irrdiff - Mathbox for Jim Kingdon

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Theorem irrdiff 36981

Description: The irrationals are exactly those reals that are a different distance from every rational. (Contributed by Jim Kingdon, 19-May-2024.)

**Assertion**
Ref	Expression
irrdiff	⊢ (𝐴 ∈ ℝ → (¬ 𝐴 ∈ ℚ ↔ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))))

Distinct variable group: 𝐴,𝑞,𝑟

**Proof of Theorem irrdiff**
Step	Hyp	Ref	Expression
1		simplll 773	. . . . 5 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → 𝐴 ∈ ℝ)
2		simpllr 774	. . . . 5 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → ¬ 𝐴 ∈ ℚ)
3		simplrl 775	. . . . 5 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → 𝑞 ∈ ℚ)
4		simplrr 776	. . . . 5 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → 𝑟 ∈ ℚ)
5		simpr 483	. . . . 5 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → 𝑞 ≠ 𝑟)
6	1, 2, 3, 4, 5	irrdifflemf 36980	. . . 4 ⊢ ((((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) ∧ 𝑞 ≠ 𝑟) → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))
7	6	ex 411	. . 3 ⊢ (((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) ∧ (𝑞 ∈ ℚ ∧ 𝑟 ∈ ℚ)) → (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))))
8	7	ralrimivva 3190	. 2 ⊢ ((𝐴 ∈ ℝ ∧ ¬ 𝐴 ∈ ℚ) → ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))))
9		simplr 767	. . . 4 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))))
10		peano2rem 11573	. . . . . 6 ⊢ (𝐴 ∈ ℝ → (𝐴 − 1) ∈ ℝ)
11		recn 11244	. . . . . . . 8 ⊢ (𝐴 ∈ ℝ → 𝐴 ∈ ℂ)
12		1cnd 11255	. . . . . . . 8 ⊢ (𝐴 ∈ ℝ → 1 ∈ ℂ)
13	11, 12	negsubd 11623	. . . . . . 7 ⊢ (𝐴 ∈ ℝ → (𝐴 + -1) = (𝐴 − 1))
14		neg1lt0 12376	. . . . . . . . 9 ⊢ -1 < 0
15		0lt1 11782	. . . . . . . . 9 ⊢ 0 < 1
16		neg1rr 12374	. . . . . . . . . 10 ⊢ -1 ∈ ℝ
17		0re 11262	. . . . . . . . . 10 ⊢ 0 ∈ ℝ
18		1re 11260	. . . . . . . . . 10 ⊢ 1 ∈ ℝ
19	16, 17, 18	lttri 11386	. . . . . . . . 9 ⊢ ((-1 < 0 ∧ 0 < 1) → -1 < 1)
20	14, 15, 19	mp2an 690	. . . . . . . 8 ⊢ -1 < 1
21	16	a1i 11	. . . . . . . . 9 ⊢ (𝐴 ∈ ℝ → -1 ∈ ℝ)
22		1red 11261	. . . . . . . . 9 ⊢ (𝐴 ∈ ℝ → 1 ∈ ℝ)
23		id 22	. . . . . . . . 9 ⊢ (𝐴 ∈ ℝ → 𝐴 ∈ ℝ)
24	21, 22, 23	ltadd2d 11416	. . . . . . . 8 ⊢ (𝐴 ∈ ℝ → (-1 < 1 ↔ (𝐴 + -1) < (𝐴 + 1)))
25	20, 24	mpbii 232	. . . . . . 7 ⊢ (𝐴 ∈ ℝ → (𝐴 + -1) < (𝐴 + 1))
26	13, 25	eqbrtrrd 5176	. . . . . 6 ⊢ (𝐴 ∈ ℝ → (𝐴 − 1) < (𝐴 + 1))
27	10, 26	ltned 11396	. . . . 5 ⊢ (𝐴 ∈ ℝ → (𝐴 − 1) ≠ (𝐴 + 1))
28	27	ad2antrr 724	. . . 4 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → (𝐴 − 1) ≠ (𝐴 + 1))
29		1z 12639	. . . . . . 7 ⊢ 1 ∈ ℤ
30		zq 12985	. . . . . . 7 ⊢ (1 ∈ ℤ → 1 ∈ ℚ)
31	29, 30	ax-mp 5	. . . . . 6 ⊢ 1 ∈ ℚ
32		qsubcl 12999	. . . . . 6 ⊢ ((𝐴 ∈ ℚ ∧ 1 ∈ ℚ) → (𝐴 − 1) ∈ ℚ)
33	31, 32	mpan2 689	. . . . 5 ⊢ (𝐴 ∈ ℚ → (𝐴 − 1) ∈ ℚ)
34		qaddcl 12996	. . . . . . 7 ⊢ ((𝐴 ∈ ℚ ∧ 1 ∈ ℚ) → (𝐴 + 1) ∈ ℚ)
35	31, 34	mpan2 689	. . . . . 6 ⊢ (𝐴 ∈ ℚ → (𝐴 + 1) ∈ ℚ)
36	35	adantl 480	. . . . 5 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → (𝐴 + 1) ∈ ℚ)
37		simpl 481	. . . . . . . 8 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → 𝑞 = (𝐴 − 1))
38		simpr 483	. . . . . . . 8 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → 𝑟 = (𝐴 + 1))
39	37, 38	neeq12d 2991	. . . . . . 7 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → (𝑞 ≠ 𝑟 ↔ (𝐴 − 1) ≠ (𝐴 + 1)))
40		oveq2 7431	. . . . . . . . . 10 ⊢ (𝑞 = (𝐴 − 1) → (𝐴 − 𝑞) = (𝐴 − (𝐴 − 1)))
41	40	adantr 479	. . . . . . . . 9 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → (𝐴 − 𝑞) = (𝐴 − (𝐴 − 1)))
42	41	fveq2d 6904	. . . . . . . 8 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → (abs‘(𝐴 − 𝑞)) = (abs‘(𝐴 − (𝐴 − 1))))
43		oveq2 7431	. . . . . . . . . 10 ⊢ (𝑟 = (𝐴 + 1) → (𝐴 − 𝑟) = (𝐴 − (𝐴 + 1)))
44	43	adantl 480	. . . . . . . . 9 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → (𝐴 − 𝑟) = (𝐴 − (𝐴 + 1)))
45	44	fveq2d 6904	. . . . . . . 8 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → (abs‘(𝐴 − 𝑟)) = (abs‘(𝐴 − (𝐴 + 1))))
46	42, 45	neeq12d 2991	. . . . . . 7 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → ((abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)) ↔ (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1)))))
47	39, 46	imbi12d 343	. . . . . 6 ⊢ ((𝑞 = (𝐴 − 1) ∧ 𝑟 = (𝐴 + 1)) → ((𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))) ↔ ((𝐴 − 1) ≠ (𝐴 + 1) → (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))))
48	47	rspc2gv 3617	. . . . 5 ⊢ (((𝐴 − 1) ∈ ℚ ∧ (𝐴 + 1) ∈ ℚ) → (∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))) → ((𝐴 − 1) ≠ (𝐴 + 1) → (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))))
49	33, 36, 48	syl2an2 684	. . . 4 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → (∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟))) → ((𝐴 − 1) ≠ (𝐴 + 1) → (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))))
50	9, 28, 49	mp2d 49	. . 3 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))
51		neirr 2938	. . . . 5 ⊢ ¬ (abs‘1) ≠ (abs‘1)
52	11, 12	nncand 11622	. . . . . . 7 ⊢ (𝐴 ∈ ℝ → (𝐴 − (𝐴 − 1)) = 1)
53	52	fveq2d 6904	. . . . . 6 ⊢ (𝐴 ∈ ℝ → (abs‘(𝐴 − (𝐴 − 1))) = (abs‘1))
54	11, 12	subnegd 11624	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℝ → (𝐴 − -1) = (𝐴 + 1))
55	54	oveq2d 7439	. . . . . . . . 9 ⊢ (𝐴 ∈ ℝ → (𝐴 − (𝐴 − -1)) = (𝐴 − (𝐴 + 1)))
56	21	recnd 11288	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℝ → -1 ∈ ℂ)
57	11, 56	nncand 11622	. . . . . . . . 9 ⊢ (𝐴 ∈ ℝ → (𝐴 − (𝐴 − -1)) = -1)
58	55, 57	eqtr3d 2767	. . . . . . . 8 ⊢ (𝐴 ∈ ℝ → (𝐴 − (𝐴 + 1)) = -1)
59	58	fveq2d 6904	. . . . . . 7 ⊢ (𝐴 ∈ ℝ → (abs‘(𝐴 − (𝐴 + 1))) = (abs‘-1))
60	12	absnegd 15449	. . . . . . 7 ⊢ (𝐴 ∈ ℝ → (abs‘-1) = (abs‘1))
61	59, 60	eqtrd 2765	. . . . . 6 ⊢ (𝐴 ∈ ℝ → (abs‘(𝐴 − (𝐴 + 1))) = (abs‘1))
62	53, 61	neeq12d 2991	. . . . 5 ⊢ (𝐴 ∈ ℝ → ((abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))) ↔ (abs‘1) ≠ (abs‘1)))
63	51, 62	mtbiri 326	. . . 4 ⊢ (𝐴 ∈ ℝ → ¬ (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))
64	63	ad2antrr 724	. . 3 ⊢ (((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) ∧ 𝐴 ∈ ℚ) → ¬ (abs‘(𝐴 − (𝐴 − 1))) ≠ (abs‘(𝐴 − (𝐴 + 1))))
65	50, 64	pm2.65da 815	. 2 ⊢ ((𝐴 ∈ ℝ ∧ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))) → ¬ 𝐴 ∈ ℚ)
66	8, 65	impbida 799	1 ⊢ (𝐴 ∈ ℝ → (¬ 𝐴 ∈ ℚ ↔ ∀𝑞 ∈ ℚ ∀𝑟 ∈ ℚ (𝑞 ≠ 𝑟 → (abs‘(𝐴 − 𝑞)) ≠ (abs‘(𝐴 − 𝑟)))))

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 205 ∧ wa 394 = wceq 1533 ∈ wcel 2098 ≠ wne 2929 ∀wral 3050 class class class wbr 5152 ‘cfv 6553 (class class class)co 7423 ℝcr 11153 0cc0 11154 1c1 11155 + caddc 11157 < clt 11294 − cmin 11490 -cneg 11491 ℤcz 12605 ℚcq 12979 abscabs 15234

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2166 ax-ext 2696 ax-sep 5303 ax-nul 5310 ax-pow 5368 ax-pr 5432 ax-un 7745 ax-cnex 11210 ax-resscn 11211 ax-1cn 11212 ax-icn 11213 ax-addcl 11214 ax-addrcl 11215 ax-mulcl 11216 ax-mulrcl 11217 ax-mulcom 11218 ax-addass 11219 ax-mulass 11220 ax-distr 11221 ax-i2m1 11222 ax-1ne0 11223 ax-1rid 11224 ax-rnegex 11225 ax-rrecex 11226 ax-cnre 11227 ax-pre-lttri 11228 ax-pre-lttrn 11229 ax-pre-ltadd 11230 ax-pre-mulgt0 11231 ax-pre-sup 11232

This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2703 df-cleq 2717 df-clel 2802 df-nfc 2877 df-ne 2930 df-nel 3036 df-ral 3051 df-rex 3060 df-rmo 3363 df-reu 3364 df-rab 3419 df-v 3463 df-sbc 3776 df-csb 3892 df-dif 3949 df-un 3951 df-in 3953 df-ss 3963 df-pss 3966 df-nul 4325 df-if 4533 df-pw 4608 df-sn 4633 df-pr 4635 df-op 4639 df-uni 4913 df-iun 5002 df-br 5153 df-opab 5215 df-mpt 5236 df-tr 5270 df-id 5579 df-eprel 5585 df-po 5593 df-so 5594 df-fr 5636 df-we 5638 df-xp 5687 df-rel 5688 df-cnv 5689 df-co 5690 df-dm 5691 df-rn 5692 df-res 5693 df-ima 5694 df-pred 6311 df-ord 6378 df-on 6379 df-lim 6380 df-suc 6381 df-iota 6505 df-fun 6555 df-fn 6556 df-f 6557 df-f1 6558 df-fo 6559 df-f1o 6560 df-fv 6561 df-riota 7379 df-ov 7426 df-oprab 7427 df-mpo 7428 df-om 7876 df-1st 8002 df-2nd 8003 df-frecs 8295 df-wrecs 8326 df-recs 8400 df-rdg 8439 df-er 8733 df-en 8974 df-dom 8975 df-sdom 8976 df-sup 9481 df-pnf 11296 df-mnf 11297 df-xr 11298 df-ltxr 11299 df-le 11300 df-sub 11492 df-neg 11493 df-div 11918 df-nn 12260 df-2 12322 df-3 12323 df-n0 12520 df-z 12606 df-uz 12870 df-q 12980 df-rp 13024 df-seq 14017 df-exp 14077 df-cj 15099 df-re 15100 df-im 15101 df-sqrt 15235 df-abs 15236

This theorem is referenced by: (None)

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