Theorem mosubopt 5529

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 2152	. . 3 ⊢ Ⅎ𝑦∀𝑦∀𝑧∃*𝑥𝜑
2		nfe1 2151	. . . 4 ⊢ Ⅎ𝑦∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
3	2	nfmov 2563	. . 3 ⊢ Ⅎ𝑦∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
4		nfa1 2152	. . . . 5 ⊢ Ⅎ𝑧∀𝑧∃*𝑥𝜑
5		nfe1 2151	. . . . . . 7 ⊢ Ⅎ𝑧∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
6	5	nfex 2328	. . . . . 6 ⊢ Ⅎ𝑧∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
7	6	nfmov 2563	. . . . 5 ⊢ Ⅎ𝑧∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)
8		copsexgw 5510	. . . . . . . 8 ⊢ (𝐴 = ⟨𝑦, 𝑧⟩ → (𝜑 ↔ ∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
9	8	mobidv 2552	. . . . . . 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 2186	. . . . 5 ⊢ (∀𝑧∃*𝑥𝜑 → (𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
12	4, 7, 11	exlimd 2219	. . . 4 ⊢ (∀𝑧∃*𝑥𝜑 → (∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
13	12	sps 2186	. . 3 ⊢ (∀𝑦∀𝑧∃*𝑥𝜑 → (∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩ → ∃*𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑)))
14	1, 3, 13	exlimd 2219	. 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 1834	. . . 4 ⊢ (∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → ∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩)
17	16	exlimiv 1929	. . 3 ⊢ (∃𝑥∃𝑦∃𝑧(𝐴 = ⟨𝑦, 𝑧⟩ ∧ 𝜑) → ∃𝑦∃𝑧 𝐴 = ⟨𝑦, 𝑧⟩)
18		nexmo 2544	. . 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 1535   = wceq 1537  ∃wex 1777  ∃*wmo 2541  ⟨cop 4654

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-11 2158  ax-12 2178  ax-ext 2711  ax-sep 5317  ax-nul 5324  ax-pr 5447

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 847  df-3an 1089  df-tru 1540  df-fal 1550  df-ex 1778  df-nf 1782  df-sb 2065  df-mo 2543  df-eu 2572  df-clab 2718  df-cleq 2732  df-clel 2819  df-rab 3444  df-v 3490  df-dif 3979  df-un 3981  df-ss 3993  df-nul 4353  df-if 4549  df-sn 4649  df-pr 4651  df-op 4655

This theorem is referenced by:  mosubop  5530  funoprabg  7571