Theorem eliunxp2 48250

Description: Membership in a union of Cartesian products over its second component, analogous to eliunxp 5848. (Contributed by AV, 30-Mar-2019.)

Assertion

Ref	Expression
eliunxp2	⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ ∃𝑥∃𝑦(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝑥,𝑦,𝐶

Allowed substitution hints:   𝐴(𝑦)   𝐵(𝑦)

Proof of Theorem eliunxp2

Step	Hyp	Ref	Expression
1		relxp 5703	. . . . . . . 8 ⊢ Rel (𝐴 × {𝑦})
2	1	rgenw 3065	. . . . . . 7 ⊢ ∀𝑦 ∈ 𝐵 Rel (𝐴 × {𝑦})
3		reliun 5826	. . . . . . 7 ⊢ (Rel ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ ∀𝑦 ∈ 𝐵 Rel (𝐴 × {𝑦}))
4	2, 3	mpbir 231	. . . . . 6 ⊢ Rel ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})
5		elrel 5808	. . . . . 6 ⊢ ((Rel ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) → ∃𝑥∃𝑦 𝐶 = ⟨𝑥, 𝑦⟩)
6	4, 5	mpan 690	. . . . 5 ⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) → ∃𝑥∃𝑦 𝐶 = ⟨𝑥, 𝑦⟩)
7		excom 2162	. . . . 5 ⊢ (∃𝑦∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ↔ ∃𝑥∃𝑦 𝐶 = ⟨𝑥, 𝑦⟩)
8	6, 7	sylibr 234	. . . 4 ⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) → ∃𝑦∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩)
9	8	pm4.71ri 560	. . 3 ⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ (∃𝑦∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})))
10		nfiu1 5027	. . . . 5 ⊢ Ⅎ𝑦∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})
11	10	nfel2 2924	. . . 4 ⊢ Ⅎ𝑦 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})
12	11	19.41 2235	. . 3 ⊢ (∃𝑦(∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ (∃𝑦∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})))
13		19.41v 1949	. . . . 5 ⊢ (∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ (∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})))
14		eleq1 2829	. . . . . . . 8 ⊢ (𝐶 = ⟨𝑥, 𝑦⟩ → (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ ⟨𝑥, 𝑦⟩ ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})))
15		opeliun2xp 5753	. . . . . . . . 9 ⊢ (⟨𝑥, 𝑦⟩ ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ (𝑦 ∈ 𝐵 ∧ 𝑥 ∈ 𝐴))
16	15	biancomi 462	. . . . . . . 8 ⊢ (⟨𝑥, 𝑦⟩ ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵))
17	14, 16	bitrdi 287	. . . . . . 7 ⊢ (𝐶 = ⟨𝑥, 𝑦⟩ → (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
18	17	pm5.32i 574	. . . . . 6 ⊢ ((𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ (𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
19	18	exbii 1848	. . . . 5 ⊢ (∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ ∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
20	13, 19	bitr3i 277	. . . 4 ⊢ ((∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ ∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
21	20	exbii 1848	. . 3 ⊢ (∃𝑦(∃𝑥 𝐶 = ⟨𝑥, 𝑦⟩ ∧ 𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦})) ↔ ∃𝑦∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
22	9, 12, 21	3bitr2i 299	. 2 ⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ ∃𝑦∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
23		excom 2162	. 2 ⊢ (∃𝑦∃𝑥(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)) ↔ ∃𝑥∃𝑦(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))
24	22, 23	bitri 275	1 ⊢ (𝐶 ∈ ∪ 𝑦 ∈ 𝐵 (𝐴 × {𝑦}) ↔ ∃𝑥∃𝑦(𝐶 = ⟨𝑥, 𝑦⟩ ∧ (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐵)))

Syntax hints:   ↔ wb 206   ∧ wa 395   = wceq 1540  ∃wex 1779   ∈ wcel 2108  ∀wral 3061  {csn 4626  ⟨cop 4632  ∪ ciun 4991   × cxp 5683  Rel wrel 5690

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 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-11 2157  ax-12 2177  ax-ext 2708  ax-sep 5296  ax-nul 5306  ax-pr 5432

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 849  df-3an 1089  df-tru 1543  df-fal 1553  df-ex 1780  df-nf 1784  df-sb 2065  df-clab 2715  df-cleq 2729  df-clel 2816  df-nfc 2892  df-ral 3062  df-rex 3071  df-rab 3437  df-v 3482  df-sbc 3789  df-csb 3900  df-dif 3954  df-un 3956  df-ss 3968  df-nul 4334  df-if 4526  df-sn 4627  df-pr 4629  df-op 4633  df-iun 4993  df-opab 5206  df-xp 5691  df-rel 5692

This theorem is referenced by:  mpomptx2  48251