MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  4sqlem19 Structured version   Visualization version   GIF version

Theorem 4sqlem19 16299
Description: Lemma for 4sq 16300. The proof is by strong induction - we show that if all the integers less than 𝑘 are in 𝑆, then 𝑘 is as well. In this part of the proof we do the induction argument and dispense with all the cases except the odd prime case, which is sent to 4sqlem18 16298. If 𝑘 is 0, 1, 2, we show 𝑘𝑆 directly; otherwise if 𝑘 is composite, 𝑘 is the product of two numbers less than it (and hence in 𝑆 by assumption), so by mul4sq 16290 𝑘𝑆. (Contributed by Mario Carneiro, 14-Jul-2014.) (Revised by Mario Carneiro, 20-Jun-2015.)
Hypothesis
Ref Expression
4sq.1 𝑆 = {𝑛 ∣ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ ∃𝑧 ∈ ℤ ∃𝑤 ∈ ℤ 𝑛 = (((𝑥↑2) + (𝑦↑2)) + ((𝑧↑2) + (𝑤↑2)))}
Assertion
Ref Expression
4sqlem19 0 = 𝑆
Distinct variable groups:   𝑤,𝑛,𝑥,𝑦,𝑧   𝑆,𝑛
Allowed substitution hints:   𝑆(𝑥,𝑦,𝑧,𝑤)

Proof of Theorem 4sqlem19
Dummy variables 𝑗 𝑘 𝑖 𝑚 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 elnn0 11900 . . . 4 (𝑘 ∈ ℕ0 ↔ (𝑘 ∈ ℕ ∨ 𝑘 = 0))
2 eleq1 2900 . . . . . 6 (𝑗 = 1 → (𝑗𝑆 ↔ 1 ∈ 𝑆))
3 eleq1 2900 . . . . . 6 (𝑗 = 𝑚 → (𝑗𝑆𝑚𝑆))
4 eleq1 2900 . . . . . 6 (𝑗 = 𝑖 → (𝑗𝑆𝑖𝑆))
5 eleq1 2900 . . . . . 6 (𝑗 = (𝑚 · 𝑖) → (𝑗𝑆 ↔ (𝑚 · 𝑖) ∈ 𝑆))
6 eleq1 2900 . . . . . 6 (𝑗 = 𝑘 → (𝑗𝑆𝑘𝑆))
7 abs1 14657 . . . . . . . . . . 11 (abs‘1) = 1
87oveq1i 7166 . . . . . . . . . 10 ((abs‘1)↑2) = (1↑2)
9 sq1 13559 . . . . . . . . . 10 (1↑2) = 1
108, 9eqtri 2844 . . . . . . . . 9 ((abs‘1)↑2) = 1
11 abs0 14645 . . . . . . . . . . 11 (abs‘0) = 0
1211oveq1i 7166 . . . . . . . . . 10 ((abs‘0)↑2) = (0↑2)
13 sq0 13556 . . . . . . . . . 10 (0↑2) = 0
1412, 13eqtri 2844 . . . . . . . . 9 ((abs‘0)↑2) = 0
1510, 14oveq12i 7168 . . . . . . . 8 (((abs‘1)↑2) + ((abs‘0)↑2)) = (1 + 0)
16 1p0e1 11762 . . . . . . . 8 (1 + 0) = 1
1715, 16eqtri 2844 . . . . . . 7 (((abs‘1)↑2) + ((abs‘0)↑2)) = 1
18 1z 12013 . . . . . . . . 9 1 ∈ ℤ
19 zgz 16269 . . . . . . . . 9 (1 ∈ ℤ → 1 ∈ ℤ[i])
2018, 19ax-mp 5 . . . . . . . 8 1 ∈ ℤ[i]
21 0z 11993 . . . . . . . . 9 0 ∈ ℤ
22 zgz 16269 . . . . . . . . 9 (0 ∈ ℤ → 0 ∈ ℤ[i])
2321, 22ax-mp 5 . . . . . . . 8 0 ∈ ℤ[i]
24 4sq.1 . . . . . . . . 9 𝑆 = {𝑛 ∣ ∃𝑥 ∈ ℤ ∃𝑦 ∈ ℤ ∃𝑧 ∈ ℤ ∃𝑤 ∈ ℤ 𝑛 = (((𝑥↑2) + (𝑦↑2)) + ((𝑧↑2) + (𝑤↑2)))}
25244sqlem4a 16287 . . . . . . . 8 ((1 ∈ ℤ[i] ∧ 0 ∈ ℤ[i]) → (((abs‘1)↑2) + ((abs‘0)↑2)) ∈ 𝑆)
2620, 23, 25mp2an 690 . . . . . . 7 (((abs‘1)↑2) + ((abs‘0)↑2)) ∈ 𝑆
2717, 26eqeltrri 2910 . . . . . 6 1 ∈ 𝑆
28 eleq1 2900 . . . . . . 7 (𝑗 = 2 → (𝑗𝑆 ↔ 2 ∈ 𝑆))
29 eldifsn 4719 . . . . . . . . 9 (𝑗 ∈ (ℙ ∖ {2}) ↔ (𝑗 ∈ ℙ ∧ 𝑗 ≠ 2))
30 oddprm 16147 . . . . . . . . . . 11 (𝑗 ∈ (ℙ ∖ {2}) → ((𝑗 − 1) / 2) ∈ ℕ)
3130adantr 483 . . . . . . . . . 10 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ((𝑗 − 1) / 2) ∈ ℕ)
32 eldifi 4103 . . . . . . . . . . . . . . . 16 (𝑗 ∈ (ℙ ∖ {2}) → 𝑗 ∈ ℙ)
3332adantr 483 . . . . . . . . . . . . . . 15 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗 ∈ ℙ)
34 prmnn 16018 . . . . . . . . . . . . . . 15 (𝑗 ∈ ℙ → 𝑗 ∈ ℕ)
35 nncn 11646 . . . . . . . . . . . . . . 15 (𝑗 ∈ ℕ → 𝑗 ∈ ℂ)
3633, 34, 353syl 18 . . . . . . . . . . . . . 14 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗 ∈ ℂ)
37 ax-1cn 10595 . . . . . . . . . . . . . 14 1 ∈ ℂ
38 subcl 10885 . . . . . . . . . . . . . 14 ((𝑗 ∈ ℂ ∧ 1 ∈ ℂ) → (𝑗 − 1) ∈ ℂ)
3936, 37, 38sylancl 588 . . . . . . . . . . . . 13 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (𝑗 − 1) ∈ ℂ)
40 2cnd 11716 . . . . . . . . . . . . 13 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 2 ∈ ℂ)
41 2ne0 11742 . . . . . . . . . . . . . 14 2 ≠ 0
4241a1i 11 . . . . . . . . . . . . 13 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 2 ≠ 0)
4339, 40, 42divcan2d 11418 . . . . . . . . . . . 12 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (2 · ((𝑗 − 1) / 2)) = (𝑗 − 1))
4443oveq1d 7171 . . . . . . . . . . 11 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ((2 · ((𝑗 − 1) / 2)) + 1) = ((𝑗 − 1) + 1))
45 npcan 10895 . . . . . . . . . . . 12 ((𝑗 ∈ ℂ ∧ 1 ∈ ℂ) → ((𝑗 − 1) + 1) = 𝑗)
4636, 37, 45sylancl 588 . . . . . . . . . . 11 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ((𝑗 − 1) + 1) = 𝑗)
4744, 46eqtr2d 2857 . . . . . . . . . 10 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗 = ((2 · ((𝑗 − 1) / 2)) + 1))
4843oveq2d 7172 . . . . . . . . . . . 12 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (0...(2 · ((𝑗 − 1) / 2))) = (0...(𝑗 − 1)))
49 nnm1nn0 11939 . . . . . . . . . . . . . . 15 (𝑗 ∈ ℕ → (𝑗 − 1) ∈ ℕ0)
5033, 34, 493syl 18 . . . . . . . . . . . . . 14 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (𝑗 − 1) ∈ ℕ0)
51 elnn0uz 12284 . . . . . . . . . . . . . 14 ((𝑗 − 1) ∈ ℕ0 ↔ (𝑗 − 1) ∈ (ℤ‘0))
5250, 51sylib 220 . . . . . . . . . . . . 13 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (𝑗 − 1) ∈ (ℤ‘0))
53 eluzfz1 12915 . . . . . . . . . . . . 13 ((𝑗 − 1) ∈ (ℤ‘0) → 0 ∈ (0...(𝑗 − 1)))
54 fzsplit 12934 . . . . . . . . . . . . 13 (0 ∈ (0...(𝑗 − 1)) → (0...(𝑗 − 1)) = ((0...0) ∪ ((0 + 1)...(𝑗 − 1))))
5552, 53, 543syl 18 . . . . . . . . . . . 12 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (0...(𝑗 − 1)) = ((0...0) ∪ ((0 + 1)...(𝑗 − 1))))
5648, 55eqtrd 2856 . . . . . . . . . . 11 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (0...(2 · ((𝑗 − 1) / 2))) = ((0...0) ∪ ((0 + 1)...(𝑗 − 1))))
57 fz0sn 13008 . . . . . . . . . . . . . 14 (0...0) = {0}
5814, 14oveq12i 7168 . . . . . . . . . . . . . . . . 17 (((abs‘0)↑2) + ((abs‘0)↑2)) = (0 + 0)
59 00id 10815 . . . . . . . . . . . . . . . . 17 (0 + 0) = 0
6058, 59eqtri 2844 . . . . . . . . . . . . . . . 16 (((abs‘0)↑2) + ((abs‘0)↑2)) = 0
61244sqlem4a 16287 . . . . . . . . . . . . . . . . 17 ((0 ∈ ℤ[i] ∧ 0 ∈ ℤ[i]) → (((abs‘0)↑2) + ((abs‘0)↑2)) ∈ 𝑆)
6223, 23, 61mp2an 690 . . . . . . . . . . . . . . . 16 (((abs‘0)↑2) + ((abs‘0)↑2)) ∈ 𝑆
6360, 62eqeltrri 2910 . . . . . . . . . . . . . . 15 0 ∈ 𝑆
64 snssi 4741 . . . . . . . . . . . . . . 15 (0 ∈ 𝑆 → {0} ⊆ 𝑆)
6563, 64ax-mp 5 . . . . . . . . . . . . . 14 {0} ⊆ 𝑆
6657, 65eqsstri 4001 . . . . . . . . . . . . 13 (0...0) ⊆ 𝑆
6766a1i 11 . . . . . . . . . . . 12 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (0...0) ⊆ 𝑆)
68 0p1e1 11760 . . . . . . . . . . . . . 14 (0 + 1) = 1
6968oveq1i 7166 . . . . . . . . . . . . 13 ((0 + 1)...(𝑗 − 1)) = (1...(𝑗 − 1))
70 simpr 487 . . . . . . . . . . . . . 14 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆)
71 dfss3 3956 . . . . . . . . . . . . . 14 ((1...(𝑗 − 1)) ⊆ 𝑆 ↔ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆)
7270, 71sylibr 236 . . . . . . . . . . . . 13 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (1...(𝑗 − 1)) ⊆ 𝑆)
7369, 72eqsstrid 4015 . . . . . . . . . . . 12 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ((0 + 1)...(𝑗 − 1)) ⊆ 𝑆)
7467, 73unssd 4162 . . . . . . . . . . 11 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → ((0...0) ∪ ((0 + 1)...(𝑗 − 1))) ⊆ 𝑆)
7556, 74eqsstrd 4005 . . . . . . . . . 10 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → (0...(2 · ((𝑗 − 1) / 2))) ⊆ 𝑆)
76 oveq1 7163 . . . . . . . . . . . 12 (𝑘 = 𝑖 → (𝑘 · 𝑗) = (𝑖 · 𝑗))
7776eleq1d 2897 . . . . . . . . . . 11 (𝑘 = 𝑖 → ((𝑘 · 𝑗) ∈ 𝑆 ↔ (𝑖 · 𝑗) ∈ 𝑆))
7877cbvrabv 3491 . . . . . . . . . 10 {𝑘 ∈ ℕ ∣ (𝑘 · 𝑗) ∈ 𝑆} = {𝑖 ∈ ℕ ∣ (𝑖 · 𝑗) ∈ 𝑆}
79 eqid 2821 . . . . . . . . . 10 inf({𝑘 ∈ ℕ ∣ (𝑘 · 𝑗) ∈ 𝑆}, ℝ, < ) = inf({𝑘 ∈ ℕ ∣ (𝑘 · 𝑗) ∈ 𝑆}, ℝ, < )
8024, 31, 47, 33, 75, 78, 794sqlem18 16298 . . . . . . . . 9 ((𝑗 ∈ (ℙ ∖ {2}) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗𝑆)
8129, 80sylanbr 584 . . . . . . . 8 (((𝑗 ∈ ℙ ∧ 𝑗 ≠ 2) ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗𝑆)
8281an32s 650 . . . . . . 7 (((𝑗 ∈ ℙ ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) ∧ 𝑗 ≠ 2) → 𝑗𝑆)
8310, 10oveq12i 7168 . . . . . . . . . 10 (((abs‘1)↑2) + ((abs‘1)↑2)) = (1 + 1)
84 df-2 11701 . . . . . . . . . 10 2 = (1 + 1)
8583, 84eqtr4i 2847 . . . . . . . . 9 (((abs‘1)↑2) + ((abs‘1)↑2)) = 2
86244sqlem4a 16287 . . . . . . . . . 10 ((1 ∈ ℤ[i] ∧ 1 ∈ ℤ[i]) → (((abs‘1)↑2) + ((abs‘1)↑2)) ∈ 𝑆)
8720, 20, 86mp2an 690 . . . . . . . . 9 (((abs‘1)↑2) + ((abs‘1)↑2)) ∈ 𝑆
8885, 87eqeltrri 2910 . . . . . . . 8 2 ∈ 𝑆
8988a1i 11 . . . . . . 7 ((𝑗 ∈ ℙ ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 2 ∈ 𝑆)
9028, 82, 89pm2.61ne 3102 . . . . . 6 ((𝑗 ∈ ℙ ∧ ∀𝑚 ∈ (1...(𝑗 − 1))𝑚𝑆) → 𝑗𝑆)
9124mul4sq 16290 . . . . . . 7 ((𝑚𝑆𝑖𝑆) → (𝑚 · 𝑖) ∈ 𝑆)
9291a1i 11 . . . . . 6 ((𝑚 ∈ (ℤ‘2) ∧ 𝑖 ∈ (ℤ‘2)) → ((𝑚𝑆𝑖𝑆) → (𝑚 · 𝑖) ∈ 𝑆))
932, 3, 4, 5, 6, 27, 90, 92prmind2 16029 . . . . 5 (𝑘 ∈ ℕ → 𝑘𝑆)
94 id 22 . . . . . 6 (𝑘 = 0 → 𝑘 = 0)
9594, 63eqeltrdi 2921 . . . . 5 (𝑘 = 0 → 𝑘𝑆)
9693, 95jaoi 853 . . . 4 ((𝑘 ∈ ℕ ∨ 𝑘 = 0) → 𝑘𝑆)
971, 96sylbi 219 . . 3 (𝑘 ∈ ℕ0𝑘𝑆)
9897ssriv 3971 . 2 0𝑆
99244sqlem1 16284 . 2 𝑆 ⊆ ℕ0
10098, 99eqssi 3983 1 0 = 𝑆
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 398  wo 843   = wceq 1537  wcel 2114  {cab 2799  wne 3016  wral 3138  wrex 3139  {crab 3142  cdif 3933  cun 3934  wss 3936  {csn 4567  cfv 6355  (class class class)co 7156  infcinf 8905  cc 10535  cr 10536  0cc0 10537  1c1 10538   + caddc 10540   · cmul 10542   < clt 10675  cmin 10870   / cdiv 11297  cn 11638  2c2 11693  0cn0 11898  cz 11982  cuz 12244  ...cfz 12893  cexp 13430  abscabs 14593  cprime 16015  ℤ[i]cgz 16265
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  ax-pre-sup 10615
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-2o 8103  df-oadd 8106  df-er 8289  df-en 8510  df-dom 8511  df-sdom 8512  df-fin 8513  df-sup 8906  df-inf 8907  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-div 11298  df-nn 11639  df-2 11701  df-3 11702  df-4 11703  df-n0 11899  df-xnn0 11969  df-z 11983  df-uz 12245  df-rp 12391  df-fz 12894  df-fl 13163  df-mod 13239  df-seq 13371  df-exp 13431  df-hash 13692  df-cj 14458  df-re 14459  df-im 14460  df-sqrt 14594  df-abs 14595  df-dvds 15608  df-gcd 15844  df-prm 16016  df-gz 16266
This theorem is referenced by:  4sq  16300
  Copyright terms: Public domain W3C validator