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Theorem cnvun 4914
Description: The converse of a union is the union of converses. Theorem 16 of [Suppes] p. 62. (Contributed by NM, 25-Mar-1998.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
Assertion
Ref Expression
cnvun (𝐴𝐵) = (𝐴𝐵)

Proof of Theorem cnvun
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 df-cnv 4517 . . 3 (𝐴𝐵) = {⟨𝑥, 𝑦⟩ ∣ 𝑦(𝐴𝐵)𝑥}
2 unopab 3977 . . . 4 ({⟨𝑥, 𝑦⟩ ∣ 𝑦𝐴𝑥} ∪ {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐵𝑥}) = {⟨𝑥, 𝑦⟩ ∣ (𝑦𝐴𝑥𝑦𝐵𝑥)}
3 brun 3949 . . . . 5 (𝑦(𝐴𝐵)𝑥 ↔ (𝑦𝐴𝑥𝑦𝐵𝑥))
43opabbii 3965 . . . 4 {⟨𝑥, 𝑦⟩ ∣ 𝑦(𝐴𝐵)𝑥} = {⟨𝑥, 𝑦⟩ ∣ (𝑦𝐴𝑥𝑦𝐵𝑥)}
52, 4eqtr4i 2141 . . 3 ({⟨𝑥, 𝑦⟩ ∣ 𝑦𝐴𝑥} ∪ {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐵𝑥}) = {⟨𝑥, 𝑦⟩ ∣ 𝑦(𝐴𝐵)𝑥}
61, 5eqtr4i 2141 . 2 (𝐴𝐵) = ({⟨𝑥, 𝑦⟩ ∣ 𝑦𝐴𝑥} ∪ {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐵𝑥})
7 df-cnv 4517 . . 3 𝐴 = {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐴𝑥}
8 df-cnv 4517 . . 3 𝐵 = {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐵𝑥}
97, 8uneq12i 3198 . 2 (𝐴𝐵) = ({⟨𝑥, 𝑦⟩ ∣ 𝑦𝐴𝑥} ∪ {⟨𝑥, 𝑦⟩ ∣ 𝑦𝐵𝑥})
106, 9eqtr4i 2141 1 (𝐴𝐵) = (𝐴𝐵)
Colors of variables: wff set class
Syntax hints:  wo 682   = wceq 1316  cun 3039   class class class wbr 3899  {copab 3958  ccnv 4508
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099
This theorem depends on definitions:  df-bi 116  df-tru 1319  df-nf 1422  df-sb 1721  df-clab 2104  df-cleq 2110  df-clel 2113  df-nfc 2247  df-v 2662  df-un 3045  df-br 3900  df-opab 3960  df-cnv 4517
This theorem is referenced by:  rnun  4917  f1oun  5355  sbthlemi8  6820  caseinj  6942  djuinj  6959
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