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| Mirrors > Home > ILE Home > Th. List > Mathboxes > bdsetindis | GIF version | ||
| Description: Axiom of bounded set induction using implicit substitutions. (Contributed by BJ, 22-Nov-2019.) (Proof modification is discouraged.) | 
| Ref | Expression | 
|---|---|
| bdsetindis.bd | ⊢ BOUNDED 𝜑 | 
| bdsetindis.nf0 | ⊢ Ⅎ𝑥𝜓 | 
| bdsetindis.nf1 | ⊢ Ⅎ𝑥𝜒 | 
| bdsetindis.nf2 | ⊢ Ⅎ𝑦𝜑 | 
| bdsetindis.nf3 | ⊢ Ⅎ𝑦𝜓 | 
| bdsetindis.1 | ⊢ (𝑥 = 𝑧 → (𝜑 → 𝜓)) | 
| bdsetindis.2 | ⊢ (𝑥 = 𝑦 → (𝜒 → 𝜑)) | 
| Ref | Expression | 
|---|---|
| bdsetindis | ⊢ (∀𝑦(∀𝑧 ∈ 𝑦 𝜓 → 𝜒) → ∀𝑥𝜑) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | nfcv 2339 | . . . . 5 ⊢ Ⅎ𝑥𝑦 | |
| 2 | bdsetindis.nf0 | . . . . 5 ⊢ Ⅎ𝑥𝜓 | |
| 3 | 1, 2 | nfralxy 2535 | . . . 4 ⊢ Ⅎ𝑥∀𝑧 ∈ 𝑦 𝜓 | 
| 4 | bdsetindis.nf1 | . . . 4 ⊢ Ⅎ𝑥𝜒 | |
| 5 | 3, 4 | nfim 1586 | . . 3 ⊢ Ⅎ𝑥(∀𝑧 ∈ 𝑦 𝜓 → 𝜒) | 
| 6 | nfcv 2339 | . . . . 5 ⊢ Ⅎ𝑦𝑥 | |
| 7 | bdsetindis.nf3 | . . . . 5 ⊢ Ⅎ𝑦𝜓 | |
| 8 | 6, 7 | nfralxy 2535 | . . . 4 ⊢ Ⅎ𝑦∀𝑧 ∈ 𝑥 𝜓 | 
| 9 | bdsetindis.nf2 | . . . 4 ⊢ Ⅎ𝑦𝜑 | |
| 10 | 8, 9 | nfim 1586 | . . 3 ⊢ Ⅎ𝑦(∀𝑧 ∈ 𝑥 𝜓 → 𝜑) | 
| 11 | raleq 2693 | . . . . 5 ⊢ (𝑦 = 𝑥 → (∀𝑧 ∈ 𝑦 𝜓 ↔ ∀𝑧 ∈ 𝑥 𝜓)) | |
| 12 | 11 | biimprd 158 | . . . 4 ⊢ (𝑦 = 𝑥 → (∀𝑧 ∈ 𝑥 𝜓 → ∀𝑧 ∈ 𝑦 𝜓)) | 
| 13 | bdsetindis.2 | . . . . 5 ⊢ (𝑥 = 𝑦 → (𝜒 → 𝜑)) | |
| 14 | 13 | equcoms 1722 | . . . 4 ⊢ (𝑦 = 𝑥 → (𝜒 → 𝜑)) | 
| 15 | 12, 14 | imim12d 74 | . . 3 ⊢ (𝑦 = 𝑥 → ((∀𝑧 ∈ 𝑦 𝜓 → 𝜒) → (∀𝑧 ∈ 𝑥 𝜓 → 𝜑))) | 
| 16 | 5, 10, 15 | cbv3 1756 | . 2 ⊢ (∀𝑦(∀𝑧 ∈ 𝑦 𝜓 → 𝜒) → ∀𝑥(∀𝑧 ∈ 𝑥 𝜓 → 𝜑)) | 
| 17 | bdsetindis.1 | . . . . . 6 ⊢ (𝑥 = 𝑧 → (𝜑 → 𝜓)) | |
| 18 | 2, 17 | bj-sbime 15419 | . . . . 5 ⊢ ([𝑧 / 𝑥]𝜑 → 𝜓) | 
| 19 | 18 | ralimi 2560 | . . . 4 ⊢ (∀𝑧 ∈ 𝑥 [𝑧 / 𝑥]𝜑 → ∀𝑧 ∈ 𝑥 𝜓) | 
| 20 | 19 | imim1i 60 | . . 3 ⊢ ((∀𝑧 ∈ 𝑥 𝜓 → 𝜑) → (∀𝑧 ∈ 𝑥 [𝑧 / 𝑥]𝜑 → 𝜑)) | 
| 21 | 20 | alimi 1469 | . 2 ⊢ (∀𝑥(∀𝑧 ∈ 𝑥 𝜓 → 𝜑) → ∀𝑥(∀𝑧 ∈ 𝑥 [𝑧 / 𝑥]𝜑 → 𝜑)) | 
| 22 | bdsetindis.bd | . . 3 ⊢ BOUNDED 𝜑 | |
| 23 | 22 | ax-bdsetind 15614 | . 2 ⊢ (∀𝑥(∀𝑧 ∈ 𝑥 [𝑧 / 𝑥]𝜑 → 𝜑) → ∀𝑥𝜑) | 
| 24 | 16, 21, 23 | 3syl 17 | 1 ⊢ (∀𝑦(∀𝑧 ∈ 𝑦 𝜓 → 𝜒) → ∀𝑥𝜑) | 
| Colors of variables: wff set class | 
| Syntax hints: → wi 4 ∀wal 1362 Ⅎwnf 1474 [wsb 1776 ∀wral 2475 BOUNDED wbd 15458 | 
| 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-io 710 ax-5 1461 ax-7 1462 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-10 1519 ax-11 1520 ax-i12 1521 ax-bndl 1523 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-i5r 1549 ax-ext 2178 ax-bdsetind 15614 | 
| This theorem depends on definitions: df-bi 117 df-tru 1367 df-nf 1475 df-sb 1777 df-cleq 2189 df-clel 2192 df-nfc 2328 df-ral 2480 | 
| This theorem is referenced by: bj-inf2vnlem3 15618 | 
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