Theorem lgsval 27240

Description: Value of the Legendre symbol at an arbitrary integer. (Contributed by Mario Carneiro, 4-Feb-2015.)

Hypothesis

Ref	Expression
lgsval.1	⊢ 𝐹 = (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑁)), 1))

Assertion

Ref	Expression
lgsval	⊢ ((𝐴 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝐴 /L 𝑁) = if(𝑁 = 0, if((𝐴↑2) = 1, 1, 0), (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁)))))

Distinct variable groups:   𝐴,𝑛   𝑛,𝑁

Allowed substitution hint:   𝐹(𝑛)

Proof of Theorem lgsval

Dummy variables 𝑎 𝑚 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		simpr 484	. . . 4 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → 𝑚 = 𝑁)
2	1	eqeq1d 2735	. . 3 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑚 = 0 ↔ 𝑁 = 0))
3		simpl 482	. . . . . 6 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → 𝑎 = 𝐴)
4	3	oveq1d 7367	. . . . 5 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑎↑2) = (𝐴↑2))
5	4	eqeq1d 2735	. . . 4 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → ((𝑎↑2) = 1 ↔ (𝐴↑2) = 1))
6	5	ifbid 4498	. . 3 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if((𝑎↑2) = 1, 1, 0) = if((𝐴↑2) = 1, 1, 0))
7	1	breq1d 5103	. . . . . 6 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑚 < 0 ↔ 𝑁 < 0))
8	3	breq1d 5103	. . . . . 6 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑎 < 0 ↔ 𝐴 < 0))
9	7, 8	anbi12d 632	. . . . 5 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → ((𝑚 < 0 ∧ 𝑎 < 0) ↔ (𝑁 < 0 ∧ 𝐴 < 0)))
10	9	ifbid 4498	. . . 4 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if((𝑚 < 0 ∧ 𝑎 < 0), -1, 1) = if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1))
11	3	breq2d 5105	. . . . . . . . . . . 12 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (2 ∥ 𝑎 ↔ 2 ∥ 𝐴))
12	3	oveq1d 7367	. . . . . . . . . . . . . 14 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑎 mod 8) = (𝐴 mod 8))
13	12	eleq1d 2818	. . . . . . . . . . . . 13 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → ((𝑎 mod 8) ∈ {1, 7} ↔ (𝐴 mod 8) ∈ {1, 7}))
14	13	ifbid 4498	. . . . . . . . . . . 12 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if((𝑎 mod 8) ∈ {1, 7}, 1, -1) = if((𝐴 mod 8) ∈ {1, 7}, 1, -1))
15	11, 14	ifbieq2d 4501	. . . . . . . . . . 11 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)) = if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)))
16	3	oveq1d 7367	. . . . . . . . . . . . . 14 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑎↑((𝑛 − 1) / 2)) = (𝐴↑((𝑛 − 1) / 2)))
17	16	oveq1d 7367	. . . . . . . . . . . . 13 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → ((𝑎↑((𝑛 − 1) / 2)) + 1) = ((𝐴↑((𝑛 − 1) / 2)) + 1))
18	17	oveq1d 7367	. . . . . . . . . . . 12 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) = (((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛))
19	18	oveq1d 7367	. . . . . . . . . . 11 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1) = ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))
20	15, 19	ifeq12d 4496	. . . . . . . . . 10 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1)) = if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1)))
21	1	oveq2d 7368	. . . . . . . . . 10 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑛 pCnt 𝑚) = (𝑛 pCnt 𝑁))
22	20, 21	oveq12d 7370	. . . . . . . . 9 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)) = (if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑁)))
23	22	ifeq1d 4494	. . . . . . . 8 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1) = if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑁)), 1))
24	23	mpteq2dv 5187	. . . . . . 7 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)) = (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑁)), 1)))
25		lgsval.1	. . . . . . 7 ⊢ 𝐹 = (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝐴, 0, if((𝐴 mod 8) ∈ {1, 7}, 1, -1)), ((((𝐴↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑁)), 1))
26	24, 25	eqtr4di 2786	. . . . . 6 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)) = 𝐹)
27	26	seqeq3d 13918	. . . . 5 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → seq1( · , (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1))) = seq1( · , 𝐹))
28	1	fveq2d 6832	. . . . 5 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (abs‘𝑚) = (abs‘𝑁))
29	27, 28	fveq12d 6835	. . . 4 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (seq1( · , (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)))‘(abs‘𝑚)) = (seq1( · , 𝐹)‘(abs‘𝑁)))
30	10, 29	oveq12d 7370	. . 3 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → (if((𝑚 < 0 ∧ 𝑎 < 0), -1, 1) · (seq1( · , (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)))‘(abs‘𝑚))) = (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁))))
31	2, 6, 30	ifbieq12d 4503	. 2 ⊢ ((𝑎 = 𝐴 ∧ 𝑚 = 𝑁) → if(𝑚 = 0, if((𝑎↑2) = 1, 1, 0), (if((𝑚 < 0 ∧ 𝑎 < 0), -1, 1) · (seq1( · , (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)))‘(abs‘𝑚)))) = if(𝑁 = 0, if((𝐴↑2) = 1, 1, 0), (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁)))))
32		df-lgs 27234	. 2 ⊢ /L = (𝑎 ∈ ℤ, 𝑚 ∈ ℤ ↦ if(𝑚 = 0, if((𝑎↑2) = 1, 1, 0), (if((𝑚 < 0 ∧ 𝑎 < 0), -1, 1) · (seq1( · , (𝑛 ∈ ℕ ↦ if(𝑛 ∈ ℙ, (if(𝑛 = 2, if(2 ∥ 𝑎, 0, if((𝑎 mod 8) ∈ {1, 7}, 1, -1)), ((((𝑎↑((𝑛 − 1) / 2)) + 1) mod 𝑛) − 1))↑(𝑛 pCnt 𝑚)), 1)))‘(abs‘𝑚)))))
33		1nn0 12404	. . . . 5 ⊢ 1 ∈ ℕ0
34		0nn0 12403	. . . . 5 ⊢ 0 ∈ ℕ0
35	33, 34	ifcli 4522	. . . 4 ⊢ if((𝐴↑2) = 1, 1, 0) ∈ ℕ0
36	35	elexi 3460	. . 3 ⊢ if((𝐴↑2) = 1, 1, 0) ∈ V
37		ovex 7385	. . 3 ⊢ (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁))) ∈ V
38	36, 37	ifex 4525	. 2 ⊢ if(𝑁 = 0, if((𝐴↑2) = 1, 1, 0), (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁)))) ∈ V
39	31, 32, 38	ovmpoa 7507	1 ⊢ ((𝐴 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (𝐴 /L 𝑁) = if(𝑁 = 0, if((𝐴↑2) = 1, 1, 0), (if((𝑁 < 0 ∧ 𝐴 < 0), -1, 1) · (seq1( · , 𝐹)‘(abs‘𝑁)))))

Syntax hints:   → wi 4   ∧ wa 395   = wceq 1541   ∈ wcel 2113  ifcif 4474  {cpr 4577   class class class wbr 5093   ↦ cmpt 5174  ‘cfv 6486  (class class class)co 7352  0cc0 11013  1c1 11014   + caddc 11016   · cmul 11018   < clt 11153   − cmin 11351  -cneg 11352   / cdiv 11781  ℕcn 12132  2c2 12187  7c7 12192  8c8 12193  ℕ₀cn0 12388  ℤcz 12475   mod cmo 13775  seqcseq 13910  ↑cexp 13970  abscabs 15143   ∥ cdvds 16165  ℙcprime 16584   pCnt cpc 16750   /_L clgs 27233

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 1968  ax-7 2009  ax-8 2115  ax-9 2123  ax-10 2146  ax-11 2162  ax-12 2182  ax-ext 2705  ax-sep 5236  ax-nul 5246  ax-pr 5372  ax-un 7674  ax-1cn 11071  ax-icn 11072  ax-addcl 11073  ax-mulcl 11075  ax-i2m1 11081

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3or 1087  df-3an 1088  df-tru 1544  df-fal 1554  df-ex 1781  df-nf 1785  df-sb 2068  df-mo 2537  df-eu 2566  df-clab 2712  df-cleq 2725  df-clel 2808  df-nfc 2882  df-ne 2930  df-ral 3049  df-rex 3058  df-reu 3348  df-rab 3397  df-v 3439  df-sbc 3738  df-csb 3847  df-dif 3901  df-un 3903  df-in 3905  df-ss 3915  df-pss 3918  df-nul 4283  df-if 4475  df-pw 4551  df-sn 4576  df-pr 4578  df-op 4582  df-uni 4859  df-iun 4943  df-br 5094  df-opab 5156  df-mpt 5175  df-tr 5201  df-id 5514  df-eprel 5519  df-po 5527  df-so 5528  df-fr 5572  df-we 5574  df-xp 5625  df-rel 5626  df-cnv 5627  df-co 5628  df-dm 5629  df-rn 5630  df-res 5631  df-ima 5632  df-pred 6253  df-ord 6314  df-on 6315  df-lim 6316  df-suc 6317  df-iota 6442  df-fun 6488  df-fn 6489  df-f 6490  df-f1 6491  df-fo 6492  df-f1o 6493  df-fv 6494  df-ov 7355  df-oprab 7356  df-mpo 7357  df-om 7803  df-2nd 7928  df-frecs 8217  df-wrecs 8248  df-recs 8297  df-rdg 8335  df-nn 12133  df-n0 12389  df-seq 13911  df-lgs 27234

This theorem is referenced by:  lgscllem  27243  lgsval2lem  27246  lgs0  27249  lgsval4  27256