subfacp1lem6 - Mathbox for Mario Carneiro

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Theorem subfacp1lem6 35153

Description: Lemma for subfacp1 35154. By induction, we cut up the set of all derangements on 𝑁 + 1 according to the 𝑁 possible values of (𝑓‘1) (since (𝑓‘1) ≠ 1), and for each set for fixed 𝑀 = (𝑓‘1), the subset of derangements with (𝑓‘𝑀) = 1 has size 𝑆(𝑁 − 1) (by subfacp1lem3 35150), while the subset with (𝑓‘𝑀) ≠ 1 has size 𝑆(𝑁) (by subfacp1lem5 35152). Adding it all up yields the desired equation 𝑁(𝑆(𝑁) + 𝑆(𝑁 − 1)) for the number of derangements on 𝑁 + 1. (Contributed by Mario Carneiro, 22-Jan-2015.)

**Hypotheses**
Ref	Expression
derang.d	⊢ 𝐷 = (𝑥 ∈ Fin ↦ (♯‘{𝑓 ∣ (𝑓:𝑥–1-1-onto→𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) ≠ 𝑦)}))
subfac.n	⊢ 𝑆 = (𝑛 ∈ ℕ₀ ↦ (𝐷‘(1...𝑛)))
subfacp1lem.a	⊢ 𝐴 = {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)}

**Assertion**
Ref	Expression
subfacp1lem6	⊢ (𝑁 ∈ ℕ → (𝑆‘(𝑁 + 1)) = (𝑁 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))

Distinct variable groups: 𝑓,𝑛,𝑥,𝑦,𝐴 𝑓,𝑁,𝑛,𝑥,𝑦 𝐷,𝑛 𝑆,𝑛,𝑥,𝑦 Allowed substitution hints: 𝐷(𝑥,𝑦,𝑓) 𝑆(𝑓)

Proof of Theorem subfacp1lem6 Dummy variables 𝑔 ℎ 𝑚 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		peano2nn 12305	. . . . 5 ⊢ (𝑁 ∈ ℕ → (𝑁 + 1) ∈ ℕ)
2	1	nnnn0d 12613	. . . 4 ⊢ (𝑁 ∈ ℕ → (𝑁 + 1) ∈ ℕ₀)
3		derang.d	. . . . 5 ⊢ 𝐷 = (𝑥 ∈ Fin ↦ (♯‘{𝑓 ∣ (𝑓:𝑥–1-1-onto→𝑥 ∧ ∀𝑦 ∈ 𝑥 (𝑓‘𝑦) ≠ 𝑦)}))
4		subfac.n	. . . . 5 ⊢ 𝑆 = (𝑛 ∈ ℕ₀ ↦ (𝐷‘(1...𝑛)))
5	3, 4	subfacval 35141	. . . 4 ⊢ ((𝑁 + 1) ∈ ℕ₀ → (𝑆‘(𝑁 + 1)) = (𝐷‘(1...(𝑁 + 1))))
6	2, 5	syl 17	. . 3 ⊢ (𝑁 ∈ ℕ → (𝑆‘(𝑁 + 1)) = (𝐷‘(1...(𝑁 + 1))))
7		fzfid 14024	. . . . 5 ⊢ (𝑁 ∈ ℕ → (1...(𝑁 + 1)) ∈ Fin)
8	3	derangval 35135	. . . . 5 ⊢ ((1...(𝑁 + 1)) ∈ Fin → (𝐷‘(1...(𝑁 + 1))) = (♯‘{𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)}))
9	7, 8	syl 17	. . . 4 ⊢ (𝑁 ∈ ℕ → (𝐷‘(1...(𝑁 + 1))) = (♯‘{𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)}))
10		subfacp1lem.a	. . . . 5 ⊢ 𝐴 = {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)}
11	10	fveq2i 6923	. . . 4 ⊢ (♯‘𝐴) = (♯‘{𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)})
12	9, 11	eqtr4di 2798	. . 3 ⊢ (𝑁 ∈ ℕ → (𝐷‘(1...(𝑁 + 1))) = (♯‘𝐴))
13		nnuz 12946	. . . . . . . . . . 11 ⊢ ℕ = (ℤ_≥‘1)
14	1, 13	eleqtrdi 2854	. . . . . . . . . 10 ⊢ (𝑁 ∈ ℕ → (𝑁 + 1) ∈ (ℤ_≥‘1))
15		eluzfz1 13591	. . . . . . . . . 10 ⊢ ((𝑁 + 1) ∈ (ℤ_≥‘1) → 1 ∈ (1...(𝑁 + 1)))
16	14, 15	syl 17	. . . . . . . . 9 ⊢ (𝑁 ∈ ℕ → 1 ∈ (1...(𝑁 + 1)))
17		f1of 6862	. . . . . . . . . 10 ⊢ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) → 𝑓:(1...(𝑁 + 1))⟶(1...(𝑁 + 1)))
18	17	adantr 480	. . . . . . . . 9 ⊢ ((𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦) → 𝑓:(1...(𝑁 + 1))⟶(1...(𝑁 + 1)))
19		ffvelcdm 7115	. . . . . . . . . 10 ⊢ ((𝑓:(1...(𝑁 + 1))⟶(1...(𝑁 + 1)) ∧ 1 ∈ (1...(𝑁 + 1))) → (𝑓‘1) ∈ (1...(𝑁 + 1)))
20	19	expcom 413	. . . . . . . . 9 ⊢ (1 ∈ (1...(𝑁 + 1)) → (𝑓:(1...(𝑁 + 1))⟶(1...(𝑁 + 1)) → (𝑓‘1) ∈ (1...(𝑁 + 1))))
21	16, 18, 20	syl2im 40	. . . . . . . 8 ⊢ (𝑁 ∈ ℕ → ((𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦) → (𝑓‘1) ∈ (1...(𝑁 + 1))))
22	21	ss2abdv 4089	. . . . . . 7 ⊢ (𝑁 ∈ ℕ → {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)} ⊆ {𝑓 ∣ (𝑓‘1) ∈ (1...(𝑁 + 1))})
23		fveq1 6919	. . . . . . . . 9 ⊢ (𝑔 = 𝑓 → (𝑔‘1) = (𝑓‘1))
24	23	eleq1d 2829	. . . . . . . 8 ⊢ (𝑔 = 𝑓 → ((𝑔‘1) ∈ (1...(𝑁 + 1)) ↔ (𝑓‘1) ∈ (1...(𝑁 + 1))))
25	24	cbvabv 2815	. . . . . . 7 ⊢ {𝑔 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))} = {𝑓 ∣ (𝑓‘1) ∈ (1...(𝑁 + 1))}
26	22, 10, 25	3sstr4g 4054	. . . . . 6 ⊢ (𝑁 ∈ ℕ → 𝐴 ⊆ {𝑔 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))})
27		ssabral 4088	. . . . . 6 ⊢ (𝐴 ⊆ {𝑔 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))} ↔ ∀𝑔 ∈ 𝐴 (𝑔‘1) ∈ (1...(𝑁 + 1)))
28	26, 27	sylib 218	. . . . 5 ⊢ (𝑁 ∈ ℕ → ∀𝑔 ∈ 𝐴 (𝑔‘1) ∈ (1...(𝑁 + 1)))
29		rabid2 3478	. . . . 5 ⊢ (𝐴 = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))} ↔ ∀𝑔 ∈ 𝐴 (𝑔‘1) ∈ (1...(𝑁 + 1)))
30	28, 29	sylibr 234	. . . 4 ⊢ (𝑁 ∈ ℕ → 𝐴 = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))})
31	30	fveq2d 6924	. . 3 ⊢ (𝑁 ∈ ℕ → (♯‘𝐴) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}))
32	6, 12, 31	3eqtrd 2784	. 2 ⊢ (𝑁 ∈ ℕ → (𝑆‘(𝑁 + 1)) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}))
33		elfz1end 13614	. . . 4 ⊢ ((𝑁 + 1) ∈ ℕ ↔ (𝑁 + 1) ∈ (1...(𝑁 + 1)))
34	1, 33	sylib 218	. . 3 ⊢ (𝑁 ∈ ℕ → (𝑁 + 1) ∈ (1...(𝑁 + 1)))
35		eleq1 2832	. . . . . . 7 ⊢ (𝑥 = 1 → (𝑥 ∈ (1...(𝑁 + 1)) ↔ 1 ∈ (1...(𝑁 + 1))))
36		oveq2 7456	. . . . . . . . . . . . 13 ⊢ (𝑥 = 1 → (1...𝑥) = (1...1))
37		1z 12673	. . . . . . . . . . . . . 14 ⊢ 1 ∈ ℤ
38		fzsn 13626	. . . . . . . . . . . . . 14 ⊢ (1 ∈ ℤ → (1...1) = {1})
39	37, 38	ax-mp 5	. . . . . . . . . . . . 13 ⊢ (1...1) = {1}
40	36, 39	eqtrdi 2796	. . . . . . . . . . . 12 ⊢ (𝑥 = 1 → (1...𝑥) = {1})
41	40	eleq2d 2830	. . . . . . . . . . 11 ⊢ (𝑥 = 1 → ((𝑔‘1) ∈ (1...𝑥) ↔ (𝑔‘1) ∈ {1}))
42		fvex 6933	. . . . . . . . . . . 12 ⊢ (𝑔‘1) ∈ V
43	42	elsn 4663	. . . . . . . . . . 11 ⊢ ((𝑔‘1) ∈ {1} ↔ (𝑔‘1) = 1)
44	41, 43	bitrdi 287	. . . . . . . . . 10 ⊢ (𝑥 = 1 → ((𝑔‘1) ∈ (1...𝑥) ↔ (𝑔‘1) = 1))
45	44	rabbidv 3451	. . . . . . . . 9 ⊢ (𝑥 = 1 → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)} = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1})
46	45	fveq2d 6924	. . . . . . . 8 ⊢ (𝑥 = 1 → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}))
47		oveq1 7455	. . . . . . . . . 10 ⊢ (𝑥 = 1 → (𝑥 − 1) = (1 − 1))
48		1m1e0 12365	. . . . . . . . . 10 ⊢ (1 − 1) = 0
49	47, 48	eqtrdi 2796	. . . . . . . . 9 ⊢ (𝑥 = 1 → (𝑥 − 1) = 0)
50	49	oveq1d 7463	. . . . . . . 8 ⊢ (𝑥 = 1 → ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
51	46, 50	eqeq12d 2756	. . . . . . 7 ⊢ (𝑥 = 1 → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) ↔ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
52	35, 51	imbi12d 344	. . . . . 6 ⊢ (𝑥 = 1 → ((𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) ↔ (1 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
53	52	imbi2d 340	. . . . 5 ⊢ (𝑥 = 1 → ((𝑁 ∈ ℕ → (𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))) ↔ (𝑁 ∈ ℕ → (1 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
54		eleq1 2832	. . . . . . 7 ⊢ (𝑥 = 𝑚 → (𝑥 ∈ (1...(𝑁 + 1)) ↔ 𝑚 ∈ (1...(𝑁 + 1))))
55		oveq2 7456	. . . . . . . . . . 11 ⊢ (𝑥 = 𝑚 → (1...𝑥) = (1...𝑚))
56	55	eleq2d 2830	. . . . . . . . . 10 ⊢ (𝑥 = 𝑚 → ((𝑔‘1) ∈ (1...𝑥) ↔ (𝑔‘1) ∈ (1...𝑚)))
57	56	rabbidv 3451	. . . . . . . . 9 ⊢ (𝑥 = 𝑚 → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)} = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)})
58	57	fveq2d 6924	. . . . . . . 8 ⊢ (𝑥 = 𝑚 → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}))
59		oveq1 7455	. . . . . . . . 9 ⊢ (𝑥 = 𝑚 → (𝑥 − 1) = (𝑚 − 1))
60	59	oveq1d 7463	. . . . . . . 8 ⊢ (𝑥 = 𝑚 → ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
61	58, 60	eqeq12d 2756	. . . . . . 7 ⊢ (𝑥 = 𝑚 → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) ↔ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
62	54, 61	imbi12d 344	. . . . . 6 ⊢ (𝑥 = 𝑚 → ((𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) ↔ (𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
63	62	imbi2d 340	. . . . 5 ⊢ (𝑥 = 𝑚 → ((𝑁 ∈ ℕ → (𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))) ↔ (𝑁 ∈ ℕ → (𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
64		eleq1 2832	. . . . . . 7 ⊢ (𝑥 = (𝑚 + 1) → (𝑥 ∈ (1...(𝑁 + 1)) ↔ (𝑚 + 1) ∈ (1...(𝑁 + 1))))
65		oveq2 7456	. . . . . . . . . . 11 ⊢ (𝑥 = (𝑚 + 1) → (1...𝑥) = (1...(𝑚 + 1)))
66	65	eleq2d 2830	. . . . . . . . . 10 ⊢ (𝑥 = (𝑚 + 1) → ((𝑔‘1) ∈ (1...𝑥) ↔ (𝑔‘1) ∈ (1...(𝑚 + 1))))
67	66	rabbidv 3451	. . . . . . . . 9 ⊢ (𝑥 = (𝑚 + 1) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)} = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))})
68	67	fveq2d 6924	. . . . . . . 8 ⊢ (𝑥 = (𝑚 + 1) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}))
69		oveq1 7455	. . . . . . . . 9 ⊢ (𝑥 = (𝑚 + 1) → (𝑥 − 1) = ((𝑚 + 1) − 1))
70	69	oveq1d 7463	. . . . . . . 8 ⊢ (𝑥 = (𝑚 + 1) → ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
71	68, 70	eqeq12d 2756	. . . . . . 7 ⊢ (𝑥 = (𝑚 + 1) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) ↔ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
72	64, 71	imbi12d 344	. . . . . 6 ⊢ (𝑥 = (𝑚 + 1) → ((𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) ↔ ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
73	72	imbi2d 340	. . . . 5 ⊢ (𝑥 = (𝑚 + 1) → ((𝑁 ∈ ℕ → (𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))) ↔ (𝑁 ∈ ℕ → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
74		eleq1 2832	. . . . . . 7 ⊢ (𝑥 = (𝑁 + 1) → (𝑥 ∈ (1...(𝑁 + 1)) ↔ (𝑁 + 1) ∈ (1...(𝑁 + 1))))
75		oveq2 7456	. . . . . . . . . . 11 ⊢ (𝑥 = (𝑁 + 1) → (1...𝑥) = (1...(𝑁 + 1)))
76	75	eleq2d 2830	. . . . . . . . . 10 ⊢ (𝑥 = (𝑁 + 1) → ((𝑔‘1) ∈ (1...𝑥) ↔ (𝑔‘1) ∈ (1...(𝑁 + 1))))
77	76	rabbidv 3451	. . . . . . . . 9 ⊢ (𝑥 = (𝑁 + 1) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)} = {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))})
78	77	fveq2d 6924	. . . . . . . 8 ⊢ (𝑥 = (𝑁 + 1) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}))
79		oveq1 7455	. . . . . . . . 9 ⊢ (𝑥 = (𝑁 + 1) → (𝑥 − 1) = ((𝑁 + 1) − 1))
80	79	oveq1d 7463	. . . . . . . 8 ⊢ (𝑥 = (𝑁 + 1) → ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
81	78, 80	eqeq12d 2756	. . . . . . 7 ⊢ (𝑥 = (𝑁 + 1) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) ↔ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
82	74, 81	imbi12d 344	. . . . . 6 ⊢ (𝑥 = (𝑁 + 1) → ((𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) ↔ ((𝑁 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
83	82	imbi2d 340	. . . . 5 ⊢ (𝑥 = (𝑁 + 1) → ((𝑁 ∈ ℕ → (𝑥 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑥)}) = ((𝑥 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))) ↔ (𝑁 ∈ ℕ → ((𝑁 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
84		hash0 14416	. . . . . . 7 ⊢ (♯‘∅) = 0
85		fveq2 6920	. . . . . . . . . . . . . . . 16 ⊢ (𝑦 = 1 → (𝑓‘𝑦) = (𝑓‘1))
86		id 22	. . . . . . . . . . . . . . . 16 ⊢ (𝑦 = 1 → 𝑦 = 1)
87	85, 86	neeq12d 3008	. . . . . . . . . . . . . . 15 ⊢ (𝑦 = 1 → ((𝑓‘𝑦) ≠ 𝑦 ↔ (𝑓‘1) ≠ 1))
88	87	rspcv 3631	. . . . . . . . . . . . . 14 ⊢ (1 ∈ (1...(𝑁 + 1)) → (∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦 → (𝑓‘1) ≠ 1))
89	16, 88	syl 17	. . . . . . . . . . . . 13 ⊢ (𝑁 ∈ ℕ → (∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦 → (𝑓‘1) ≠ 1))
90	89	adantld 490	. . . . . . . . . . . 12 ⊢ (𝑁 ∈ ℕ → ((𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦) → (𝑓‘1) ≠ 1))
91	90	ss2abdv 4089	. . . . . . . . . . 11 ⊢ (𝑁 ∈ ℕ → {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)} ⊆ {𝑓 ∣ (𝑓‘1) ≠ 1})
92		df-ne 2947	. . . . . . . . . . . . 13 ⊢ ((𝑔‘1) ≠ 1 ↔ ¬ (𝑔‘1) = 1)
93	23	neeq1d 3006	. . . . . . . . . . . . 13 ⊢ (𝑔 = 𝑓 → ((𝑔‘1) ≠ 1 ↔ (𝑓‘1) ≠ 1))
94	92, 93	bitr3id 285	. . . . . . . . . . . 12 ⊢ (𝑔 = 𝑓 → (¬ (𝑔‘1) = 1 ↔ (𝑓‘1) ≠ 1))
95	94	cbvabv 2815	. . . . . . . . . . 11 ⊢ {𝑔 ∣ ¬ (𝑔‘1) = 1} = {𝑓 ∣ (𝑓‘1) ≠ 1}
96	91, 10, 95	3sstr4g 4054	. . . . . . . . . 10 ⊢ (𝑁 ∈ ℕ → 𝐴 ⊆ {𝑔 ∣ ¬ (𝑔‘1) = 1})
97		ssabral 4088	. . . . . . . . . 10 ⊢ (𝐴 ⊆ {𝑔 ∣ ¬ (𝑔‘1) = 1} ↔ ∀𝑔 ∈ 𝐴 ¬ (𝑔‘1) = 1)
98	96, 97	sylib 218	. . . . . . . . 9 ⊢ (𝑁 ∈ ℕ → ∀𝑔 ∈ 𝐴 ¬ (𝑔‘1) = 1)
99		rabeq0 4411	. . . . . . . . 9 ⊢ ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1} = ∅ ↔ ∀𝑔 ∈ 𝐴 ¬ (𝑔‘1) = 1)
100	98, 99	sylibr 234	. . . . . . . 8 ⊢ (𝑁 ∈ ℕ → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1} = ∅)
101	100	fveq2d 6924	. . . . . . 7 ⊢ (𝑁 ∈ ℕ → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (♯‘∅))
102		nnnn0 12560	. . . . . . . . . . 11 ⊢ (𝑁 ∈ ℕ → 𝑁 ∈ ℕ₀)
103	3, 4	subfacf 35143	. . . . . . . . . . . 12 ⊢ 𝑆:ℕ₀⟶ℕ₀
104	103	ffvelcdmi 7117	. . . . . . . . . . 11 ⊢ (𝑁 ∈ ℕ₀ → (𝑆‘𝑁) ∈ ℕ₀)
105	102, 104	syl 17	. . . . . . . . . 10 ⊢ (𝑁 ∈ ℕ → (𝑆‘𝑁) ∈ ℕ₀)
106		nnm1nn0 12594	. . . . . . . . . . 11 ⊢ (𝑁 ∈ ℕ → (𝑁 − 1) ∈ ℕ₀)
107	103	ffvelcdmi 7117	. . . . . . . . . . 11 ⊢ ((𝑁 − 1) ∈ ℕ₀ → (𝑆‘(𝑁 − 1)) ∈ ℕ₀)
108	106, 107	syl 17	. . . . . . . . . 10 ⊢ (𝑁 ∈ ℕ → (𝑆‘(𝑁 − 1)) ∈ ℕ₀)
109	105, 108	nn0addcld 12617	. . . . . . . . 9 ⊢ (𝑁 ∈ ℕ → ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))) ∈ ℕ₀)
110	109	nn0cnd 12615	. . . . . . . 8 ⊢ (𝑁 ∈ ℕ → ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))) ∈ ℂ)
111	110	mul02d 11488	. . . . . . 7 ⊢ (𝑁 ∈ ℕ → (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = 0)
112	84, 101, 111	3eqtr4a 2806	. . . . . 6 ⊢ (𝑁 ∈ ℕ → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
113	112	a1d 25	. . . . 5 ⊢ (𝑁 ∈ ℕ → (1 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = 1}) = (0 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
114		simplr 768	. . . . . . . . . . . 12 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑚 ∈ ℕ)
115	114, 13	eleqtrdi 2854	. . . . . . . . . . 11 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑚 ∈ (ℤ_≥‘1))
116		peano2fzr 13597	. . . . . . . . . . 11 ⊢ ((𝑚 ∈ (ℤ_≥‘1) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑚 ∈ (1...(𝑁 + 1)))
117	115, 116	sylancom 587	. . . . . . . . . 10 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑚 ∈ (1...(𝑁 + 1)))
118	117	ex 412	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → 𝑚 ∈ (1...(𝑁 + 1))))
119	118	imim1d 82	. . . . . . . 8 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → ((𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
120		oveq1 7455	. . . . . . . . . . 11 ⊢ ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})) = (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
121		elfzp1 13634	. . . . . . . . . . . . . . . . 17 ⊢ (𝑚 ∈ (ℤ_≥‘1) → ((𝑔‘1) ∈ (1...(𝑚 + 1)) ↔ ((𝑔‘1) ∈ (1...𝑚) ∨ (𝑔‘1) = (𝑚 + 1))))
122	115, 121	syl 17	. . . . . . . . . . . . . . . 16 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((𝑔‘1) ∈ (1...(𝑚 + 1)) ↔ ((𝑔‘1) ∈ (1...𝑚) ∨ (𝑔‘1) = (𝑚 + 1))))
123	122	rabbidv 3451	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))} = {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) ∈ (1...𝑚) ∨ (𝑔‘1) = (𝑚 + 1))})
124		unrab 4334	. . . . . . . . . . . . . . 15 ⊢ ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∪ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) ∈ (1...𝑚) ∨ (𝑔‘1) = (𝑚 + 1))}
125	123, 124	eqtr4di 2798	. . . . . . . . . . . . . 14 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))} = ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∪ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}))
126	125	fveq2d 6924	. . . . . . . . . . . . 13 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (♯‘({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∪ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
127		fzfi 14023	. . . . . . . . . . . . . . . . 17 ⊢ (1...(𝑁 + 1)) ∈ Fin
128		deranglem 35134	. . . . . . . . . . . . . . . . 17 ⊢ ((1...(𝑁 + 1)) ∈ Fin → {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)} ∈ Fin)
129	127, 128	ax-mp 5	. . . . . . . . . . . . . . . 16 ⊢ {𝑓 ∣ (𝑓:(1...(𝑁 + 1))–1-1-onto→(1...(𝑁 + 1)) ∧ ∀𝑦 ∈ (1...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)} ∈ Fin
130	10, 129	eqeltri 2840	. . . . . . . . . . . . . . 15 ⊢ 𝐴 ∈ Fin
131		ssrab2 4103	. . . . . . . . . . . . . . 15 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ⊆ 𝐴
132		ssfi 9240	. . . . . . . . . . . . . . 15 ⊢ ((𝐴 ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ⊆ 𝐴) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∈ Fin)
133	130, 131, 132	mp2an 691	. . . . . . . . . . . . . 14 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∈ Fin
134		ssrab2 4103	. . . . . . . . . . . . . . 15 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} ⊆ 𝐴
135		ssfi 9240	. . . . . . . . . . . . . . 15 ⊢ ((𝐴 ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} ⊆ 𝐴) → {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} ∈ Fin)
136	130, 134, 135	mp2an 691	. . . . . . . . . . . . . 14 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} ∈ Fin
137		inrab 4335	. . . . . . . . . . . . . . 15 ⊢ ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∩ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1))}
138		fzp1disj 13643	. . . . . . . . . . . . . . . . . 18 ⊢ ((1...𝑚) ∩ {(𝑚 + 1)}) = ∅
139	42	elsn 4663	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((𝑔‘1) ∈ {(𝑚 + 1)} ↔ (𝑔‘1) = (𝑚 + 1))
140		inelcm 4488	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) ∈ {(𝑚 + 1)}) → ((1...𝑚) ∩ {(𝑚 + 1)}) ≠ ∅)
141	139, 140	sylan2br 594	. . . . . . . . . . . . . . . . . . 19 ⊢ (((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1)) → ((1...𝑚) ∩ {(𝑚 + 1)}) ≠ ∅)
142	141	necon2bi 2977	. . . . . . . . . . . . . . . . . 18 ⊢ (((1...𝑚) ∩ {(𝑚 + 1)}) = ∅ → ¬ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1)))
143	138, 142	ax-mp 5	. . . . . . . . . . . . . . . . 17 ⊢ ¬ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1))
144	143	rgenw 3071	. . . . . . . . . . . . . . . 16 ⊢ ∀𝑔 ∈ 𝐴 ¬ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1))
145		rabeq0 4411	. . . . . . . . . . . . . . . 16 ⊢ ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1))} = ∅ ↔ ∀𝑔 ∈ 𝐴 ¬ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1)))
146	144, 145	mpbir 231	. . . . . . . . . . . . . . 15 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) ∈ (1...𝑚) ∧ (𝑔‘1) = (𝑚 + 1))} = ∅
147	137, 146	eqtri 2768	. . . . . . . . . . . . . 14 ⊢ ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∩ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = ∅
148		hashun 14431	. . . . . . . . . . . . . 14 ⊢ (({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} ∈ Fin ∧ ({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∩ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = ∅) → (♯‘({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∪ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})) = ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
149	133, 136, 147, 148	mp3an 1461	. . . . . . . . . . . . 13 ⊢ (♯‘({𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)} ∪ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})) = ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}))
150	126, 149	eqtrdi 2796	. . . . . . . . . . . 12 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
151		nncn 12301	. . . . . . . . . . . . . . . 16 ⊢ (𝑚 ∈ ℕ → 𝑚 ∈ ℂ)
152	151	ad2antlr 726	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑚 ∈ ℂ)
153		ax-1cn 11242	. . . . . . . . . . . . . . . 16 ⊢ 1 ∈ ℂ
154	153	a1i 11	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 1 ∈ ℂ)
155	152, 154, 154	addsubd 11668	. . . . . . . . . . . . . 14 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((𝑚 + 1) − 1) = ((𝑚 − 1) + 1))
156	155	oveq1d 7463	. . . . . . . . . . . . 13 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (((𝑚 − 1) + 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
157		subcl 11535	. . . . . . . . . . . . . . 15 ⊢ ((𝑚 ∈ ℂ ∧ 1 ∈ ℂ) → (𝑚 − 1) ∈ ℂ)
158	152, 153, 157	sylancl 585	. . . . . . . . . . . . . 14 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (𝑚 − 1) ∈ ℂ)
159	109	ad2antrr 725	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))) ∈ ℕ₀)
160	159	nn0cnd 12615	. . . . . . . . . . . . . 14 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))) ∈ ℂ)
161	158, 154, 160	adddird 11315	. . . . . . . . . . . . 13 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (((𝑚 − 1) + 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (1 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
162	160	mullidd 11308	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (1 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))
163		exmidne 2956	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ ((𝑔‘(𝑚 + 1)) = 1 ∨ (𝑔‘(𝑚 + 1)) ≠ 1)
164		orcom 869	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝑔‘(𝑚 + 1)) = 1 ∨ (𝑔‘(𝑚 + 1)) ≠ 1) ↔ ((𝑔‘(𝑚 + 1)) ≠ 1 ∨ (𝑔‘(𝑚 + 1)) = 1))
165	163, 164	mpbi 230	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝑔‘(𝑚 + 1)) ≠ 1 ∨ (𝑔‘(𝑚 + 1)) = 1)
166	165	biantru 529	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((𝑔‘1) = (𝑚 + 1) ↔ ((𝑔‘1) = (𝑚 + 1) ∧ ((𝑔‘(𝑚 + 1)) ≠ 1 ∨ (𝑔‘(𝑚 + 1)) = 1)))
167		andi 1008	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑔‘1) = (𝑚 + 1) ∧ ((𝑔‘(𝑚 + 1)) ≠ 1 ∨ (𝑔‘(𝑚 + 1)) = 1)) ↔ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∨ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)))
168	166, 167	bitri 275	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((𝑔‘1) = (𝑚 + 1) ↔ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∨ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)))
169	168	rabbii 3449	. . . . . . . . . . . . . . . . . . 19 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} = {𝑔 ∈ 𝐴 ∣ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∨ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))}
170		unrab 4334	. . . . . . . . . . . . . . . . . . 19 ⊢ ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∪ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}) = {𝑔 ∈ 𝐴 ∣ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∨ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))}
171	169, 170	eqtr4i 2771	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)} = ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∪ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)})
172	171	fveq2i 6923	. . . . . . . . . . . . . . . . 17 ⊢ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = (♯‘({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∪ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}))
173		ssrab2 4103	. . . . . . . . . . . . . . . . . . 19 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ⊆ 𝐴
174		ssfi 9240	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝐴 ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ⊆ 𝐴) → {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∈ Fin)
175	130, 173, 174	mp2an 691	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∈ Fin
176		ssrab2 4103	. . . . . . . . . . . . . . . . . . 19 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} ⊆ 𝐴
177		ssfi 9240	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝐴 ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} ⊆ 𝐴) → {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} ∈ Fin)
178	130, 176, 177	mp2an 691	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} ∈ Fin
179		inrab 4335	. . . . . . . . . . . . . . . . . . 19 ⊢ ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∩ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}) = {𝑔 ∈ 𝐴 ∣ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))}
180		simpr 484	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1) → (𝑔‘(𝑚 + 1)) = 1)
181	180	necon3ai 2971	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ ((𝑔‘(𝑚 + 1)) ≠ 1 → ¬ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))
182	181	adantl 481	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) → ¬ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))
183		imnan 399	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) → ¬ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)) ↔ ¬ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)))
184	182, 183	mpbi 230	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ¬ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))
185	184	rgenw 3071	. . . . . . . . . . . . . . . . . . . 20 ⊢ ∀𝑔 ∈ 𝐴 ¬ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))
186		rabeq0 4411	. . . . . . . . . . . . . . . . . . . 20 ⊢ ({𝑔 ∈ 𝐴 ∣ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))} = ∅ ↔ ∀𝑔 ∈ 𝐴 ¬ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)))
187	185, 186	mpbir 231	. . . . . . . . . . . . . . . . . . 19 ⊢ {𝑔 ∈ 𝐴 ∣ (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ∧ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1))} = ∅
188	179, 187	eqtri 2768	. . . . . . . . . . . . . . . . . 18 ⊢ ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∩ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}) = ∅
189		hashun 14431	. . . . . . . . . . . . . . . . . 18 ⊢ (({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∈ Fin ∧ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} ∈ Fin ∧ ({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∩ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}) = ∅) → (♯‘({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∪ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)})) = ((♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)}) + (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)})))
190	175, 178, 188, 189	mp3an 1461	. . . . . . . . . . . . . . . . 17 ⊢ (♯‘({𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} ∪ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)})) = ((♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)}) + (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}))
191	172, 190	eqtri 2768	. . . . . . . . . . . . . . . 16 ⊢ (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = ((♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)}) + (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}))
192		simpll 766	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → 𝑁 ∈ ℕ)
193		nnne0 12327	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑚 ∈ ℕ → 𝑚 ≠ 0)
194		0p1e1 12415	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ (0 + 1) = 1
195	194	eqeq2i 2753	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ ((𝑚 + 1) = (0 + 1) ↔ (𝑚 + 1) = 1)
196		0cn 11282	. . . . . . . . . . . . . . . . . . . . . . . . . 26 ⊢ 0 ∈ ℂ
197		addcan2 11475	. . . . . . . . . . . . . . . . . . . . . . . . . 26 ⊢ ((𝑚 ∈ ℂ ∧ 0 ∈ ℂ ∧ 1 ∈ ℂ) → ((𝑚 + 1) = (0 + 1) ↔ 𝑚 = 0))
198	196, 153, 197	mp3an23 1453	. . . . . . . . . . . . . . . . . . . . . . . . 25 ⊢ (𝑚 ∈ ℂ → ((𝑚 + 1) = (0 + 1) ↔ 𝑚 = 0))
199	151, 198	syl 17	. . . . . . . . . . . . . . . . . . . . . . . 24 ⊢ (𝑚 ∈ ℕ → ((𝑚 + 1) = (0 + 1) ↔ 𝑚 = 0))
200	195, 199	bitr3id 285	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑚 ∈ ℕ → ((𝑚 + 1) = 1 ↔ 𝑚 = 0))
201	200	necon3bbid 2984	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑚 ∈ ℕ → (¬ (𝑚 + 1) = 1 ↔ 𝑚 ≠ 0))
202	193, 201	mpbird 257	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑚 ∈ ℕ → ¬ (𝑚 + 1) = 1)
203	202	ad2antlr 726	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ¬ (𝑚 + 1) = 1)
204	14	adantr 480	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → (𝑁 + 1) ∈ (ℤ_≥‘1))
205		elfzp12 13663	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ ((𝑁 + 1) ∈ (ℤ_≥‘1) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) ↔ ((𝑚 + 1) = 1 ∨ (𝑚 + 1) ∈ ((1 + 1)...(𝑁 + 1)))))
206	204, 205	syl 17	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) ↔ ((𝑚 + 1) = 1 ∨ (𝑚 + 1) ∈ ((1 + 1)...(𝑁 + 1)))))
207	206	biimpa 476	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((𝑚 + 1) = 1 ∨ (𝑚 + 1) ∈ ((1 + 1)...(𝑁 + 1))))
208	207	ord 863	. . . . . . . . . . . . . . . . . . . 20 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (¬ (𝑚 + 1) = 1 → (𝑚 + 1) ∈ ((1 + 1)...(𝑁 + 1))))
209	203, 208	mpd 15	. . . . . . . . . . . . . . . . . . 19 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (𝑚 + 1) ∈ ((1 + 1)...(𝑁 + 1)))
210		df-2 12356	. . . . . . . . . . . . . . . . . . . 20 ⊢ 2 = (1 + 1)
211	210	oveq1i 7458	. . . . . . . . . . . . . . . . . . 19 ⊢ (2...(𝑁 + 1)) = ((1 + 1)...(𝑁 + 1))
212	209, 211	eleqtrrdi 2855	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (𝑚 + 1) ∈ (2...(𝑁 + 1)))
213		ovex 7481	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑚 + 1) ∈ V
214		eqid 2740	. . . . . . . . . . . . . . . . . 18 ⊢ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) = ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})
215		fveq1 6919	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑔 = ℎ → (𝑔‘1) = (ℎ‘1))
216	215	eqeq1d 2742	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = ℎ → ((𝑔‘1) = (𝑚 + 1) ↔ (ℎ‘1) = (𝑚 + 1)))
217		fveq1 6919	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑔 = ℎ → (𝑔‘(𝑚 + 1)) = (ℎ‘(𝑚 + 1)))
218	217	neeq1d 3006	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = ℎ → ((𝑔‘(𝑚 + 1)) ≠ 1 ↔ (ℎ‘(𝑚 + 1)) ≠ 1))
219	216, 218	anbi12d 631	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑔 = ℎ → (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1) ↔ ((ℎ‘1) = (𝑚 + 1) ∧ (ℎ‘(𝑚 + 1)) ≠ 1)))
220	219	cbvrabv 3454	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)} = {ℎ ∈ 𝐴 ∣ ((ℎ‘1) = (𝑚 + 1) ∧ (ℎ‘(𝑚 + 1)) ≠ 1)}
221		eqid 2740	. . . . . . . . . . . . . . . . . 18 ⊢ (( I ↾ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})) ∪ {⟨1, (𝑚 + 1)⟩, ⟨(𝑚 + 1), 1⟩}) = (( I ↾ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})) ∪ {⟨1, (𝑚 + 1)⟩, ⟨(𝑚 + 1), 1⟩})
222		f1oeq1 6850	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = 𝑓 → (𝑔:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1)) ↔ 𝑓:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1))))
223		fveq2 6920	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑧 = 𝑦 → (𝑔‘𝑧) = (𝑔‘𝑦))
224		id 22	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑧 = 𝑦 → 𝑧 = 𝑦)
225	223, 224	neeq12d 3008	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑧 = 𝑦 → ((𝑔‘𝑧) ≠ 𝑧 ↔ (𝑔‘𝑦) ≠ 𝑦))
226	225	cbvralvw 3243	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (∀𝑧 ∈ (2...(𝑁 + 1))(𝑔‘𝑧) ≠ 𝑧 ↔ ∀𝑦 ∈ (2...(𝑁 + 1))(𝑔‘𝑦) ≠ 𝑦)
227		fveq1 6919	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑔 = 𝑓 → (𝑔‘𝑦) = (𝑓‘𝑦))
228	227	neeq1d 3006	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑔 = 𝑓 → ((𝑔‘𝑦) ≠ 𝑦 ↔ (𝑓‘𝑦) ≠ 𝑦))
229	228	ralbidv 3184	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑔 = 𝑓 → (∀𝑦 ∈ (2...(𝑁 + 1))(𝑔‘𝑦) ≠ 𝑦 ↔ ∀𝑦 ∈ (2...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦))
230	226, 229	bitrid 283	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = 𝑓 → (∀𝑧 ∈ (2...(𝑁 + 1))(𝑔‘𝑧) ≠ 𝑧 ↔ ∀𝑦 ∈ (2...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦))
231	222, 230	anbi12d 631	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑔 = 𝑓 → ((𝑔:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1)) ∧ ∀𝑧 ∈ (2...(𝑁 + 1))(𝑔‘𝑧) ≠ 𝑧) ↔ (𝑓:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1)) ∧ ∀𝑦 ∈ (2...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)))
232	231	cbvabv 2815	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∣ (𝑔:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1)) ∧ ∀𝑧 ∈ (2...(𝑁 + 1))(𝑔‘𝑧) ≠ 𝑧)} = {𝑓 ∣ (𝑓:(2...(𝑁 + 1))–1-1-onto→(2...(𝑁 + 1)) ∧ ∀𝑦 ∈ (2...(𝑁 + 1))(𝑓‘𝑦) ≠ 𝑦)}
233	3, 4, 10, 192, 212, 213, 214, 220, 221, 232	subfacp1lem5 35152	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)}) = (𝑆‘𝑁))
234	217	eqeq1d 2742	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = ℎ → ((𝑔‘(𝑚 + 1)) = 1 ↔ (ℎ‘(𝑚 + 1)) = 1))
235	216, 234	anbi12d 631	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑔 = ℎ → (((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1) ↔ ((ℎ‘1) = (𝑚 + 1) ∧ (ℎ‘(𝑚 + 1)) = 1)))
236	235	cbvrabv 3454	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)} = {ℎ ∈ 𝐴 ∣ ((ℎ‘1) = (𝑚 + 1) ∧ (ℎ‘(𝑚 + 1)) = 1)}
237		f1oeq1 6850	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = 𝑓 → (𝑔:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) ↔ 𝑓:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})))
238	225	cbvralvw 3243	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (∀𝑧 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑧) ≠ 𝑧 ↔ ∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑦) ≠ 𝑦)
239	228	ralbidv 3184	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑔 = 𝑓 → (∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑦) ≠ 𝑦 ↔ ∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑓‘𝑦) ≠ 𝑦))
240	238, 239	bitrid 283	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝑔 = 𝑓 → (∀𝑧 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑧) ≠ 𝑧 ↔ ∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑓‘𝑦) ≠ 𝑦))
241	237, 240	anbi12d 631	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑔 = 𝑓 → ((𝑔:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) ∧ ∀𝑧 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑧) ≠ 𝑧) ↔ (𝑓:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) ∧ ∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑓‘𝑦) ≠ 𝑦)))
242	241	cbvabv 2815	. . . . . . . . . . . . . . . . . 18 ⊢ {𝑔 ∣ (𝑔:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) ∧ ∀𝑧 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑔‘𝑧) ≠ 𝑧)} = {𝑓 ∣ (𝑓:((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})–1-1-onto→((2...(𝑁 + 1)) ∖ {(𝑚 + 1)}) ∧ ∀𝑦 ∈ ((2...(𝑁 + 1)) ∖ {(𝑚 + 1)})(𝑓‘𝑦) ≠ 𝑦)}
243	3, 4, 10, 192, 212, 213, 214, 236, 242	subfacp1lem3 35150	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)}) = (𝑆‘(𝑁 − 1)))
244	233, 243	oveq12d 7466	. . . . . . . . . . . . . . . 16 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) ≠ 1)}) + (♯‘{𝑔 ∈ 𝐴 ∣ ((𝑔‘1) = (𝑚 + 1) ∧ (𝑔‘(𝑚 + 1)) = 1)})) = ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))
245	191, 244	eqtrid 2792	. . . . . . . . . . . . . . 15 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}) = ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))
246	162, 245	eqtr4d 2783	. . . . . . . . . . . . . 14 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (1 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}))
247	246	oveq2d 7464	. . . . . . . . . . . . 13 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (1 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) = (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
248	156, 161, 247	3eqtrd 2784	. . . . . . . . . . . 12 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})))
249	150, 248	eqeq12d 2756	. . . . . . . . . . 11 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) ↔ ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)})) = (((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) + (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) = (𝑚 + 1)}))))
250	120, 249	imbitrrid 246	. . . . . . . . . 10 ⊢ (((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) ∧ (𝑚 + 1) ∈ (1...(𝑁 + 1))) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
251	250	ex 412	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → ((♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
252	251	a2d 29	. . . . . . . 8 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → (((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
253	119, 252	syld 47	. . . . . . 7 ⊢ ((𝑁 ∈ ℕ ∧ 𝑚 ∈ ℕ) → ((𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
254	253	expcom 413	. . . . . 6 ⊢ (𝑚 ∈ ℕ → (𝑁 ∈ ℕ → ((𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))) → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
255	254	a2d 29	. . . . 5 ⊢ (𝑚 ∈ ℕ → ((𝑁 ∈ ℕ → (𝑚 ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...𝑚)}) = ((𝑚 − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))) → (𝑁 ∈ ℕ → ((𝑚 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑚 + 1))}) = (((𝑚 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))))
256	53, 63, 73, 83, 113, 255	nnind 12311	. . . 4 ⊢ ((𝑁 + 1) ∈ ℕ → (𝑁 ∈ ℕ → ((𝑁 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))))
257	1, 256	mpcom 38	. . 3 ⊢ (𝑁 ∈ ℕ → ((𝑁 + 1) ∈ (1...(𝑁 + 1)) → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1))))))
258	34, 257	mpd 15	. 2 ⊢ (𝑁 ∈ ℕ → (♯‘{𝑔 ∈ 𝐴 ∣ (𝑔‘1) ∈ (1...(𝑁 + 1))}) = (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
259		nncn 12301	. . . 4 ⊢ (𝑁 ∈ ℕ → 𝑁 ∈ ℂ)
260		pncan 11542	. . . 4 ⊢ ((𝑁 ∈ ℂ ∧ 1 ∈ ℂ) → ((𝑁 + 1) − 1) = 𝑁)
261	259, 153, 260	sylancl 585	. . 3 ⊢ (𝑁 ∈ ℕ → ((𝑁 + 1) − 1) = 𝑁)
262	261	oveq1d 7463	. 2 ⊢ (𝑁 ∈ ℕ → (((𝑁 + 1) − 1) · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))) = (𝑁 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))
263	32, 258, 262	3eqtrd 2784	1 ⊢ (𝑁 ∈ ℕ → (𝑆‘(𝑁 + 1)) = (𝑁 · ((𝑆‘𝑁) + (𝑆‘(𝑁 − 1)))))

Colors of variables: wff setvar class

Syntax hints: ¬ wn 3 → wi 4 ↔ wb 206 ∧ wa 395 ∨ wo 846 = wceq 1537 ∈ wcel 2108 {cab 2717 ≠ wne 2946 ∀wral 3067 {crab 3443 ∖ cdif 3973 ∪ cun 3974 ∩ cin 3975 ⊆ wss 3976 ∅c0 4352 {csn 4648 {cpr 4650 ⟨cop 4654 ↦ cmpt 5249 I cid 5592 ↾ cres 5702 ⟶wf 6569 –1-1-onto→wf1o 6572 ‘cfv 6573 (class class class)co 7448 Fincfn 9003 ℂcc 11182 0cc0 11184 1c1 11185 + caddc 11187 · cmul 11189 − cmin 11520 ℕcn 12293 2c2 12348 ℕ₀cn0 12553 ℤcz 12639 ℤ_≥cuz 12903 ...cfz 13567 ♯chash 14379

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1793 ax-4 1807 ax-5 1909 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2158 ax-12 2178 ax-ext 2711 ax-rep 5303 ax-sep 5317 ax-nul 5324 ax-pow 5383 ax-pr 5447 ax-un 7770 ax-cnex 11240 ax-resscn 11241 ax-1cn 11242 ax-icn 11243 ax-addcl 11244 ax-addrcl 11245 ax-mulcl 11246 ax-mulrcl 11247 ax-mulcom 11248 ax-addass 11249 ax-mulass 11250 ax-distr 11251 ax-i2m1 11252 ax-1ne0 11253 ax-1rid 11254 ax-rnegex 11255 ax-rrecex 11256 ax-cnre 11257 ax-pre-lttri 11258 ax-pre-lttrn 11259 ax-pre-ltadd 11260 ax-pre-mulgt0 11261

This theorem depends on definitions: df-bi 207 df-an 396 df-or 847 df-3or 1088 df-3an 1089 df-tru 1540 df-fal 1550 df-ex 1778 df-nf 1782 df-sb 2065 df-mo 2543 df-eu 2572 df-clab 2718 df-cleq 2732 df-clel 2819 df-nfc 2895 df-ne 2947 df-nel 3053 df-ral 3068 df-rex 3077 df-reu 3389 df-rab 3444 df-v 3490 df-sbc 3805 df-csb 3922 df-dif 3979 df-un 3981 df-in 3983 df-ss 3993 df-pss 3996 df-nul 4353 df-if 4549 df-pw 4624 df-sn 4649 df-pr 4651 df-op 4655 df-uni 4932 df-int 4971 df-iun 5017 df-br 5167 df-opab 5229 df-mpt 5250 df-tr 5284 df-id 5593 df-eprel 5599 df-po 5607 df-so 5608 df-fr 5652 df-we 5654 df-xp 5706 df-rel 5707 df-cnv 5708 df-co 5709 df-dm 5710 df-rn 5711 df-res 5712 df-ima 5713 df-pred 6332 df-ord 6398 df-on 6399 df-lim 6400 df-suc 6401 df-iota 6525 df-fun 6575 df-fn 6576 df-f 6577 df-f1 6578 df-fo 6579 df-f1o 6580 df-fv 6581 df-riota 7404 df-ov 7451 df-oprab 7452 df-mpo 7453 df-om 7904 df-1st 8030 df-2nd 8031 df-frecs 8322 df-wrecs 8353 df-recs 8427 df-rdg 8466 df-1o 8522 df-2o 8523 df-oadd 8526 df-er 8763 df-map 8886 df-pm 8887 df-en 9004 df-dom 9005 df-sdom 9006 df-fin 9007 df-dju 9970 df-card 10008 df-pnf 11326 df-mnf 11327 df-xr 11328 df-ltxr 11329 df-le 11330 df-sub 11522 df-neg 11523 df-nn 12294 df-2 12356 df-n0 12554 df-xnn0 12626 df-z 12640 df-uz 12904 df-fz 13568 df-hash 14380

This theorem is referenced by: subfacp1 35154

W3C validator