Theorem erov 8819

Description: The value of an operation defined on equivalence classes. (Contributed by Jeff Madsen, 10-Jun-2010.) (Revised by Mario Carneiro, 30-Dec-2014.)

Hypotheses

Ref	Expression
eropr.1	⊢ 𝐽 = (𝐴 / 𝑅)
eropr.2	⊢ 𝐾 = (𝐵 / 𝑆)
eropr.3	⊢ (𝜑 → 𝑇 ∈ 𝑍)
eropr.4	⊢ (𝜑 → 𝑅 Er 𝑈)
eropr.5	⊢ (𝜑 → 𝑆 Er 𝑉)
eropr.6	⊢ (𝜑 → 𝑇 Er 𝑊)
eropr.7	⊢ (𝜑 → 𝐴 ⊆ 𝑈)
eropr.8	⊢ (𝜑 → 𝐵 ⊆ 𝑉)
eropr.9	⊢ (𝜑 → 𝐶 ⊆ 𝑊)
eropr.10	⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶)
eropr.11	⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢)))
eropr.12	⊢ ⨣ = {⟨⟨𝑥, 𝑦⟩, 𝑧⟩ ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)}
eropr.13	⊢ (𝜑 → 𝑅 ∈ 𝑋)
eropr.14	⊢ (𝜑 → 𝑆 ∈ 𝑌)

Assertion

Ref	Expression
erov	⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ([𝑃]𝑅 ⨣ [𝑄]𝑆) = [(𝑃 + 𝑄)]𝑇)

Distinct variable groups:   𝑞,𝑝,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧,𝐴   𝐵,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝐽,𝑝,𝑞,𝑥,𝑦,𝑧   𝑃,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝑅,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝐾,𝑝,𝑞,𝑥,𝑦,𝑧   𝑄,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝑆,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   + ,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝜑,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝑇,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑥,𝑦,𝑧   𝑋,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑧   𝑌,𝑝,𝑞,𝑟,𝑠,𝑡,𝑢,𝑧

Allowed substitution hints:   𝐶(𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)   ⨣ (𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)   𝑈(𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)   𝐽(𝑢, 𝑡, 𝑠, 𝑟)   𝐾(𝑢, 𝑡, 𝑠, 𝑟)   𝑉(𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)   𝑊(𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)   𝑋(𝑥, 𝑦)   𝑌(𝑥, 𝑦)   𝑍(𝑥, 𝑦, 𝑧, 𝑢, 𝑡, 𝑠, 𝑟, 𝑞, 𝑝)

Proof of Theorem erov

Step	Hyp	Ref	Expression
1		eropr.1	. . . . 5 ⊢ 𝐽 = (𝐴 / 𝑅)
2		eropr.2	. . . . 5 ⊢ 𝐾 = (𝐵 / 𝑆)
3		eropr.3	. . . . 5 ⊢ (𝜑 → 𝑇 ∈ 𝑍)
4		eropr.4	. . . . 5 ⊢ (𝜑 → 𝑅 Er 𝑈)
5		eropr.5	. . . . 5 ⊢ (𝜑 → 𝑆 Er 𝑉)
6		eropr.6	. . . . 5 ⊢ (𝜑 → 𝑇 Er 𝑊)
7		eropr.7	. . . . 5 ⊢ (𝜑 → 𝐴 ⊆ 𝑈)
8		eropr.8	. . . . 5 ⊢ (𝜑 → 𝐵 ⊆ 𝑉)
9		eropr.9	. . . . 5 ⊢ (𝜑 → 𝐶 ⊆ 𝑊)
10		eropr.10	. . . . 5 ⊢ (𝜑 → + :(𝐴 × 𝐵)⟶𝐶)
11		eropr.11	. . . . 5 ⊢ ((𝜑 ∧ ((𝑟 ∈ 𝐴 ∧ 𝑠 ∈ 𝐴) ∧ (𝑡 ∈ 𝐵 ∧ 𝑢 ∈ 𝐵))) → ((𝑟𝑅𝑠 ∧ 𝑡𝑆𝑢) → (𝑟 + 𝑡)𝑇(𝑠 + 𝑢)))
12		eropr.12	. . . . 5 ⊢ ⨣ = {⟨⟨𝑥, 𝑦⟩, 𝑧⟩ ∣ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)}
13	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12	erovlem 8818	. . . 4 ⊢ (𝜑 → ⨣ = (𝑥 ∈ 𝐽, 𝑦 ∈ 𝐾 ↦ (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇))))
14	13	3ad2ant1 1151	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ⨣ = (𝑥 ∈ 𝐽, 𝑦 ∈ 𝐾 ↦ (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇))))
15		simprl 783	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → 𝑥 = [𝑃]𝑅)
16	15	eqeq1d 2763	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → (𝑥 = [𝑝]𝑅 ↔ [𝑃]𝑅 = [𝑝]𝑅))
17		simprr 785	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → 𝑦 = [𝑄]𝑆)
18	17	eqeq1d 2763	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → (𝑦 = [𝑞]𝑆 ↔ [𝑄]𝑆 = [𝑞]𝑆))
19	16, 18	anbi12d 644	. . . . . 6 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ↔ ([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆)))
20	19	anbi1d 643	. . . . 5 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → (((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇) ↔ (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)))
21	20	2rexbidv 3228	. . . 4 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → (∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇) ↔ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)))
22	21	iotabidv 6515	. . 3 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ (𝑥 = [𝑃]𝑅 ∧ 𝑦 = [𝑄]𝑆)) → (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 ((𝑥 = [𝑝]𝑅 ∧ 𝑦 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) = (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)))
23		eropr.13	. . . . 5 ⊢ (𝜑 → 𝑅 ∈ 𝑋)
24		ecelqsw 8773	. . . . . 6 ⊢ ((𝑅 ∈ 𝑋 ∧ 𝑃 ∈ 𝐴) → [𝑃]𝑅 ∈ (𝐴 / 𝑅))
25	24, 1	eleqtrrdi 2872	. . . . 5 ⊢ ((𝑅 ∈ 𝑋 ∧ 𝑃 ∈ 𝐴) → [𝑃]𝑅 ∈ 𝐽)
26	23, 25	sylan 592	. . . 4 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴) → [𝑃]𝑅 ∈ 𝐽)
27	26	3adant3 1150	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → [𝑃]𝑅 ∈ 𝐽)
28		eropr.14	. . . . 5 ⊢ (𝜑 → 𝑆 ∈ 𝑌)
29		ecelqsw 8773	. . . . . 6 ⊢ ((𝑆 ∈ 𝑌 ∧ 𝑄 ∈ 𝐵) → [𝑄]𝑆 ∈ (𝐵 / 𝑆))
30	29, 2	eleqtrrdi 2872	. . . . 5 ⊢ ((𝑆 ∈ 𝑌 ∧ 𝑄 ∈ 𝐵) → [𝑄]𝑆 ∈ 𝐾)
31	28, 30	sylan 592	. . . 4 ⊢ ((𝜑 ∧ 𝑄 ∈ 𝐵) → [𝑄]𝑆 ∈ 𝐾)
32	31	3adant2 1149	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → [𝑄]𝑆 ∈ 𝐾)
33		iotaex 6507	. . . 4 ⊢ (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) ∈ V
34	33	a1i 11	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) ∈ V)
35	14, 22, 27, 32, 34	ovmpod 7564	. 2 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ([𝑃]𝑅 ⨣ [𝑄]𝑆) = (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)))
36		eqid 2761	. . . . . . 7 ⊢ [𝑃]𝑅 = [𝑃]𝑅
37		eqid 2761	. . . . . . 7 ⊢ [𝑄]𝑆 = [𝑄]𝑆
38	36, 37	pm3.2i 476	. . . . . 6 ⊢ ([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑄]𝑆)
39		eqid 2761	. . . . . 6 ⊢ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑄)]𝑇
40	38, 39	pm3.2i 476	. . . . 5 ⊢ (([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑄]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑄)]𝑇)
41		eceq1 8741	. . . . . . . . 9 ⊢ (𝑝 = 𝑃 → [𝑝]𝑅 = [𝑃]𝑅)
42	41	eqeq2d 2772	. . . . . . . 8 ⊢ (𝑝 = 𝑃 → ([𝑃]𝑅 = [𝑝]𝑅 ↔ [𝑃]𝑅 = [𝑃]𝑅))
43	42	anbi1d 643	. . . . . . 7 ⊢ (𝑝 = 𝑃 → (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ↔ ([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆)))
44		oveq1 7419	. . . . . . . . 9 ⊢ (𝑝 = 𝑃 → (𝑝 + 𝑞) = (𝑃 + 𝑞))
45	44	eceq1d 8742	. . . . . . . 8 ⊢ (𝑝 = 𝑃 → [(𝑝 + 𝑞)]𝑇 = [(𝑃 + 𝑞)]𝑇)
46	45	eqeq2d 2772	. . . . . . 7 ⊢ (𝑝 = 𝑃 → ([(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇 ↔ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑞)]𝑇))
47	43, 46	anbi12d 644	. . . . . 6 ⊢ (𝑝 = 𝑃 → ((([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇) ↔ (([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑞)]𝑇)))
48		eceq1 8741	. . . . . . . . 9 ⊢ (𝑞 = 𝑄 → [𝑞]𝑆 = [𝑄]𝑆)
49	48	eqeq2d 2772	. . . . . . . 8 ⊢ (𝑞 = 𝑄 → ([𝑄]𝑆 = [𝑞]𝑆 ↔ [𝑄]𝑆 = [𝑄]𝑆))
50	49	anbi2d 642	. . . . . . 7 ⊢ (𝑞 = 𝑄 → (([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ↔ ([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑄]𝑆)))
51		oveq2 7420	. . . . . . . . 9 ⊢ (𝑞 = 𝑄 → (𝑃 + 𝑞) = (𝑃 + 𝑄))
52	51	eceq1d 8742	. . . . . . . 8 ⊢ (𝑞 = 𝑄 → [(𝑃 + 𝑞)]𝑇 = [(𝑃 + 𝑄)]𝑇)
53	52	eqeq2d 2772	. . . . . . 7 ⊢ (𝑞 = 𝑄 → ([(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑞)]𝑇 ↔ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑄)]𝑇))
54	50, 53	anbi12d 644	. . . . . 6 ⊢ (𝑞 = 𝑄 → ((([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑞)]𝑇) ↔ (([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑄]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑄)]𝑇)))
55	47, 54	rspc2ev 3589	. . . . 5 ⊢ ((𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵 ∧ (([𝑃]𝑅 = [𝑃]𝑅 ∧ [𝑄]𝑆 = [𝑄]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑃 + 𝑄)]𝑇)) → ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇))
56	40, 55	mp3an3 1479	. . . 4 ⊢ ((𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇))
57	56	3adant1 1148	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇))
58		ecexg 8705	. . . . . 6 ⊢ (𝑇 ∈ 𝑍 → [(𝑃 + 𝑄)]𝑇 ∈ V)
59	3, 58	syl 18	. . . . 5 ⊢ (𝜑 → [(𝑃 + 𝑄)]𝑇 ∈ V)
60	59	3ad2ant1 1151	. . . 4 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → [(𝑃 + 𝑄)]𝑇 ∈ V)
61		simp1 1154	. . . . 5 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → 𝜑)
62	1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11	eroveu 8817	. . . . 5 ⊢ ((𝜑 ∧ ([𝑃]𝑅 ∈ 𝐽 ∧ [𝑄]𝑆 ∈ 𝐾)) → ∃!𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇))
63	61, 27, 32, 62	syl12anc 850	. . . 4 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ∃!𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇))
64		simpr 490	. . . . . . 7 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ 𝑧 = [(𝑃 + 𝑄)]𝑇) → 𝑧 = [(𝑃 + 𝑄)]𝑇)
65	64	eqeq1d 2763	. . . . . 6 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ 𝑧 = [(𝑃 + 𝑄)]𝑇) → (𝑧 = [(𝑝 + 𝑞)]𝑇 ↔ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇))
66	65	anbi2d 642	. . . . 5 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ 𝑧 = [(𝑃 + 𝑄)]𝑇) → ((([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇) ↔ (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇)))
67	66	2rexbidv 3228	. . . 4 ⊢ (((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) ∧ 𝑧 = [(𝑃 + 𝑄)]𝑇) → (∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇) ↔ ∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇)))
68	60, 63, 67	iota2d 6519	. . 3 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → (∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ [(𝑃 + 𝑄)]𝑇 = [(𝑝 + 𝑞)]𝑇) ↔ (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) = [(𝑃 + 𝑄)]𝑇))
69	57, 68	mpbid 235	. 2 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → (℩𝑧∃𝑝 ∈ 𝐴 ∃𝑞 ∈ 𝐵 (([𝑃]𝑅 = [𝑝]𝑅 ∧ [𝑄]𝑆 = [𝑞]𝑆) ∧ 𝑧 = [(𝑝 + 𝑞)]𝑇)) = [(𝑃 + 𝑄)]𝑇)
70	35, 69	eqtrd 2796	1 ⊢ ((𝜑 ∧ 𝑃 ∈ 𝐴 ∧ 𝑄 ∈ 𝐵) → ([𝑃]𝑅 ⨣ [𝑄]𝑆) = [(𝑃 + 𝑄)]𝑇)

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   ∧ w3a 1103   = wceq 1570   ∈ wcel 2145  ∃!weu 2594  ∃wrex 3087  Vcvv 3451   ⊆ wss 3899   class class class wbr 5103   × cxp 5649  ℩cio 6485  ⟶wf 6527  (class class class)co 7412  {coprab 7413   ∈ cmpo 7414   Er wer 8698  [cec 8699   / cqs 8700

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-10 2178  ax-11 2194  ax-12 2213  ax-ext 2733  ax-sep 5249  ax-nul 5260  ax-pr 5391  ax-un 7740

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2100  df-mo 2565  df-eu 2595  df-clab 2740  df-cleq 2753  df-clel 2836  df-nfc 2910  df-ne 2957  df-ral 3078  df-rex 3088  df-rab 3414  df-v 3453  df-sbc 3740  df-dif 3902  df-un 3904  df-in 3906  df-ss 3916  df-nul 4280  df-if 4483  df-sn 4585  df-pr 4587  df-op 4591  df-uni 4868  df-br 5104  df-opab 5168  df-id 5546  df-xp 5657  df-rel 5658  df-cnv 5659  df-co 5660  df-dm 5661  df-rn 5662  df-res 5663  df-ima 5664  df-iota 6487  df-fun 6533  df-fn 6534  df-f 6535  df-fv 6539  df-ov 7415  df-oprab 7416  df-mpo 7417  df-er 8701  df-ec 8703  df-qs 8707

This theorem is used by:  erov2  8821