Theorem cnvco2 36525

Description: Another distributive law of converse over class composition. (Contributed by Scott Fenton, 3-May-2014.)

Assertion

Ref	Expression
cnvco2	⊢ ◡(𝐴 ∘ ◡𝐵) = (𝐵 ∘ ◡𝐴)

Proof of Theorem cnvco2

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

Step	Hyp	Ref	Expression
1		relcnv 6099	. 2 ⊢ Rel ◡(𝐴 ∘ ◡𝐵)
2		relco 6103	. 2 ⊢ Rel (𝐵 ∘ ◡𝐴)
3		vex 3454	. . . . . 6 ⊢ 𝑦 ∈ V
4		vex 3454	. . . . . 6 ⊢ 𝑧 ∈ V
5	3, 4	brcnv 5859	. . . . 5 ⊢ (𝑦◡𝐵𝑧 ↔ 𝑧𝐵𝑦)
6		vex 3454	. . . . . . 7 ⊢ 𝑥 ∈ V
7	6, 4	brcnv 5859	. . . . . 6 ⊢ (𝑥◡𝐴𝑧 ↔ 𝑧𝐴𝑥)
8	7	bicomi 227	. . . . 5 ⊢ (𝑧𝐴𝑥 ↔ 𝑥◡𝐴𝑧)
9	5, 8	anbi12ci 641	. . . 4 ⊢ ((𝑦◡𝐵𝑧 ∧ 𝑧𝐴𝑥) ↔ (𝑥◡𝐴𝑧 ∧ 𝑧𝐵𝑦))
10	9	exbii 1880	. . 3 ⊢ (∃𝑧(𝑦◡𝐵𝑧 ∧ 𝑧𝐴𝑥) ↔ ∃𝑧(𝑥◡𝐴𝑧 ∧ 𝑧𝐵𝑦))
11	6, 3	opelcnv 5858	. . . 4 ⊢ (⟨𝑥, 𝑦⟩ ∈ ◡(𝐴 ∘ ◡𝐵) ↔ ⟨𝑦, 𝑥⟩ ∈ (𝐴 ∘ ◡𝐵))
12	3, 6	opelco 5848	. . . 4 ⊢ (⟨𝑦, 𝑥⟩ ∈ (𝐴 ∘ ◡𝐵) ↔ ∃𝑧(𝑦◡𝐵𝑧 ∧ 𝑧𝐴𝑥))
13	11, 12	bitri 278	. . 3 ⊢ (⟨𝑥, 𝑦⟩ ∈ ◡(𝐴 ∘ ◡𝐵) ↔ ∃𝑧(𝑦◡𝐵𝑧 ∧ 𝑧𝐴𝑥))
14	6, 3	opelco 5848	. . 3 ⊢ (⟨𝑥, 𝑦⟩ ∈ (𝐵 ∘ ◡𝐴) ↔ ∃𝑧(𝑥◡𝐴𝑧 ∧ 𝑧𝐵𝑦))
15	10, 13, 14	3bitr4i 306	. 2 ⊢ (⟨𝑥, 𝑦⟩ ∈ ◡(𝐴 ∘ ◡𝐵) ↔ ⟨𝑥, 𝑦⟩ ∈ (𝐵 ∘ ◡𝐴))
16	1, 2, 15	eqrelriiv 5765	1 ⊢ ◡(𝐴 ∘ ◡𝐵) = (𝐵 ∘ ◡𝐴)

This proof depends on syntax axioms:   ∧ wa 401   = wceq 1569  ∃wex 1811   ∈ wcel 2144  ⟨cop 4589   class class class wbr 5102  ^◡ccnv 5649   ∘ ccom 5654

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-ext 2732  ax-sep 5248  ax-pr 5390

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-sb 2099  df-clab 2739  df-cleq 2752  df-clel 2835  df-rab 3413  df-v 3452  df-ss 3896  df-dif 4047  df-in 4091  df-un 4151  df-nul 4279  df-if 4482  df-sn 4584  df-pr 4586  df-op 4590  df-br 5103  df-opab 5167  df-xp 5656  df-rel 5657  df-cnv 5658  df-co 5659

This theorem is used by: (None)