537 ∃wex 1780 ∈ wcel 2114 ≠ wne 3016 ∀wral 3138 ∃wrex 3139 Vcvv 3494 ∖ cdif 3933 ∪ cun 3934 {csn 4567 class class class wbr 5066 ‘cfv 6355 (class class class)co 7156 0cc0 10537 1c1 10538 + caddc 10540 ℝ^*cxr 10674 < clt 10675 2c2 11693 ℕ₀cn0 11898 ♯chash 13691

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 ax-rep 5190 ax-sep 5203 ax-nul 5210 ax-pow 5266 ax-pr 5330 ax-un 7461 ax-cnex 10593 ax-resscn 10594 ax-1cn 10595 ax-icn 10596 ax-addcl 10597 ax-addrcl 10598 ax-mulcl 10599 ax-mulrcl 10600 ax-mulcom 10601 ax-addass 10602 ax-mulass 10603 ax-distr 10604 ax-i2m1 10605 ax-1ne0 10606 ax-1rid 10607 ax-rnegex 10608 ax-rrecex 10609 ax-cnre 10610 ax-pre-lttri 10611 ax-pre-lttrn 10612 ax-pre-ltadd 10613 ax-pre-mulgt0 10614

This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-nel 3124 df-ral 3143 df-rex 3144 df-reu 3145 df-rmo 3146 df-rab 3147 df-v 3496 df-sbc 3773 df-csb 3884 df-dif 3939 df-un 3941 df-in 3943 df-ss 3952 df-pss 3954 df-nul 4292 df-if 4468 df-pw 4541 df-sn 4568 df-pr 4570 df-tp 4572 df-op 4574 df-uni 4839 df-int 4877 df-iun 4921 df-br 5067 df-opab 5129 df-mpt 5147 df-tr 5173 df-id 5460 df-eprel 5465 df-po 5474 df-so 5475 df-fr 5514 df-we 5516 df-xp 5561 df-rel 5562 df-cnv 5563 df-co 5564 df-dm 5565 df-rn 5566 df-res 5567 df-ima 5568 df-pred 6148 df-ord 6194 df-on 6195 df-lim 6196 df-suc 6197 df-iota 6314 df-fun 6357 df-fn 6358 df-f 6359 df-f1 6360 df-fo 6361 df-f1o 6362 df-fv 6363 df-riota 7114 df-ov 7159 df-oprab 7160 df-mpo 7161 df-om 7581 df-1st 7689 df-2nd 7690 df-wrecs 7947 df-recs 8008 df-rdg 8046 df-1o 8102 df-oadd 8106 df-er 8289 df-en 8510 df-dom 8511 df-sdom 8512 df-fin 8513 df-dju 9330 df-card 9368 df-pnf 10677 df-mnf 10678 df-xr 10679 df-ltxr 10680 df-le 10681 df-sub 10872 df-neg 10873 df-nn 11639 df-2 11701 df-n0 11899 df-xnn0 11969 df-z 11983 df-uz 12245 df-xneg 12508 df-xadd 12509 df-fz 12894 df-hash 13692

This theorem is referenced by: cusgr3cyclex 32383

W3C validator