Theorem funpartfun 35931

Description: The functional part of 𝐹 is a function. (Contributed by Scott Fenton, 16-Apr-2014.) (Revised by Mario Carneiro, 19-Apr-2014.) (Proof shortened by Peter Mazsa, 2-Oct-2022.)

Assertion

Ref	Expression
funpartfun	⊢ Fun Funpart𝐹

Proof of Theorem funpartfun

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

Step	Hyp	Ref	Expression
1		relres 5976	. 2 ⊢ Rel (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))
2		vex 3451	. . . . . . 7 ⊢ 𝑧 ∈ V
3	2	brresi 5959	. . . . . 6 ⊢ (𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧 ↔ (𝑥 ∈ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )) ∧ 𝑥𝐹𝑧))
4	3	simprbi 496	. . . . 5 ⊢ (𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧 → 𝑥𝐹𝑧)
5		vex 3451	. . . . . . . 8 ⊢ 𝑦 ∈ V
6	5	brresi 5959	. . . . . . 7 ⊢ (𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ↔ (𝑥 ∈ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )) ∧ 𝑥𝐹𝑦))
7		funpartlem 35930	. . . . . . . 8 ⊢ (𝑥 ∈ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )) ↔ ∃𝑤(𝐹 “ {𝑥}) = {𝑤})
8	7	anbi1i 624	. . . . . . 7 ⊢ ((𝑥 ∈ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )) ∧ 𝑥𝐹𝑦) ↔ (∃𝑤(𝐹 “ {𝑥}) = {𝑤} ∧ 𝑥𝐹𝑦))
9	6, 8	bitri 275	. . . . . 6 ⊢ (𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ↔ (∃𝑤(𝐹 “ {𝑥}) = {𝑤} ∧ 𝑥𝐹𝑦))
10		df-br 5108	. . . . . . . . . . 11 ⊢ (𝑥𝐹𝑦 ↔ ⟨𝑥, 𝑦⟩ ∈ 𝐹)
11		df-br 5108	. . . . . . . . . . 11 ⊢ (𝑥𝐹𝑧 ↔ ⟨𝑥, 𝑧⟩ ∈ 𝐹)
12	10, 11	anbi12i 628	. . . . . . . . . 10 ⊢ ((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) ↔ (⟨𝑥, 𝑦⟩ ∈ 𝐹 ∧ ⟨𝑥, 𝑧⟩ ∈ 𝐹))
13		vex 3451	. . . . . . . . . . . 12 ⊢ 𝑥 ∈ V
14	13, 5	elimasn 6061	. . . . . . . . . . 11 ⊢ (𝑦 ∈ (𝐹 “ {𝑥}) ↔ ⟨𝑥, 𝑦⟩ ∈ 𝐹)
15	13, 2	elimasn 6061	. . . . . . . . . . 11 ⊢ (𝑧 ∈ (𝐹 “ {𝑥}) ↔ ⟨𝑥, 𝑧⟩ ∈ 𝐹)
16	14, 15	anbi12i 628	. . . . . . . . . 10 ⊢ ((𝑦 ∈ (𝐹 “ {𝑥}) ∧ 𝑧 ∈ (𝐹 “ {𝑥})) ↔ (⟨𝑥, 𝑦⟩ ∈ 𝐹 ∧ ⟨𝑥, 𝑧⟩ ∈ 𝐹))
17	12, 16	bitr4i 278	. . . . . . . . 9 ⊢ ((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) ↔ (𝑦 ∈ (𝐹 “ {𝑥}) ∧ 𝑧 ∈ (𝐹 “ {𝑥})))
18		eleq2 2817	. . . . . . . . . . 11 ⊢ ((𝐹 “ {𝑥}) = {𝑤} → (𝑦 ∈ (𝐹 “ {𝑥}) ↔ 𝑦 ∈ {𝑤}))
19		eleq2 2817	. . . . . . . . . . 11 ⊢ ((𝐹 “ {𝑥}) = {𝑤} → (𝑧 ∈ (𝐹 “ {𝑥}) ↔ 𝑧 ∈ {𝑤}))
20	18, 19	anbi12d 632	. . . . . . . . . 10 ⊢ ((𝐹 “ {𝑥}) = {𝑤} → ((𝑦 ∈ (𝐹 “ {𝑥}) ∧ 𝑧 ∈ (𝐹 “ {𝑥})) ↔ (𝑦 ∈ {𝑤} ∧ 𝑧 ∈ {𝑤})))
21		velsn 4605	. . . . . . . . . . 11 ⊢ (𝑦 ∈ {𝑤} ↔ 𝑦 = 𝑤)
22		velsn 4605	. . . . . . . . . . 11 ⊢ (𝑧 ∈ {𝑤} ↔ 𝑧 = 𝑤)
23		equtr2 2027	. . . . . . . . . . 11 ⊢ ((𝑦 = 𝑤 ∧ 𝑧 = 𝑤) → 𝑦 = 𝑧)
24	21, 22, 23	syl2anb 598	. . . . . . . . . 10 ⊢ ((𝑦 ∈ {𝑤} ∧ 𝑧 ∈ {𝑤}) → 𝑦 = 𝑧)
25	20, 24	biimtrdi 253	. . . . . . . . 9 ⊢ ((𝐹 “ {𝑥}) = {𝑤} → ((𝑦 ∈ (𝐹 “ {𝑥}) ∧ 𝑧 ∈ (𝐹 “ {𝑥})) → 𝑦 = 𝑧))
26	17, 25	biimtrid 242	. . . . . . . 8 ⊢ ((𝐹 “ {𝑥}) = {𝑤} → ((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧))
27	26	exlimiv 1930	. . . . . . 7 ⊢ (∃𝑤(𝐹 “ {𝑥}) = {𝑤} → ((𝑥𝐹𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧))
28	27	impl 455	. . . . . 6 ⊢ (((∃𝑤(𝐹 “ {𝑥}) = {𝑤} ∧ 𝑥𝐹𝑦) ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧)
29	9, 28	sylanb 581	. . . . 5 ⊢ ((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥𝐹𝑧) → 𝑦 = 𝑧)
30	4, 29	sylan2 593	. . . 4 ⊢ ((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧) → 𝑦 = 𝑧)
31	30	gen2 1796	. . 3 ⊢ ∀𝑦∀𝑧((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧) → 𝑦 = 𝑧)
32	31	ax-gen 1795	. 2 ⊢ ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧) → 𝑦 = 𝑧)
33		df-funpart 35862	. . . 4 ⊢ Funpart𝐹 = (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))
34	33	funeqi 6537	. . 3 ⊢ (Fun Funpart𝐹 ↔ Fun (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons ))))
35		dffun2 6521	. . 3 ⊢ (Fun (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons ))) ↔ (Rel (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons ))) ∧ ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧) → 𝑦 = 𝑧)))
36	34, 35	bitri 275	. 2 ⊢ (Fun Funpart𝐹 ↔ (Rel (𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons ))) ∧ ∀𝑥∀𝑦∀𝑧((𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑦 ∧ 𝑥(𝐹 ↾ dom ((Image𝐹 ∘ Singleton) ∩ (V × Singletons )))𝑧) → 𝑦 = 𝑧)))
37	1, 32, 36	mpbir2an 711	1 ⊢ Fun Funpart𝐹

Syntax hints:   → wi 4   ∧ wa 395  ∀wal 1538   = wceq 1540  ∃wex 1779   ∈ wcel 2109  Vcvv 3447   ∩ cin 3913  {csn 4589  ⟨cop 4595   class class class wbr 5107   × cxp 5636  dom cdm 5638   ↾ cres 5640   “ cima 5641   ∘ ccom 5642  Rel wrel 5643  Fun wfun 6505  Singletoncsingle 35826   Singletons csingles 35827  Imagecimage 35828  Funpartcfunpart 35837

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 2701  ax-sep 5251  ax-nul 5261  ax-pr 5387  ax-un 7711

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-mo 2533  df-eu 2562  df-clab 2708  df-cleq 2721  df-clel 2803  df-nfc 2878  df-ne 2926  df-ral 3045  df-rex 3054  df-rab 3406  df-v 3449  df-dif 3917  df-un 3919  df-in 3921  df-ss 3931  df-symdif 4216  df-nul 4297  df-if 4489  df-sn 4590  df-pr 4592  df-op 4596  df-uni 4872  df-br 5108  df-opab 5170  df-mpt 5189  df-id 5533  df-eprel 5538  df-xp 5644  df-rel 5645  df-cnv 5646  df-co 5647  df-dm 5648  df-rn 5649  df-res 5650  df-ima 5651  df-iota 6464  df-fun 6513  df-fn 6514  df-f 6515  df-fo 6517  df-fv 6519  df-1st 7968  df-2nd 7969  df-txp 35842  df-singleton 35850  df-singles 35851  df-image 35852  df-funpart 35862

This theorem is referenced by:  fullfunfnv  35934  fullfunfv  35935