Theorem cnvco 5874

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 1890	. . . 4 ⊢ (∃𝑧(𝑥𝐵𝑧 ∧ 𝑧𝐴𝑦) ↔ ∃𝑧(𝑧𝐴𝑦 ∧ 𝑥𝐵𝑧))
2		vex 3458	. . . . 5 ⊢ 𝑥 ∈ V
3		vex 3458	. . . . 5 ⊢ 𝑦 ∈ V
4	2, 3	brco 5855	. . . 4 ⊢ (𝑥(𝐴 ∘ 𝐵)𝑦 ↔ ∃𝑧(𝑥𝐵𝑧 ∧ 𝑧𝐴𝑦))
5		vex 3458	. . . . . . 7 ⊢ 𝑧 ∈ V
6	3, 5	brcnv 5867	. . . . . 6 ⊢ (𝑦◡𝐴𝑧 ↔ 𝑧𝐴𝑦)
7	5, 2	brcnv 5867	. . . . . 6 ⊢ (𝑧◡𝐵𝑥 ↔ 𝑥𝐵𝑧)
8	6, 7	anbi12i 639	. . . . 5 ⊢ ((𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥) ↔ (𝑧𝐴𝑦 ∧ 𝑥𝐵𝑧))
9	8	exbii 1877	. . . 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 5668	. 2 ⊢ ◡(𝐴 ∘ 𝐵) = {⟨𝑦, 𝑥⟩ ∣ 𝑥(𝐴 ∘ 𝐵)𝑦}
13		df-co 5669	. 2 ⊢ (◡𝐵 ∘ ◡𝐴) = {⟨𝑦, 𝑥⟩ ∣ ∃𝑧(𝑦◡𝐴𝑧 ∧ 𝑧◡𝐵𝑥)}
14	11, 12, 13	3eqtr4i 2795	1 ⊢ ◡(𝐴 ∘ 𝐵) = (◡𝐵 ∘ ◡𝐴)

This proof depends on syntax axioms:   ∧ wa 400   = wceq 1569  ∃wex 1808   class class class wbr 5108  {copab 5172  ^◡ccnv 5659   ∘ ccom 5664

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-ext 2734  ax-sep 5256  ax-pr 5403

This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1104  df-tru 1572  df-fal 1582  df-ex 1809  df-sb 2096  df-clab 2741  df-cleq 2754  df-clel 2837  df-rab 3416  df-v 3456  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 5668  df-co 5669

This theorem is used by:  rncoss  5966  rncoeq  5970  dmco  6255  cores2  6260  co01  6262  coi2  6264  relcnvtrg  6267  relcnvtrgOLD  6268  dfdm2  6282  f1cof1  6786  cofunex2g  7945  fparlem3  8107  fparlem4  8108  suppco  8200  fsuppcolem  9359  relexpcnv  15079  relexpaddg  15097  cnvps  18640  gimco  19344  gsumzf1o  19988  rimco  20606  cnco  23434  ptrescn  23807  qtopcn  23882  hmeoco  23940  cncombf  25828  deg1val  26264  fcoinver  32960  ofpreima  33021  cycpmconjv  33471  cycpmconjs  33485  cyc3conja  33486  esplysply  33970  mbfmco  34663  eulerpartlemmf  34774  cvmliftmolem1  35781  cvmlift2lem9a  35803  cvmlift2lem9  35811  mclsppslem  36083  ftc1anclem3  38374  trlcocnv  41522  tendoicl  41598  cdlemk45  41749  cononrel1  44348  cononrel2  44349  cnvtrcl0  44380  cnvtrrel  44424  relexpaddss  44472  frege131d  44518  brco2f1o  44786  brco3f1o  44787  clsneicnv  44859  neicvgnvo  44869  smfco  47544  upgrimpthslem1  48700  upgrimspths  48703