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| Mirrors > Home > MPE Home > Th. List > uniun | Structured version Visualization version GIF version | ||
| Description: The class union of the union of two classes. Theorem 8.3 of [Quine] p. 53. (Contributed by NM, 20-Aug-1993.) |
| Ref | Expression |
|---|---|
| uniun | ⊢ ∪ (𝐴 ∪ 𝐵) = (∪ 𝐴 ∪ ∪ 𝐵) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 19.43 1882 | . . . 4 ⊢ (∃𝑦((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ (𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵)) ↔ (∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵))) | |
| 2 | elun 4153 | . . . . . . 7 ⊢ (𝑦 ∈ (𝐴 ∪ 𝐵) ↔ (𝑦 ∈ 𝐴 ∨ 𝑦 ∈ 𝐵)) | |
| 3 | 2 | anbi2i 623 | . . . . . 6 ⊢ ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ (𝐴 ∪ 𝐵)) ↔ (𝑥 ∈ 𝑦 ∧ (𝑦 ∈ 𝐴 ∨ 𝑦 ∈ 𝐵))) |
| 4 | andi 1010 | . . . . . 6 ⊢ ((𝑥 ∈ 𝑦 ∧ (𝑦 ∈ 𝐴 ∨ 𝑦 ∈ 𝐵)) ↔ ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ (𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵))) | |
| 5 | 3, 4 | bitri 275 | . . . . 5 ⊢ ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ (𝐴 ∪ 𝐵)) ↔ ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ (𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵))) |
| 6 | 5 | exbii 1848 | . . . 4 ⊢ (∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ (𝐴 ∪ 𝐵)) ↔ ∃𝑦((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ (𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵))) |
| 7 | eluni 4910 | . . . . 5 ⊢ (𝑥 ∈ ∪ 𝐴 ↔ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴)) | |
| 8 | eluni 4910 | . . . . 5 ⊢ (𝑥 ∈ ∪ 𝐵 ↔ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵)) | |
| 9 | 7, 8 | orbi12i 915 | . . . 4 ⊢ ((𝑥 ∈ ∪ 𝐴 ∨ 𝑥 ∈ ∪ 𝐵) ↔ (∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐴) ∨ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝐵))) |
| 10 | 1, 6, 9 | 3bitr4i 303 | . . 3 ⊢ (∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ (𝐴 ∪ 𝐵)) ↔ (𝑥 ∈ ∪ 𝐴 ∨ 𝑥 ∈ ∪ 𝐵)) |
| 11 | eluni 4910 | . . 3 ⊢ (𝑥 ∈ ∪ (𝐴 ∪ 𝐵) ↔ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ (𝐴 ∪ 𝐵))) | |
| 12 | elun 4153 | . . 3 ⊢ (𝑥 ∈ (∪ 𝐴 ∪ ∪ 𝐵) ↔ (𝑥 ∈ ∪ 𝐴 ∨ 𝑥 ∈ ∪ 𝐵)) | |
| 13 | 10, 11, 12 | 3bitr4i 303 | . 2 ⊢ (𝑥 ∈ ∪ (𝐴 ∪ 𝐵) ↔ 𝑥 ∈ (∪ 𝐴 ∪ ∪ 𝐵)) |
| 14 | 13 | eqriv 2734 | 1 ⊢ ∪ (𝐴 ∪ 𝐵) = (∪ 𝐴 ∪ ∪ 𝐵) |
| Colors of variables: wff setvar class |
| Syntax hints: ∧ wa 395 ∨ wo 848 = wceq 1540 ∃wex 1779 ∈ wcel 2108 ∪ cun 3949 ∪ cuni 4907 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-ext 2708 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 849 df-tru 1543 df-ex 1780 df-sb 2065 df-clab 2715 df-cleq 2729 df-clel 2816 df-v 3482 df-un 3956 df-uni 4908 |
| This theorem is referenced by: unidif0 5360 unisucs 6461 fvssunirnOLD 6940 fvun 6999 onuninsuci 7861 tc2 9782 fin1a2lem10 10449 fin1a2lem12 10451 incexclem 15872 dprd2da 20062 dmdprdsplit2lem 20065 ordtuni 23198 cmpcld 23410 uncmp 23411 refun0 23523 lfinun 23533 1stckgenlem 23561 filconn 23891 ufildr 23939 alexsubALTlem3 24057 cldsubg 24119 icccmplem2 24845 uniioombllem3 25620 madeoldsuc 27923 zs12bday 28424 sxbrsigalem0 34273 fiunelcarsg 34318 carsgclctunlem1 34319 carsggect 34320 cvmscld 35278 refssfne 36359 topjoin 36366 pibt2 37418 mbfresfi 37673 onsucunitp 43386 oaun3 43395 fourierdlem80 46201 isomenndlem 46545 |
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