Theorem fresaunres2 6750

Description: From the union of two functions that agree on the domain overlap, either component can be recovered by restriction. (Contributed by Stefan O'Rear, 9-Oct-2014.)

Assertion

Ref	Expression
fresaunres2	⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ∪ 𝐺) ↾ 𝐵) = 𝐺)

Proof of Theorem fresaunres2

Step	Hyp	Ref	Expression
1		ffn 6704	. . . 4 ⊢ (𝐹:𝐴⟶𝐶 → 𝐹 Fn 𝐴)
2		ffn 6704	. . . 4 ⊢ (𝐺:𝐵⟶𝐶 → 𝐺 Fn 𝐵)
3		id 22	. . . 4 ⊢ ((𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵)) → (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵)))
4		resasplit 6748	. . . 4 ⊢ ((𝐹 Fn 𝐴 ∧ 𝐺 Fn 𝐵 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → (𝐹 ∪ 𝐺) = ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))))
5	1, 2, 3, 4	syl3an 1160	. . 3 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → (𝐹 ∪ 𝐺) = ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))))
6	5	reseq1d 5972	. 2 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ∪ 𝐺) ↾ 𝐵) = (((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) ↾ 𝐵))
7		resundir 5988	. . 3 ⊢ (((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) ↾ 𝐵) = (((𝐹 ↾ (𝐴 ∩ 𝐵)) ↾ 𝐵) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) ↾ 𝐵))
8		inss2 4225	. . . . . 6 ⊢ (𝐴 ∩ 𝐵) ⊆ 𝐵
9		resabs2 6005	. . . . . 6 ⊢ ((𝐴 ∩ 𝐵) ⊆ 𝐵 → ((𝐹 ↾ (𝐴 ∩ 𝐵)) ↾ 𝐵) = (𝐹 ↾ (𝐴 ∩ 𝐵)))
10	8, 9	ax-mp 5	. . . . 5 ⊢ ((𝐹 ↾ (𝐴 ∩ 𝐵)) ↾ 𝐵) = (𝐹 ↾ (𝐴 ∩ 𝐵))
11		resundir 5988	. . . . 5 ⊢ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) ↾ 𝐵) = (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) ∪ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵))
12	10, 11	uneq12i 4157	. . . 4 ⊢ (((𝐹 ↾ (𝐴 ∩ 𝐵)) ↾ 𝐵) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) ↾ 𝐵)) = ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) ∪ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵)))
13		dmres 5995	. . . . . . . . 9 ⊢ dom ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = (𝐵 ∩ dom (𝐹 ↾ (𝐴 ∖ 𝐵)))
14		dmres 5995	. . . . . . . . . . 11 ⊢ dom (𝐹 ↾ (𝐴 ∖ 𝐵)) = ((𝐴 ∖ 𝐵) ∩ dom 𝐹)
15	14	ineq2i 4205	. . . . . . . . . 10 ⊢ (𝐵 ∩ dom (𝐹 ↾ (𝐴 ∖ 𝐵))) = (𝐵 ∩ ((𝐴 ∖ 𝐵) ∩ dom 𝐹))
16		disjdif 4467	. . . . . . . . . . . 12 ⊢ (𝐵 ∩ (𝐴 ∖ 𝐵)) = ∅
17	16	ineq1i 4204	. . . . . . . . . . 11 ⊢ ((𝐵 ∩ (𝐴 ∖ 𝐵)) ∩ dom 𝐹) = (∅ ∩ dom 𝐹)
18		inass 4215	. . . . . . . . . . 11 ⊢ ((𝐵 ∩ (𝐴 ∖ 𝐵)) ∩ dom 𝐹) = (𝐵 ∩ ((𝐴 ∖ 𝐵) ∩ dom 𝐹))
19		0in 4389	. . . . . . . . . . 11 ⊢ (∅ ∩ dom 𝐹) = ∅
20	17, 18, 19	3eqtr3i 2767	. . . . . . . . . 10 ⊢ (𝐵 ∩ ((𝐴 ∖ 𝐵) ∩ dom 𝐹)) = ∅
21	15, 20	eqtri 2759	. . . . . . . . 9 ⊢ (𝐵 ∩ dom (𝐹 ↾ (𝐴 ∖ 𝐵))) = ∅
22	13, 21	eqtri 2759	. . . . . . . 8 ⊢ dom ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅
23		relres 6002	. . . . . . . . 9 ⊢ Rel ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵)
24		reldm0 5919	. . . . . . . . 9 ⊢ (Rel ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) → (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅ ↔ dom ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅))
25	23, 24	ax-mp 5	. . . . . . . 8 ⊢ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅ ↔ dom ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅)
26	22, 25	mpbir 230	. . . . . . 7 ⊢ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) = ∅
27		difss 4127	. . . . . . . 8 ⊢ (𝐵 ∖ 𝐴) ⊆ 𝐵
28		resabs2 6005	. . . . . . . 8 ⊢ ((𝐵 ∖ 𝐴) ⊆ 𝐵 → ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵) = (𝐺 ↾ (𝐵 ∖ 𝐴)))
29	27, 28	ax-mp 5	. . . . . . 7 ⊢ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵) = (𝐺 ↾ (𝐵 ∖ 𝐴))
30	26, 29	uneq12i 4157	. . . . . 6 ⊢ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) ∪ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵)) = (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))
31	30	uneq2i 4156	. . . . 5 ⊢ ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) ∪ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵))) = ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))))
32		simp3 1138	. . . . . . 7 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵)))
33	32	uneq1d 4158	. . . . . 6 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) = ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))))
34		uncom 4149	. . . . . . . . . 10 ⊢ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) = ((𝐺 ↾ (𝐵 ∖ 𝐴)) ∪ ∅)
35		un0 4386	. . . . . . . . . 10 ⊢ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ∪ ∅) = (𝐺 ↾ (𝐵 ∖ 𝐴))
36	34, 35	eqtri 2759	. . . . . . . . 9 ⊢ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) = (𝐺 ↾ (𝐵 ∖ 𝐴))
37	36	uneq2i 4156	. . . . . . . 8 ⊢ ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) = ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))
38		resundi 5987	. . . . . . . . 9 ⊢ (𝐺 ↾ ((𝐴 ∩ 𝐵) ∪ (𝐵 ∖ 𝐴))) = ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))
39		incom 4197	. . . . . . . . . . . . 13 ⊢ (𝐴 ∩ 𝐵) = (𝐵 ∩ 𝐴)
40	39	uneq1i 4155	. . . . . . . . . . . 12 ⊢ ((𝐴 ∩ 𝐵) ∪ (𝐵 ∖ 𝐴)) = ((𝐵 ∩ 𝐴) ∪ (𝐵 ∖ 𝐴))
41		inundif 4474	. . . . . . . . . . . 12 ⊢ ((𝐵 ∩ 𝐴) ∪ (𝐵 ∖ 𝐴)) = 𝐵
42	40, 41	eqtri 2759	. . . . . . . . . . 11 ⊢ ((𝐴 ∩ 𝐵) ∪ (𝐵 ∖ 𝐴)) = 𝐵
43	42	reseq2i 5970	. . . . . . . . . 10 ⊢ (𝐺 ↾ ((𝐴 ∩ 𝐵) ∪ (𝐵 ∖ 𝐴))) = (𝐺 ↾ 𝐵)
44		fnresdm 6656	. . . . . . . . . . . 12 ⊢ (𝐺 Fn 𝐵 → (𝐺 ↾ 𝐵) = 𝐺)
45	2, 44	syl 17	. . . . . . . . . . 11 ⊢ (𝐺:𝐵⟶𝐶 → (𝐺 ↾ 𝐵) = 𝐺)
46	45	adantl 482	. . . . . . . . . 10 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶) → (𝐺 ↾ 𝐵) = 𝐺)
47	43, 46	eqtrid 2783	. . . . . . . . 9 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶) → (𝐺 ↾ ((𝐴 ∩ 𝐵) ∪ (𝐵 ∖ 𝐴))) = 𝐺)
48	38, 47	eqtr3id 2785	. . . . . . . 8 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶) → ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) = 𝐺)
49	37, 48	eqtrid 2783	. . . . . . 7 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶) → ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) = 𝐺)
50	49	3adant3 1132	. . . . . 6 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐺 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) = 𝐺)
51	33, 50	eqtrd 2771	. . . . 5 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (∅ ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) = 𝐺)
52	31, 51	eqtrid 2783	. . . 4 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ↾ 𝐵) ∪ ((𝐺 ↾ (𝐵 ∖ 𝐴)) ↾ 𝐵))) = 𝐺)
53	12, 52	eqtrid 2783	. . 3 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → (((𝐹 ↾ (𝐴 ∩ 𝐵)) ↾ 𝐵) ∪ (((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴))) ↾ 𝐵)) = 𝐺)
54	7, 53	eqtrid 2783	. 2 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → (((𝐹 ↾ (𝐴 ∩ 𝐵)) ∪ ((𝐹 ↾ (𝐴 ∖ 𝐵)) ∪ (𝐺 ↾ (𝐵 ∖ 𝐴)))) ↾ 𝐵) = 𝐺)
55	6, 54	eqtrd 2771	1 ⊢ ((𝐹:𝐴⟶𝐶 ∧ 𝐺:𝐵⟶𝐶 ∧ (𝐹 ↾ (𝐴 ∩ 𝐵)) = (𝐺 ↾ (𝐴 ∩ 𝐵))) → ((𝐹 ∪ 𝐺) ↾ 𝐵) = 𝐺)

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 396   ∧ w3a 1087   = wceq 1541   ∖ cdif 3941   ∪ cun 3942   ∩ cin 3943   ⊆ wss 3944  ∅c0 4318  dom cdm 5669   ↾ cres 5671  Rel wrel 5674   Fn wfn 6527  ⟶wf 6528

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1913  ax-6 1971  ax-7 2011  ax-8 2108  ax-9 2116  ax-10 2137  ax-12 2171  ax-ext 2702  ax-sep 5292  ax-nul 5299  ax-pr 5420

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 846  df-3an 1089  df-tru 1544  df-fal 1554  df-ex 1782  df-nf 1786  df-sb 2068  df-clab 2709  df-cleq 2723  df-clel 2809  df-ral 3061  df-rex 3070  df-rab 3432  df-v 3475  df-dif 3947  df-un 3949  df-in 3951  df-ss 3961  df-nul 4319  df-if 4523  df-sn 4623  df-pr 4625  df-op 4629  df-br 5142  df-opab 5204  df-xp 5675  df-rel 5676  df-dm 5679  df-res 5681  df-fun 6534  df-fn 6535  df-f 6536

This theorem is referenced by:  fresaunres1  6751  mapunen  9129  ptuncnv  23240  cvmliftlem10  34116  elmapresaunres2  41280