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Mirrors > Home > ILE Home > Th. List > elcnv2 | GIF version |
Description: Membership in a converse. Equation 5 of [Suppes] p. 62. (Contributed by NM, 11-Aug-2004.) |
Ref | Expression |
---|---|
elcnv2 | ⊢ (𝐴 ∈ ◡𝑅 ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 〈𝑦, 𝑥〉 ∈ 𝑅)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elcnv 4540 | . 2 ⊢ (𝐴 ∈ ◡𝑅 ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥)) | |
2 | df-br 3794 | . . . 4 ⊢ (𝑦𝑅𝑥 ↔ 〈𝑦, 𝑥〉 ∈ 𝑅) | |
3 | 2 | anbi2i 445 | . . 3 ⊢ ((𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥) ↔ (𝐴 = 〈𝑥, 𝑦〉 ∧ 〈𝑦, 𝑥〉 ∈ 𝑅)) |
4 | 3 | 2exbii 1538 | . 2 ⊢ (∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 𝑦𝑅𝑥) ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 〈𝑦, 𝑥〉 ∈ 𝑅)) |
5 | 1, 4 | bitri 182 | 1 ⊢ (𝐴 ∈ ◡𝑅 ↔ ∃𝑥∃𝑦(𝐴 = 〈𝑥, 𝑦〉 ∧ 〈𝑦, 𝑥〉 ∈ 𝑅)) |
Colors of variables: wff set class |
Syntax hints: ∧ wa 102 ↔ wb 103 = wceq 1285 ∃wex 1422 ∈ wcel 1434 〈cop 3409 class class class wbr 3793 ◡ccnv 4370 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 663 ax-5 1377 ax-7 1378 ax-gen 1379 ax-ie1 1423 ax-ie2 1424 ax-8 1436 ax-10 1437 ax-11 1438 ax-i12 1439 ax-bndl 1440 ax-4 1441 ax-14 1446 ax-17 1460 ax-i9 1464 ax-ial 1468 ax-i5r 1469 ax-ext 2064 ax-sep 3904 ax-pow 3956 ax-pr 3972 |
This theorem depends on definitions: df-bi 115 df-3an 922 df-tru 1288 df-nf 1391 df-sb 1687 df-clab 2069 df-cleq 2075 df-clel 2078 df-nfc 2209 df-v 2604 df-un 2978 df-in 2980 df-ss 2987 df-pw 3392 df-sn 3412 df-pr 3413 df-op 3415 df-br 3794 df-opab 3848 df-cnv 4379 |
This theorem is referenced by: cnvuni 4549 |
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