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| Mirrors > Home > ILE Home > Th. List > Mathboxes > bj-omex2 | GIF version | ||
| Description: Using bounded set induction and the strong axiom of infinity, ω is a set, that is, we recover ax-infvn 16760 (see bj-2inf 16757 for the equivalence of the latter with bj-omex 16761). (Contributed by BJ, 8-Dec-2019.) (Proof modification is discouraged.) (New usage is discouraged.) |
| Ref | Expression |
|---|---|
| bj-omex2 | ⊢ ω ∈ V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ax-inf2 16795 | . . 3 ⊢ ∃𝑎∀𝑥(𝑥 ∈ 𝑎 ↔ (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝑎 𝑥 = suc 𝑦)) | |
| 2 | vex 2818 | . . . 4 ⊢ 𝑎 ∈ V | |
| 3 | bdcv 16667 | . . . . 5 ⊢ BOUNDED 𝑎 | |
| 4 | 3 | bj-inf2vn 16793 | . . . 4 ⊢ (𝑎 ∈ V → (∀𝑥(𝑥 ∈ 𝑎 ↔ (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝑎 𝑥 = suc 𝑦)) → 𝑎 = ω)) |
| 5 | 2, 4 | ax-mp 5 | . . 3 ⊢ (∀𝑥(𝑥 ∈ 𝑎 ↔ (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝑎 𝑥 = suc 𝑦)) → 𝑎 = ω) |
| 6 | 1, 5 | eximii 1651 | . 2 ⊢ ∃𝑎 𝑎 = ω |
| 7 | 6 | issetri 2825 | 1 ⊢ ω ∈ V |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ↔ wb 105 ∨ wo 716 ∀wal 1396 = wceq 1398 ∈ wcel 2205 ∃wrex 2523 Vcvv 2815 ∅c0 3510 suc csuc 4488 ωcom 4714 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 619 ax-in2 620 ax-io 717 ax-5 1496 ax-7 1497 ax-gen 1498 ax-ie1 1542 ax-ie2 1543 ax-8 1553 ax-10 1554 ax-11 1555 ax-i12 1556 ax-bndl 1558 ax-4 1559 ax-17 1575 ax-i9 1579 ax-ial 1583 ax-i5r 1584 ax-13 2207 ax-14 2208 ax-ext 2216 ax-nul 4238 ax-pr 4324 ax-un 4556 ax-bd0 16632 ax-bdim 16633 ax-bdor 16635 ax-bdex 16638 ax-bdeq 16639 ax-bdel 16640 ax-bdsb 16641 ax-bdsep 16703 ax-bdsetind 16787 ax-inf2 16795 |
| This theorem depends on definitions: df-bi 117 df-tru 1401 df-nf 1510 df-sb 1812 df-clab 2221 df-cleq 2227 df-clel 2230 df-nfc 2375 df-ral 2527 df-rex 2528 df-rab 2531 df-v 2817 df-dif 3215 df-un 3217 df-in 3219 df-ss 3226 df-nul 3511 df-sn 3697 df-pr 3698 df-uni 3917 df-int 3952 df-suc 4494 df-iom 4715 df-bdc 16660 df-bj-ind 16746 |
| This theorem is referenced by: (None) |
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