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Theorem qbtwnre 11904

Description: The rational numbers are dense in ℝ: any two real numbers have a rational between them. Exercise 6 of [Apostol] p. 28. (Contributed by NM, 18-Nov-2004.) (Proof shortened by Mario Carneiro, 13-Jun-2014.)

**Assertion**
Ref	Expression
qbtwnre	⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐴 < 𝐵) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))

Distinct variable groups: 𝑥,𝐴 𝑥,𝐵

Proof of Theorem qbtwnre Dummy variables 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		posdif 10400	. . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ 0 < (𝐵 − 𝐴)))
2		resubcl 10224	. . . . . . 7 ⊢ ((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (𝐵 − 𝐴) ∈ ℝ)
3		nnrecl 11167	. . . . . . 7 ⊢ (((𝐵 − 𝐴) ∈ ℝ ∧ 0 < (𝐵 − 𝐴)) → ∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴))
4	2, 3	sylan 487	. . . . . 6 ⊢ (((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) ∧ 0 < (𝐵 − 𝐴)) → ∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴))
5	4	ex 449	. . . . 5 ⊢ ((𝐵 ∈ ℝ ∧ 𝐴 ∈ ℝ) → (0 < (𝐵 − 𝐴) → ∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴)))
6	5	ancoms 468	. . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (0 < (𝐵 − 𝐴) → ∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴)))
7	1, 6	sylbid 229	. . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 → ∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴)))
8		nnre 10904	. . . . . . . . 9 ⊢ (𝑦 ∈ ℕ → 𝑦 ∈ ℝ)
9	8	adantl 481	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → 𝑦 ∈ ℝ)
10		simplr 788	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → 𝐵 ∈ ℝ)
11	9, 10	remulcld 9949	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → (𝑦 · 𝐵) ∈ ℝ)
12		peano2rem 10227	. . . . . . 7 ⊢ ((𝑦 · 𝐵) ∈ ℝ → ((𝑦 · 𝐵) − 1) ∈ ℝ)
13	11, 12	syl 17	. . . . . 6 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → ((𝑦 · 𝐵) − 1) ∈ ℝ)
14		zbtwnre 11662	. . . . . 6 ⊢ (((𝑦 · 𝐵) − 1) ∈ ℝ → ∃!𝑧 ∈ ℤ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)))
15		reurex 3137	. . . . . 6 ⊢ (∃!𝑧 ∈ ℤ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) → ∃𝑧 ∈ ℤ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)))
16	13, 14, 15	3syl 18	. . . . 5 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → ∃𝑧 ∈ ℤ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)))
17		znq 11668	. . . . . . . . . . 11 ⊢ ((𝑧 ∈ ℤ ∧ 𝑦 ∈ ℕ) → (𝑧 / 𝑦) ∈ ℚ)
18	17	ancoms 468	. . . . . . . . . 10 ⊢ ((𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ) → (𝑧 / 𝑦) ∈ ℚ)
19	18	adantl 481	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑧 / 𝑦) ∈ ℚ)
20		an32 835	. . . . . . . . . 10 ⊢ (((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) ∧ (1 / 𝑦) < (𝐵 − 𝐴)) ↔ ((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ (1 / 𝑦) < (𝐵 − 𝐴)) ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)))
21	8	ad2antrl 760	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝑦 ∈ ℝ)
22		simpll 786	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝐴 ∈ ℝ)
23	21, 22	remulcld 9949	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑦 · 𝐴) ∈ ℝ)
24	13	adantrr 749	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((𝑦 · 𝐵) − 1) ∈ ℝ)
25		zre 11258	. . . . . . . . . . . . . 14 ⊢ (𝑧 ∈ ℤ → 𝑧 ∈ ℝ)
26	25	ad2antll 761	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝑧 ∈ ℝ)
27		ltletr 10008	. . . . . . . . . . . . 13 ⊢ (((𝑦 · 𝐴) ∈ ℝ ∧ ((𝑦 · 𝐵) − 1) ∈ ℝ ∧ 𝑧 ∈ ℝ) → (((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧) → (𝑦 · 𝐴) < 𝑧))
28	23, 24, 26, 27	syl3anc 1318	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧) → (𝑦 · 𝐴) < 𝑧))
29	21	recnd 9947	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝑦 ∈ ℂ)
30		simplr 788	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝐵 ∈ ℝ)
31	30	recnd 9947	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝐵 ∈ ℂ)
32	22	recnd 9947	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 𝐴 ∈ ℂ)
33	29, 31, 32	subdid 10365	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑦 · (𝐵 − 𝐴)) = ((𝑦 · 𝐵) − (𝑦 · 𝐴)))
34	33	breq2d 4595	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (1 < (𝑦 · (𝐵 − 𝐴)) ↔ 1 < ((𝑦 · 𝐵) − (𝑦 · 𝐴))))
35		1red 9934	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 1 ∈ ℝ)
36	30, 22	resubcld 10337	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝐵 − 𝐴) ∈ ℝ)
37		nngt0 10926	. . . . . . . . . . . . . . . . 17 ⊢ (𝑦 ∈ ℕ → 0 < 𝑦)
38	37	ad2antrl 760	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → 0 < 𝑦)
39		ltdivmul 10777	. . . . . . . . . . . . . . . 16 ⊢ ((1 ∈ ℝ ∧ (𝐵 − 𝐴) ∈ ℝ ∧ (𝑦 ∈ ℝ ∧ 0 < 𝑦)) → ((1 / 𝑦) < (𝐵 − 𝐴) ↔ 1 < (𝑦 · (𝐵 − 𝐴))))
40	35, 36, 21, 38, 39	syl112anc 1322	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((1 / 𝑦) < (𝐵 − 𝐴) ↔ 1 < (𝑦 · (𝐵 − 𝐴))))
41	11	adantrr 749	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑦 · 𝐵) ∈ ℝ)
42		ltsub13 10388	. . . . . . . . . . . . . . . 16 ⊢ (((𝑦 · 𝐴) ∈ ℝ ∧ (𝑦 · 𝐵) ∈ ℝ ∧ 1 ∈ ℝ) → ((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ↔ 1 < ((𝑦 · 𝐵) − (𝑦 · 𝐴))))
43	23, 41, 35, 42	syl3anc 1318	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ↔ 1 < ((𝑦 · 𝐵) − (𝑦 · 𝐴))))
44	34, 40, 43	3bitr4rd 300	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ↔ (1 / 𝑦) < (𝐵 − 𝐴)))
45	44	anbi1d 737	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧) ↔ ((1 / 𝑦) < (𝐵 − 𝐴) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧)))
46		ancom 465	. . . . . . . . . . . . 13 ⊢ (((1 / 𝑦) < (𝐵 − 𝐴) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧) ↔ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ (1 / 𝑦) < (𝐵 − 𝐴)))
47	45, 46	syl6bb 275	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((𝑦 · 𝐴) < ((𝑦 · 𝐵) − 1) ∧ ((𝑦 · 𝐵) − 1) ≤ 𝑧) ↔ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ (1 / 𝑦) < (𝐵 − 𝐴))))
48		ltmuldiv2 10776	. . . . . . . . . . . . 13 ⊢ ((𝐴 ∈ ℝ ∧ 𝑧 ∈ ℝ ∧ (𝑦 ∈ ℝ ∧ 0 < 𝑦)) → ((𝑦 · 𝐴) < 𝑧 ↔ 𝐴 < (𝑧 / 𝑦)))
49	22, 26, 21, 38, 48	syl112anc 1322	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((𝑦 · 𝐴) < 𝑧 ↔ 𝐴 < (𝑧 / 𝑦)))
50	28, 47, 49	3imtr3d 281	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ (1 / 𝑦) < (𝐵 − 𝐴)) → 𝐴 < (𝑧 / 𝑦)))
51	41	recnd 9947	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑦 · 𝐵) ∈ ℂ)
52		ax-1cn 9873	. . . . . . . . . . . . . . 15 ⊢ 1 ∈ ℂ
53		npcan 10169	. . . . . . . . . . . . . . 15 ⊢ (((𝑦 · 𝐵) ∈ ℂ ∧ 1 ∈ ℂ) → (((𝑦 · 𝐵) − 1) + 1) = (𝑦 · 𝐵))
54	51, 52, 53	sylancl 693	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((𝑦 · 𝐵) − 1) + 1) = (𝑦 · 𝐵))
55	54	breq2d 4595	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑧 < (((𝑦 · 𝐵) − 1) + 1) ↔ 𝑧 < (𝑦 · 𝐵)))
56		ltdivmul 10777	. . . . . . . . . . . . . 14 ⊢ ((𝑧 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ (𝑦 ∈ ℝ ∧ 0 < 𝑦)) → ((𝑧 / 𝑦) < 𝐵 ↔ 𝑧 < (𝑦 · 𝐵)))
57	26, 30, 21, 38, 56	syl112anc 1322	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((𝑧 / 𝑦) < 𝐵 ↔ 𝑧 < (𝑦 · 𝐵)))
58	55, 57	bitr4d 270	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑧 < (((𝑦 · 𝐵) − 1) + 1) ↔ (𝑧 / 𝑦) < 𝐵))
59	58	biimpd 218	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (𝑧 < (((𝑦 · 𝐵) − 1) + 1) → (𝑧 / 𝑦) < 𝐵))
60	50, 59	anim12d 584	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ (1 / 𝑦) < (𝐵 − 𝐴)) ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) → (𝐴 < (𝑧 / 𝑦) ∧ (𝑧 / 𝑦) < 𝐵)))
61	20, 60	syl5bi 231	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) ∧ (1 / 𝑦) < (𝐵 − 𝐴)) → (𝐴 < (𝑧 / 𝑦) ∧ (𝑧 / 𝑦) < 𝐵)))
62		breq2 4587	. . . . . . . . . . 11 ⊢ (𝑥 = (𝑧 / 𝑦) → (𝐴 < 𝑥 ↔ 𝐴 < (𝑧 / 𝑦)))
63		breq1 4586	. . . . . . . . . . 11 ⊢ (𝑥 = (𝑧 / 𝑦) → (𝑥 < 𝐵 ↔ (𝑧 / 𝑦) < 𝐵))
64	62, 63	anbi12d 743	. . . . . . . . . 10 ⊢ (𝑥 = (𝑧 / 𝑦) → ((𝐴 < 𝑥 ∧ 𝑥 < 𝐵) ↔ (𝐴 < (𝑧 / 𝑦) ∧ (𝑧 / 𝑦) < 𝐵)))
65	64	rspcev 3282	. . . . . . . . 9 ⊢ (((𝑧 / 𝑦) ∈ ℚ ∧ (𝐴 < (𝑧 / 𝑦) ∧ (𝑧 / 𝑦) < 𝐵)) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))
66	19, 61, 65	syl6an 566	. . . . . . . 8 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → (((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) ∧ (1 / 𝑦) < (𝐵 − 𝐴)) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)))
67	66	expd 451	. . . . . . 7 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ (𝑦 ∈ ℕ ∧ 𝑧 ∈ ℤ)) → ((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) → ((1 / 𝑦) < (𝐵 − 𝐴) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))))
68	67	expr 641	. . . . . 6 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → (𝑧 ∈ ℤ → ((((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) → ((1 / 𝑦) < (𝐵 − 𝐴) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)))))
69	68	rexlimdv 3012	. . . . 5 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → (∃𝑧 ∈ ℤ (((𝑦 · 𝐵) − 1) ≤ 𝑧 ∧ 𝑧 < (((𝑦 · 𝐵) − 1) + 1)) → ((1 / 𝑦) < (𝐵 − 𝐴) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))))
70	16, 69	mpd 15	. . . 4 ⊢ (((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) ∧ 𝑦 ∈ ℕ) → ((1 / 𝑦) < (𝐵 − 𝐴) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)))
71	70	rexlimdva 3013	. . 3 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (∃𝑦 ∈ ℕ (1 / 𝑦) < (𝐵 − 𝐴) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)))
72	7, 71	syld 46	. 2 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵)))
73	72	3impia 1253	1 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ ∧ 𝐴 < 𝐵) → ∃𝑥 ∈ ℚ (𝐴 < 𝑥 ∧ 𝑥 < 𝐵))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 195 ∧ wa 383 ∧ w3a 1031 = wceq 1475 ∈ wcel 1977 ∃wrex 2897 ∃!wreu 2898 class class class wbr 4583 (class class class)co 6549 ℂcc 9813 ℝcr 9814 0cc0 9815 1c1 9816 + caddc 9818 · cmul 9820 < clt 9953 ≤ cle 9954 − cmin 10145 / cdiv 10563 ℕcn 10897 ℤcz 11254 ℚcq 11664

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pow 4769 ax-pr 4833 ax-un 6847 ax-cnex 9871 ax-resscn 9872 ax-1cn 9873 ax-icn 9874 ax-addcl 9875 ax-addrcl 9876 ax-mulcl 9877 ax-mulrcl 9878 ax-mulcom 9879 ax-addass 9880 ax-mulass 9881 ax-distr 9882 ax-i2m1 9883 ax-1ne0 9884 ax-1rid 9885 ax-rnegex 9886 ax-rrecex 9887 ax-cnre 9888 ax-pre-lttri 9889 ax-pre-lttrn 9890 ax-pre-ltadd 9891 ax-pre-mulgt0 9892 ax-pre-sup 9893

This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-nel 2783 df-ral 2901 df-rex 2902 df-reu 2903 df-rmo 2904 df-rab 2905 df-v 3175 df-sbc 3403 df-csb 3500 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-uni 4373 df-iun 4457 df-br 4584 df-opab 4644 df-mpt 4645 df-tr 4681 df-eprel 4949 df-id 4953 df-po 4959 df-so 4960 df-fr 4997 df-we 4999 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-pred 5597 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-riota 6511 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-om 6958 df-1st 7059 df-2nd 7060 df-wrecs 7294 df-recs 7355 df-rdg 7393 df-er 7629 df-en 7842 df-dom 7843 df-sdom 7844 df-sup 8231 df-inf 8232 df-pnf 9955 df-mnf 9956 df-xr 9957 df-ltxr 9958 df-le 9959 df-sub 10147 df-neg 10148 df-div 10564 df-nn 10898 df-n0 11170 df-z 11255 df-uz 11564 df-q 11665

This theorem is referenced by: qbtwnxr 11905 qsqueeze 11906 nmoleub2lem3 22723 mbfaddlem 23233 rpnnen3lem 36616

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