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Theorem measres 31499
 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 ∧ 𝑇𝑆) → (𝑀𝑇) ∈ (measures‘𝑇))

Proof of Theorem measres
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 simp2 1134 . 2 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → 𝑇 ran sigAlgebra)
2 measfrge0 31480 . . . . 5 (𝑀 ∈ (measures‘𝑆) → 𝑀:𝑆⟶(0[,]+∞))
323ad2ant1 1130 . . . 4 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → 𝑀:𝑆⟶(0[,]+∞))
4 simp3 1135 . . . 4 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → 𝑇𝑆)
53, 4fssresd 6526 . . 3 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → (𝑀𝑇):𝑇⟶(0[,]+∞))
6 0elsiga 31391 . . . . 5 (𝑇 ran sigAlgebra → ∅ ∈ 𝑇)
7 fvres 6670 . . . . 5 (∅ ∈ 𝑇 → ((𝑀𝑇)‘∅) = (𝑀‘∅))
81, 6, 73syl 18 . . . 4 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → ((𝑀𝑇)‘∅) = (𝑀‘∅))
9 measvnul 31483 . . . . 5 (𝑀 ∈ (measures‘𝑆) → (𝑀‘∅) = 0)
1093ad2ant1 1130 . . . 4 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → (𝑀‘∅) = 0)
118, 10eqtrd 2859 . . 3 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → ((𝑀𝑇)‘∅) = 0)
12 simp11 1200 . . . . . . 7 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑀 ∈ (measures‘𝑆))
13 simp13 1202 . . . . . . . 8 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑇𝑆)
14 simp2 1134 . . . . . . . 8 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑥 ∈ 𝒫 𝑇)
15 sspw 4533 . . . . . . . . 9 (𝑇𝑆 → 𝒫 𝑇 ⊆ 𝒫 𝑆)
1615sselda 3951 . . . . . . . 8 ((𝑇𝑆𝑥 ∈ 𝒫 𝑇) → 𝑥 ∈ 𝒫 𝑆)
1713, 14, 16syl2anc 587 . . . . . . 7 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑥 ∈ 𝒫 𝑆)
18 simp3 1135 . . . . . . 7 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦))
19 measvun 31486 . . . . . . 7 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑥 ∈ 𝒫 𝑆 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → (𝑀 𝑥) = Σ*𝑦𝑥(𝑀𝑦))
2012, 17, 18, 19syl3anc 1368 . . . . . 6 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → (𝑀 𝑥) = Σ*𝑦𝑥(𝑀𝑦))
2113ad2ant1 1130 . . . . . . . 8 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑇 ran sigAlgebra)
22 simp3l 1198 . . . . . . . 8 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑥 ≼ ω)
23 sigaclcu 31394 . . . . . . . 8 ((𝑇 ran sigAlgebra ∧ 𝑥 ∈ 𝒫 𝑇𝑥 ≼ ω) → 𝑥𝑇)
2421, 14, 22, 23syl3anc 1368 . . . . . . 7 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → 𝑥𝑇)
2524fvresd 6671 . . . . . 6 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → ((𝑀𝑇)‘ 𝑥) = (𝑀 𝑥))
26 elpwi 4529 . . . . . . . . . . 11 (𝑥 ∈ 𝒫 𝑇𝑥𝑇)
2726sselda 3951 . . . . . . . . . 10 ((𝑥 ∈ 𝒫 𝑇𝑦𝑥) → 𝑦𝑇)
2827adantll 713 . . . . . . . . 9 ((((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) ∧ 𝑦𝑥) → 𝑦𝑇)
2928fvresd 6671 . . . . . . . 8 ((((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) ∧ 𝑦𝑥) → ((𝑀𝑇)‘𝑦) = (𝑀𝑦))
3029esumeq2dv 31315 . . . . . . 7 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) → Σ*𝑦𝑥((𝑀𝑇)‘𝑦) = Σ*𝑦𝑥(𝑀𝑦))
31303adant3 1129 . . . . . 6 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → Σ*𝑦𝑥((𝑀𝑇)‘𝑦) = Σ*𝑦𝑥(𝑀𝑦))
3220, 25, 313eqtr4d 2869 . . . . 5 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇 ∧ (𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦)) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦))
33323expia 1118 . . . 4 (((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) ∧ 𝑥 ∈ 𝒫 𝑇) → ((𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦)))
3433ralrimiva 3176 . . 3 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦)))
355, 11, 343jca 1125 . 2 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → ((𝑀𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦))))
36 ismeas 31476 . . 3 (𝑇 ran sigAlgebra → ((𝑀𝑇) ∈ (measures‘𝑇) ↔ ((𝑀𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦)))))
3736biimprd 251 . 2 (𝑇 ran sigAlgebra → (((𝑀𝑇):𝑇⟶(0[,]+∞) ∧ ((𝑀𝑇)‘∅) = 0 ∧ ∀𝑥 ∈ 𝒫 𝑇((𝑥 ≼ ω ∧ Disj 𝑦𝑥 𝑦) → ((𝑀𝑇)‘ 𝑥) = Σ*𝑦𝑥((𝑀𝑇)‘𝑦))) → (𝑀𝑇) ∈ (measures‘𝑇)))
381, 35, 37sylc 65 1 ((𝑀 ∈ (measures‘𝑆) ∧ 𝑇 ran sigAlgebra ∧ 𝑇𝑆) → (𝑀𝑇) ∈ (measures‘𝑇))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ∧ wa 399   ∧ w3a 1084   = wceq 1538   ∈ wcel 2115  ∀wral 3132   ⊆ wss 3918  ∅c0 4274  𝒫 cpw 4520  ∪ cuni 4819  Disj wdisj 5012   class class class wbr 5047  ran crn 5537   ↾ cres 5538  ⟶wf 6332  ‘cfv 6336  (class class class)co 7138  ωcom 7563   ≼ cdom 8490  0cc0 10522  +∞cpnf 10657  [,]cicc 12727  Σ*cesum 31304  sigAlgebracsiga 31385  measurescmeas 31472 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 1971  ax-7 2016  ax-8 2117  ax-9 2125  ax-10 2146  ax-11 2162  ax-12 2179  ax-ext 2796  ax-sep 5184  ax-nul 5191  ax-pow 5247  ax-pr 5311  ax-un 7444 This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-fal 1551  df-ex 1782  df-nf 1786  df-sb 2071  df-mo 2624  df-eu 2655  df-clab 2803  df-cleq 2817  df-clel 2896  df-nfc 2964  df-ral 3137  df-rex 3138  df-rmo 3140  df-rab 3141  df-v 3481  df-sbc 3758  df-csb 3866  df-dif 3921  df-un 3923  df-in 3925  df-ss 3935  df-nul 4275  df-if 4449  df-pw 4522  df-sn 4549  df-pr 4551  df-op 4555  df-uni 4820  df-disj 5013  df-br 5048  df-opab 5110  df-mpt 5128  df-id 5441  df-xp 5542  df-rel 5543  df-cnv 5544  df-co 5545  df-dm 5546  df-rn 5547  df-res 5548  df-ima 5549  df-iota 6295  df-fun 6338  df-fn 6339  df-f 6340  df-fv 6344  df-ov 7141  df-esum 31305  df-siga 31386  df-meas 31473 This theorem is referenced by:  measinb2  31500
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