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| Mirrors > Home > ILE Home > Th. List > cbvrexvw | GIF version | ||
| Description: Version of cbvrexv 2738 with a disjoint variable condition. (Contributed by GG, 10-Jan-2024.) Reduce axiom usage. (Revised by GG, 25-Aug-2024.) |
| Ref | Expression |
|---|---|
| cbvralvw.1 | ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) |
| Ref | Expression |
|---|---|
| cbvrexvw | ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑦 ∈ 𝐴 𝜓) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eleq1w 2265 | . . . 4 ⊢ (𝑥 = 𝑦 → (𝑥 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)) | |
| 2 | cbvralvw.1 | . . . 4 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | |
| 3 | 1, 2 | anbi12d 473 | . . 3 ⊢ (𝑥 = 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝜑) ↔ (𝑦 ∈ 𝐴 ∧ 𝜓))) |
| 4 | 3 | cbvexvw 1943 | . 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝜓)) |
| 5 | df-rex 2489 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 6 | df-rex 2489 | . 2 ⊢ (∃𝑦 ∈ 𝐴 𝜓 ↔ ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝜓)) | |
| 7 | 4, 5, 6 | 3bitr4i 212 | 1 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑦 ∈ 𝐴 𝜓) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∧ wa 104 ↔ wb 105 ∃wex 1514 ∈ wcel 2175 ∃wrex 2484 |
| 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-5 1469 ax-gen 1471 ax-ie1 1515 ax-ie2 1516 ax-8 1526 ax-4 1532 ax-17 1548 ax-i9 1552 ax-ial 1556 |
| This theorem depends on definitions: df-bi 117 df-tru 1375 df-nf 1483 df-clel 2200 df-rex 2489 |
| This theorem is referenced by: cbvrex2vw 2749 zsupssdc 10362 prodmodclem2 11807 prodmodc 11808 pceu 12537 4sqlem12 12644 nninfdclemcl 12738 grprida 13137 dfgrp2 13277 dfgrp3mlem 13348 lss1d 14063 2lgslem1b 15484 bj-charfunbi 15611 |
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