Theorem eldmqsres 38310

Description: Elementhood in a restricted domain quotient set. (Contributed by Peter Mazsa, 21-Aug-2020.)

Assertion

Ref	Expression
eldmqsres	⊢ (𝐵 ∈ 𝑉 → (𝐵 ∈ (dom (𝑅 ↾ 𝐴) / (𝑅 ↾ 𝐴)) ↔ ∃𝑢 ∈ 𝐴 (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅)))

Distinct variable groups:   𝑢,𝐴,𝑥   𝑢,𝐵   𝑢,𝑅,𝑥

Allowed substitution hints:   𝐵(𝑥)   𝑉(𝑥,𝑢)

Proof of Theorem eldmqsres

Step	Hyp	Ref	Expression
1		elqsg 8787	. 2 ⊢ (𝐵 ∈ 𝑉 → (𝐵 ∈ (dom (𝑅 ↾ 𝐴) / (𝑅 ↾ 𝐴)) ↔ ∃𝑢 ∈ dom (𝑅 ↾ 𝐴)𝐵 = [𝑢](𝑅 ↾ 𝐴)))
2		eldmres2 38298	. . . . . 6 ⊢ (𝑢 ∈ V → (𝑢 ∈ dom (𝑅 ↾ 𝐴) ↔ (𝑢 ∈ 𝐴 ∧ ∃𝑥 𝑥 ∈ [𝑢]𝑅)))
3	2	elv 3469	. . . . 5 ⊢ (𝑢 ∈ dom (𝑅 ↾ 𝐴) ↔ (𝑢 ∈ 𝐴 ∧ ∃𝑥 𝑥 ∈ [𝑢]𝑅))
4	3	anbi1i 624	. . . 4 ⊢ ((𝑢 ∈ dom (𝑅 ↾ 𝐴) ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)) ↔ ((𝑢 ∈ 𝐴 ∧ ∃𝑥 𝑥 ∈ [𝑢]𝑅) ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)))
5		ecres2 38302	. . . . . . . 8 ⊢ (𝑢 ∈ 𝐴 → [𝑢](𝑅 ↾ 𝐴) = [𝑢]𝑅)
6	5	eqeq2d 2747	. . . . . . 7 ⊢ (𝑢 ∈ 𝐴 → (𝐵 = [𝑢](𝑅 ↾ 𝐴) ↔ 𝐵 = [𝑢]𝑅))
7	6	pm5.32i 574	. . . . . 6 ⊢ ((𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)) ↔ (𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢]𝑅))
8	7	anbi2i 623	. . . . 5 ⊢ ((∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ (𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴))) ↔ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ (𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢]𝑅)))
9		an21 644	. . . . 5 ⊢ (((𝑢 ∈ 𝐴 ∧ ∃𝑥 𝑥 ∈ [𝑢]𝑅) ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)) ↔ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ (𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴))))
10		an12 645	. . . . 5 ⊢ ((𝑢 ∈ 𝐴 ∧ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅)) ↔ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ (𝑢 ∈ 𝐴 ∧ 𝐵 = [𝑢]𝑅)))
11	8, 9, 10	3bitr4i 303	. . . 4 ⊢ (((𝑢 ∈ 𝐴 ∧ ∃𝑥 𝑥 ∈ [𝑢]𝑅) ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)) ↔ (𝑢 ∈ 𝐴 ∧ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅)))
12	4, 11	bitri 275	. . 3 ⊢ ((𝑢 ∈ dom (𝑅 ↾ 𝐴) ∧ 𝐵 = [𝑢](𝑅 ↾ 𝐴)) ↔ (𝑢 ∈ 𝐴 ∧ (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅)))
13	12	rexbii2 3080	. 2 ⊢ (∃𝑢 ∈ dom (𝑅 ↾ 𝐴)𝐵 = [𝑢](𝑅 ↾ 𝐴) ↔ ∃𝑢 ∈ 𝐴 (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅))
14	1, 13	bitrdi 287	1 ⊢ (𝐵 ∈ 𝑉 → (𝐵 ∈ (dom (𝑅 ↾ 𝐴) / (𝑅 ↾ 𝐴)) ↔ ∃𝑢 ∈ 𝐴 (∃𝑥 𝑥 ∈ [𝑢]𝑅 ∧ 𝐵 = [𝑢]𝑅)))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   = wceq 1540  ∃wex 1779   ∈ wcel 2109  ∃wrex 3061  Vcvv 3464  dom cdm 5659   ↾ cres 5661  [cec 8722   / cqs 8723

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-10 2142  ax-11 2158  ax-12 2178  ax-ext 2708  ax-sep 5271  ax-nul 5281  ax-pr 5407

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3an 1088  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2066  df-clab 2715  df-cleq 2728  df-clel 2810  df-ral 3053  df-rex 3062  df-rab 3421  df-v 3466  df-dif 3934  df-un 3936  df-in 3938  df-ss 3948  df-nul 4314  df-if 4506  df-sn 4607  df-pr 4609  df-op 4613  df-br 5125  df-opab 5187  df-xp 5665  df-rel 5666  df-cnv 5667  df-dm 5669  df-rn 5670  df-res 5671  df-ima 5672  df-ec 8726  df-qs 8730

This theorem is referenced by:  eldmqsres2  38311