Theorem tz9.1regs 35555

Description: Every set has a transitive closure (the smallest transitive extension). This version of tz9.1 9696 depends on ax-regs 35547 instead of ax-reg 9552 and ax-inf2 9608. This suggests a possible answer to the third question posed in tz9.1 9696, namely that the missing property is that countably infinite classes must obey regularity. In ZF set theory we can prove this by showing that countably infinite classes are sets and thus ax-reg 9552 applies to them directly, but in a finitist context it seems that an axiom like ax-regs 35547 is required since countably infinite classes are proper classes.

A related candidate for the missing property is the non-existence of infinite descending ∈-chains, proven as noinfep 9627 using ax-reg 9552 and ax-inf2 9608 and as noinfepregs 35554 using ax-regs 35547. If all sets are finite, then the existence of such a chain implies there is a set which does not have a transitive closure, as shown in fineqvinfep 35546. (Contributed by BTernaryTau, 31-Dec-2025.)

Hypothesis

Ref	Expression
tz9.1regs.1	⊢ 𝐴 ∈ V

Assertion

Ref	Expression
tz9.1regs	⊢ ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))

Distinct variable group:   𝑥,𝐴,𝑦

Proof of Theorem tz9.1regs

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

Step	Hyp	Ref	Expression
1		tz9.1regs.1	. 2 ⊢ 𝐴 ∈ V
2		sseq1 3961	. . . 4 ⊢ (𝑧 = 𝐴 → (𝑧 ⊆ 𝑥 ↔ 𝐴 ⊆ 𝑥))
3		cleq1lem 15026	. . . . . 6 ⊢ (𝑧 = 𝐴 → ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) ↔ (𝐴 ⊆ 𝑦 ∧ Tr 𝑦)))
4	3	imbi1d 344	. . . . 5 ⊢ (𝑧 = 𝐴 → (((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
5	4	albidv 1949	. . . 4 ⊢ (𝑧 = 𝐴 → (∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
6	2, 5	3anbi13d 1465	. . 3 ⊢ (𝑧 = 𝐴 → ((𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) ↔ (𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
7	6	exbidv 1950	. 2 ⊢ (𝑧 = 𝐴 → (∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) ↔ ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
8		sseq1 3961	. . . . 5 ⊢ (𝑧 = 𝑤 → (𝑧 ⊆ 𝑥 ↔ 𝑤 ⊆ 𝑥))
9		cleq1lem 15026	. . . . . . 7 ⊢ (𝑧 = 𝑤 → ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) ↔ (𝑤 ⊆ 𝑦 ∧ Tr 𝑦)))
10	9	imbi1d 344	. . . . . 6 ⊢ (𝑧 = 𝑤 → (((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
11	10	albidv 1949	. . . . 5 ⊢ (𝑧 = 𝑤 → (∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦) ↔ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
12	8, 11	3anbi13d 1465	. . . 4 ⊢ (𝑧 = 𝑤 → ((𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) ↔ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
13	12	exbidv 1950	. . 3 ⊢ (𝑧 = 𝑤 → (∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) ↔ ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
14		vex 3458	. . . . 5 ⊢ 𝑧 ∈ V
15		3simpa 1165	. . . . . . . . 9 ⊢ ((𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → (𝑤 ⊆ 𝑥 ∧ Tr 𝑥))
16	15	eximi 1864	. . . . . . . 8 ⊢ (∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥))
17		intexab 5315	. . . . . . . 8 ⊢ (∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥) ↔ ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V)
18	16, 17	sylib 221	. . . . . . 7 ⊢ (∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V)
19	18	ralimi 3101	. . . . . 6 ⊢ (∀𝑤 ∈ 𝑧 ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → ∀𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V)
20		iunexg 7958	. . . . . 6 ⊢ ((𝑧 ∈ V ∧ ∀𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V) → ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V)
21	14, 19, 20	sylancr 598	. . . . 5 ⊢ (∀𝑤 ∈ 𝑧 ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V)
22		unexg 7743	. . . . 5 ⊢ ((𝑧 ∈ V ∧ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ∈ V) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∈ V)
23	14, 21, 22	sylancr 598	. . . 4 ⊢ (∀𝑤 ∈ 𝑧 ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∈ V)
24		ssun1 4130	. . . . 5 ⊢ 𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
25		uniun 4894	. . . . . . 7 ⊢ ∪ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) = (∪ 𝑧 ∪ ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
26		uniiun 5022	. . . . . . . . . 10 ⊢ ∪ 𝑧 = ∪ 𝑤 ∈ 𝑧 𝑤
27		ssmin 4931	. . . . . . . . . . . 12 ⊢ 𝑤 ⊆ ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
28	27	rgenw 3082	. . . . . . . . . . 11 ⊢ ∀𝑤 ∈ 𝑧 𝑤 ⊆ ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
29		ss2iun 4974	. . . . . . . . . . 11 ⊢ (∀𝑤 ∈ 𝑧 𝑤 ⊆ ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} → ∪ 𝑤 ∈ 𝑧 𝑤 ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
30	28, 29	ax-mp 5	. . . . . . . . . 10 ⊢ ∪ 𝑤 ∈ 𝑧 𝑤 ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
31	26, 30	eqsstri 3982	. . . . . . . . 9 ⊢ ∪ 𝑧 ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
32		ssun4 4133	. . . . . . . . 9 ⊢ (∪ 𝑧 ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} → ∪ 𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}))
33	31, 32	ax-mp 5	. . . . . . . 8 ⊢ ∪ 𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
34		trint 5235	. . . . . . . . . . . . 13 ⊢ (∀𝑦 ∈ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}Tr 𝑦 → Tr ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
35		sseq2 3962	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 = 𝑦 → (𝑤 ⊆ 𝑥 ↔ 𝑤 ⊆ 𝑦))
36		treq 5224	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 = 𝑦 → (Tr 𝑥 ↔ Tr 𝑦))
37	35, 36	anbi12d 643	. . . . . . . . . . . . . . . 16 ⊢ (𝑥 = 𝑦 → ((𝑤 ⊆ 𝑥 ∧ Tr 𝑥) ↔ (𝑤 ⊆ 𝑦 ∧ Tr 𝑦)))
38	37	cbvabv 2832	. . . . . . . . . . . . . . 15 ⊢ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} = {𝑦 ∣ (𝑤 ⊆ 𝑦 ∧ Tr 𝑦)}
39	38	eqabri 2904	. . . . . . . . . . . . . 14 ⊢ (𝑦 ∈ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ↔ (𝑤 ⊆ 𝑦 ∧ Tr 𝑦))
40	39	simprbi 502	. . . . . . . . . . . . 13 ⊢ (𝑦 ∈ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} → Tr 𝑦)
41	34, 40	mprg 3084	. . . . . . . . . . . 12 ⊢ Tr ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
42	41	rgenw 3082	. . . . . . . . . . 11 ⊢ ∀𝑤 ∈ 𝑧 Tr ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
43		triun 5232	. . . . . . . . . . 11 ⊢ (∀𝑤 ∈ 𝑧 Tr ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} → Tr ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
44	42, 43	ax-mp 5	. . . . . . . . . 10 ⊢ Tr ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
45		df-tr 5218	. . . . . . . . . 10 ⊢ (Tr ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ↔ ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
46	44, 45	mpbi 233	. . . . . . . . 9 ⊢ ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
47		ssun4 4133	. . . . . . . . 9 ⊢ (∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} → ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}))
48	46, 47	ax-mp 5	. . . . . . . 8 ⊢ ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
49	33, 48	unssi 4143	. . . . . . 7 ⊢ (∪ 𝑧 ∪ ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
50	25, 49	eqsstri 3982	. . . . . 6 ⊢ ∪ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
51		df-tr 5218	. . . . . 6 ⊢ (Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ↔ ∪ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}))
52	50, 51	mpbir 234	. . . . 5 ⊢ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})
53		ssel 3930	. . . . . . . . . . . 12 ⊢ (𝑧 ⊆ 𝑦 → (𝑤 ∈ 𝑧 → 𝑤 ∈ 𝑦))
54		trss 5227	. . . . . . . . . . . 12 ⊢ (Tr 𝑦 → (𝑤 ∈ 𝑦 → 𝑤 ⊆ 𝑦))
55	53, 54	sylan9 516	. . . . . . . . . . 11 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑤 ∈ 𝑧 → 𝑤 ⊆ 𝑦))
56		simpr 489	. . . . . . . . . . 11 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → Tr 𝑦)
57	55, 56	jctird 535	. . . . . . . . . 10 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑤 ∈ 𝑧 → (𝑤 ⊆ 𝑦 ∧ Tr 𝑦)))
58		rabab 3484	. . . . . . . . . . . 12 ⊢ {𝑥 ∈ V ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} = {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
59	58	inteqi 4915	. . . . . . . . . . 11 ⊢ ∩ {𝑥 ∈ V ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} = ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}
60		vex 3458	. . . . . . . . . . . 12 ⊢ 𝑦 ∈ V
61	37	intminss 4938	. . . . . . . . . . . 12 ⊢ ((𝑦 ∈ V ∧ (𝑤 ⊆ 𝑦 ∧ Tr 𝑦)) → ∩ {𝑥 ∈ V ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
62	60, 61	mpan 702	. . . . . . . . . . 11 ⊢ ((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → ∩ {𝑥 ∈ V ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
63	59, 62	eqsstrrid 3975	. . . . . . . . . 10 ⊢ ((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
64	57, 63	syl6 36	. . . . . . . . 9 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑤 ∈ 𝑧 → ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦))
65	64	ralrimiv 3155	. . . . . . . 8 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → ∀𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
66		iunss 5008	. . . . . . . 8 ⊢ (∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦 ↔ ∀𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
67	65, 66	sylibr 237	. . . . . . 7 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦)
68		unss 4142	. . . . . . . 8 ⊢ ((𝑧 ⊆ 𝑦 ∧ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦) ↔ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)
69	68	biimpi 219	. . . . . . 7 ⊢ ((𝑧 ⊆ 𝑦 ∧ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)} ⊆ 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)
70	67, 69	syldan 602	. . . . . 6 ⊢ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)
71	70	ax-gen 1824	. . . . 5 ⊢ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)
72	24, 52, 71	3pm3.2i 1357	. . . 4 ⊢ (𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦))
73		sseq2 3962	. . . . . . 7 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → (𝑧 ⊆ 𝑢 ↔ 𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})))
74		treq 5224	. . . . . . 7 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → (Tr 𝑢 ↔ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)})))
75		sseq1 3961	. . . . . . . . 9 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → (𝑢 ⊆ 𝑦 ↔ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦))
76	75	imbi2d 343	. . . . . . . 8 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → (((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦) ↔ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)))
77	76	albidv 1949	. . . . . . 7 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → (∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦) ↔ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)))
78	73, 74, 77	3anbi123d 1463	. . . . . 6 ⊢ (𝑢 = (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) → ((𝑧 ⊆ 𝑢 ∧ Tr 𝑢 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦)) ↔ (𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦))))
79	78	spcegv 3555	. . . . 5 ⊢ ((𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∈ V → ((𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)) → ∃𝑢(𝑧 ⊆ 𝑢 ∧ Tr 𝑢 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦))))
80		sseq2 3962	. . . . . . 7 ⊢ (𝑢 = 𝑥 → (𝑧 ⊆ 𝑢 ↔ 𝑧 ⊆ 𝑥))
81		treq 5224	. . . . . . 7 ⊢ (𝑢 = 𝑥 → (Tr 𝑢 ↔ Tr 𝑥))
82		sseq1 3961	. . . . . . . . 9 ⊢ (𝑢 = 𝑥 → (𝑢 ⊆ 𝑦 ↔ 𝑥 ⊆ 𝑦))
83	82	imbi2d 343	. . . . . . . 8 ⊢ (𝑢 = 𝑥 → (((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦) ↔ ((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
84	83	albidv 1949	. . . . . . 7 ⊢ (𝑢 = 𝑥 → (∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦) ↔ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
85	80, 81, 84	3anbi123d 1463	. . . . . 6 ⊢ (𝑢 = 𝑥 → ((𝑧 ⊆ 𝑢 ∧ Tr 𝑢 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦)) ↔ (𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
86	85	cbvexvw 2066	. . . . 5 ⊢ (∃𝑢(𝑧 ⊆ 𝑢 ∧ Tr 𝑢 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑢 ⊆ 𝑦)) ↔ ∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
87	79, 86	imbitrdi 254	. . . 4 ⊢ ((𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∈ V → ((𝑧 ⊆ (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ Tr (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → (𝑧 ∪ ∪ 𝑤 ∈ 𝑧 ∩ {𝑥 ∣ (𝑤 ⊆ 𝑥 ∧ Tr 𝑥)}) ⊆ 𝑦)) → ∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))))
88	23, 72, 87	mpisyl 22	. . 3 ⊢ (∀𝑤 ∈ 𝑧 ∃𝑥(𝑤 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑤 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)) → ∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦)))
89	13, 88	setinds2regs 35552	. 2 ⊢ ∃𝑥(𝑧 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝑧 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))
90	1, 7, 89	vtocl 3524	1 ⊢ ∃𝑥(𝐴 ⊆ 𝑥 ∧ Tr 𝑥 ∧ ∀𝑦((𝐴 ⊆ 𝑦 ∧ Tr 𝑦) → 𝑥 ⊆ 𝑦))

This proof depends on syntax axioms:   → wi 4   ∧ wa 400   ∧ w3a 1102  ∀wal 1567   = wceq 1569  ∃wex 1808   ∈ wcel 2142  {cab 2740  ∀wral 3078  {crab 3415  Vcvv 3454   ∪ cun 3902   ⊆ wss 3904  ∪ cuni 4871  ∩ cint 4911  ∪ ciun 4955  Tr wtr 5217

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-10 2175  ax-11 2191  ax-12 2212  ax-ext 2734  ax-rep 5237  ax-sep 5256  ax-pr 5403  ax-un 7734  ax-regs 35547

This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-3an 1104  df-tru 1572  df-fal 1582  df-ex 1809  df-nf 1813  df-sb 2096  df-mo 2566  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ne 2958  df-ral 3079  df-rex 3089  df-rab 3416  df-v 3456  df-dif 3907  df-un 3909  df-in 3911  df-ss 3921  df-nul 4286  df-sn 4589  df-pr 4591  df-uni 4872  df-int 4912  df-iun 4957  df-iin 4958  df-tr 5218

This theorem is used by: (None)