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| Mirrors > Home > ILE Home > Th. List > elcnv | GIF version | ||
| Description: Membership in a converse. Equation 5 of [Suppes] p. 62. (Contributed by NM, 24-Mar-1998.) |
| Ref | Expression |
|---|---|
| elcnv | ⊢ (𝐴 ∈ ◡𝑅 ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-cnv 4757 | . . 3 ⊢ ◡𝑅 = {〈𝑥, 𝑦〉 ∣ 𝑦𝑅𝑥} | |
| 2 | 1 | eleq2i 2299 | . 2 ⊢ (𝐴 ∈ ◡𝑅 ↔ 𝐴 ∈ {〈𝑥, 𝑦〉 ∣ 𝑦𝑅𝑥}) |
| 3 | elopab 4376 | . 2 ⊢ (𝐴 ∈ {〈𝑥, 𝑦〉 ∣ 𝑦𝑅𝑥} ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥)) | |
| 4 | 2, 3 | bitri 184 | 1 ⊢ (𝐴 ∈ ◡𝑅 ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥)) |
| Colors of variables: wff set class |
| Syntax hints: ∧ wa 104 ↔ wb 105 = wceq 1398 ∃wex 1541 ∈ wcel 2203 〈cop 3692 class class class wbr 4109 {copab 4170 ◡ccnv 4748 |
| 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 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-14 2206 ax-ext 2214 ax-sep 4228 ax-pow 4287 ax-pr 4322 |
| This theorem depends on definitions: df-bi 117 df-3an 1007 df-tru 1401 df-nf 1510 df-sb 1812 df-clab 2219 df-cleq 2225 df-clel 2228 df-nfc 2373 df-v 2815 df-un 3215 df-in 3217 df-ss 3224 df-pw 3671 df-sn 3695 df-pr 3696 df-op 3698 df-opab 4172 df-cnv 4757 |
| This theorem is referenced by: elcnv2 4933 |
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