![]() |
Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > ILE Home > Th. List > unipw | GIF version |
Description: A class equals the union of its power class. Exercise 6(a) of [Enderton] p. 38. (Contributed by NM, 14-Oct-1996.) (Proof shortened by Alan Sare, 28-Dec-2008.) |
Ref | Expression |
---|---|
unipw | ⊢ ∪ 𝒫 𝐴 = 𝐴 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eluni 3662 | . . . 4 ⊢ (𝑥 ∈ ∪ 𝒫 𝐴 ↔ ∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝒫 𝐴)) | |
2 | elelpwi 3445 | . . . . 5 ⊢ ((𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝒫 𝐴) → 𝑥 ∈ 𝐴) | |
3 | 2 | exlimiv 1535 | . . . 4 ⊢ (∃𝑦(𝑥 ∈ 𝑦 ∧ 𝑦 ∈ 𝒫 𝐴) → 𝑥 ∈ 𝐴) |
4 | 1, 3 | sylbi 120 | . . 3 ⊢ (𝑥 ∈ ∪ 𝒫 𝐴 → 𝑥 ∈ 𝐴) |
5 | vex 2623 | . . . . 5 ⊢ 𝑥 ∈ V | |
6 | 5 | snid 3479 | . . . 4 ⊢ 𝑥 ∈ {𝑥} |
7 | snelpwi 4048 | . . . 4 ⊢ (𝑥 ∈ 𝐴 → {𝑥} ∈ 𝒫 𝐴) | |
8 | elunii 3664 | . . . 4 ⊢ ((𝑥 ∈ {𝑥} ∧ {𝑥} ∈ 𝒫 𝐴) → 𝑥 ∈ ∪ 𝒫 𝐴) | |
9 | 6, 7, 8 | sylancr 406 | . . 3 ⊢ (𝑥 ∈ 𝐴 → 𝑥 ∈ ∪ 𝒫 𝐴) |
10 | 4, 9 | impbii 125 | . 2 ⊢ (𝑥 ∈ ∪ 𝒫 𝐴 ↔ 𝑥 ∈ 𝐴) |
11 | 10 | eqriv 2086 | 1 ⊢ ∪ 𝒫 𝐴 = 𝐴 |
Colors of variables: wff set class |
Syntax hints: ∧ wa 103 = wceq 1290 ∃wex 1427 ∈ wcel 1439 𝒫 cpw 3433 {csn 3450 ∪ cuni 3659 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 666 ax-5 1382 ax-7 1383 ax-gen 1384 ax-ie1 1428 ax-ie2 1429 ax-8 1441 ax-10 1442 ax-11 1443 ax-i12 1444 ax-bndl 1445 ax-4 1446 ax-14 1451 ax-17 1465 ax-i9 1469 ax-ial 1473 ax-i5r 1474 ax-ext 2071 ax-sep 3963 ax-pow 4015 |
This theorem depends on definitions: df-bi 116 df-tru 1293 df-nf 1396 df-sb 1694 df-clab 2076 df-cleq 2082 df-clel 2085 df-nfc 2218 df-v 2622 df-in 3006 df-ss 3013 df-pw 3435 df-sn 3456 df-uni 3660 |
This theorem is referenced by: pwtr 4055 pwexb 4309 univ 4311 unixpss 4564 eltg4i 11809 distop 11839 distopon 11841 distps 11845 ntrss2 11875 isopn3 11879 discld 11890 |
Copyright terms: Public domain | W3C validator |