Theorem mosubopt 5515

Description: "At most one" remains true inside ordered pair quantification. (Contributed by NM, 28-Aug-2007.)

Assertion

Ref	Expression
mosubopt	⊢ (∀𝑦∀𝑧∃*𝑥𝜑 → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑))

Distinct variable group:   𝑥,𝑦,𝑧,𝐴

Allowed substitution hints:   𝜑(𝑥,𝑦,𝑧)

Proof of Theorem mosubopt

Step	Hyp	Ref	Expression
1		nfa1 2151	. . 3 ⊢ Ⅎ𝑦∀𝑦∀𝑧∃*𝑥𝜑
2		nfe1 2150	. . . 4 ⊢ Ⅎ𝑦∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
3	2	nfmov 2560	. . 3 ⊢ Ⅎ𝑦∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
4		nfa1 2151	. . . . 5 ⊢ Ⅎ𝑧∀𝑧∃*𝑥𝜑
5		nfe1 2150	. . . . . . 7 ⊢ Ⅎ𝑧∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
6	5	nfex 2324	. . . . . 6 ⊢ Ⅎ𝑧∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
7	6	nfmov 2560	. . . . 5 ⊢ Ⅎ𝑧∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
8		copsexgw 5495	. . . . . . . 8 ⊢ (𝐴 = ⟨𝑦, 𝑧⟩ → (𝜑 ↔ ∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
9	8	mobidv 2549	. . . . . . 7 ⊢ (𝐴 = ⟨𝑦, 𝑧⟩ → (∃*𝑥𝜑 ↔ ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
10	9	biimpcd 249	. . . . . 6 ⊢ (∃*𝑥𝜑 → (𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
11	10	sps 2185	. . . . 5 ⊢ (∀𝑧∃*𝑥𝜑 → (𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
12	4, 7, 11	exlimd 2218	. . . 4 ⊢ (∀𝑧∃*𝑥𝜑 → (∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
13	12	sps 2185	. . 3 ⊢ (∀𝑦∀𝑧∃*𝑥𝜑 → (∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
14	1, 3, 13	exlimd 2218	. 2 ⊢ (∀𝑦∀𝑧∃*𝑥𝜑 → (∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
15		simpl 482	. . . . 5 ⊢ ((𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → 𝐴 = ⟨𝑦, 𝑧⟩)
16	15	2eximi 1836	. . . 4 ⊢ (∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → ∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩)
17	16	exlimiv 1930	. . 3 ⊢ (∃𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → ∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩)
18		nexmo 2541	. . 3 ⊢ (¬ ∃𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑))
19	17, 18	nsyl5 159	. 2 ⊢ (¬ ∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑))
20	14, 19	pm2.61d1 180	1 ⊢ (∀𝑦∀𝑧∃*𝑥𝜑 → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑))

Syntax hints:   → wi 4   ∧ wa 395  ∀wal 1538   = wceq 1540  ∃wex 1779  ∃*wmo 2538  ⟨cop 4632

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-mo 2540  df-eu 2569  df-clab 2715  df-cleq 2729  df-clel 2816  df-rab 3437  df-v 3482  df-dif 3954  df-un 3956  df-ss 3968  df-nul 4334  df-if 4526  df-sn 4627  df-pr 4629  df-op 4633

This theorem is referenced by:  mosubop  5516  funoprabg  7554