Theorem issgon 31991

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 6785	. . . 4 ⊢ (sigAlgebra‘𝑂) ⊆ ∪ ran sigAlgebra
2	1	sseli 3913	. . 3 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑆 ∈ ∪ ran sigAlgebra)
3		elex 3440	. . . 4 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑆 ∈ V)
4		issiga 31980	. . . . 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 5030	. . . . . . . 8 ⊢ (𝑂 ∈ 𝑆 → (𝑆 ⊆ 𝒫 𝑂 ↔ ∪ 𝑆 = 𝑂))
6	5	biimpa 476	. . . . . . 7 ⊢ ((𝑂 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑂) → ∪ 𝑆 = 𝑂)
7		ancom 460	. . . . . . 7 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ 𝑂 ∈ 𝑆) ↔ (𝑂 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑂))
8		eqcom 2745	. . . . . . 7 ⊢ (𝑂 = ∪ 𝑆 ↔ ∪ 𝑆 = 𝑂)
9	6, 7, 8	3imtr4i 291	. . . . . 6 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ 𝑂 ∈ 𝑆) → 𝑂 = ∪ 𝑆)
10	9	3ad2antr1 1186	. . . . 5 ⊢ ((𝑆 ⊆ 𝒫 𝑂 ∧ (𝑂 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → 𝑂 = ∪ 𝑆)
11	4, 10	syl6bi 252	. . . 4 ⊢ (𝑆 ∈ V → (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑂 = ∪ 𝑆))
12	3, 11	mpcom 38	. . 3 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → 𝑂 = ∪ 𝑆)
13	2, 12	jca 511	. 2 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) → (𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆))
14		elex 3440	. . . . 5 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → 𝑆 ∈ V)
15		isrnsiga 31981	. . . . . . . 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 496	. . . . . . 7 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → ∃𝑜(𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
17		elpwuni 5030	. . . . . . . . . . . . 13 ⊢ (𝑜 ∈ 𝑆 → (𝑆 ⊆ 𝒫 𝑜 ↔ ∪ 𝑆 = 𝑜))
18	17	biimpa 476	. . . . . . . . . . . 12 ⊢ ((𝑜 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑜) → ∪ 𝑆 = 𝑜)
19		ancom 460	. . . . . . . . . . . 12 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ 𝑜 ∈ 𝑆) ↔ (𝑜 ∈ 𝑆 ∧ 𝑆 ⊆ 𝒫 𝑜))
20		eqcom 2745	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 ↔ ∪ 𝑆 = 𝑜)
21	18, 19, 20	3imtr4i 291	. . . . . . . . . . 11 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ 𝑜 ∈ 𝑆) → 𝑜 = ∪ 𝑆)
22	21	3ad2antr1 1186	. . . . . . . . . 10 ⊢ ((𝑆 ⊆ 𝒫 𝑜 ∧ (𝑜 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))) → 𝑜 = ∪ 𝑆)
23		pweq 4546	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → 𝒫 𝑜 = 𝒫 ∪ 𝑆)
24	23	sseq2d 3949	. . . . . . . . . . 11 ⊢ (𝑜 = ∪ 𝑆 → (𝑆 ⊆ 𝒫 𝑜 ↔ 𝑆 ⊆ 𝒫 ∪ 𝑆))
25		eleq1 2826	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → (𝑜 ∈ 𝑆 ↔ ∪ 𝑆 ∈ 𝑆))
26		difeq1 4046	. . . . . . . . . . . . . 14 ⊢ (𝑜 = ∪ 𝑆 → (𝑜 ∖ 𝑥) = (∪ 𝑆 ∖ 𝑥))
27	26	eleq1d 2823	. . . . . . . . . . . . 13 ⊢ (𝑜 = ∪ 𝑆 → ((𝑜 ∖ 𝑥) ∈ 𝑆 ↔ (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
28	27	ralbidv 3120	. . . . . . . . . . . 12 ⊢ (𝑜 = ∪ 𝑆 → (∀𝑥 ∈ 𝑆 (𝑜 ∖ 𝑥) ∈ 𝑆 ↔ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
29	25, 28	3anbi12d 1435	. . . . . . . . . . 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 630	. . . . . . . . . 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 17	. . . . . . . . 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 266	. . . . . . . 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 1934	. . . . . . 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 17	. . . . . 6 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (𝑆 ⊆ 𝒫 ∪ 𝑆 ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
35	34	simprd 495	. . . . 5 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆)))
36	14, 35	jca 511	. . . 4 ⊢ (𝑆 ∈ ∪ ran sigAlgebra → (𝑆 ∈ V ∧ (∪ 𝑆 ∈ 𝑆 ∧ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆 ∧ ∀𝑥 ∈ 𝒫 𝑆(𝑥 ≼ ω → ∪ 𝑥 ∈ 𝑆))))
37		eleq1 2826	. . . . . . . 8 ⊢ (𝑂 = ∪ 𝑆 → (𝑂 ∈ 𝑆 ↔ ∪ 𝑆 ∈ 𝑆))
38		difeq1 4046	. . . . . . . . . 10 ⊢ (𝑂 = ∪ 𝑆 → (𝑂 ∖ 𝑥) = (∪ 𝑆 ∖ 𝑥))
39	38	eleq1d 2823	. . . . . . . . 9 ⊢ (𝑂 = ∪ 𝑆 → ((𝑂 ∖ 𝑥) ∈ 𝑆 ↔ (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
40	39	ralbidv 3120	. . . . . . . 8 ⊢ (𝑂 = ∪ 𝑆 → (∀𝑥 ∈ 𝑆 (𝑂 ∖ 𝑥) ∈ 𝑆 ↔ ∀𝑥 ∈ 𝑆 (∪ 𝑆 ∖ 𝑥) ∈ 𝑆))
41	37, 40	3anbi12d 1435	. . . . . . 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 247	. . . . . 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 4875	. . . . . . 7 ⊢ 𝑆 ⊆ 𝒫 ∪ 𝑆
44		pweq 4546	. . . . . . 7 ⊢ (𝑂 = ∪ 𝑆 → 𝒫 𝑂 = 𝒫 ∪ 𝑆)
45	43, 44	sseqtrrid 3970	. . . . . 6 ⊢ (𝑂 = ∪ 𝑆 → 𝑆 ⊆ 𝒫 𝑂)
46	42, 45	jctild 525	. . . . 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 611	. . . 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 477	. . . 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 36	. . 3 ⊢ (𝑂 = ∪ 𝑆 → (𝑆 ∈ ∪ ran sigAlgebra → 𝑆 ∈ (sigAlgebra‘𝑂)))
50	49	impcom 407	. 2 ⊢ ((𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆) → 𝑆 ∈ (sigAlgebra‘𝑂))
51	13, 50	impbii 208	1 ⊢ (𝑆 ∈ (sigAlgebra‘𝑂) ↔ (𝑆 ∈ ∪ ran sigAlgebra ∧ 𝑂 = ∪ 𝑆))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 395   ∧ w3a 1085   = wceq 1539  ∃wex 1783   ∈ wcel 2108  ∀wral 3063  Vcvv 3422   ∖ cdif 3880   ⊆ wss 3883  𝒫 cpw 4530  ∪ cuni 4836   class class class wbr 5070  ran crn 5581  ‘cfv 6418  ωcom 7687   ≼ cdom 8689  sigAlgebracsiga 31976

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-8 2110  ax-9 2118  ax-10 2139  ax-11 2156  ax-12 2173  ax-ext 2709  ax-sep 5218  ax-nul 5225  ax-pow 5283  ax-pr 5347

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-3an 1087  df-tru 1542  df-fal 1552  df-ex 1784  df-nf 1788  df-sb 2069  df-mo 2540  df-eu 2569  df-clab 2716  df-cleq 2730  df-clel 2817  df-nfc 2888  df-ne 2943  df-ral 3068  df-rex 3069  df-rab 3072  df-v 3424  df-sbc 3712  df-csb 3829  df-dif 3886  df-un 3888  df-in 3890  df-ss 3900  df-nul 4254  df-if 4457  df-pw 4532  df-sn 4559  df-pr 4561  df-op 4565  df-uni 4837  df-br 5071  df-opab 5133  df-mpt 5154  df-id 5480  df-xp 5586  df-rel 5587  df-cnv 5588  df-co 5589  df-dm 5590  df-rn 5591  df-res 5592  df-ima 5593  df-iota 6376  df-fun 6420  df-fn 6421  df-fv 6426  df-siga 31977

This theorem is referenced by:  sgon  31992  unisg  32011  sxsigon  32060  sxuni  32061  1stmbfm  32127  2ndmbfm  32128  mbfmvolf  32133