Theorem issgon 34579

Description: Property of being a sigma-algebra with a given base set, noting that the base set of a sigma-algebra is actually its union set. (Contributed by Thierry Arnoux, 24-Sep-2016.) (Revised by Thierry Arnoux, 23-Oct-2016.)

Assertion

Ref	Expression
issgon	⊢ (𝑆 ∈ (sigAlgebra‘𝑂) ↔ (𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆))

Proof of Theorem issgon

Dummy variables 𝑥 𝑜 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		fvssunirn 6916	. . . 4 ⊢ (sigAlgebra‘𝑂) ⊆ ∪ ran sigAlgebra
2	1	sseli 3934	. . 3 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑆 ∈ ∪ ran sigAlgebra)
3		elex 3478	. . . 4 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑆 ∈ V)
4		issiga 34568	. . . . 5 ⊢ (𝑆 ∈ V → (𝑆 ∈ (sigAlgebra‘𝑂) ↔ (𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))))
5		elpwuni 5073	. . . . . . . 8 ⊢ (𝑂 ∈ 𝑆 → (𝑆 ⊆ 𝒫 𝑂 ↔ ∪ 𝑆 = 𝑂))
6	5	biimpa 482	. . . . . . 7 ⊢ ((𝑂 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑂) → ∪ 𝑆 = 𝑂)
7		ancom 466	. . . . . . 7 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ 𝑂 ∈ 𝑆) ↔ (𝑂 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑂))
8		eqcom 2772	. . . . . . 7 ⊢ (𝑂 = ∪ 𝑆 ↔ ∪ 𝑆 = 𝑂)
9	6, 7, 8	3imtr4i 295	. . . . . 6 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ 𝑂 ∈ 𝑆) → 𝑂 = ∪ 𝑆)
10	9	3ad2antr1 1207	. . . . 5 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → 𝑂 = ∪ 𝑆)
11	4, 10	biimtrdi 256	. . . 4 ⊢ (𝑆 ∈ V → (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑂 = ∪ 𝑆))
12	3, 11	mpcom 39	. . 3 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑂 = ∪ 𝑆)
13	2, 12	jca 521	. 2 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → (𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆))
14		elex 3478	. . . . 5 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → 𝑆 ∈ V)
15		isrnsiga 34569	. . . . . . . 8 ⊢ (𝑆 ∈ ∪ ran sigAlgebra ↔ (𝑆 ∈ V ∧ ∃𝑜(𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))))
16	15	simprbi 503	. . . . . . 7 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → ∃𝑜(𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
17		elpwuni 5073	. . . . . . . . . . . . 13 ⊢ (𝑜 ∈ 𝑆 → (𝑆 ⊆ 𝒫 𝑜 ↔ ∪ 𝑆 = 𝑜))
18	17	biimpa 482	. . . . . . . . . . . 12 ⊢ ((𝑜 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑜) → ∪ 𝑆 = 𝑜)
19		ancom 466	. . . . . . . . . . . 12 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ 𝑜 ∈ 𝑆) ↔ (𝑜 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑜))
20		eqcom 2772	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 ↔ ∪ 𝑆 = 𝑜)
21	18, 19, 20	3imtr4i 295	. . . . . . . . . . 11 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ 𝑜 ∈ 𝑆) → 𝑜 = ∪ 𝑆)
22	21	3ad2antr1 1207	. . . . . . . . . 10 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → 𝑜 = ∪ 𝑆)
23		pweq 4578	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → 𝒫 𝑜 = 𝒫 ∪ 𝑆)
24	23	sseq2d 3970	. . . . . . . . . . 11 ⊢ (𝑜 = ∪ 𝑆 → (𝑆 ⊆ 𝒫 𝑜 ↔ 𝑆 ⊆ 𝒫 ∪ 𝑆))
25		eleq1 2853	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → (𝑜 ∈ 𝑆 ↔ ∪ 𝑆 ∈ 𝑆))
26		difeq1 4074	. . . . . . . . . . . . . 14 ⊢ (𝑜 = ∪ 𝑆 → (𝑜 ∖ 𝑥) = (∪ 𝑆 ∖ 𝑥))
27	26	eleq1d 2850	. . . . . . . . . . . . 13 ⊢ (𝑜 = ∪ 𝑆 → ((𝑜 ∖ 𝑥) ∈ 𝑆 ↔ (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
28	27	ralbidv 3190	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → (∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ↔ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
29	25, 28	3anbi12d 1465	. . . . . . . . . . 11 ⊢ (𝑜 = ∪ 𝑆 → ((𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)) ↔ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
30	24, 29	anbi12d 644	. . . . . . . . . 10 ⊢ (𝑜 = ∪ 𝑆 → ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) ↔ (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))))
31	22, 30	syl 18	. . . . . . . . 9 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) ↔ (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))))
32	31	ibi 270	. . . . . . . 8 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
33	32	exlimiv 1963	. . . . . . 7 ⊢ (∃𝑜(𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
34	16, 33	syl 18	. . . . . 6 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
35	34	simprd 501	. . . . 5 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))
36	14, 35	jca 521	. . . 4 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (𝑆 ∈ V ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
37		eleq1 2853	. . . . . . . 8 ⊢ (𝑂 = ∪ 𝑆 → (𝑂 ∈ 𝑆 ↔ ∪ 𝑆 ∈ 𝑆))
38		difeq1 4074	. . . . . . . . . 10 ⊢ (𝑂 = ∪ 𝑆 → (𝑂 ∖ 𝑥) = (∪ 𝑆 ∖ 𝑥))
39	38	eleq1d 2850	. . . . . . . . 9 ⊢ (𝑂 = ∪ 𝑆 → ((𝑂 ∖ 𝑥) ∈ 𝑆 ↔ (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
40	39	ralbidv 3190	. . . . . . . 8 ⊢ (𝑂 = ∪ 𝑆 → (∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ↔ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
41	37, 40	3anbi12d 1465	. . . . . . 7 ⊢ (𝑂 = ∪ 𝑆 → ((𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)) ↔ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
42	41	biimprd 251	. . . . . 6 ⊢ (𝑂 = ∪ 𝑆 → ((∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)) → (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
43		pwuni 4913	. . . . . . 7 ⊢ 𝑆 ⊆ 𝒫 ∪ 𝑆
44		pweq 4578	. . . . . . 7 ⊢ (𝑂 = ∪ 𝑆 → 𝒫 𝑂 = 𝒫 ∪ 𝑆)
45	43, 44	sseqtrrid 3981	. . . . . 6 ⊢ (𝑂 = ∪ 𝑆 → 𝑆 ⊆ 𝒫 𝑂)
46	42, 45	jctild 535	. . . . 5 ⊢ (𝑂 = ∪ 𝑆 → ((∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)) → (𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))))
47	46	anim2d 624	. . . 4 ⊢ (𝑂 = ∪ 𝑆 → ((𝑆 ∈ V ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → (𝑆 ∈ V ∧ (𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))))
48	4	biimpar 483	. . . 4 ⊢ ((𝑆 ∈ V ∧ (𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))) → 𝑆 ∈ (sigAlgebra‘𝑂))
49	36, 47, 48	syl56 37	. . 3 ⊢ (𝑂 = ∪ 𝑆 → (𝑆 ∈ ∪ ran sigAlgebra → 𝑆 ∈ (sigAlgebra‘𝑂)))
50	49	impcom 413	. 2 ⊢ ((𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆) → 𝑆 ∈ (sigAlgebra‘𝑂))
51	13, 50	impbii 212	1 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) ↔ (𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆))

This proof depends on syntax axioms:   → wi 4   ↔ wb 209   ∧ wa 401   ∧ w3a 1103   = wceq 1570  ∃wex 1812   ∈ wcel 2146  ∀wral 3081  Vcvv 3457   ∖ cdif 3903   ⊆ wss 3906  𝒫 cpw 4564  ∪ cuni 4874   class class class wbr 5111  ran crn 5664  ‘cfv 6540  ωcom 7868   ≼ cdom 8947  sigAlgebracsiga 34564

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2148  ax-9 2156  ax-10 2179  ax-11 2195  ax-12 2216  ax-ext 2737  ax-sep 5259  ax-nul 5271  ax-pow 5338  ax-pr 5406

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2569  df-eu 2599  df-clab 2744  df-cleq 2757  df-clel 2840  df-nfc 2914  df-ne 2961  df-ral 3082  df-rex 3092  df-rab 3419  df-v 3459  df-sbc 3747  df-csb 3855  df-dif 3909  df-un 3911  df-in 3913  df-ss 3923  df-nul 4287  df-if 4490  df-pw 4566  df-sn 4592  df-pr 4594  df-op 4598  df-uni 4875  df-br 5112  df-opab 5176  df-mpt 5195  df-id 5558  df-xp 5669  df-rel 5670  df-cnv 5671  df-co 5672  df-dm 5673  df-rn 5674  df-res 5675  df-ima 5676  df-iota 6496  df-fun 6542  df-fn 6543  df-fv 6548  df-siga 34565

This theorem is used by:  sgon  34580  unisg  34600  sxsigon  34649  sxuni  34650  1stmbfm  34717  2ndmbfm  34718  mbfmvolf  34723