Theorem bj-inf2vnlem2 13863

Description: Lemma for bj-inf2vnlem3 13864 and bj-inf2vnlem4 13865. Remark: unoptimized proof (have to use more deduction style). (Contributed by BJ, 8-Dec-2019.) (Proof modification is discouraged.)

Assertion

Ref	Expression
bj-inf2vnlem2	⊢ (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (Ind 𝑍 → ∀𝑢(∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑢 ∈ 𝐴 → 𝑢 ∈ 𝑍))))

Distinct variable groups:   𝑥,𝑦,𝑡,𝑢,𝐴   𝑥,𝑍,𝑦,𝑡,𝑢

Proof of Theorem bj-inf2vnlem2

Dummy variable 𝑣 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		eqeq1 2172	. . . . . . 7 ⊢ (𝑥 = 𝑢 → (𝑥 = ∅ ↔ 𝑢 = ∅))
2		eqeq1 2172	. . . . . . . 8 ⊢ (𝑥 = 𝑢 → (𝑥 = suc 𝑦 ↔ 𝑢 = suc 𝑦))
3	2	rexbidv 2467	. . . . . . 7 ⊢ (𝑥 = 𝑢 → (∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦 ↔ ∃𝑦 ∈ 𝐴 𝑢 = suc 𝑦))
4	1, 3	orbi12d 783	. . . . . 6 ⊢ (𝑥 = 𝑢 → ((𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) ↔ (𝑢 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑢 = suc 𝑦)))
5	4	rspcv 2826	. . . . 5 ⊢ (𝑢 ∈ 𝐴 → (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (𝑢 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑢 = suc 𝑦)))
6		df-bj-ind 13819	. . . . . . . . 9 ⊢ (Ind 𝑍 ↔ (∅ ∈ 𝑍 ∧ ∀𝑣 ∈ 𝑍 suc 𝑣 ∈ 𝑍))
7	6	simplbi 272	. . . . . . . 8 ⊢ (Ind 𝑍 → ∅ ∈ 𝑍)
8		eleq1 2229	. . . . . . . 8 ⊢ (𝑢 = ∅ → (𝑢 ∈ 𝑍 ↔ ∅ ∈ 𝑍))
9	7, 8	syl5ibr 155	. . . . . . 7 ⊢ (𝑢 = ∅ → (Ind 𝑍 → 𝑢 ∈ 𝑍))
10	9	a1dd 48	. . . . . 6 ⊢ (𝑢 = ∅ → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)))
11		vex 2729	. . . . . . . . . 10 ⊢ 𝑦 ∈ V
12	11	sucid 4395	. . . . . . . . 9 ⊢ 𝑦 ∈ suc 𝑦
13		eleq2 2230	. . . . . . . . . 10 ⊢ (suc 𝑦 = 𝑢 → (𝑦 ∈ suc 𝑦 ↔ 𝑦 ∈ 𝑢))
14	13	eqcoms 2168	. . . . . . . . 9 ⊢ (𝑢 = suc 𝑦 → (𝑦 ∈ suc 𝑦 ↔ 𝑦 ∈ 𝑢))
15	12, 14	mpbii 147	. . . . . . . 8 ⊢ (𝑢 = suc 𝑦 → 𝑦 ∈ 𝑢)
16		eleq1 2229	. . . . . . . . . . . . 13 ⊢ (𝑡 = 𝑦 → (𝑡 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴))
17		eleq1 2229	. . . . . . . . . . . . 13 ⊢ (𝑡 = 𝑦 → (𝑡 ∈ 𝑍 ↔ 𝑦 ∈ 𝑍))
18	16, 17	imbi12d 233	. . . . . . . . . . . 12 ⊢ (𝑡 = 𝑦 → ((𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) ↔ (𝑦 ∈ 𝐴 → 𝑦 ∈ 𝑍)))
19	18	rspcv 2826	. . . . . . . . . . 11 ⊢ (𝑦 ∈ 𝑢 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑦 ∈ 𝐴 → 𝑦 ∈ 𝑍)))
20		bj-indsuc 13820	. . . . . . . . . . . 12 ⊢ (Ind 𝑍 → (𝑦 ∈ 𝑍 → suc 𝑦 ∈ 𝑍))
21		eleq1a 2238	. . . . . . . . . . . 12 ⊢ (suc 𝑦 ∈ 𝑍 → (𝑢 = suc 𝑦 → 𝑢 ∈ 𝑍))
22	20, 21	syl6com 35	. . . . . . . . . . 11 ⊢ (𝑦 ∈ 𝑍 → (Ind 𝑍 → (𝑢 = suc 𝑦 → 𝑢 ∈ 𝑍)))
23	19, 22	syl8 71	. . . . . . . . . 10 ⊢ (𝑦 ∈ 𝑢 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑦 ∈ 𝐴 → (Ind 𝑍 → (𝑢 = suc 𝑦 → 𝑢 ∈ 𝑍)))))
24	23	com13 80	. . . . . . . . 9 ⊢ (𝑦 ∈ 𝐴 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑦 ∈ 𝑢 → (Ind 𝑍 → (𝑢 = suc 𝑦 → 𝑢 ∈ 𝑍)))))
25	24	com25 91	. . . . . . . 8 ⊢ (𝑦 ∈ 𝐴 → (𝑢 = suc 𝑦 → (𝑦 ∈ 𝑢 → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)))))
26	15, 25	mpdi 43	. . . . . . 7 ⊢ (𝑦 ∈ 𝐴 → (𝑢 = suc 𝑦 → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍))))
27	26	rexlimiv 2577	. . . . . 6 ⊢ (∃𝑦 ∈ 𝐴 𝑢 = suc 𝑦 → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)))
28	10, 27	jaoi 706	. . . . 5 ⊢ ((𝑢 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑢 = suc 𝑦) → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)))
29	5, 28	syl6 33	. . . 4 ⊢ (𝑢 ∈ 𝐴 → (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (Ind 𝑍 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍))))
30	29	com3l 81	. . 3 ⊢ (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (Ind 𝑍 → (𝑢 ∈ 𝐴 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍))))
31	30	alrimdv 1864	. 2 ⊢ (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (Ind 𝑍 → ∀𝑢(𝑢 ∈ 𝐴 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍))))
32		bi2.04 247	. . 3 ⊢ ((𝑢 ∈ 𝐴 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)) ↔ (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑢 ∈ 𝐴 → 𝑢 ∈ 𝑍)))
33	32	albii 1458	. 2 ⊢ (∀𝑢(𝑢 ∈ 𝐴 → (∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → 𝑢 ∈ 𝑍)) ↔ ∀𝑢(∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑢 ∈ 𝐴 → 𝑢 ∈ 𝑍)))
34	31, 33	syl6ib 160	1 ⊢ (∀𝑥 ∈ 𝐴 (𝑥 = ∅ ∨ ∃𝑦 ∈ 𝐴 𝑥 = suc 𝑦) → (Ind 𝑍 → ∀𝑢(∀𝑡 ∈ 𝑢 (𝑡 ∈ 𝐴 → 𝑡 ∈ 𝑍) → (𝑢 ∈ 𝐴 → 𝑢 ∈ 𝑍))))

Syntax hints:   → wi 4   ↔ wb 104   ∨ wo 698  ∀wal 1341   = wceq 1343   ∈ wcel 2136  ∀wral 2444  ∃wrex 2445  ∅c0 3409  suc csuc 4343  Ind wind 13818

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-ext 2147

This theorem depends on definitions:  df-bi 116  df-tru 1346  df-nf 1449  df-sb 1751  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ral 2449  df-rex 2450  df-v 2728  df-un 3120  df-sn 3582  df-suc 4349  df-bj-ind 13819

This theorem is referenced by:  bj-inf2vnlem3  13864  bj-inf2vnlem4  13865