Theorem addsasslem1 28394

Description: Lemma for addition associativity. Expand one form of the triple sum. (Contributed by Scott Fenton, 21-Jan-2025.)

Hypotheses

Ref	Expression
addsasslem.1	⊢ (𝜑 → 𝐴 ∈ No)
addsasslem.2	⊢ (𝜑 → 𝐵 ∈ No)
addsasslem.3	⊢ (𝜑 → 𝐶 ∈ No)

Assertion

Ref	Expression
addsasslem1	⊢ (𝜑 → ((𝐴 +s 𝐵) +s 𝐶) = ((({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)}) ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) |s (({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)}) ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)})))

Distinct variable groups:   𝐴,𝑎,𝑏,𝑐,𝑙,𝑚,𝑛,𝑝,𝑞,𝑟,𝑤,𝑦,𝑧   𝐵,𝑎,𝑏,𝑐,𝑙,𝑚,𝑛,𝑝,𝑞,𝑟,𝑤,𝑦,𝑧   𝐶,𝑎,𝑏,𝑐,𝑙,𝑚,𝑛,𝑝,𝑞,𝑟,𝑤,𝑦,𝑧   𝜑,𝑎,𝑏,𝑐,𝑙,𝑚,𝑛,𝑝,𝑞,𝑟,𝑤,𝑦,𝑧

Proof of Theorem addsasslem1

Dummy variables 𝑑 𝑒 𝑓 𝑔 ℎ 𝑖 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		addsasslem.1	. . . . . 6 ⊢ (𝜑 → 𝐴 ∈ No)
2		addsasslem.2	. . . . . 6 ⊢ (𝜑 → 𝐵 ∈ No)
3	1, 2	addcuts 28369	. . . . 5 ⊢ (𝜑 → ((𝐴 +s 𝐵) ∈ No ∧ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s {(𝐴 +s 𝐵)} ∧ {(𝐴 +s 𝐵)} <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})))
4	3	simp2d 1161	. . . 4 ⊢ (𝜑 → ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s {(𝐴 +s 𝐵)})
5	3	simp3d 1162	. . . 4 ⊢ (𝜑 → {(𝐴 +s 𝐵)} <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}))
6		ovex 7453	. . . . . 6 ⊢ (𝐴 +s 𝐵) ∈ V
7	6	snnz 4733	. . . . 5 ⊢ {(𝐴 +s 𝐵)} ≠ ∅
8		sltstr 28178	. . . . 5 ⊢ ((({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s {(𝐴 +s 𝐵)} ∧ {(𝐴 +s 𝐵)} <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}) ∧ {(𝐴 +s 𝐵)} ≠ ∅) → ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}))
9	7, 8	mp3an3 1479	. . . 4 ⊢ ((({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s {(𝐴 +s 𝐵)} ∧ {(𝐴 +s 𝐵)} <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})) → ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}))
10	4, 5, 9	syl2anc 596	. . 3 ⊢ (𝜑 → ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) <<s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}))
11		lltr 28253	. . . 4 ⊢ (L‘𝐶) <<s (R‘𝐶)
12	11	a1i 11	. . 3 ⊢ (𝜑 → (L‘𝐶) <<s (R‘𝐶))
13		addsval2 28354	. . . 4 ⊢ ((𝐴 ∈ No ∧ 𝐵 ∈ No) → (𝐴 +s 𝐵) = (({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) |s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})))
14	1, 2, 13	syl2anc 596	. . 3 ⊢ (𝜑 → (𝐴 +s 𝐵) = (({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}) |s ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})))
15		addsasslem.3	. . . . 5 ⊢ (𝜑 → 𝐶 ∈ No)
16		lrcut 28295	. . . . 5 ⊢ (𝐶 ∈ No → ((L‘𝐶) |s (R‘𝐶)) = 𝐶)
17	15, 16	syl 18	. . . 4 ⊢ (𝜑 → ((L‘𝐶) |s (R‘𝐶)) = 𝐶)
18	17	eqcomd 2766	. . 3 ⊢ (𝜑 → 𝐶 = ((L‘𝐶) |s (R‘𝐶)))
19	10, 12, 14, 18	addsunif 28393	. 2 ⊢ (𝜑 → ((𝐴 +s 𝐵) +s 𝐶) = (({𝑦 ∣ ∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶)} ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) |s ({𝑎 ∣ ∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶)} ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)})))
20		unab 4253	. . . . 5 ⊢ ({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑦 ∣ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)}) = {𝑦 ∣ (∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶) ∨ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶))}
21		eqeq1 2764	. . . . . . . 8 ⊢ (𝑧 = 𝑦 → (𝑧 = ((𝐴 +s 𝑚) +s 𝐶) ↔ 𝑦 = ((𝐴 +s 𝑚) +s 𝐶)))
22	21	rexbidv 3186	. . . . . . 7 ⊢ (𝑧 = 𝑦 → (∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶) ↔ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)))
23	22	cbvabv 2830	. . . . . 6 ⊢ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)} = {𝑦 ∣ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)}
24	23	uneq2i 4164	. . . . 5 ⊢ ({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)}) = ({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑦 ∣ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)})
25		rexun 4194	. . . . . . 7 ⊢ (∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶) ↔ (∃ℎ ∈ {𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)}𝑦 = (ℎ +s 𝐶) ∨ ∃ℎ ∈ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}𝑦 = (ℎ +s 𝐶)))
26		eqeq1 2764	. . . . . . . . . . 11 ⊢ (𝑑 = ℎ → (𝑑 = (𝑙 +s 𝐵) ↔ ℎ = (𝑙 +s 𝐵)))
27	26	rexbidv 3186	. . . . . . . . . 10 ⊢ (𝑑 = ℎ → (∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵) ↔ ∃𝑙 ∈ (L‘𝐴)ℎ = (𝑙 +s 𝐵)))
28	27	rexab 3652	. . . . . . . . 9 ⊢ (∃ℎ ∈ {𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)}𝑦 = (ℎ +s 𝐶) ↔ ∃ℎ(∃𝑙 ∈ (L‘𝐴)ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)))
29		rexcom4 3289	. . . . . . . . . 10 ⊢ (∃𝑙 ∈ (L‘𝐴)∃ℎ(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃ℎ∃𝑙 ∈ (L‘𝐴)(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)))
30		ovex 7453	. . . . . . . . . . . 12 ⊢ (𝑙 +s 𝐵) ∈ V
31		oveq1 7427	. . . . . . . . . . . . 13 ⊢ (ℎ = (𝑙 +s 𝐵) → (ℎ +s 𝐶) = ((𝑙 +s 𝐵) +s 𝐶))
32	31	eqeq2d 2771	. . . . . . . . . . . 12 ⊢ (ℎ = (𝑙 +s 𝐵) → (𝑦 = (ℎ +s 𝐶) ↔ 𝑦 = ((𝑙 +s 𝐵) +s 𝐶)))
33	30, 32	ceqsexv 3498	. . . . . . . . . . 11 ⊢ (∃ℎ(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ 𝑦 = ((𝑙 +s 𝐵) +s 𝐶))
34	33	rexbii 3109	. . . . . . . . . 10 ⊢ (∃𝑙 ∈ (L‘𝐴)∃ℎ(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶))
35		r19.41v 3192	. . . . . . . . . . 11 ⊢ (∃𝑙 ∈ (L‘𝐴)(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ (∃𝑙 ∈ (L‘𝐴)ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)))
36	35	exbii 1880	. . . . . . . . . 10 ⊢ (∃ℎ∃𝑙 ∈ (L‘𝐴)(ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃ℎ(∃𝑙 ∈ (L‘𝐴)ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)))
37	29, 34, 36	3bitr3ri 305	. . . . . . . . 9 ⊢ (∃ℎ(∃𝑙 ∈ (L‘𝐴)ℎ = (𝑙 +s 𝐵) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶))
38	28, 37	bitri 278	. . . . . . . 8 ⊢ (∃ℎ ∈ {𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)}𝑦 = (ℎ +s 𝐶) ↔ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶))
39		eqeq1 2764	. . . . . . . . . . 11 ⊢ (𝑒 = ℎ → (𝑒 = (𝐴 +s 𝑚) ↔ ℎ = (𝐴 +s 𝑚)))
40	39	rexbidv 3186	. . . . . . . . . 10 ⊢ (𝑒 = ℎ → (∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚) ↔ ∃𝑚 ∈ (L‘𝐵)ℎ = (𝐴 +s 𝑚)))
41	40	rexab 3652	. . . . . . . . 9 ⊢ (∃ℎ ∈ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}𝑦 = (ℎ +s 𝐶) ↔ ∃ℎ(∃𝑚 ∈ (L‘𝐵)ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)))
42		rexcom4 3289	. . . . . . . . . 10 ⊢ (∃𝑚 ∈ (L‘𝐵)∃ℎ(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃ℎ∃𝑚 ∈ (L‘𝐵)(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)))
43		ovex 7453	. . . . . . . . . . . 12 ⊢ (𝐴 +s 𝑚) ∈ V
44		oveq1 7427	. . . . . . . . . . . . 13 ⊢ (ℎ = (𝐴 +s 𝑚) → (ℎ +s 𝐶) = ((𝐴 +s 𝑚) +s 𝐶))
45	44	eqeq2d 2771	. . . . . . . . . . . 12 ⊢ (ℎ = (𝐴 +s 𝑚) → (𝑦 = (ℎ +s 𝐶) ↔ 𝑦 = ((𝐴 +s 𝑚) +s 𝐶)))
46	43, 45	ceqsexv 3498	. . . . . . . . . . 11 ⊢ (∃ℎ(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ 𝑦 = ((𝐴 +s 𝑚) +s 𝐶))
47	46	rexbii 3109	. . . . . . . . . 10 ⊢ (∃𝑚 ∈ (L‘𝐵)∃ℎ(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶))
48		r19.41v 3192	. . . . . . . . . . 11 ⊢ (∃𝑚 ∈ (L‘𝐵)(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ (∃𝑚 ∈ (L‘𝐵)ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)))
49	48	exbii 1880	. . . . . . . . . 10 ⊢ (∃ℎ∃𝑚 ∈ (L‘𝐵)(ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃ℎ(∃𝑚 ∈ (L‘𝐵)ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)))
50	42, 47, 49	3bitr3ri 305	. . . . . . . . 9 ⊢ (∃ℎ(∃𝑚 ∈ (L‘𝐵)ℎ = (𝐴 +s 𝑚) ∧ 𝑦 = (ℎ +s 𝐶)) ↔ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶))
51	41, 50	bitri 278	. . . . . . . 8 ⊢ (∃ℎ ∈ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}𝑦 = (ℎ +s 𝐶) ↔ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶))
52	38, 51	orbi12i 928	. . . . . . 7 ⊢ ((∃ℎ ∈ {𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)}𝑦 = (ℎ +s 𝐶) ∨ ∃ℎ ∈ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)}𝑦 = (ℎ +s 𝐶)) ↔ (∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶) ∨ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)))
53	25, 52	bitri 278	. . . . . 6 ⊢ (∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶) ↔ (∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶) ∨ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶)))
54	53	abbii 2827	. . . . 5 ⊢ {𝑦 ∣ ∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶)} = {𝑦 ∣ (∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶) ∨ ∃𝑚 ∈ (L‘𝐵)𝑦 = ((𝐴 +s 𝑚) +s 𝐶))}
55	20, 24, 54	3eqtr4ri 2794	. . . 4 ⊢ {𝑦 ∣ ∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶)} = ({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)})
56	55	uneq1i 4163	. . 3 ⊢ ({𝑦 ∣ ∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶)} ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) = (({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)}) ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)})
57		unab 4253	. . . . 5 ⊢ ({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑎 ∣ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)}) = {𝑎 ∣ (∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶) ∨ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶))}
58		eqeq1 2764	. . . . . . . 8 ⊢ (𝑏 = 𝑎 → (𝑏 = ((𝐴 +s 𝑞) +s 𝐶) ↔ 𝑎 = ((𝐴 +s 𝑞) +s 𝐶)))
59	58	rexbidv 3186	. . . . . . 7 ⊢ (𝑏 = 𝑎 → (∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶) ↔ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)))
60	59	cbvabv 2830	. . . . . 6 ⊢ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)} = {𝑎 ∣ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)}
61	60	uneq2i 4164	. . . . 5 ⊢ ({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)}) = ({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑎 ∣ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)})
62		rexun 4194	. . . . . . 7 ⊢ (∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶) ↔ (∃𝑖 ∈ {𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)}𝑎 = (𝑖 +s 𝐶) ∨ ∃𝑖 ∈ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}𝑎 = (𝑖 +s 𝐶)))
63		eqeq1 2764	. . . . . . . . . . 11 ⊢ (𝑓 = 𝑖 → (𝑓 = (𝑝 +s 𝐵) ↔ 𝑖 = (𝑝 +s 𝐵)))
64	63	rexbidv 3186	. . . . . . . . . 10 ⊢ (𝑓 = 𝑖 → (∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵) ↔ ∃𝑝 ∈ (R‘𝐴)𝑖 = (𝑝 +s 𝐵)))
65	64	rexab 3652	. . . . . . . . 9 ⊢ (∃𝑖 ∈ {𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)}𝑎 = (𝑖 +s 𝐶) ↔ ∃𝑖(∃𝑝 ∈ (R‘𝐴)𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)))
66		rexcom4 3289	. . . . . . . . . 10 ⊢ (∃𝑝 ∈ (R‘𝐴)∃𝑖(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑖∃𝑝 ∈ (R‘𝐴)(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)))
67		ovex 7453	. . . . . . . . . . . 12 ⊢ (𝑝 +s 𝐵) ∈ V
68		oveq1 7427	. . . . . . . . . . . . 13 ⊢ (𝑖 = (𝑝 +s 𝐵) → (𝑖 +s 𝐶) = ((𝑝 +s 𝐵) +s 𝐶))
69	68	eqeq2d 2771	. . . . . . . . . . . 12 ⊢ (𝑖 = (𝑝 +s 𝐵) → (𝑎 = (𝑖 +s 𝐶) ↔ 𝑎 = ((𝑝 +s 𝐵) +s 𝐶)))
70	67, 69	ceqsexv 3498	. . . . . . . . . . 11 ⊢ (∃𝑖(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ 𝑎 = ((𝑝 +s 𝐵) +s 𝐶))
71	70	rexbii 3109	. . . . . . . . . 10 ⊢ (∃𝑝 ∈ (R‘𝐴)∃𝑖(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶))
72		r19.41v 3192	. . . . . . . . . . 11 ⊢ (∃𝑝 ∈ (R‘𝐴)(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ (∃𝑝 ∈ (R‘𝐴)𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)))
73	72	exbii 1880	. . . . . . . . . 10 ⊢ (∃𝑖∃𝑝 ∈ (R‘𝐴)(𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑖(∃𝑝 ∈ (R‘𝐴)𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)))
74	66, 71, 73	3bitr3ri 305	. . . . . . . . 9 ⊢ (∃𝑖(∃𝑝 ∈ (R‘𝐴)𝑖 = (𝑝 +s 𝐵) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶))
75	65, 74	bitri 278	. . . . . . . 8 ⊢ (∃𝑖 ∈ {𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)}𝑎 = (𝑖 +s 𝐶) ↔ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶))
76		eqeq1 2764	. . . . . . . . . . 11 ⊢ (𝑔 = 𝑖 → (𝑔 = (𝐴 +s 𝑞) ↔ 𝑖 = (𝐴 +s 𝑞)))
77	76	rexbidv 3186	. . . . . . . . . 10 ⊢ (𝑔 = 𝑖 → (∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞) ↔ ∃𝑞 ∈ (R‘𝐵)𝑖 = (𝐴 +s 𝑞)))
78	77	rexab 3652	. . . . . . . . 9 ⊢ (∃𝑖 ∈ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}𝑎 = (𝑖 +s 𝐶) ↔ ∃𝑖(∃𝑞 ∈ (R‘𝐵)𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)))
79		rexcom4 3289	. . . . . . . . . 10 ⊢ (∃𝑞 ∈ (R‘𝐵)∃𝑖(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑖∃𝑞 ∈ (R‘𝐵)(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)))
80		ovex 7453	. . . . . . . . . . . 12 ⊢ (𝐴 +s 𝑞) ∈ V
81		oveq1 7427	. . . . . . . . . . . . 13 ⊢ (𝑖 = (𝐴 +s 𝑞) → (𝑖 +s 𝐶) = ((𝐴 +s 𝑞) +s 𝐶))
82	81	eqeq2d 2771	. . . . . . . . . . . 12 ⊢ (𝑖 = (𝐴 +s 𝑞) → (𝑎 = (𝑖 +s 𝐶) ↔ 𝑎 = ((𝐴 +s 𝑞) +s 𝐶)))
83	80, 82	ceqsexv 3498	. . . . . . . . . . 11 ⊢ (∃𝑖(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ 𝑎 = ((𝐴 +s 𝑞) +s 𝐶))
84	83	rexbii 3109	. . . . . . . . . 10 ⊢ (∃𝑞 ∈ (R‘𝐵)∃𝑖(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶))
85		r19.41v 3192	. . . . . . . . . . 11 ⊢ (∃𝑞 ∈ (R‘𝐵)(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ (∃𝑞 ∈ (R‘𝐵)𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)))
86	85	exbii 1880	. . . . . . . . . 10 ⊢ (∃𝑖∃𝑞 ∈ (R‘𝐵)(𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑖(∃𝑞 ∈ (R‘𝐵)𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)))
87	79, 84, 86	3bitr3ri 305	. . . . . . . . 9 ⊢ (∃𝑖(∃𝑞 ∈ (R‘𝐵)𝑖 = (𝐴 +s 𝑞) ∧ 𝑎 = (𝑖 +s 𝐶)) ↔ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶))
88	78, 87	bitri 278	. . . . . . . 8 ⊢ (∃𝑖 ∈ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}𝑎 = (𝑖 +s 𝐶) ↔ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶))
89	75, 88	orbi12i 928	. . . . . . 7 ⊢ ((∃𝑖 ∈ {𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)}𝑎 = (𝑖 +s 𝐶) ∨ ∃𝑖 ∈ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)}𝑎 = (𝑖 +s 𝐶)) ↔ (∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶) ∨ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)))
90	62, 89	bitri 278	. . . . . 6 ⊢ (∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶) ↔ (∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶) ∨ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶)))
91	90	abbii 2827	. . . . 5 ⊢ {𝑎 ∣ ∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶)} = {𝑎 ∣ (∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶) ∨ ∃𝑞 ∈ (R‘𝐵)𝑎 = ((𝐴 +s 𝑞) +s 𝐶))}
92	57, 61, 91	3eqtr4ri 2794	. . . 4 ⊢ {𝑎 ∣ ∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶)} = ({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)})
93	92	uneq1i 4163	. . 3 ⊢ ({𝑎 ∣ ∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶)} ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)}) = (({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)}) ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)})
94	56, 93	oveq12i 7432	. 2 ⊢ (({𝑦 ∣ ∃ℎ ∈ ({𝑑 ∣ ∃𝑙 ∈ (L‘𝐴)𝑑 = (𝑙 +s 𝐵)} ∪ {𝑒 ∣ ∃𝑚 ∈ (L‘𝐵)𝑒 = (𝐴 +s 𝑚)})𝑦 = (ℎ +s 𝐶)} ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) |s ({𝑎 ∣ ∃𝑖 ∈ ({𝑓 ∣ ∃𝑝 ∈ (R‘𝐴)𝑓 = (𝑝 +s 𝐵)} ∪ {𝑔 ∣ ∃𝑞 ∈ (R‘𝐵)𝑔 = (𝐴 +s 𝑞)})𝑎 = (𝑖 +s 𝐶)} ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)})) = ((({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)}) ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) |s (({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)}) ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)}))
95	19, 94	eqtrdi 2811	1 ⊢ (𝜑 → ((𝐴 +s 𝐵) +s 𝐶) = ((({𝑦 ∣ ∃𝑙 ∈ (L‘𝐴)𝑦 = ((𝑙 +s 𝐵) +s 𝐶)} ∪ {𝑧 ∣ ∃𝑚 ∈ (L‘𝐵)𝑧 = ((𝐴 +s 𝑚) +s 𝐶)}) ∪ {𝑤 ∣ ∃𝑛 ∈ (L‘𝐶)𝑤 = ((𝐴 +s 𝐵) +s 𝑛)}) |s (({𝑎 ∣ ∃𝑝 ∈ (R‘𝐴)𝑎 = ((𝑝 +s 𝐵) +s 𝐶)} ∪ {𝑏 ∣ ∃𝑞 ∈ (R‘𝐵)𝑏 = ((𝐴 +s 𝑞) +s 𝐶)}) ∪ {𝑐 ∣ ∃𝑟 ∈ (R‘𝐶)𝑐 = ((𝐴 +s 𝐵) +s 𝑟)})))

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   ∨ wo 861   = wceq 1569  ∃wex 1811   ∈ wcel 2144  {cab 2738   ≠ wne 2955  ∃wrex 3086   ∪ cun 4149  ∅c0 4278  {csn 4584   class class class wbr 5102  ‘cfv 6538  (class class class)co 7420  Nocsur 28002   <<s cslts 28148   |s ccuts 28150  Lcleft 28216  Rcright 28217   +_s cadds 28350

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1827  ax-4 1841  ax-5 1942  ax-6 1999  ax-7 2040  ax-8 2146  ax-9 2154  ax-10 2177  ax-11 2193  ax-12 2212  ax-ext 2732  ax-rep 5231  ax-sep 5248  ax-nul 5259  ax-pow 5326  ax-pr 5390  ax-un 7751

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3or 1104  df-3an 1105  df-tru 1572  df-fal 1582  df-ex 1812  df-nf 1816  df-sb 2099  df-mo 2564  df-eu 2594  df-clab 2739  df-cleq 2752  df-clel 2835  df-nfc 2909  df-ne 2956  df-ral 3077  df-rex 3087  df-rmo 3365  df-reu 3366  df-rab 3413  df-v 3452  df-sbc 3739  df-csb 3847  df-ss 3896  df-pss 4014  df-dif 4047  df-in 4091  df-un 4151  df-nul 4279  df-if 4482  df-pw 4558  df-sn 4585  df-pr 4587  df-tp 4589  df-op 4835  df-ot 4858  df-uni 4867  df-int 4907  df-iun 4952  df-br 5103  df-opab 5167  df-mpt 5186  df-tr 5212  df-id 5545  df-eprel 5550  df-po 5558  df-so 5559  df-fr 5603  df-se 5604  df-we 5605  df-xp 5656  df-rel 5657  df-cnv 5658  df-co 5659  df-dm 5660  df-rn 5661  df-res 5662  df-ima 5663  df-pred 6304  df-ord 6365  df-on 6366  df-suc 6368  df-iota 6494  df-fun 6540  df-fn 6541  df-f 6542  df-f1 6543  df-fo 6544  df-f1o 6545  df-fv 6546  df-riota 7377  df-ov 7423  df-oprab 7424  df-mpo 7425  df-1st 8001  df-2nd 8002  df-frecs 8302  df-wrecs 8333  df-recs 8382  df-1o 8479  df-2o 8480  df-nadd 8678  df-no 28005  df-lts 28006  df-bday 28007  df-les 28107  df-slts 28149  df-cuts 28151  df-0s 28198  df-made 28218  df-old 28219  df-left 28221  df-right 28222  df-norec2 28340  df-adds 28351

This theorem is used by:  addsass  28396