inductionexd - Mathbox for Stanislas Polu

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Theorem inductionexd 44505

Description: Simple induction example. (Contributed by Stanislas Polu, 9-Mar-2020.)

**Assertion**
Ref	Expression
inductionexd	⊢ (𝑁 ∈ ℕ → 3 ∥ ((4↑𝑁) + 5))

Proof of Theorem inductionexd Dummy variables 𝑘 𝑛 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		oveq2 7376	. . . 4 ⊢ (𝑘 = 1 → (4↑𝑘) = (4↑1))
2	1	oveq1d 7383	. . 3 ⊢ (𝑘 = 1 → ((4↑𝑘) + 5) = ((4↑1) + 5))
3	2	breq2d 5112	. 2 ⊢ (𝑘 = 1 → (3 ∥ ((4↑𝑘) + 5) ↔ 3 ∥ ((4↑1) + 5)))
4		oveq2 7376	. . . 4 ⊢ (𝑘 = 𝑛 → (4↑𝑘) = (4↑𝑛))
5	4	oveq1d 7383	. . 3 ⊢ (𝑘 = 𝑛 → ((4↑𝑘) + 5) = ((4↑𝑛) + 5))
6	5	breq2d 5112	. 2 ⊢ (𝑘 = 𝑛 → (3 ∥ ((4↑𝑘) + 5) ↔ 3 ∥ ((4↑𝑛) + 5)))
7		oveq2 7376	. . . 4 ⊢ (𝑘 = (𝑛 + 1) → (4↑𝑘) = (4↑(𝑛 + 1)))
8	7	oveq1d 7383	. . 3 ⊢ (𝑘 = (𝑛 + 1) → ((4↑𝑘) + 5) = ((4↑(𝑛 + 1)) + 5))
9	8	breq2d 5112	. 2 ⊢ (𝑘 = (𝑛 + 1) → (3 ∥ ((4↑𝑘) + 5) ↔ 3 ∥ ((4↑(𝑛 + 1)) + 5)))
10		oveq2 7376	. . . 4 ⊢ (𝑘 = 𝑁 → (4↑𝑘) = (4↑𝑁))
11	10	oveq1d 7383	. . 3 ⊢ (𝑘 = 𝑁 → ((4↑𝑘) + 5) = ((4↑𝑁) + 5))
12	11	breq2d 5112	. 2 ⊢ (𝑘 = 𝑁 → (3 ∥ ((4↑𝑘) + 5) ↔ 3 ∥ ((4↑𝑁) + 5)))
13		3z 12536	. . . 4 ⊢ 3 ∈ ℤ
14		4z 12537	. . . . . 6 ⊢ 4 ∈ ℤ
15		1nn0 12429	. . . . . 6 ⊢ 1 ∈ ℕ₀
16		zexpcl 14011	. . . . . 6 ⊢ ((4 ∈ ℤ ∧ 1 ∈ ℕ₀) → (4↑1) ∈ ℤ)
17	14, 15, 16	mp2an 693	. . . . 5 ⊢ (4↑1) ∈ ℤ
18		5nn 12243	. . . . . 6 ⊢ 5 ∈ ℕ
19	18	nnzi 12527	. . . . 5 ⊢ 5 ∈ ℤ
20		zaddcl 12543	. . . . 5 ⊢ (((4↑1) ∈ ℤ ∧ 5 ∈ ℤ) → ((4↑1) + 5) ∈ ℤ)
21	17, 19, 20	mp2an 693	. . . 4 ⊢ ((4↑1) + 5) ∈ ℤ
22	13, 13, 21	3pm3.2i 1341	. . 3 ⊢ (3 ∈ ℤ ∧ 3 ∈ ℤ ∧ ((4↑1) + 5) ∈ ℤ)
23		3t3e9 12319	. . . 4 ⊢ (3 · 3) = 9
24		4nn0 12432	. . . . . . 7 ⊢ 4 ∈ ℕ₀
25	24	numexp1 17016	. . . . . 6 ⊢ (4↑1) = 4
26	25	oveq1i 7378	. . . . 5 ⊢ ((4↑1) + 5) = (4 + 5)
27		5cn 12245	. . . . . 6 ⊢ 5 ∈ ℂ
28		4cn 12242	. . . . . 6 ⊢ 4 ∈ ℂ
29		5p4e9 12310	. . . . . 6 ⊢ (5 + 4) = 9
30	27, 28, 29	addcomli 11337	. . . . 5 ⊢ (4 + 5) = 9
31	26, 30	eqtri 2760	. . . 4 ⊢ ((4↑1) + 5) = 9
32	23, 31	eqtr4i 2763	. . 3 ⊢ (3 · 3) = ((4↑1) + 5)
33		dvds0lem 16205	. . 3 ⊢ (((3 ∈ ℤ ∧ 3 ∈ ℤ ∧ ((4↑1) + 5) ∈ ℤ) ∧ (3 · 3) = ((4↑1) + 5)) → 3 ∥ ((4↑1) + 5))
34	22, 32, 33	mp2an 693	. 2 ⊢ 3 ∥ ((4↑1) + 5)
35	13	a1i 11	. . . . 5 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∈ ℤ)
36		4nn 12240	. . . . . . . . . . 11 ⊢ 4 ∈ ℕ
37	36	a1i 11	. . . . . . . . . 10 ⊢ (𝑛 ∈ ℕ → 4 ∈ ℕ)
38		nnnn0 12420	. . . . . . . . . 10 ⊢ (𝑛 ∈ ℕ → 𝑛 ∈ ℕ₀)
39	37, 38	nnexpcld 14180	. . . . . . . . 9 ⊢ (𝑛 ∈ ℕ → (4↑𝑛) ∈ ℕ)
40	39	nnzd 12526	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → (4↑𝑛) ∈ ℤ)
41	40	adantr 480	. . . . . . 7 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → (4↑𝑛) ∈ ℤ)
42	19	a1i 11	. . . . . . 7 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 5 ∈ ℤ)
43	41, 42	zaddcld 12612	. . . . . 6 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → ((4↑𝑛) + 5) ∈ ℤ)
44	14	a1i 11	. . . . . 6 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 4 ∈ ℤ)
45	43, 44	zmulcld 12614	. . . . 5 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → (((4↑𝑛) + 5) · 4) ∈ ℤ)
46	35, 42	zmulcld 12614	. . . . 5 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → (3 · 5) ∈ ℤ)
47		simpr 484	. . . . . 6 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∥ ((4↑𝑛) + 5))
48	35, 43, 44, 47	dvdsmultr1d 16236	. . . . 5 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∥ (((4↑𝑛) + 5) · 4))
49		dvdsmul1 16216	. . . . . . 7 ⊢ ((3 ∈ ℤ ∧ 5 ∈ ℤ) → 3 ∥ (3 · 5))
50	13, 19, 49	mp2an 693	. . . . . 6 ⊢ 3 ∥ (3 · 5)
51	50	a1i 11	. . . . 5 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∥ (3 · 5))
52	35, 45, 46, 48, 51	dvds2subd 16232	. . . 4 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∥ ((((4↑𝑛) + 5) · 4) − (3 · 5)))
53	39	nncnd 12173	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → (4↑𝑛) ∈ ℂ)
54	27	a1i 11	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → 5 ∈ ℂ)
55	28	a1i 11	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → 4 ∈ ℂ)
56	53, 54, 55	adddird 11169	. . . . . . 7 ⊢ (𝑛 ∈ ℕ → (((4↑𝑛) + 5) · 4) = (((4↑𝑛) · 4) + (5 · 4)))
57	56	oveq1d 7383	. . . . . 6 ⊢ (𝑛 ∈ ℕ → ((((4↑𝑛) + 5) · 4) − ;15) = ((((4↑𝑛) · 4) + (5 · 4)) − ;15))
58		3cn 12238	. . . . . . . . 9 ⊢ 3 ∈ ℂ
59		5t3e15 12720	. . . . . . . . 9 ⊢ (5 · 3) = ;15
60	27, 58, 59	mulcomli 11153	. . . . . . . 8 ⊢ (3 · 5) = ;15
61	60	a1i 11	. . . . . . 7 ⊢ (𝑛 ∈ ℕ → (3 · 5) = ;15)
62	61	oveq2d 7384	. . . . . 6 ⊢ (𝑛 ∈ ℕ → ((((4↑𝑛) + 5) · 4) − (3 · 5)) = ((((4↑𝑛) + 5) · 4) − ;15))
63	55, 38	expp1d 14082	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → (4↑(𝑛 + 1)) = ((4↑𝑛) · 4))
64		ax-1cn 11096	. . . . . . . . . . . . . . . 16 ⊢ 1 ∈ ℂ
65		3p1e4 12297	. . . . . . . . . . . . . . . 16 ⊢ (3 + 1) = 4
66	58, 64, 65	addcomli 11337	. . . . . . . . . . . . . . 15 ⊢ (1 + 3) = 4
67	66	eqcomi 2746	. . . . . . . . . . . . . 14 ⊢ 4 = (1 + 3)
68	67	oveq1i 7378	. . . . . . . . . . . . 13 ⊢ (4 − 3) = ((1 + 3) − 3)
69	64, 58	pncan3oi 11408	. . . . . . . . . . . . 13 ⊢ ((1 + 3) − 3) = 1
70	68, 69	eqtri 2760	. . . . . . . . . . . 12 ⊢ (4 − 3) = 1
71	70	oveq2i 7379	. . . . . . . . . . 11 ⊢ (5 · (4 − 3)) = (5 · 1)
72	27, 28, 58	subdii 11598	. . . . . . . . . . 11 ⊢ (5 · (4 − 3)) = ((5 · 4) − (5 · 3))
73	27	mulridi 11148	. . . . . . . . . . 11 ⊢ (5 · 1) = 5
74	71, 72, 73	3eqtr3ri 2769	. . . . . . . . . 10 ⊢ 5 = ((5 · 4) − (5 · 3))
75	59	eqcomi 2746	. . . . . . . . . . 11 ⊢ ;15 = (5 · 3)
76	75	oveq2i 7379	. . . . . . . . . 10 ⊢ ((5 · 4) − ;15) = ((5 · 4) − (5 · 3))
77	74, 76	eqtr4i 2763	. . . . . . . . 9 ⊢ 5 = ((5 · 4) − ;15)
78	77	a1i 11	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → 5 = ((5 · 4) − ;15))
79	63, 78	oveq12d 7386	. . . . . . 7 ⊢ (𝑛 ∈ ℕ → ((4↑(𝑛 + 1)) + 5) = (((4↑𝑛) · 4) + ((5 · 4) − ;15)))
80	53, 55	mulcld 11164	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → ((4↑𝑛) · 4) ∈ ℂ)
81	54, 55	mulcld 11164	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → (5 · 4) ∈ ℂ)
82		5nn0 12433	. . . . . . . . . . 11 ⊢ 5 ∈ ℕ₀
83	15, 82	deccl 12634	. . . . . . . . . 10 ⊢ ;15 ∈ ℕ₀
84	83	nn0cni 12425	. . . . . . . . 9 ⊢ ;15 ∈ ℂ
85	84	a1i 11	. . . . . . . 8 ⊢ (𝑛 ∈ ℕ → ;15 ∈ ℂ)
86	80, 81, 85	addsubassd 11524	. . . . . . 7 ⊢ (𝑛 ∈ ℕ → ((((4↑𝑛) · 4) + (5 · 4)) − ;15) = (((4↑𝑛) · 4) + ((5 · 4) − ;15)))
87	79, 86	eqtr4d 2775	. . . . . 6 ⊢ (𝑛 ∈ ℕ → ((4↑(𝑛 + 1)) + 5) = ((((4↑𝑛) · 4) + (5 · 4)) − ;15))
88	57, 62, 87	3eqtr4rd 2783	. . . . 5 ⊢ (𝑛 ∈ ℕ → ((4↑(𝑛 + 1)) + 5) = ((((4↑𝑛) + 5) · 4) − (3 · 5)))
89	88	adantr 480	. . . 4 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → ((4↑(𝑛 + 1)) + 5) = ((((4↑𝑛) + 5) · 4) − (3 · 5)))
90	52, 89	breqtrrd 5128	. . 3 ⊢ ((𝑛 ∈ ℕ ∧ 3 ∥ ((4↑𝑛) + 5)) → 3 ∥ ((4↑(𝑛 + 1)) + 5))
91	90	ex 412	. 2 ⊢ (𝑛 ∈ ℕ → (3 ∥ ((4↑𝑛) + 5) → 3 ∥ ((4↑(𝑛 + 1)) + 5)))
92	3, 6, 9, 12, 34, 91	nnind 12175	1 ⊢ (𝑁 ∈ ℕ → 3 ∥ ((4↑𝑁) + 5))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ∧ wa 395 ∧ w3a 1087 = wceq 1542 ∈ wcel 2114 class class class wbr 5100 (class class class)co 7368 ℂcc 11036 1c1 11039 + caddc 11041 · cmul 11043 − cmin 11376 ℕcn 12157 3c3 12213 4c4 12214 5c5 12215 9c9 12219 ℕ₀cn0 12413 ℤcz 12500 cdc 12619 ↑cexp 13996 ∥ cdvds 16191

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1912 ax-6 1969 ax-7 2010 ax-8 2116 ax-9 2124 ax-10 2147 ax-11 2163 ax-12 2185 ax-ext 2709 ax-sep 5243 ax-nul 5253 ax-pow 5312 ax-pr 5379 ax-un 7690 ax-cnex 11094 ax-resscn 11095 ax-1cn 11096 ax-icn 11097 ax-addcl 11098 ax-addrcl 11099 ax-mulcl 11100 ax-mulrcl 11101 ax-mulcom 11102 ax-addass 11103 ax-mulass 11104 ax-distr 11105 ax-i2m1 11106 ax-1ne0 11107 ax-1rid 11108 ax-rnegex 11109 ax-rrecex 11110 ax-cnre 11111 ax-pre-lttri 11112 ax-pre-lttrn 11113 ax-pre-ltadd 11114 ax-pre-mulgt0 11115

This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-3or 1088 df-3an 1089 df-tru 1545 df-fal 1555 df-ex 1782 df-nf 1786 df-sb 2069 df-mo 2540 df-eu 2570 df-clab 2716 df-cleq 2729 df-clel 2812 df-nfc 2886 df-ne 2934 df-nel 3038 df-ral 3053 df-rex 3063 df-reu 3353 df-rab 3402 df-v 3444 df-sbc 3743 df-csb 3852 df-dif 3906 df-un 3908 df-in 3910 df-ss 3920 df-pss 3923 df-nul 4288 df-if 4482 df-pw 4558 df-sn 4583 df-pr 4585 df-op 4589 df-uni 4866 df-iun 4950 df-br 5101 df-opab 5163 df-mpt 5182 df-tr 5208 df-id 5527 df-eprel 5532 df-po 5540 df-so 5541 df-fr 5585 df-we 5587 df-xp 5638 df-rel 5639 df-cnv 5640 df-co 5641 df-dm 5642 df-rn 5643 df-res 5644 df-ima 5645 df-pred 6267 df-ord 6328 df-on 6329 df-lim 6330 df-suc 6331 df-iota 6456 df-fun 6502 df-fn 6503 df-f 6504 df-f1 6505 df-fo 6506 df-f1o 6507 df-fv 6508 df-riota 7325 df-ov 7371 df-oprab 7372 df-mpo 7373 df-om 7819 df-2nd 7944 df-frecs 8233 df-wrecs 8264 df-recs 8313 df-rdg 8351 df-er 8645 df-en 8896 df-dom 8897 df-sdom 8898 df-pnf 11180 df-mnf 11181 df-xr 11182 df-ltxr 11183 df-le 11184 df-sub 11378 df-neg 11379 df-nn 12158 df-2 12220 df-3 12221 df-4 12222 df-5 12223 df-6 12224 df-7 12225 df-8 12226 df-9 12227 df-n0 12414 df-z 12501 df-dec 12620 df-uz 12764 df-seq 13937 df-exp 13997 df-dvds 16192

This theorem is referenced by: (None)

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