Theorem cnvco 5875

Description: Distributive law of converse over class composition. Theorem 26 of [Suppes] p. 64. (Contributed by NM, 19-Mar-1998.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)

Assertion

Ref	Expression
cnvco	⊢ ◡(𝐴 ∘ 𝐵) = (◡𝐵 ∘ ◡𝐴)

Proof of Theorem cnvco

Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		exancom 1889	. . . 4 ⊢ (∃𝑧(𝑥𝐵𝑧 ∧ 𝑧𝐴𝑦) ↔ ∃𝑧(𝑧𝐴𝑦 ∧ 𝑥𝐵𝑧))
2		vex 3457	. . . . 5 ⊢ 𝑥 ∈ V
3		vex 3457	. . . . 5 ⊢ 𝑦 ∈ V
4	2, 3	brco 5856	. . . 4 ⊢ (𝑥(𝐴 ∘ 𝐵)𝑦 ↔ ∃𝑧(𝑥𝐵𝑧 ∧ 𝑧𝐴𝑦))
5		vex 3457	. . . . . . 7 ⊢ 𝑧 ∈ V
6	3, 5	brcnv 5868	. . . . . 6 ⊢ (𝑦◡𝐴𝑧 ↔ 𝑧𝐴𝑦)
7	5, 2	brcnv 5868	. . . . . 6 ⊢ (𝑧◡𝐵𝑥 ↔ 𝑥𝐵𝑧)
8	6, 7	anbi12i 639	. . . . 5 ⊢ ((𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥) ↔ (𝑧𝐴𝑦 ∧ 𝑥𝐵𝑧))
9	8	exbii 1876	. . . 4 ⊢ (∃𝑧(𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥) ↔ ∃𝑧(𝑧𝐴𝑦 ∧ 𝑥𝐵𝑧))
10	1, 4, 9	3bitr4i 306	. . 3 ⊢ (𝑥(𝐴 ∘ 𝐵)𝑦 ↔ ∃𝑧(𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥))
11	10	opabbii 5177	. 2 ⊢ {⟨𝑦, 𝑥⟩ ∣ 𝑥(𝐴 ∘ 𝐵)𝑦} = {⟨𝑦, 𝑥⟩ ∣ ∃𝑧(𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥)}
12		df-cnv 5669	. 2 ⊢ ◡(𝐴 ∘ 𝐵) = {⟨𝑦, 𝑥⟩ ∣ 𝑥(𝐴 ∘ 𝐵)𝑦}
13		df-co 5670	. 2 ⊢ (◡𝐵 ∘ ◡𝐴) = {⟨𝑦, 𝑥⟩ ∣ ∃𝑧(𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥)}
14	11, 12, 13	3eqtr4i 2794	1 ⊢ ◡(𝐴 ∘ 𝐵) = (◡𝐵 ∘ ◡𝐴)

Syntax hints:   ∧ wa 400   = wceq 1568  ∃wex 1807   class class class wbr 5108  {copab 5172  ^◡ccnv 5660   ∘ ccom 5665

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-8 2143  ax-9 2151  ax-ext 2733  ax-sep 5256  ax-pr 5404

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1103  df-tru 1571  df-fal 1581  df-ex 1808  df-sb 2095  df-clab 2740  df-cleq 2753  df-clel 2836  df-rab 3415  df-v 3455  df-dif 3907  df-un 3909  df-in 3911  df-ss 3921  df-nul 4286  df-if 4487  df-sn 4589  df-pr 4591  df-op 4595  df-br 5109  df-opab 5173  df-cnv 5669  df-co 5670

This theorem is referenced by:  rncoss  5967  rncoeq  5971  dmco  6256  cores2  6261  co01  6263  coi2  6265  relcnvtrg  6268  dfdm2  6282  f1cof1  6786  cofunex2g  7946  fparlem3  8108  fparlem4  8109  suppco  8201  fsuppcolem  9360  relexpcnv  15071  relexpaddg  15089  cnvps  18633  gimco  19337  gsumzf1o  19981  cnco  23402  ptrescn  23775  qtopcn  23850  hmeoco  23908  cncombf  25796  deg1val  26232  fcoinver  32915  ofpreima  32976  cycpmconjv  33428  cycpmconjs  33442  cyc3conja  33443  esplysply  33927  mbfmco  34620  eulerpartlemmf  34731  cvmliftmolem1  35727  cvmlift2lem9a  35749  cvmlift2lem9  35757  mclsppslem  36029  ftc1anclem3  38290  trlcocnv  41440  tendoicl  41516  cdlemk45  41667  rimco  43235  cononrel1  44268  cononrel2  44269  cnvtrcl0  44300  cnvtrrel  44344  relexpaddss  44392  frege131d  44438  brco2f1o  44706  brco3f1o  44707  clsneicnv  44779  neicvgnvo  44789  smfco  47464  upgrimpthslem1  48617  upgrimspths  48620