Theorem measres 31483

Description: Building a measure restricted to a smaller sigma-algebra. (Contributed by Thierry Arnoux, 25-Dec-2016.)

Assertion

Ref	Expression
measres	⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → (𝑀 ↾ 𝑇) ∈ (measures‘𝑇))

Proof of Theorem measres

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

Step	Hyp	Ref	Expression
1		simp2 1133	. 2 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → 𝑇 ∈ ∪ ran sigAlgebra)
2		measfrge0 31464	. . . . 5 ⊢ (𝑀 ∈ (measures‘𝑆) → 𝑀:𝑆⟶(0[,]+∞))
3	2	3ad2ant1 1129	. . . 4 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → 𝑀:𝑆⟶(0[,]+∞))
4		simp3 1134	. . . 4 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → 𝑇 ⊆ 𝑆)
5	3, 4	fssresd 6547	. . 3 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → (𝑀 ↾ 𝑇):𝑇⟶(0[,]+∞))
6		0elsiga 31375	. . . . 5 ⊢ (𝑇 ∈ ∪ ran sigAlgebra → ∅ ∈ 𝑇)
7		fvres 6691	. . . . 5 ⊢ (∅ ∈ 𝑇 → ((𝑀 ↾ 𝑇)‘∅) = (𝑀‘∅))
8	1, 6, 7	3syl 18	. . . 4 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → ((𝑀 ↾ 𝑇)‘∅) = (𝑀‘∅))
9		measvnul 31467	. . . . 5 ⊢ (𝑀 ∈ (measures‘𝑆) → (𝑀‘∅) = 0)
10	9	3ad2ant1 1129	. . . 4 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → (𝑀‘∅) = 0)
11	8, 10	eqtrd 2858	. . 3 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → ((𝑀 ↾ 𝑇)‘∅) = 0)
12		simp11 1199	. . . . . . 7 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑀 ∈ (measures‘𝑆))
13		simp13 1201	. . . . . . . 8 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑇 ⊆ 𝑆)
14		simp2 1133	. . . . . . . 8 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑥 ∈ 𝒫 𝑇)
15		sspw 4554	. . . . . . . . 9 ⊢ (𝑇 ⊆ 𝑆 → 𝒫 𝑇 ⊆ 𝒫 𝑆)
16	15	sselda 3969	. . . . . . . 8 ⊢ ((𝑇 ⊆ 𝑆 ∧ 𝑥 ∈ 𝒫 𝑇) → 𝑥 ∈ 𝒫 𝑆)
17	13, 14, 16	syl2anc 586	. . . . . . 7 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑥 ∈ 𝒫 𝑆)
18		simp3 1134	. . . . . . 7 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦))
19		measvun 31470	. . . . . . 7 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑥 ∈ 𝒫 𝑆 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → (𝑀‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥(𝑀‘𝑦))
20	12, 17, 18, 19	syl3anc 1367	. . . . . 6 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → (𝑀‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥(𝑀‘𝑦))
21	1	3ad2ant1 1129	. . . . . . . 8 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑇 ∈ ∪ ran sigAlgebra)
22		simp3l 1197	. . . . . . . 8 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → 𝑥 ≼ ω)
23		sigaclcu 31378	. . . . . . . 8 ⊢ ((𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑥 ∈ 𝒫 𝑇 ∧ 𝑥 ≼ ω) → ∪ 𝑥 ∈ 𝑇)
24	21, 14, 22, 23	syl3anc 1367	. . . . . . 7 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → ∪ 𝑥 ∈ 𝑇)
25	24	fvresd 6692	. . . . . 6 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = (𝑀‘∪ 𝑥))
26		elpwi 4550	. . . . . . . . . . 11 ⊢ (𝑥 ∈ 𝒫 𝑇 → 𝑥 ⊆ 𝑇)
27	26	sselda 3969	. . . . . . . . . 10 ⊢ ((𝑥 ∈ 𝒫 𝑇 ∧ 𝑦 ∈ 𝑥) → 𝑦 ∈ 𝑇)
28	27	adantll 712	. . . . . . . . 9 ⊢ ((((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) ∧ 𝑦 ∈ 𝑥) → 𝑦 ∈ 𝑇)
29	28	fvresd 6692	. . . . . . . 8 ⊢ ((((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) ∧ 𝑦 ∈ 𝑥) → ((𝑀 ↾ 𝑇)‘𝑦) = (𝑀‘𝑦))
30	29	esumeq2dv 31299	. . . . . . 7 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) → Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦) = Σ*𝑦 ∈ 𝑥(𝑀‘𝑦))
31	30	3adant3 1128	. . . . . 6 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦) = Σ*𝑦 ∈ 𝑥(𝑀‘𝑦))
32	20, 25, 31	3eqtr4d 2868	. . . . 5 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦)) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦))
33	32	3expia 1117	. . . 4 ⊢ (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) → ((𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦)))
34	33	ralrimiva 3184	. . 3 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦)))
35	5, 11, 34	3jca 1124	. 2 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → ((𝑀 ↾ 𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀 ↾ 𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦))))
36		ismeas 31460	. . 3 ⊢ (𝑇 ∈ ∪ ran sigAlgebra → ((𝑀 ↾ 𝑇) ∈ (measures‘𝑇) ↔ ((𝑀 ↾ 𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀 ↾ 𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦)))))
37	36	biimprd 250	. 2 ⊢ (𝑇 ∈ ∪ ran sigAlgebra → (((𝑀 ↾ 𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀 ↾ 𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦 ∈ 𝑥 𝑦) → ((𝑀 ↾ 𝑇)‘∪ 𝑥) = Σ*𝑦 ∈ 𝑥((𝑀 ↾ 𝑇)‘𝑦))) → (𝑀 ↾ 𝑇) ∈ (measures‘𝑇)))
38	1, 35, 37	sylc 65	1 ⊢ ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ∈ ∪ ran sigAlgebra ∧ 𝑇 ⊆ 𝑆) → (𝑀 ↾ 𝑇) ∈ (measures‘𝑇))

Syntax hints:   → wi 4   ∧ wa 398   ∧ w3a 1083   = wceq 1537   ∈ wcel 2114  ∀wral 3140   ⊆ wss 3938  ∅c0 4293  𝒫 cpw 4541  ∪ cuni 4840  Disj wdisj 5033   class class class wbr 5068  ran crn 5558   ↾ cres 5559  ⟶wf 6353  ‘cfv 6357  (class class class)co 7158  ωcom 7582   ≼ cdom 8509  0cc0 10539  +∞cpnf 10674  [,]cicc 12744  Σ^*cesum 31288  sigAlgebracsiga 31369  measurescmeas 31456

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2116  ax-9 2124  ax-10 2145  ax-11 2161  ax-12 2177  ax-ext 2795  ax-sep 5205  ax-nul 5212  ax-pow 5268  ax-pr 5332  ax-un 7463

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3an 1085  df-tru 1540  df-fal 1550  df-ex 1781  df-nf 1785  df-sb 2070  df-mo 2622  df-eu 2654  df-clab 2802  df-cleq 2816  df-clel 2895  df-nfc 2965  df-ral 3145  df-rex 3146  df-rmo 3148  df-rab 3149  df-v 3498  df-sbc 3775  df-csb 3886  df-dif 3941  df-un 3943  df-in 3945  df-ss 3954  df-nul 4294  df-if 4470  df-pw 4543  df-sn 4570  df-pr 4572  df-op 4576  df-uni 4841  df-disj 5034  df-br 5069  df-opab 5131  df-mpt 5149  df-id 5462  df-xp 5563  df-rel 5564  df-cnv 5565  df-co 5566  df-dm 5567  df-rn 5568  df-res 5569  df-ima 5570  df-iota 6316  df-fun 6359  df-fn 6360  df-f 6361  df-fv 6365  df-ov 7161  df-esum 31289  df-siga 31370  df-meas 31457

This theorem is referenced by:  measinb2  31484