Theorem fiunlem 7965

Description: Lemma for fiun 7966 and f1iun 7967. Formerly part of f1iun 7967. (Contributed by AV, 6-Oct-2023.)

Hypothesis

Ref	Expression
fiun.1	⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶)

Assertion

Ref	Expression
fiunlem	⊢ (((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) → ∀𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵} (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))

Distinct variable groups:   𝑣,𝐴,𝑥,𝑧   𝑦,𝐴,𝑣   𝑣,𝐵,𝑦   𝑧,𝐵   𝑣,𝐶,𝑥   𝑣,𝐷   𝑣,𝑆   𝑣,𝑢,𝑦   𝑥,𝑦

Allowed substitution hints:   𝐴(𝑢)   𝐵(𝑥,𝑢)   𝐶(𝑦,𝑧,𝑢)   𝐷(𝑥,𝑦,𝑧,𝑢)   𝑆(𝑥,𝑦,𝑧,𝑢)

Proof of Theorem fiunlem

Step	Hyp	Ref	Expression
1		vex 3482	. . . 4 ⊢ 𝑣 ∈ V
2		eqeq1 2739	. . . . 5 ⊢ (𝑧 = 𝑣 → (𝑧 = 𝐵 ↔ 𝑣 = 𝐵))
3	2	rexbidv 3177	. . . 4 ⊢ (𝑧 = 𝑣 → (∃𝑥 ∈ 𝐴 𝑧 = 𝐵 ↔ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵))
4	1, 3	elab 3681	. . 3 ⊢ (𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵} ↔ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵)
5		fiun.1	. . . . . 6 ⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶)
6	5	eqeq2d 2746	. . . . 5 ⊢ (𝑥 = 𝑦 → (𝑣 = 𝐵 ↔ 𝑣 = 𝐶))
7	6	cbvrexvw 3236	. . . 4 ⊢ (∃𝑥 ∈ 𝐴 𝑣 = 𝐵 ↔ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶)
8		r19.29 3112	. . . . . . 7 ⊢ ((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → ∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶))
9		sseq12 4023	. . . . . . . . . . . . 13 ⊢ ((𝑢 = 𝐵 ∧ 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ↔ 𝐵 ⊆ 𝐶))
10	9	ancoms 458	. . . . . . . . . . . 12 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ↔ 𝐵 ⊆ 𝐶))
11		sseq12 4023	. . . . . . . . . . . 12 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑣 ⊆ 𝑢 ↔ 𝐶 ⊆ 𝐵))
12	10, 11	orbi12d 918	. . . . . . . . . . 11 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → ((𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢) ↔ (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)))
13	12	biimprcd 250	. . . . . . . . . 10 ⊢ ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) → ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
14	13	expdimp 452	. . . . . . . . 9 ⊢ (((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) → (𝑢 = 𝐵 → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
15	14	rexlimivw 3149	. . . . . . . 8 ⊢ (∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) → (𝑢 = 𝐵 → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
16	15	imp 406	. . . . . . 7 ⊢ ((∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
17	8, 16	sylan 580	. . . . . 6 ⊢ (((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
18	17	an32s 652	. . . . 5 ⊢ (((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑢 = 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
19	18	adantlll 718	. . . 4 ⊢ ((((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
20	7, 19	sylan2b 594	. . 3 ⊢ ((((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) ∧ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
21	4, 20	sylan2b 594	. 2 ⊢ ((((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) ∧ 𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵}) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
22	21	ralrimiva 3144	1 ⊢ (((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) → ∀𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵} (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))

Syntax hints:   → wi 4   ↔ wb 206   ∧ wa 395   ∨ wo 847   = wceq 1537   ∈ wcel 2106  {cab 2712  ∀wral 3059  ∃wrex 3068   ⊆ wss 3963  ⟶wf 6559

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-8 2108  ax-9 2116  ax-ext 2706

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-tru 1540  df-ex 1777  df-sb 2063  df-clab 2713  df-cleq 2727  df-clel 2814  df-ral 3060  df-rex 3069  df-v 3480  df-ss 3980

This theorem is referenced by:  fiun  7966  f1iun  7967