![]() |
Mathbox for Glauco Siliprandi |
< Previous
Next >
Nearby theorems |
|
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 4947 | . . . 4 ⊢ ((𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → ∪ {𝐸, 𝐹} = (𝐸 ∪ 𝐹)) | |
2 | 1 | eqcomd 2746 | . . 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 9391 | . . . . 5 ⊢ {𝐸, 𝐹} ∈ Fin | |
5 | isfinite 9721 | . . . . . . 7 ⊢ ({𝐸, 𝐹} ∈ Fin ↔ {𝐸, 𝐹} ≺ ω) | |
6 | 5 | biimpi 216 | . . . . . 6 ⊢ ({𝐸, 𝐹} ∈ Fin → {𝐸, 𝐹} ≺ ω) |
7 | sdomdom 9040 | . . . . . 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 5467 | . . . . 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 46235 | . . . . . . 7 ⊢ (𝑆 ∈ SAlg → (𝑆 ∈ SAlg ↔ (∅ ∈ 𝑆 ∧ ∀𝑦 ∈ 𝑆 (∪ 𝑆 ∖ 𝑦) ∈ 𝑆 ∧ ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)))) | |
14 | 13 | ibi 267 | . . . . . 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 5169 | . . . . . 6 ⊢ (𝑦 = {𝐸, 𝐹} → (𝑦 ≼ ω ↔ {𝐸, 𝐹} ≼ ω)) | |
18 | unieq 4942 | . . . . . . 7 ⊢ (𝑦 = {𝐸, 𝐹} → ∪ 𝑦 = ∪ {𝐸, 𝐹}) | |
19 | 18 | eleq1d 2829 | . . . . . 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 3633 | . . . 4 ⊢ (({𝐸, 𝐹} ∈ 𝒫 𝑆 ∧ ∀𝑦 ∈ 𝒫 𝑆(𝑦 ≼ ω → ∪ 𝑦 ∈ 𝑆)) → ({𝐸, 𝐹} ≼ ω → ∪ {𝐸, 𝐹} ∈ 𝑆)) |
22 | 12, 16, 21 | syl2anc 583 | . . 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 2844 | 1 ⊢ ((𝑆 ∈ SAlg ∧ 𝐸 ∈ 𝑆 ∧ 𝐹 ∈ 𝑆) → (𝐸 ∪ 𝐹) ∈ 𝑆) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 395 ∧ w3a 1087 = wceq 1537 ∈ wcel 2108 ∀wral 3067 ∖ cdif 3973 ∪ cun 3974 ∅c0 4352 𝒫 cpw 4622 {cpr 4650 ∪ cuni 4931 class class class wbr 5166 ωcom 7903 ≼ cdom 9001 ≺ csdm 9002 Fincfn 9003 SAlgcsalg 46229 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1793 ax-4 1807 ax-5 1909 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-10 2141 ax-11 2158 ax-12 2178 ax-ext 2711 ax-sep 5317 ax-nul 5324 ax-pow 5383 ax-pr 5447 ax-un 7770 ax-inf2 9710 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 847 df-3or 1088 df-3an 1089 df-tru 1540 df-fal 1550 df-ex 1778 df-nf 1782 df-sb 2065 df-mo 2543 df-eu 2572 df-clab 2718 df-cleq 2732 df-clel 2819 df-nfc 2895 df-ne 2947 df-ral 3068 df-rex 3077 df-reu 3389 df-rab 3444 df-v 3490 df-sbc 3805 df-csb 3922 df-dif 3979 df-un 3981 df-in 3983 df-ss 3993 df-pss 3996 df-nul 4353 df-if 4549 df-pw 4624 df-sn 4649 df-pr 4651 df-op 4655 df-uni 4932 df-int 4971 df-iun 5017 df-br 5167 df-opab 5229 df-mpt 5250 df-tr 5284 df-id 5593 df-eprel 5599 df-po 5607 df-so 5608 df-fr 5652 df-we 5654 df-xp 5706 df-rel 5707 df-cnv 5708 df-co 5709 df-dm 5710 df-rn 5711 df-res 5712 df-ima 5713 df-pred 6332 df-ord 6398 df-on 6399 df-lim 6400 df-suc 6401 df-iota 6525 df-fun 6575 df-fn 6576 df-f 6577 df-f1 6578 df-fo 6579 df-f1o 6580 df-fv 6581 df-ov 7451 df-om 7904 df-2nd 8031 df-frecs 8322 df-wrecs 8353 df-recs 8427 df-rdg 8466 df-1o 8522 df-2o 8523 df-er 8763 df-en 9004 df-dom 9005 df-sdom 9006 df-fin 9007 df-salg 46230 |
This theorem is referenced by: salincl 46245 saluncld 46269 |
Copyright terms: Public domain | W3C validator |