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| Mirrors > Home > ILE Home > Th. List > cbvrexvw | GIF version | ||
| Description: Version of cbvrexv 2787 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 2299 | . . . 4 ⊢ (𝑥 = 𝑦 → (𝑥 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)) | |
| 2 | cbvralvw.1 | . . . 4 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | |
| 3 | 1, 2 | anbi12d 477 | . . 3 ⊢ (𝑥 = 𝑦 → ((𝑥 ∈ 𝐴 ∧ 𝜑) ↔ (𝑦 ∈ 𝐴 ∧ 𝜓))) |
| 4 | 3 | cbvexvw 1976 | . 2 ⊢ (∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑) ↔ ∃𝑦(𝑦 ∈ 𝐴 ∧ 𝜓)) |
| 5 | df-rex 2534 | . 2 ⊢ (∃𝑥 ∈ 𝐴 𝜑 ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝜑)) | |
| 6 | df-rex 2534 | . 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 1545 ∈ wcel 2209 ∃wrex 2529 |
| 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 1500 ax-gen 1502 ax-ie1 1546 ax-ie2 1547 ax-8 1557 ax-4 1563 ax-17 1579 ax-i9 1583 ax-ial 1587 |
| This theorem depends on definitions: df-bi 117 df-tru 1405 df-nf 1514 df-clel 2234 df-rex 2534 |
| This theorem is referenced by: cbvrex2vw 2798 zsupssdc 10651 prodmodclem2 12322 prodmodc 12323 pceu 13052 4sqlem12 13159 nninfdclemcl 13317 grprida 13684 dfgrp2 13809 dfgrp3mlem 13880 lss1d 14692 2lgslem1b 16122 bj-charfunbi 16751 |
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