Theorem phisum 12876

Description: The divisor sum identity of the totient function. Theorem 2.2 in [ApostolNT] p. 26. (Contributed by Stefan O'Rear, 12-Sep-2015.)

Assertion

Ref	Expression
phisum	⊢ (𝑁 ∈ ℕ → Σ𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘𝑑) = 𝑁)

Distinct variable group:   𝑥,𝑁,𝑑

Proof of Theorem phisum

Dummy variables 𝑧 𝑦 𝑤 𝑗 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		breq1 4096	. . . . . 6 ⊢ (𝑥 = 𝑦 → (𝑥 ∥ 𝑁 ↔ 𝑦 ∥ 𝑁))
2	1	elrab 2963	. . . . 5 ⊢ (𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↔ (𝑦 ∈ ℕ ∧ 𝑦 ∥ 𝑁))
3		hashgcdeq 12875	. . . . . . 7 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ ℕ) → (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = if(𝑦 ∥ 𝑁, (ϕ‘(𝑁 / 𝑦)), 0))
4	3	adantrr 479	. . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ (𝑦 ∈ ℕ ∧ 𝑦 ∥ 𝑁)) → (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = if(𝑦 ∥ 𝑁, (ϕ‘(𝑁 / 𝑦)), 0))
5		iftrue 3614	. . . . . . 7 ⊢ (𝑦 ∥ 𝑁 → if(𝑦 ∥ 𝑁, (ϕ‘(𝑁 / 𝑦)), 0) = (ϕ‘(𝑁 / 𝑦)))
6	5	ad2antll 491	. . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ (𝑦 ∈ ℕ ∧ 𝑦 ∥ 𝑁)) → if(𝑦 ∥ 𝑁, (ϕ‘(𝑁 / 𝑦)), 0) = (ϕ‘(𝑁 / 𝑦)))
7	4, 6	eqtrd 2264	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ (𝑦 ∈ ℕ ∧ 𝑦 ∥ 𝑁)) → (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = (ϕ‘(𝑁 / 𝑦)))
8	2, 7	sylan2b 287	. . . 4 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = (ϕ‘(𝑁 / 𝑦)))
9	8	sumeq2dv 11991	. . 3 ⊢ (𝑁 ∈ ℕ → Σ𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = Σ𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘(𝑁 / 𝑦)))
10		dvdsfi 12874	. . . 4 ⊢ (𝑁 ∈ ℕ → {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ∈ Fin)
11		0z 9534	. . . . . . 7 ⊢ 0 ∈ ℤ
12		nnz 9542	. . . . . . 7 ⊢ (𝑁 ∈ ℕ → 𝑁 ∈ ℤ)
13		fzofig 10740	. . . . . . 7 ⊢ ((0 ∈ ℤ ∧ 𝑁 ∈ ℤ) → (0..^𝑁) ∈ Fin)
14	11, 12, 13	sylancr 414	. . . . . 6 ⊢ (𝑁 ∈ ℕ → (0..^𝑁) ∈ Fin)
15	14	adantr 276	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → (0..^𝑁) ∈ Fin)
16		ssrab2 3313	. . . . . 6 ⊢ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ⊆ (0..^𝑁)
17	16	a1i 9	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ⊆ (0..^𝑁))
18		elfzoelz 10427	. . . . . . . . . . 11 ⊢ (𝑗 ∈ (0..^𝑁) → 𝑗 ∈ ℤ)
19	18	adantl 277	. . . . . . . . . 10 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → 𝑗 ∈ ℤ)
20	12	ad2antrr 488	. . . . . . . . . 10 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → 𝑁 ∈ ℤ)
21	19, 20	gcdcld 12602	. . . . . . . . 9 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → (𝑗 gcd 𝑁) ∈ ℕ0)
22	21	nn0zd 9644	. . . . . . . 8 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → (𝑗 gcd 𝑁) ∈ ℤ)
23		elrabi 2960	. . . . . . . . . 10 ⊢ (𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} → 𝑦 ∈ ℕ)
24	23	ad2antlr 489	. . . . . . . . 9 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → 𝑦 ∈ ℕ)
25	24	nnzd 9645	. . . . . . . 8 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → 𝑦 ∈ ℤ)
26		zdceq 9599	. . . . . . . 8 ⊢ (((𝑗 gcd 𝑁) ∈ ℤ ∧ 𝑦 ∈ ℤ) → DECID (𝑗 gcd 𝑁) = 𝑦)
27	22, 25, 26	syl2anc 411	. . . . . . 7 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → DECID (𝑗 gcd 𝑁) = 𝑦)
28		oveq1 6035	. . . . . . . . . . . 12 ⊢ (𝑧 = 𝑗 → (𝑧 gcd 𝑁) = (𝑗 gcd 𝑁))
29	28	eqeq1d 2240	. . . . . . . . . . 11 ⊢ (𝑧 = 𝑗 → ((𝑧 gcd 𝑁) = 𝑦 ↔ (𝑗 gcd 𝑁) = 𝑦))
30	29	elrab 2963	. . . . . . . . . 10 ⊢ (𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ↔ (𝑗 ∈ (0..^𝑁) ∧ (𝑗 gcd 𝑁) = 𝑦))
31	30	baibr 928	. . . . . . . . 9 ⊢ (𝑗 ∈ (0..^𝑁) → ((𝑗 gcd 𝑁) = 𝑦 ↔ 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}))
32	31	dcbid 846	. . . . . . . 8 ⊢ (𝑗 ∈ (0..^𝑁) → (DECID (𝑗 gcd 𝑁) = 𝑦 ↔ DECID 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}))
33	32	adantl 277	. . . . . . 7 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → (DECID (𝑗 gcd 𝑁) = 𝑦 ↔ DECID 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}))
34	27, 33	mpbid 147	. . . . . 6 ⊢ (((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) ∧ 𝑗 ∈ (0..^𝑁)) → DECID 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦})
35	34	ralrimiva 2606	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → ∀𝑗 ∈ (0..^𝑁)DECID 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦})
36		ssfidc 7173	. . . . 5 ⊢ (((0..^𝑁) ∈ Fin ∧ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ⊆ (0..^𝑁) ∧ ∀𝑗 ∈ (0..^𝑁)DECID 𝑗 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) → {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ∈ Fin)
37	15, 17, 35, 36	syl3anc 1274	. . . 4 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ∈ Fin)
38		oveq1 6035	. . . . . . . . . 10 ⊢ (𝑧 = 𝑤 → (𝑧 gcd 𝑁) = (𝑤 gcd 𝑁))
39	38	eqeq1d 2240	. . . . . . . . 9 ⊢ (𝑧 = 𝑤 → ((𝑧 gcd 𝑁) = 𝑦 ↔ (𝑤 gcd 𝑁) = 𝑦))
40	39	elrab 2963	. . . . . . . 8 ⊢ (𝑤 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} ↔ (𝑤 ∈ (0..^𝑁) ∧ (𝑤 gcd 𝑁) = 𝑦))
41	40	simprbi 275	. . . . . . 7 ⊢ (𝑤 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} → (𝑤 gcd 𝑁) = 𝑦)
42	41	rgen 2586	. . . . . 6 ⊢ ∀𝑤 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} (𝑤 gcd 𝑁) = 𝑦
43	42	rgenw 2588	. . . . 5 ⊢ ∀𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}∀𝑤 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} (𝑤 gcd 𝑁) = 𝑦
44		invdisj 4086	. . . . 5 ⊢ (∀𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}∀𝑤 ∈ {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} (𝑤 gcd 𝑁) = 𝑦 → Disj 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦})
45	43, 44	mp1i 10	. . . 4 ⊢ (𝑁 ∈ ℕ → Disj 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦})
46	10, 37, 45	hashiun 12102	. . 3 ⊢ (𝑁 ∈ ℕ → (♯‘∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = Σ𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (♯‘{𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}))
47		fveq2 5648	. . . 4 ⊢ (𝑑 = (𝑁 / 𝑦) → (ϕ‘𝑑) = (ϕ‘(𝑁 / 𝑦)))
48		eqid 2231	. . . . 5 ⊢ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} = {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}
49		eqid 2231	. . . . 5 ⊢ (𝑧 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↦ (𝑁 / 𝑧)) = (𝑧 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↦ (𝑁 / 𝑧))
50	48, 49	dvdsflip 12475	. . . 4 ⊢ (𝑁 ∈ ℕ → (𝑧 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↦ (𝑁 / 𝑧)):{𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}–1-1-onto→{𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁})
51		oveq2 6036	. . . . 5 ⊢ (𝑧 = 𝑦 → (𝑁 / 𝑧) = (𝑁 / 𝑦))
52		simpr 110	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁})
53	12	adantr 276	. . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → 𝑁 ∈ ℤ)
54	23	adantl 277	. . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → 𝑦 ∈ ℕ)
55		znq 9902	. . . . . 6 ⊢ ((𝑁 ∈ ℤ ∧ 𝑦 ∈ ℕ) → (𝑁 / 𝑦) ∈ ℚ)
56	53, 54, 55	syl2anc 411	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → (𝑁 / 𝑦) ∈ ℚ)
57	49, 51, 52, 56	fvmptd3 5749	. . . 4 ⊢ ((𝑁 ∈ ℕ ∧ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → ((𝑧 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↦ (𝑁 / 𝑧))‘𝑦) = (𝑁 / 𝑦))
58		elrabi 2960	. . . . . . 7 ⊢ (𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} → 𝑑 ∈ ℕ)
59	58	adantl 277	. . . . . 6 ⊢ ((𝑁 ∈ ℕ ∧ 𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → 𝑑 ∈ ℕ)
60	59	phicld 12853	. . . . 5 ⊢ ((𝑁 ∈ ℕ ∧ 𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → (ϕ‘𝑑) ∈ ℕ)
61	60	nncnd 9199	. . . 4 ⊢ ((𝑁 ∈ ℕ ∧ 𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁}) → (ϕ‘𝑑) ∈ ℂ)
62	47, 10, 50, 57, 61	fsumf1o 12014	. . 3 ⊢ (𝑁 ∈ ℕ → Σ𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘𝑑) = Σ𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘(𝑁 / 𝑦)))
63	9, 46, 62	3eqtr4rd 2275	. 2 ⊢ (𝑁 ∈ ℕ → Σ𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘𝑑) = (♯‘∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}))
64		iunrab 4023	. . . . 5 ⊢ ∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} = {𝑧 ∈ (0..^𝑁) ∣ ∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦}
65		breq1 4096	. . . . . . . . 9 ⊢ (𝑥 = (𝑧 gcd 𝑁) → (𝑥 ∥ 𝑁 ↔ (𝑧 gcd 𝑁) ∥ 𝑁))
66		elfzoelz 10427	. . . . . . . . . . 11 ⊢ (𝑧 ∈ (0..^𝑁) → 𝑧 ∈ ℤ)
67	66	adantl 277	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → 𝑧 ∈ ℤ)
68	12	adantr 276	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → 𝑁 ∈ ℤ)
69		nnne0 9213	. . . . . . . . . . . . 13 ⊢ (𝑁 ∈ ℕ → 𝑁 ≠ 0)
70	69	neneqd 2424	. . . . . . . . . . . 12 ⊢ (𝑁 ∈ ℕ → ¬ 𝑁 = 0)
71	70	intnand 939	. . . . . . . . . . 11 ⊢ (𝑁 ∈ ℕ → ¬ (𝑧 = 0 ∧ 𝑁 = 0))
72	71	adantr 276	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → ¬ (𝑧 = 0 ∧ 𝑁 = 0))
73		gcdn0cl 12596	. . . . . . . . . 10 ⊢ (((𝑧 ∈ ℤ ∧ 𝑁 ∈ ℤ) ∧ ¬ (𝑧 = 0 ∧ 𝑁 = 0)) → (𝑧 gcd 𝑁) ∈ ℕ)
74	67, 68, 72, 73	syl21anc 1273	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → (𝑧 gcd 𝑁) ∈ ℕ)
75		gcddvds 12597	. . . . . . . . . . 11 ⊢ ((𝑧 ∈ ℤ ∧ 𝑁 ∈ ℤ) → ((𝑧 gcd 𝑁) ∥ 𝑧 ∧ (𝑧 gcd 𝑁) ∥ 𝑁))
76	67, 68, 75	syl2anc 411	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → ((𝑧 gcd 𝑁) ∥ 𝑧 ∧ (𝑧 gcd 𝑁) ∥ 𝑁))
77	76	simprd 114	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → (𝑧 gcd 𝑁) ∥ 𝑁)
78	65, 74, 77	elrabd 2965	. . . . . . . 8 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → (𝑧 gcd 𝑁) ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁})
79		clel5 2944	. . . . . . . 8 ⊢ ((𝑧 gcd 𝑁) ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} ↔ ∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦)
80	78, 79	sylib 122	. . . . . . 7 ⊢ ((𝑁 ∈ ℕ ∧ 𝑧 ∈ (0..^𝑁)) → ∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦)
81	80	ralrimiva 2606	. . . . . 6 ⊢ (𝑁 ∈ ℕ → ∀𝑧 ∈ (0..^𝑁)∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦)
82		rabid2 2711	. . . . . 6 ⊢ ((0..^𝑁) = {𝑧 ∈ (0..^𝑁) ∣ ∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦} ↔ ∀𝑧 ∈ (0..^𝑁)∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦)
83	81, 82	sylibr 134	. . . . 5 ⊢ (𝑁 ∈ ℕ → (0..^𝑁) = {𝑧 ∈ (0..^𝑁) ∣ ∃𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (𝑧 gcd 𝑁) = 𝑦})
84	64, 83	eqtr4id 2283	. . . 4 ⊢ (𝑁 ∈ ℕ → ∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦} = (0..^𝑁))
85	84	fveq2d 5652	. . 3 ⊢ (𝑁 ∈ ℕ → (♯‘∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = (♯‘(0..^𝑁)))
86		nnnn0 9451	. . . 4 ⊢ (𝑁 ∈ ℕ → 𝑁 ∈ ℕ0)
87		hashfzo0 11133	. . . 4 ⊢ (𝑁 ∈ ℕ0 → (♯‘(0..^𝑁)) = 𝑁)
88	86, 87	syl 14	. . 3 ⊢ (𝑁 ∈ ℕ → (♯‘(0..^𝑁)) = 𝑁)
89	85, 88	eqtrd 2264	. 2 ⊢ (𝑁 ∈ ℕ → (♯‘∪ 𝑦 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} {𝑧 ∈ (0..^𝑁) ∣ (𝑧 gcd 𝑁) = 𝑦}) = 𝑁)
90	63, 89	eqtrd 2264	1 ⊢ (𝑁 ∈ ℕ → Σ𝑑 ∈ {𝑥 ∈ ℕ ∣ 𝑥 ∥ 𝑁} (ϕ‘𝑑) = 𝑁)

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 104   ↔ wb 105  DECID wdc 842   = wceq 1398   ∈ wcel 2202  ∀wral 2511  ∃wrex 2512  {crab 2515   ⊆ wss 3201  ifcif 3607  ∪ ciun 3975  Disj wdisj 4069   class class class wbr 4093   ↦ cmpt 4155  ‘cfv 5333  (class class class)co 6028  Fincfn 6952  0cc0 8075   / cdiv 8894  ℕcn 9185  ℕ₀cn0 9444  ℤcz 9523  ℚcq 9897  ..^cfzo 10422  ♯chash 11083  Σcsu 11976   ∥ cdvds 12411   gcd cgcd 12587  ϕcphi 12844

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2204  ax-14 2205  ax-ext 2213  ax-coll 4209  ax-sep 4212  ax-nul 4220  ax-pow 4270  ax-pr 4305  ax-un 4536  ax-setind 4641  ax-iinf 4692  ax-cnex 8166  ax-resscn 8167  ax-1cn 8168  ax-1re 8169  ax-icn 8170  ax-addcl 8171  ax-addrcl 8172  ax-mulcl 8173  ax-mulrcl 8174  ax-addcom 8175  ax-mulcom 8176  ax-addass 8177  ax-mulass 8178  ax-distr 8179  ax-i2m1 8180  ax-0lt1 8181  ax-1rid 8182  ax-0id 8183  ax-rnegex 8184  ax-precex 8185  ax-cnre 8186  ax-pre-ltirr 8187  ax-pre-ltwlin 8188  ax-pre-lttrn 8189  ax-pre-apti 8190  ax-pre-ltadd 8191  ax-pre-mulgt0 8192  ax-pre-mulext 8193  ax-arch 8194  ax-caucvg 8195

This theorem depends on definitions:  df-bi 117  df-stab 839  df-dc 843  df-3or 1006  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1811  df-eu 2082  df-mo 2083  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-ne 2404  df-nel 2499  df-ral 2516  df-rex 2517  df-reu 2518  df-rmo 2519  df-rab 2520  df-v 2805  df-sbc 3033  df-csb 3129  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-if 3608  df-pw 3658  df-sn 3679  df-pr 3680  df-op 3682  df-uni 3899  df-int 3934  df-iun 3977  df-disj 4070  df-br 4094  df-opab 4156  df-mpt 4157  df-tr 4193  df-id 4396  df-po 4399  df-iso 4400  df-iord 4469  df-on 4471  df-ilim 4472  df-suc 4474  df-iom 4695  df-xp 4737  df-rel 4738  df-cnv 4739  df-co 4740  df-dm 4741  df-rn 4742  df-res 4743  df-ima 4744  df-iota 5293  df-fun 5335  df-fn 5336  df-f 5337  df-f1 5338  df-fo 5339  df-f1o 5340  df-fv 5341  df-isom 5342  df-riota 5981  df-ov 6031  df-oprab 6032  df-mpo 6033  df-1st 6312  df-2nd 6313  df-recs 6514  df-irdg 6579  df-frec 6600  df-1o 6625  df-oadd 6629  df-er 6745  df-en 6953  df-dom 6954  df-fin 6955  df-sup 7226  df-pnf 8258  df-mnf 8259  df-xr 8260  df-ltxr 8261  df-le 8262  df-sub 8394  df-neg 8395  df-reap 8797  df-ap 8804  df-div 8895  df-inn 9186  df-2 9244  df-3 9245  df-4 9246  df-n0 9445  df-z 9524  df-uz 9800  df-q 9898  df-rp 9933  df-fz 10289  df-fzo 10423  df-fl 10576  df-mod 10631  df-seqfrec 10756  df-exp 10847  df-ihash 11084  df-cj 11465  df-re 11466  df-im 11467  df-rsqrt 11621  df-abs 11622  df-clim 11902  df-sumdc 11977  df-dvds 12412  df-gcd 12588  df-phi 12846

This theorem is referenced by: (None)