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Theorem sigagensiga 29531
 Description: A generated sigma-algebra is a sigma-algebra. (Contributed by Thierry Arnoux, 27-Dec-2016.)
Assertion
Ref Expression
sigagensiga (𝐴𝑉 → (sigaGen‘𝐴) ∈ (sigAlgebra‘ 𝐴))

Proof of Theorem sigagensiga
Dummy variable 𝑠 is distinct from all other variables.
StepHypRef Expression
1 sigagenval 29530 . 2 (𝐴𝑉 → (sigaGen‘𝐴) = {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠})
2 fvex 6113 . . . . 5 (sigaGen‘𝐴) ∈ V
31, 2syl6eqelr 2697 . . . 4 (𝐴𝑉 {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ V)
4 intex 4747 . . . 4 ({𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ≠ ∅ ↔ {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ V)
53, 4sylibr 223 . . 3 (𝐴𝑉 → {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ≠ ∅)
6 ssrab2 3650 . . . . 5 {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ⊆ (sigAlgebra‘ 𝐴)
76a1i 11 . . . 4 (𝐴𝑉 → {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ⊆ (sigAlgebra‘ 𝐴))
8 fvex 6113 . . . . 5 (sigAlgebra‘ 𝐴) ∈ V
98elpw2 4755 . . . 4 ({𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ 𝒫 (sigAlgebra‘ 𝐴) ↔ {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ⊆ (sigAlgebra‘ 𝐴))
107, 9sylibr 223 . . 3 (𝐴𝑉 → {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ 𝒫 (sigAlgebra‘ 𝐴))
11 insiga 29527 . . 3 (({𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ≠ ∅ ∧ {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ 𝒫 (sigAlgebra‘ 𝐴)) → {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ (sigAlgebra‘ 𝐴))
125, 10, 11syl2anc 691 . 2 (𝐴𝑉 {𝑠 ∈ (sigAlgebra‘ 𝐴) ∣ 𝐴𝑠} ∈ (sigAlgebra‘ 𝐴))
131, 12eqeltrd 2688 1 (𝐴𝑉 → (sigaGen‘𝐴) ∈ (sigAlgebra‘ 𝐴))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ∈ wcel 1977   ≠ wne 2780  {crab 2900  Vcvv 3173   ⊆ wss 3540  ∅c0 3874  𝒫 cpw 4108  ∪ cuni 4372  ∩ cint 4410  ‘cfv 5804  sigAlgebracsiga 29497  sigaGencsigagen 29528 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847 This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-fal 1481  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-ral 2901  df-rex 2902  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-op 4132  df-uni 4373  df-int 4411  df-br 4584  df-opab 4644  df-mpt 4645  df-id 4953  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-iota 5768  df-fun 5806  df-fv 5812  df-siga 29498  df-sigagen 29529 This theorem is referenced by:  sgsiga  29532  unisg  29533  sigagenss2  29540  brsiga  29573  brsigarn  29574  cldssbrsiga  29577  sxsiga  29581  cnmbfm  29652  sxbrsiga  29679
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