Theorem volfiniun 25508

Description: The volume of a disjoint finite union of measurable sets is the sum of the measures. (Contributed by Mario Carneiro, 25-Jun-2014.) (Revised by Mario Carneiro, 11-Dec-2016.)

Assertion

Ref	Expression
volfiniun	⊢ ((𝐴 ∈ Fin ∧ ∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝐴 𝐵) → (vol‘∪ 𝑘 ∈ 𝐴 𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵))

Distinct variable group:   𝐴,𝑘

Allowed substitution hint:   𝐵(𝑘)

Proof of Theorem volfiniun

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

Step	Hyp	Ref	Expression
1		raleq 3294	. . . . 5 ⊢ (𝑤 = ∅ → (∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ ∀𝑘 ∈ ∅ (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)))
2		disjeq1 5073	. . . . 5 ⊢ (𝑤 = ∅ → (Disj 𝑘 ∈ 𝑤 𝐵 ↔ Disj 𝑘 ∈ ∅ 𝐵))
3	1, 2	anbi12d 633	. . . 4 ⊢ (𝑤 = ∅ → ((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) ↔ (∀𝑘 ∈ ∅ (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ ∅ 𝐵)))
4		iuneq1 4964	. . . . . 6 ⊢ (𝑤 = ∅ → ∪ 𝑘 ∈ 𝑤 𝐵 = ∪ 𝑘 ∈ ∅ 𝐵)
5	4	fveq2d 6839	. . . . 5 ⊢ (𝑤 = ∅ → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = (vol‘∪ 𝑘 ∈ ∅ 𝐵))
6		sumeq1 15616	. . . . 5 ⊢ (𝑤 = ∅ → Σ𝑘 ∈ 𝑤 (vol‘𝐵) = Σ𝑘 ∈ ∅ (vol‘𝐵))
7	5, 6	eqeq12d 2753	. . . 4 ⊢ (𝑤 = ∅ → ((vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵) ↔ (vol‘∪ 𝑘 ∈ ∅ 𝐵) = Σ𝑘 ∈ ∅ (vol‘𝐵)))
8	3, 7	imbi12d 344	. . 3 ⊢ (𝑤 = ∅ → (((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵)) ↔ ((∀𝑘 ∈ ∅ (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ ∅ 𝐵) → (vol‘∪ 𝑘 ∈ ∅ 𝐵) = Σ𝑘 ∈ ∅ (vol‘𝐵))))
9		raleq 3294	. . . . 5 ⊢ (𝑤 = 𝑦 → (∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ ∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)))
10		disjeq1 5073	. . . . 5 ⊢ (𝑤 = 𝑦 → (Disj 𝑘 ∈ 𝑤 𝐵 ↔ Disj 𝑘 ∈ 𝑦 𝐵))
11	9, 10	anbi12d 633	. . . 4 ⊢ (𝑤 = 𝑦 → ((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) ↔ (∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑦 𝐵)))
12		iuneq1 4964	. . . . . 6 ⊢ (𝑤 = 𝑦 → ∪ 𝑘 ∈ 𝑤 𝐵 = ∪ 𝑘 ∈ 𝑦 𝐵)
13	12	fveq2d 6839	. . . . 5 ⊢ (𝑤 = 𝑦 → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = (vol‘∪ 𝑘 ∈ 𝑦 𝐵))
14		sumeq1 15616	. . . . 5 ⊢ (𝑤 = 𝑦 → Σ𝑘 ∈ 𝑤 (vol‘𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵))
15	13, 14	eqeq12d 2753	. . . 4 ⊢ (𝑤 = 𝑦 → ((vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵) ↔ (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵)))
16	11, 15	imbi12d 344	. . 3 ⊢ (𝑤 = 𝑦 → (((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵)) ↔ ((∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑦 𝐵) → (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵))))
17		raleq 3294	. . . . 5 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → (∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ ∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)))
18		disjeq1 5073	. . . . 5 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → (Disj 𝑘 ∈ 𝑤 𝐵 ↔ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵))
19	17, 18	anbi12d 633	. . . 4 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → ((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) ↔ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)))
20		iuneq1 4964	. . . . . 6 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → ∪ 𝑘 ∈ 𝑤 𝐵 = ∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)
21	20	fveq2d 6839	. . . . 5 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵))
22		sumeq1 15616	. . . . 5 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → Σ𝑘 ∈ 𝑤 (vol‘𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵))
23	21, 22	eqeq12d 2753	. . . 4 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → ((vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵) ↔ (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵)))
24	19, 23	imbi12d 344	. . 3 ⊢ (𝑤 = (𝑦 ∪ {𝑧}) → (((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵)) ↔ ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵))))
25		raleq 3294	. . . . 5 ⊢ (𝑤 = 𝐴 → (∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ ∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)))
26		disjeq1 5073	. . . . 5 ⊢ (𝑤 = 𝐴 → (Disj 𝑘 ∈ 𝑤 𝐵 ↔ Disj 𝑘 ∈ 𝐴 𝐵))
27	25, 26	anbi12d 633	. . . 4 ⊢ (𝑤 = 𝐴 → ((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) ↔ (∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝐴 𝐵)))
28		iuneq1 4964	. . . . . 6 ⊢ (𝑤 = 𝐴 → ∪ 𝑘 ∈ 𝑤 𝐵 = ∪ 𝑘 ∈ 𝐴 𝐵)
29	28	fveq2d 6839	. . . . 5 ⊢ (𝑤 = 𝐴 → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = (vol‘∪ 𝑘 ∈ 𝐴 𝐵))
30		sumeq1 15616	. . . . 5 ⊢ (𝑤 = 𝐴 → Σ𝑘 ∈ 𝑤 (vol‘𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵))
31	29, 30	eqeq12d 2753	. . . 4 ⊢ (𝑤 = 𝐴 → ((vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵) ↔ (vol‘∪ 𝑘 ∈ 𝐴 𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵)))
32	27, 31	imbi12d 344	. . 3 ⊢ (𝑤 = 𝐴 → (((∀𝑘 ∈ 𝑤 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑤 𝐵) → (vol‘∪ 𝑘 ∈ 𝑤 𝐵) = Σ𝑘 ∈ 𝑤 (vol‘𝐵)) ↔ ((∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝐴 𝐵) → (vol‘∪ 𝑘 ∈ 𝐴 𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵))))
33		0mbl 25500	. . . . . . 7 ⊢ ∅ ∈ dom vol
34		mblvol 25491	. . . . . . 7 ⊢ (∅ ∈ dom vol → (vol‘∅) = (vol*‘∅))
35	33, 34	ax-mp 5	. . . . . 6 ⊢ (vol‘∅) = (vol*‘∅)
36		ovol0 25454	. . . . . 6 ⊢ (vol*‘∅) = 0
37	35, 36	eqtri 2760	. . . . 5 ⊢ (vol‘∅) = 0
38		0iun 5019	. . . . . 6 ⊢ ∪ 𝑘 ∈ ∅ 𝐵 = ∅
39	38	fveq2i 6838	. . . . 5 ⊢ (vol‘∪ 𝑘 ∈ ∅ 𝐵) = (vol‘∅)
40		sum0 15648	. . . . 5 ⊢ Σ𝑘 ∈ ∅ (vol‘𝐵) = 0
41	37, 39, 40	3eqtr4i 2770	. . . 4 ⊢ (vol‘∪ 𝑘 ∈ ∅ 𝐵) = Σ𝑘 ∈ ∅ (vol‘𝐵)
42	41	a1i 11	. . 3 ⊢ ((∀𝑘 ∈ ∅ (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ ∅ 𝐵) → (vol‘∪ 𝑘 ∈ ∅ 𝐵) = Σ𝑘 ∈ ∅ (vol‘𝐵))
43		ssun1 4131	. . . . . . 7 ⊢ 𝑦 ⊆ (𝑦 ∪ {𝑧})
44		ssralv 4003	. . . . . . 7 ⊢ (𝑦 ⊆ (𝑦 ∪ {𝑧}) → (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) → ∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)))
45	43, 44	ax-mp 5	. . . . . 6 ⊢ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) → ∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ))
46		disjss1 5072	. . . . . . 7 ⊢ (𝑦 ⊆ (𝑦 ∪ {𝑧}) → (Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 → Disj 𝑘 ∈ 𝑦 𝐵))
47	43, 46	ax-mp 5	. . . . . 6 ⊢ (Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 → Disj 𝑘 ∈ 𝑦 𝐵)
48	45, 47	anim12i 614	. . . . 5 ⊢ ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑦 𝐵))
49	48	imim1i 63	. . . 4 ⊢ (((∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑦 𝐵) → (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵)) → ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵)))
50		oveq1 7367	. . . . . . . 8 ⊢ ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) → ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)) = (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
51		iunxun 5050	. . . . . . . . . . . 12 ⊢ ∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵 = (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ∪ 𝑚 ∈ {𝑧}⦋𝑚 / 𝑘⦌𝐵)
52		vex 3445	. . . . . . . . . . . . . 14 ⊢ 𝑧 ∈ V
53		csbeq1 3853	. . . . . . . . . . . . . 14 ⊢ (𝑚 = 𝑧 → ⦋𝑚 / 𝑘⦌𝐵 = ⦋𝑧 / 𝑘⦌𝐵)
54	52, 53	iunxsn 5047	. . . . . . . . . . . . 13 ⊢ ∪ 𝑚 ∈ {𝑧}⦋𝑚 / 𝑘⦌𝐵 = ⦋𝑧 / 𝑘⦌𝐵
55	54	uneq2i 4118	. . . . . . . . . . . 12 ⊢ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ∪ 𝑚 ∈ {𝑧}⦋𝑚 / 𝑘⦌𝐵) = (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ⦋𝑧 / 𝑘⦌𝐵)
56	51, 55	eqtri 2760	. . . . . . . . . . 11 ⊢ ∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵 = (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ⦋𝑧 / 𝑘⦌𝐵)
57	56	fveq2i 6838	. . . . . . . . . 10 ⊢ (vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵) = (vol‘(∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ⦋𝑧 / 𝑘⦌𝐵))
58		nfcv 2899	. . . . . . . . . . . . 13 ⊢ Ⅎ𝑚𝐵
59		nfcsb1v 3874	. . . . . . . . . . . . 13 ⊢ Ⅎ𝑘⦋𝑚 / 𝑘⦌𝐵
60		csbeq1a 3864	. . . . . . . . . . . . 13 ⊢ (𝑘 = 𝑚 → 𝐵 = ⦋𝑚 / 𝑘⦌𝐵)
61	58, 59, 60	cbviun 4991	. . . . . . . . . . . 12 ⊢ ∪ 𝑘 ∈ 𝑦 𝐵 = ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵
62		simpll 767	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → 𝑦 ∈ Fin)
63		simprl 771	. . . . . . . . . . . . . . 15 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ))
64		simpl 482	. . . . . . . . . . . . . . . 16 ⊢ ((𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) → 𝐵 ∈ dom vol)
65	64	ralimi 3074	. . . . . . . . . . . . . . 15 ⊢ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) → ∀𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 ∈ dom vol)
66	63, 65	syl 17	. . . . . . . . . . . . . 14 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 ∈ dom vol)
67		ssralv 4003	. . . . . . . . . . . . . 14 ⊢ (𝑦 ⊆ (𝑦 ∪ {𝑧}) → (∀𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 ∈ dom vol → ∀𝑘 ∈ 𝑦 𝐵 ∈ dom vol))
68	43, 66, 67	mpsyl 68	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑘 ∈ 𝑦 𝐵 ∈ dom vol)
69		finiunmbl 25505	. . . . . . . . . . . . 13 ⊢ ((𝑦 ∈ Fin ∧ ∀𝑘 ∈ 𝑦 𝐵 ∈ dom vol) → ∪ 𝑘 ∈ 𝑦 𝐵 ∈ dom vol)
70	62, 68, 69	syl2anc 585	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∪ 𝑘 ∈ 𝑦 𝐵 ∈ dom vol)
71	61, 70	eqeltrrid 2842	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol)
72		ssun2 4132	. . . . . . . . . . . . . 14 ⊢ {𝑧} ⊆ (𝑦 ∪ {𝑧})
73		vsnid 4621	. . . . . . . . . . . . . 14 ⊢ 𝑧 ∈ {𝑧}
74	72, 73	sselii 3931	. . . . . . . . . . . . 13 ⊢ 𝑧 ∈ (𝑦 ∪ {𝑧})
75		nfcsb1v 3874	. . . . . . . . . . . . . . . 16 ⊢ Ⅎ𝑘⦋𝑧 / 𝑘⦌𝐵
76	75	nfel1 2916	. . . . . . . . . . . . . . 15 ⊢ Ⅎ𝑘⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol
77		nfcv 2899	. . . . . . . . . . . . . . . . 17 ⊢ Ⅎ𝑘vol
78	77, 75	nffv 6845	. . . . . . . . . . . . . . . 16 ⊢ Ⅎ𝑘(vol‘⦋𝑧 / 𝑘⦌𝐵)
79	78	nfel1 2916	. . . . . . . . . . . . . . 15 ⊢ Ⅎ𝑘(vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ
80	76, 79	nfan 1901	. . . . . . . . . . . . . 14 ⊢ Ⅎ𝑘(⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ)
81		csbeq1a 3864	. . . . . . . . . . . . . . . 16 ⊢ (𝑘 = 𝑧 → 𝐵 = ⦋𝑧 / 𝑘⦌𝐵)
82	81	eleq1d 2822	. . . . . . . . . . . . . . 15 ⊢ (𝑘 = 𝑧 → (𝐵 ∈ dom vol ↔ ⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol))
83	81	fveq2d 6839	. . . . . . . . . . . . . . . 16 ⊢ (𝑘 = 𝑧 → (vol‘𝐵) = (vol‘⦋𝑧 / 𝑘⦌𝐵))
84	83	eleq1d 2822	. . . . . . . . . . . . . . 15 ⊢ (𝑘 = 𝑧 → ((vol‘𝐵) ∈ ℝ ↔ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ))
85	82, 84	anbi12d 633	. . . . . . . . . . . . . 14 ⊢ (𝑘 = 𝑧 → ((𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ (⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ)))
86	80, 85	rspc 3565	. . . . . . . . . . . . 13 ⊢ (𝑧 ∈ (𝑦 ∪ {𝑧}) → (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) → (⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ)))
87	74, 63, 86	mpsyl 68	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ))
88	87	simpld 494	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol)
89		simplr 769	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ¬ 𝑧 ∈ 𝑦)
90		elin 3918	. . . . . . . . . . . . . 14 ⊢ (𝑤 ∈ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∩ ⦋𝑧 / 𝑘⦌𝐵) ↔ (𝑤 ∈ ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵))
91		eliun 4951	. . . . . . . . . . . . . . . 16 ⊢ (𝑤 ∈ ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ↔ ∃𝑚 ∈ 𝑦 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵)
92		simplrr 778	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)
93		nfcv 2899	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ Ⅎ𝑛𝐵
94		nfcsb1v 3874	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ Ⅎ𝑘⦋𝑛 / 𝑘⦌𝐵
95		csbeq1a 3864	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑘 = 𝑛 → 𝐵 = ⦋𝑛 / 𝑘⦌𝐵)
96	93, 94, 95	cbvdisj 5076	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 ↔ Disj 𝑛 ∈ (𝑦 ∪ {𝑧})⦋𝑛 / 𝑘⦌𝐵)
97	92, 96	sylib 218	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → Disj 𝑛 ∈ (𝑦 ∪ {𝑧})⦋𝑛 / 𝑘⦌𝐵)
98		simpr1 1196	. . . . . . . . . . . . . . . . . . . . 21 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑚 ∈ 𝑦)
99		elun1 4135	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑚 ∈ 𝑦 → 𝑚 ∈ (𝑦 ∪ {𝑧}))
100	98, 99	syl 17	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑚 ∈ (𝑦 ∪ {𝑧}))
101	74	a1i 11	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑧 ∈ (𝑦 ∪ {𝑧}))
102		simpr2 1197	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵)
103		simpr3 1198	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)
104		csbeq1 3853	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑛 = 𝑚 → ⦋𝑛 / 𝑘⦌𝐵 = ⦋𝑚 / 𝑘⦌𝐵)
105		csbeq1 3853	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑛 = 𝑧 → ⦋𝑛 / 𝑘⦌𝐵 = ⦋𝑧 / 𝑘⦌𝐵)
106	104, 105	disji 5084	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((Disj 𝑛 ∈ (𝑦 ∪ {𝑧})⦋𝑛 / 𝑘⦌𝐵 ∧ (𝑚 ∈ (𝑦 ∪ {𝑧}) ∧ 𝑧 ∈ (𝑦 ∪ {𝑧})) ∧ (𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑚 = 𝑧)
107	97, 100, 101, 102, 103, 106	syl122anc 1382	. . . . . . . . . . . . . . . . . . 19 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑚 = 𝑧)
108	107, 98	eqeltrrd 2838	. . . . . . . . . . . . . . . . . 18 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ (𝑚 ∈ 𝑦 ∧ 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵)) → 𝑧 ∈ 𝑦)
109	108	3exp2 1356	. . . . . . . . . . . . . . . . 17 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑚 ∈ 𝑦 → (𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 → (𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵 → 𝑧 ∈ 𝑦))))
110	109	rexlimdv 3136	. . . . . . . . . . . . . . . 16 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (∃𝑚 ∈ 𝑦 𝑤 ∈ ⦋𝑚 / 𝑘⦌𝐵 → (𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵 → 𝑧 ∈ 𝑦)))
111	91, 110	biimtrid 242	. . . . . . . . . . . . . . 15 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑤 ∈ ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 → (𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵 → 𝑧 ∈ 𝑦)))
112	111	impd 410	. . . . . . . . . . . . . 14 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ((𝑤 ∈ ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∧ 𝑤 ∈ ⦋𝑧 / 𝑘⦌𝐵) → 𝑧 ∈ 𝑦))
113	90, 112	biimtrid 242	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑤 ∈ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∩ ⦋𝑧 / 𝑘⦌𝐵) → 𝑧 ∈ 𝑦))
114	89, 113	mtod 198	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ¬ 𝑤 ∈ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∩ ⦋𝑧 / 𝑘⦌𝐵))
115	114	eq0rdv 4360	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∩ ⦋𝑧 / 𝑘⦌𝐵) = ∅)
116		mblvol 25491	. . . . . . . . . . . . 13 ⊢ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol → (vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) = (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵))
117	71, 116	syl 17	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) = (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵))
118		nfv 1916	. . . . . . . . . . . . . . . . . . . . 21 ⊢ Ⅎ𝑚(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ)
119	59	nfel1 2916	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ Ⅎ𝑘⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol
120	77, 59	nffv 6845	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ Ⅎ𝑘(vol‘⦋𝑚 / 𝑘⦌𝐵)
121	120	nfel1 2916	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ Ⅎ𝑘(vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ
122	119, 121	nfan 1901	. . . . . . . . . . . . . . . . . . . . 21 ⊢ Ⅎ𝑘(⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
123	60	eleq1d 2822	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑘 = 𝑚 → (𝐵 ∈ dom vol ↔ ⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol))
124	60	fveq2d 6839	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (𝑘 = 𝑚 → (vol‘𝐵) = (vol‘⦋𝑚 / 𝑘⦌𝐵))
125	124	eleq1d 2822	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ (𝑘 = 𝑚 → ((vol‘𝐵) ∈ ℝ ↔ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
126	123, 125	anbi12d 633	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝑘 = 𝑚 → ((𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ (⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)))
127	118, 122, 126	cbvralw 3279	. . . . . . . . . . . . . . . . . . . 20 ⊢ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ↔ ∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
128	63, 127	sylib 218	. . . . . . . . . . . . . . . . . . 19 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
129	128	r19.21bi 3229	. . . . . . . . . . . . . . . . . 18 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → (⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
130	129	simpld 494	. . . . . . . . . . . . . . . . 17 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → ⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol)
131		mblss 25492	. . . . . . . . . . . . . . . . 17 ⊢ (⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol → ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
132	130, 131	syl 17	. . . . . . . . . . . . . . . 16 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
133	99, 132	sylan2 594	. . . . . . . . . . . . . . 15 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ 𝑦) → ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
134	133	ralrimiva 3129	. . . . . . . . . . . . . 14 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
135		iunss 5001	. . . . . . . . . . . . . 14 ⊢ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ↔ ∀𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
136	134, 135	sylibr 234	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
137		mblvol 25491	. . . . . . . . . . . . . . . . . 18 ⊢ (⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol → (vol‘⦋𝑚 / 𝑘⦌𝐵) = (vol*‘⦋𝑚 / 𝑘⦌𝐵))
138	137	eleq1d 2822	. . . . . . . . . . . . . . . . 17 ⊢ (⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol → ((vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ ↔ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
139	138	biimpa 476	. . . . . . . . . . . . . . . 16 ⊢ ((⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ) → (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
140	129, 139	syl 17	. . . . . . . . . . . . . . 15 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
141	99, 140	sylan2 594	. . . . . . . . . . . . . 14 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ 𝑦) → (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
142	62, 141	fsumrecl 15661	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → Σ𝑚 ∈ 𝑦 (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
143	131	adantr 480	. . . . . . . . . . . . . . . . . 18 ⊢ ((⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ) → ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ)
144	143, 139	jca 511	. . . . . . . . . . . . . . . . 17 ⊢ ((⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ) → (⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
145	144	ralimi 3074	. . . . . . . . . . . . . . . 16 ⊢ (∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ) → ∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
146	128, 145	syl 17	. . . . . . . . . . . . . . 15 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
147		ssralv 4003	. . . . . . . . . . . . . . 15 ⊢ (𝑦 ⊆ (𝑦 ∪ {𝑧}) → (∀𝑚 ∈ (𝑦 ∪ {𝑧})(⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ) → ∀𝑚 ∈ 𝑦 (⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)))
148	43, 146, 147	mpsyl 68	. . . . . . . . . . . . . 14 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ∀𝑚 ∈ 𝑦 (⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ))
149		ovolfiniun 25462	. . . . . . . . . . . . . 14 ⊢ ((𝑦 ∈ Fin ∧ ∀𝑚 ∈ 𝑦 (⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)) → (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ≤ Σ𝑚 ∈ 𝑦 (vol*‘⦋𝑚 / 𝑘⦌𝐵))
150	62, 148, 149	syl2anc 585	. . . . . . . . . . . . 13 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ≤ Σ𝑚 ∈ 𝑦 (vol*‘⦋𝑚 / 𝑘⦌𝐵))
151		ovollecl 25444	. . . . . . . . . . . . 13 ⊢ ((∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ⊆ ℝ ∧ Σ𝑚 ∈ 𝑦 (vol*‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ ∧ (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ≤ Σ𝑚 ∈ 𝑦 (vol*‘⦋𝑚 / 𝑘⦌𝐵)) → (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
152	136, 142, 150, 151	syl3anc 1374	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol*‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
153	117, 152	eqeltrd 2837	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
154	87	simprd 495	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ)
155		volun 25506	. . . . . . . . . . 11 ⊢ (((∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∈ dom vol ∧ ⦋𝑧 / 𝑘⦌𝐵 ∈ dom vol ∧ (∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∩ ⦋𝑧 / 𝑘⦌𝐵) = ∅) ∧ ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℝ)) → (vol‘(∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ⦋𝑧 / 𝑘⦌𝐵)) = ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
156	71, 88, 115, 153, 154, 155	syl32anc 1381	. . . . . . . . . 10 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘(∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵 ∪ ⦋𝑧 / 𝑘⦌𝐵)) = ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
157	57, 156	eqtrid 2784	. . . . . . . . 9 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵) = ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
158		disjsn 4669	. . . . . . . . . . . 12 ⊢ ((𝑦 ∩ {𝑧}) = ∅ ↔ ¬ 𝑧 ∈ 𝑦)
159	89, 158	sylibr 234	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑦 ∩ {𝑧}) = ∅)
160		eqidd 2738	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑦 ∪ {𝑧}) = (𝑦 ∪ {𝑧}))
161		snfi 8984	. . . . . . . . . . . 12 ⊢ {𝑧} ∈ Fin
162		unfi 9099	. . . . . . . . . . . 12 ⊢ ((𝑦 ∈ Fin ∧ {𝑧} ∈ Fin) → (𝑦 ∪ {𝑧}) ∈ Fin)
163	62, 161, 162	sylancl 587	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (𝑦 ∪ {𝑧}) ∈ Fin)
164	129	simprd 495	. . . . . . . . . . . 12 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℝ)
165	164	recnd 11164	. . . . . . . . . . 11 ⊢ ((((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) ∧ 𝑚 ∈ (𝑦 ∪ {𝑧})) → (vol‘⦋𝑚 / 𝑘⦌𝐵) ∈ ℂ)
166	159, 160, 163, 165	fsumsplit 15668	. . . . . . . . . 10 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵) = (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + Σ𝑚 ∈ {𝑧} (vol‘⦋𝑚 / 𝑘⦌𝐵)))
167	154	recnd 11164	. . . . . . . . . . . 12 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℂ)
168	53	fveq2d 6839	. . . . . . . . . . . . 13 ⊢ (𝑚 = 𝑧 → (vol‘⦋𝑚 / 𝑘⦌𝐵) = (vol‘⦋𝑧 / 𝑘⦌𝐵))
169	168	sumsn 15673	. . . . . . . . . . . 12 ⊢ ((𝑧 ∈ V ∧ (vol‘⦋𝑧 / 𝑘⦌𝐵) ∈ ℂ) → Σ𝑚 ∈ {𝑧} (vol‘⦋𝑚 / 𝑘⦌𝐵) = (vol‘⦋𝑧 / 𝑘⦌𝐵))
170	52, 167, 169	sylancr 588	. . . . . . . . . . 11 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → Σ𝑚 ∈ {𝑧} (vol‘⦋𝑚 / 𝑘⦌𝐵) = (vol‘⦋𝑧 / 𝑘⦌𝐵))
171	170	oveq2d 7376	. . . . . . . . . 10 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + Σ𝑚 ∈ {𝑧} (vol‘⦋𝑚 / 𝑘⦌𝐵)) = (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
172	166, 171	eqtrd 2772	. . . . . . . . 9 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵) = (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)))
173	157, 172	eqeq12d 2753	. . . . . . . 8 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ((vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵) ↔ ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵)) = (Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) + (vol‘⦋𝑧 / 𝑘⦌𝐵))))
174	50, 173	imbitrrid 246	. . . . . . 7 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ((vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵) → (vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵)))
175	61	fveq2i 6838	. . . . . . . 8 ⊢ (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = (vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵)
176		nfcv 2899	. . . . . . . . 9 ⊢ Ⅎ𝑚(vol‘𝐵)
177	124, 176, 120	cbvsum 15622	. . . . . . . 8 ⊢ Σ𝑘 ∈ 𝑦 (vol‘𝐵) = Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵)
178	175, 177	eqeq12i 2755	. . . . . . 7 ⊢ ((vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵) ↔ (vol‘∪ 𝑚 ∈ 𝑦 ⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ 𝑦 (vol‘⦋𝑚 / 𝑘⦌𝐵))
179	58, 59, 60	cbviun 4991	. . . . . . . . 9 ⊢ ∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵 = ∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵
180	179	fveq2i 6838	. . . . . . . 8 ⊢ (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = (vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵)
181	124, 176, 120	cbvsum 15622	. . . . . . . 8 ⊢ Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵) = Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵)
182	180, 181	eqeq12i 2755	. . . . . . 7 ⊢ ((vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵) ↔ (vol‘∪ 𝑚 ∈ (𝑦 ∪ {𝑧})⦋𝑚 / 𝑘⦌𝐵) = Σ𝑚 ∈ (𝑦 ∪ {𝑧})(vol‘⦋𝑚 / 𝑘⦌𝐵))
183	174, 178, 182	3imtr4g 296	. . . . . 6 ⊢ (((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) ∧ (∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵)) → ((vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵) → (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵)))
184	183	ex 412	. . . . 5 ⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → ((vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵) → (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵))))
185	184	a2d 29	. . . 4 ⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → (((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵)) → ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵))))
186	49, 185	syl5 34	. . 3 ⊢ ((𝑦 ∈ Fin ∧ ¬ 𝑧 ∈ 𝑦) → (((∀𝑘 ∈ 𝑦 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝑦 𝐵) → (vol‘∪ 𝑘 ∈ 𝑦 𝐵) = Σ𝑘 ∈ 𝑦 (vol‘𝐵)) → ((∀𝑘 ∈ (𝑦 ∪ {𝑧})(𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) → (vol‘∪ 𝑘 ∈ (𝑦 ∪ {𝑧})𝐵) = Σ𝑘 ∈ (𝑦 ∪ {𝑧})(vol‘𝐵))))
187	8, 16, 24, 32, 42, 186	findcard2s 9094	. 2 ⊢ (𝐴 ∈ Fin → ((∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝐴 𝐵) → (vol‘∪ 𝑘 ∈ 𝐴 𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵)))
188	187	3impib 1117	1 ⊢ ((𝐴 ∈ Fin ∧ ∀𝑘 ∈ 𝐴 (𝐵 ∈ dom vol ∧ (vol‘𝐵) ∈ ℝ) ∧ Disj 𝑘 ∈ 𝐴 𝐵) → (vol‘∪ 𝑘 ∈ 𝐴 𝐵) = Σ𝑘 ∈ 𝐴 (vol‘𝐵))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 395   ∧ w3a 1087   = wceq 1542   ∈ wcel 2114  ∀wral 3052  ∃wrex 3061  Vcvv 3441  ⦋csb 3850   ∪ cun 3900   ∩ cin 3901   ⊆ wss 3902  ∅c0 4286  {csn 4581  ∪ ciun 4947  Disj wdisj 5066   class class class wbr 5099  dom cdm 5625  ‘cfv 6493  (class class class)co 7360  Fincfn 8887  ℂcc 11028  ℝcr 11029  0cc0 11030   + caddc 11033   ≤ cle 11171  Σcsu 15613  vol*covol 25423  volcvol 25424

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-rep 5225  ax-sep 5242  ax-nul 5252  ax-pow 5311  ax-pr 5378  ax-un 7682  ax-inf2 9554  ax-cnex 11086  ax-resscn 11087  ax-1cn 11088  ax-icn 11089  ax-addcl 11090  ax-addrcl 11091  ax-mulcl 11092  ax-mulrcl 11093  ax-mulcom 11094  ax-addass 11095  ax-mulass 11096  ax-distr 11097  ax-i2m1 11098  ax-1ne0 11099  ax-1rid 11100  ax-rnegex 11101  ax-rrecex 11102  ax-cnre 11103  ax-pre-lttri 11104  ax-pre-lttrn 11105  ax-pre-ltadd 11106  ax-pre-mulgt0 11107  ax-pre-sup 11108

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 3062  df-rmo 3351  df-reu 3352  df-rab 3401  df-v 3443  df-sbc 3742  df-csb 3851  df-dif 3905  df-un 3907  df-in 3909  df-ss 3919  df-pss 3922  df-nul 4287  df-if 4481  df-pw 4557  df-sn 4582  df-pr 4584  df-op 4588  df-uni 4865  df-int 4904  df-iun 4949  df-disj 5067  df-br 5100  df-opab 5162  df-mpt 5181  df-tr 5207  df-id 5520  df-eprel 5525  df-po 5533  df-so 5534  df-fr 5578  df-se 5579  df-we 5580  df-xp 5631  df-rel 5632  df-cnv 5633  df-co 5634  df-dm 5635  df-rn 5636  df-res 5637  df-ima 5638  df-pred 6260  df-ord 6321  df-on 6322  df-lim 6323  df-suc 6324  df-iota 6449  df-fun 6495  df-fn 6496  df-f 6497  df-f1 6498  df-fo 6499  df-f1o 6500  df-fv 6501  df-isom 6502  df-riota 7317  df-ov 7363  df-oprab 7364  df-mpo 7365  df-of 7624  df-om 7811  df-1st 7935  df-2nd 7936  df-frecs 8225  df-wrecs 8256  df-recs 8305  df-rdg 8343  df-1o 8399  df-2o 8400  df-er 8637  df-map 8769  df-en 8888  df-dom 8889  df-sdom 8890  df-fin 8891  df-sup 9349  df-inf 9350  df-oi 9419  df-dju 9817  df-card 9855  df-pnf 11172  df-mnf 11173  df-xr 11174  df-ltxr 11175  df-le 11176  df-sub 11370  df-neg 11371  df-div 11799  df-nn 12150  df-2 12212  df-3 12213  df-n0 12406  df-z 12493  df-uz 12756  df-q 12866  df-rp 12910  df-xadd 13031  df-ioo 13269  df-ico 13271  df-icc 13272  df-fz 13428  df-fzo 13575  df-fl 13716  df-seq 13929  df-exp 13989  df-hash 14258  df-cj 15026  df-re 15027  df-im 15028  df-sqrt 15162  df-abs 15163  df-clim 15415  df-sum 15614  df-xmet 21306  df-met 21307  df-ovol 25425  df-vol 25426

This theorem is referenced by:  uniioovol  25540  uniioombllem4  25547  itg1addlem1  25653  volfiniune  34368