Theorem cononrel2 42331

Description: Composition with the non-relation part of a class is empty. (Contributed by RP, 22-Oct-2020.)

Assertion

Ref	Expression
cononrel2	⊢ (𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = ∅

Proof of Theorem cononrel2

Step	Hyp	Ref	Expression
1		cnvco 5883	. . . 4 ⊢ ◡(𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = (◡(𝐵 ∖ ◡◡𝐵) ∘ ◡𝐴)
2		cnvnonrel 42324	. . . . 5 ⊢ ◡(𝐵 ∖ ◡◡𝐵) = ∅
3	2	coeq1i 5857	. . . 4 ⊢ (◡(𝐵 ∖ ◡◡𝐵) ∘ ◡𝐴) = (∅ ∘ ◡𝐴)
4		co01 6257	. . . 4 ⊢ (∅ ∘ ◡𝐴) = ∅
5	1, 3, 4	3eqtri 2764	. . 3 ⊢ ◡(𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = ∅
6	5	cnveqi 5872	. 2 ⊢ ◡◡(𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = ◡∅
7		relco 6104	. . 3 ⊢ Rel (𝐴 ∘ (𝐵 ∖ ◡◡𝐵))
8		dfrel2 6185	. . 3 ⊢ (Rel (𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) ↔ ◡◡(𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = (𝐴 ∘ (𝐵 ∖ ◡◡𝐵)))
9	7, 8	mpbi 229	. 2 ⊢ ◡◡(𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = (𝐴 ∘ (𝐵 ∖ ◡◡𝐵))
10		cnv0 6137	. 2 ⊢ ◡∅ = ∅
11	6, 9, 10	3eqtr3i 2768	1 ⊢ (𝐴 ∘ (𝐵 ∖ ◡◡𝐵)) = ∅

Syntax hints:   = wceq 1541   ∖ cdif 3944  ∅c0 4321  ^◡ccnv 5674   ∘ ccom 5679  Rel wrel 5680

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-12 2171  ax-ext 2703  ax-sep 5298  ax-nul 5305  ax-pr 5426

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 846  df-3an 1089  df-tru 1544  df-fal 1554  df-ex 1782  df-sb 2068  df-clab 2710  df-cleq 2724  df-clel 2810  df-rab 3433  df-v 3476  df-dif 3950  df-un 3952  df-in 3954  df-ss 3964  df-nul 4322  df-if 4528  df-sn 4628  df-pr 4630  df-op 4634  df-br 5148  df-opab 5210  df-xp 5681  df-rel 5682  df-cnv 5683  df-co 5684

This theorem is referenced by:  cnvtrcl0  42362