Theorem funsndifnop 7023

Description: A singleton of an ordered pair is not an ordered pair if the components are different. (Contributed by AV, 23-Sep-2020.) (Avoid depending on this detail.)

Hypotheses

Ref	Expression
funsndifnop.a	⊢ 𝐴 ∈ V
funsndifnop.b	⊢ 𝐵 ∈ V
funsndifnop.g	⊢ 𝐺 = {⟨𝐴, 𝐵⟩}

Assertion

Ref	Expression
funsndifnop	⊢ (𝐴 ≠ 𝐵 → ¬ 𝐺 ∈ (V × V))

Proof of Theorem funsndifnop

Dummy variables 𝑎 𝑥 𝑦 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		elvv 5661	. . 3 ⊢ (𝐺 ∈ (V × V) ↔ ∃𝑥∃𝑦 𝐺 = ⟨𝑥, 𝑦⟩)
2		funsndifnop.g	. . . . . 6 ⊢ 𝐺 = {⟨𝐴, 𝐵⟩}
3		funsndifnop.a	. . . . . . . 8 ⊢ 𝐴 ∈ V
4		funsndifnop.b	. . . . . . . 8 ⊢ 𝐵 ∈ V
5	3, 4	funsn 6487	. . . . . . 7 ⊢ Fun {⟨𝐴, 𝐵⟩}
6		funeq 6454	. . . . . . 7 ⊢ (𝐺 = {⟨𝐴, 𝐵⟩} → (Fun 𝐺 ↔ Fun {⟨𝐴, 𝐵⟩}))
7	5, 6	mpbiri 257	. . . . . 6 ⊢ (𝐺 = {⟨𝐴, 𝐵⟩} → Fun 𝐺)
8	2, 7	ax-mp 5	. . . . 5 ⊢ Fun 𝐺
9		funeq 6454	. . . . . . 7 ⊢ (𝐺 = ⟨𝑥, 𝑦⟩ → (Fun 𝐺 ↔ Fun ⟨𝑥, 𝑦⟩))
10		vex 3436	. . . . . . . 8 ⊢ 𝑥 ∈ V
11		vex 3436	. . . . . . . 8 ⊢ 𝑦 ∈ V
12	10, 11	funop 7021	. . . . . . 7 ⊢ (Fun ⟨𝑥, 𝑦⟩ ↔ ∃𝑎(𝑥 = {𝑎} ∧ ⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩}))
13	9, 12	bitrdi 287	. . . . . 6 ⊢ (𝐺 = ⟨𝑥, 𝑦⟩ → (Fun 𝐺 ↔ ∃𝑎(𝑥 = {𝑎} ∧ ⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩})))
14		eqeq2 2750	. . . . . . . . . . 11 ⊢ (⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩} → (𝐺 = ⟨𝑥, 𝑦⟩ ↔ 𝐺 = {⟨𝑎, 𝑎⟩}))
15		eqeq1 2742	. . . . . . . . . . . . 13 ⊢ (𝐺 = {⟨𝐴, 𝐵⟩} → (𝐺 = {⟨𝑎, 𝑎⟩} ↔ {⟨𝐴, 𝐵⟩} = {⟨𝑎, 𝑎⟩}))
16		opex 5379	. . . . . . . . . . . . . . 15 ⊢ ⟨𝐴, 𝐵⟩ ∈ V
17	16	sneqr 4771	. . . . . . . . . . . . . 14 ⊢ ({⟨𝐴, 𝐵⟩} = {⟨𝑎, 𝑎⟩} → ⟨𝐴, 𝐵⟩ = ⟨𝑎, 𝑎⟩)
18	3, 4	opth 5391	. . . . . . . . . . . . . . 15 ⊢ (⟨𝐴, 𝐵⟩ = ⟨𝑎, 𝑎⟩ ↔ (𝐴 = 𝑎 ∧ 𝐵 = 𝑎))
19		eqtr3 2764	. . . . . . . . . . . . . . . 16 ⊢ ((𝐴 = 𝑎 ∧ 𝐵 = 𝑎) → 𝐴 = 𝐵)
20	19	a1d 25	. . . . . . . . . . . . . . 15 ⊢ ((𝐴 = 𝑎 ∧ 𝐵 = 𝑎) → (𝑥 = {𝑎} → 𝐴 = 𝐵))
21	18, 20	sylbi 216	. . . . . . . . . . . . . 14 ⊢ (⟨𝐴, 𝐵⟩ = ⟨𝑎, 𝑎⟩ → (𝑥 = {𝑎} → 𝐴 = 𝐵))
22	17, 21	syl 17	. . . . . . . . . . . . 13 ⊢ ({⟨𝐴, 𝐵⟩} = {⟨𝑎, 𝑎⟩} → (𝑥 = {𝑎} → 𝐴 = 𝐵))
23	15, 22	syl6bi 252	. . . . . . . . . . . 12 ⊢ (𝐺 = {⟨𝐴, 𝐵⟩} → (𝐺 = {⟨𝑎, 𝑎⟩} → (𝑥 = {𝑎} → 𝐴 = 𝐵)))
24	2, 23	ax-mp 5	. . . . . . . . . . 11 ⊢ (𝐺 = {⟨𝑎, 𝑎⟩} → (𝑥 = {𝑎} → 𝐴 = 𝐵))
25	14, 24	syl6bi 252	. . . . . . . . . 10 ⊢ (⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩} → (𝐺 = ⟨𝑥, 𝑦⟩ → (𝑥 = {𝑎} → 𝐴 = 𝐵)))
26	25	com23 86	. . . . . . . . 9 ⊢ (⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩} → (𝑥 = {𝑎} → (𝐺 = ⟨𝑥, 𝑦⟩ → 𝐴 = 𝐵)))
27	26	impcom 408	. . . . . . . 8 ⊢ ((𝑥 = {𝑎} ∧ ⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩}) → (𝐺 = ⟨𝑥, 𝑦⟩ → 𝐴 = 𝐵))
28	27	exlimiv 1933	. . . . . . 7 ⊢ (∃𝑎(𝑥 = {𝑎} ∧ ⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩}) → (𝐺 = ⟨𝑥, 𝑦⟩ → 𝐴 = 𝐵))
29	28	com12 32	. . . . . 6 ⊢ (𝐺 = ⟨𝑥, 𝑦⟩ → (∃𝑎(𝑥 = {𝑎} ∧ ⟨𝑥, 𝑦⟩ = {⟨𝑎, 𝑎⟩}) → 𝐴 = 𝐵))
30	13, 29	sylbid 239	. . . . 5 ⊢ (𝐺 = ⟨𝑥, 𝑦⟩ → (Fun 𝐺 → 𝐴 = 𝐵))
31	8, 30	mpi 20	. . . 4 ⊢ (𝐺 = ⟨𝑥, 𝑦⟩ → 𝐴 = 𝐵)
32	31	exlimivv 1935	. . 3 ⊢ (∃𝑥∃𝑦 𝐺 = ⟨𝑥, 𝑦⟩ → 𝐴 = 𝐵)
33	1, 32	sylbi 216	. 2 ⊢ (𝐺 ∈ (V × V) → 𝐴 = 𝐵)
34	33	necon3ai 2968	1 ⊢ (𝐴 ≠ 𝐵 → ¬ 𝐺 ∈ (V × V))

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 396   = wceq 1539  ∃wex 1782   ∈ wcel 2106   ≠ wne 2943  Vcvv 3432  {csn 4561  ⟨cop 4567   × cxp 5587  Fun wfun 6427

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1798  ax-4 1812  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-11 2154  ax-12 2171  ax-ext 2709  ax-sep 5223  ax-nul 5230  ax-pr 5352

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 845  df-3an 1088  df-tru 1542  df-fal 1552  df-ex 1783  df-nf 1787  df-sb 2068  df-mo 2540  df-eu 2569  df-clab 2716  df-cleq 2730  df-clel 2816  df-nfc 2889  df-ne 2944  df-ral 3069  df-rex 3070  df-reu 3072  df-rab 3073  df-v 3434  df-sbc 3717  df-csb 3833  df-dif 3890  df-un 3892  df-in 3894  df-ss 3904  df-nul 4257  df-if 4460  df-sn 4562  df-pr 4564  df-op 4568  df-uni 4840  df-iun 4926  df-br 5075  df-opab 5137  df-mpt 5158  df-id 5489  df-xp 5595  df-rel 5596  df-cnv 5597  df-co 5598  df-dm 5599  df-rn 5600  df-iota 6391  df-fun 6435  df-fn 6436  df-f 6437  df-f1 6438  df-fo 6439  df-f1o 6440  df-fv 6441

This theorem is referenced by:  funsneqopb  7024  snstrvtxval  27407  snstriedgval  27408