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Mathbox for Glauco Siliprandi |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > saluncl | Structured version Visualization version GIF version |
Description: The union of two sets in a sigma-algebra is in the sigma-algebra. (Contributed by Glauco Siliprandi, 17-Aug-2020.) |
Ref | Expression |
---|---|
saluncl | ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → (𝐸 ∪ 𝐹) ∈ 𝑆) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | uniprg 4902 | . . . 4 ⊢ ((𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → ∪ {𝐸, 𝐹} = (𝐸 ∪ 𝐹)) | |
2 | 1 | eqcomd 2737 | . . 3 ⊢ ((𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → (𝐸 ∪ 𝐹) = ∪ {𝐸, 𝐹}) |
3 | 2 | 3adant1 1130 | . 2 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → (𝐸 ∪ 𝐹) = ∪ {𝐸, 𝐹}) |
4 | prfi 9288 | . . . . 5 ⊢ {𝐸, 𝐹} ∈ Fin | |
5 | isfinite 9612 | . . . . . . 7 ⊢ ({𝐸, 𝐹} ∈ Fin ↔ {𝐸, 𝐹} ≺ ω) | |
6 | 5 | biimpi 215 | . . . . . 6 ⊢ ({𝐸, 𝐹} ∈ Fin → {𝐸, 𝐹} ≺ ω) |
7 | sdomdom 8942 | . . . . . 6 ⊢ ({𝐸, 𝐹} ≺ ω → {𝐸, 𝐹} ≼ ω) | |
8 | 6, 7 | syl 17 | . . . . 5 ⊢ ({𝐸, 𝐹} ∈ Fin → {𝐸, 𝐹} ≼ ω) |
9 | 4, 8 | ax-mp 5 | . . . 4 ⊢ {𝐸, 𝐹} ≼ ω |
10 | 9 | a1i 11 | . . 3 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → {𝐸, 𝐹} ≼ ω) |
11 | prelpwi 5424 | . . . . 5 ⊢ ((𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → {𝐸, 𝐹} ∈ 𝒫 𝑆) | |
12 | 11 | 3adant1 1130 | . . . 4 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → {𝐸, 𝐹} ∈ 𝒫 𝑆) |
13 | issal 44708 | . . . . . . 7 ⊢ (𝑆 ∈ SAlg → (𝑆 ∈ SAlg ↔ (∅ ∈ 𝑆 ∧ ∀𝑦 ∈ 𝑆 (∪ 𝑆 ∖ 𝑦) ∈ 𝑆 ∧ ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)))) | |
14 | 13 | ibi 266 | . . . . . 6 ⊢ (𝑆 ∈ SAlg → (∅ ∈ 𝑆 ∧ ∀𝑦 ∈ 𝑆 (∪ 𝑆 ∖ 𝑦) ∈ 𝑆 ∧ ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆))) |
15 | 14 | simp3d 1144 | . . . . 5 ⊢ (𝑆 ∈ SAlg → ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)) |
16 | 15 | 3ad2ant1 1133 | . . . 4 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)) |
17 | breq1 5128 | . . . . . 6 ⊢ (𝑦 = {𝐸, 𝐹} → (𝑦 ≼ ω ↔ {𝐸, 𝐹} ≼ ω)) | |
18 | unieq 4896 | . . . . . . 7 ⊢ (𝑦 = {𝐸, 𝐹} → ∪ 𝑦 = ∪ {𝐸, 𝐹}) | |
19 | 18 | eleq1d 2817 | . . . . . 6 ⊢ (𝑦 = {𝐸, 𝐹} → (∪ 𝑦 ∈ 𝑆 ↔ ∪ {𝐸, 𝐹} ∈ 𝑆)) |
20 | 17, 19 | imbi12d 344 | . . . . 5 ⊢ (𝑦 = {𝐸, 𝐹} → ((𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆) ↔ ({𝐸, 𝐹} ≼ ω → ∪ {𝐸, 𝐹} ∈ 𝑆))) |
21 | 20 | rspcva 3593 | . . . 4 ⊢ (({𝐸, 𝐹} ∈ 𝒫 𝑆 ∧ ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)) → ({𝐸, 𝐹} ≼ ω → ∪ {𝐸, 𝐹} ∈ 𝑆)) |
22 | 12, 16, 21 | syl2anc 584 | . . 3 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → ({𝐸, 𝐹} ≼ ω → ∪ {𝐸, 𝐹} ∈ 𝑆)) |
23 | 10, 22 | mpd 15 | . 2 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → ∪ {𝐸, 𝐹} ∈ 𝑆) |
24 | 3, 23 | eqeltrd 2832 | 1 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → (𝐸 ∪ 𝐹) ∈ 𝑆) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 ∧ w3a 1087 = wceq 1541 ∈ wcel 2106 ∀wral 3060 ∖ cdif 3925 ∪ cun 3926 ∅c0 4302 𝒫 cpw 4580 {cpr 4608 ∪ cuni 4885 class class class wbr 5125 ωcom 7822 ≼ cdom 8903 ≺ csdm 8904 Fincfn 8905 SAlgcsalg 44702 |
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 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-10 2137 ax-11 2154 ax-12 2171 ax-ext 2702 ax-sep 5276 ax-nul 5283 ax-pow 5340 ax-pr 5404 ax-un 7692 ax-inf2 9601 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 846 df-3or 1088 df-3an 1089 df-tru 1544 df-fal 1554 df-ex 1782 df-nf 1786 df-sb 2068 df-mo 2533 df-eu 2562 df-clab 2709 df-cleq 2723 df-clel 2809 df-nfc 2884 df-ne 2940 df-ral 3061 df-rex 3070 df-reu 3365 df-rab 3419 df-v 3461 df-sbc 3758 df-csb 3874 df-dif 3931 df-un 3933 df-in 3935 df-ss 3945 df-pss 3947 df-nul 4303 df-if 4507 df-pw 4582 df-sn 4607 df-pr 4609 df-op 4613 df-uni 4886 df-int 4928 df-iun 4976 df-br 5126 df-opab 5188 df-mpt 5209 df-tr 5243 df-id 5551 df-eprel 5557 df-po 5565 df-so 5566 df-fr 5608 df-we 5610 df-xp 5659 df-rel 5660 df-cnv 5661 df-co 5662 df-dm 5663 df-rn 5664 df-res 5665 df-ima 5666 df-pred 6273 df-ord 6340 df-on 6341 df-lim 6342 df-suc 6343 df-iota 6468 df-fun 6518 df-fn 6519 df-f 6520 df-f1 6521 df-fo 6522 df-f1o 6523 df-fv 6524 df-ov 7380 df-om 7823 df-2nd 7942 df-frecs 8232 df-wrecs 8263 df-recs 8337 df-rdg 8376 df-1o 8432 df-er 8670 df-en 8906 df-dom 8907 df-sdom 8908 df-fin 8909 df-salg 44703 |
This theorem is referenced by: salincl 44718 saluncld 44742 |
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