Theorem fiunlem 7938

Description: Lemma for fiun 7939 and f1iun 7940. Formerly part of f1iun 7940. (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 3457	. . . 4 ⊢ 𝑣 ∈ V
2		eqeq1 2765	. . . . 5 ⊢ (𝑧 = 𝑣 → (𝑧 = 𝐵 ↔ 𝑣 = 𝐵))
3	2	rexbidv 3187	. . . 4 ⊢ (𝑧 = 𝑣 → (∃𝑥 ∈ 𝐴 𝑧 = 𝐵 ↔ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵))
4	1, 3	elab 3637	. . 3 ⊢ (𝑣 ∈ {𝑧 ∣ ∃𝑥 ∈ 𝐴 𝑧 = 𝐵} ↔ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵)
5		fiun.1	. . . . . 6 ⊢ (𝑥 = 𝑦 → 𝐵 = 𝐶)
6	5	eqeq2d 2772	. . . . 5 ⊢ (𝑥 = 𝑦 → (𝑣 = 𝐵 ↔ 𝑣 = 𝐶))
7	6	cbvrexvw 3242	. . . 4 ⊢ (∃𝑥 ∈ 𝐴 𝑣 = 𝐵 ↔ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶)
8		r19.29 3126	. . . . . . 7 ⊢ ((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → ∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶))
9		sseq12 3963	. . . . . . . . . . . . 13 ⊢ ((𝑢 = 𝐵 ∧ 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ↔ 𝐵 ⊆ 𝐶))
10	9	ancoms 463	. . . . . . . . . . . 12 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ↔ 𝐵 ⊆ 𝐶))
11		sseq12 3963	. . . . . . . . . . . 12 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑣 ⊆ 𝑢 ↔ 𝐶 ⊆ 𝐵))
12	10, 11	orbi12d 931	. . . . . . . . . . 11 ⊢ ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → ((𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢) ↔ (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)))
13	12	biimprcd 253	. . . . . . . . . 10 ⊢ ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) → ((𝑣 = 𝐶 ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
14	13	expdimp 457	. . . . . . . . 9 ⊢ (((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) → (𝑢 = 𝐵 → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
15	14	rexlimivw 3160	. . . . . . . 8 ⊢ (∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) → (𝑢 = 𝐵 → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢)))
16	15	imp 411	. . . . . . 7 ⊢ ((∃𝑦 ∈ 𝐴 ((𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑣 = 𝐶) ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
17	8, 16	sylan 591	. . . . . 6 ⊢ (((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) ∧ 𝑢 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
18	17	an32s 664	. . . . 5 ⊢ (((∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵) ∧ 𝑢 = 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
19	18	adantlll 730	. . . 4 ⊢ ((((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) ∧ ∃𝑦 ∈ 𝐴 𝑣 = 𝐶) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
20	7, 19	sylan2b 605	. . 3 ⊢ ((((𝐵:𝐷⟶𝑆 ∧ ∀𝑦 ∈ 𝐴 (𝐵 ⊆ 𝐶 ∨ 𝐶 ⊆ 𝐵)) ∧ 𝑢 = 𝐵) ∧ ∃𝑥 ∈ 𝐴 𝑣 = 𝐵) → (𝑢 ⊆ 𝑣 ∨ 𝑣 ⊆ 𝑢))
21	4, 20	sylan2b 605	. 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 3155	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 209   ∧ wa 400   ∨ wo 860   = wceq 1568   ∈ wcel 2141  {cab 2739  ∀wral 3077  ∃wrex 3087   ⊆ wss 3904  ⟶wf 6532

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-8 2143  ax-9 2151  ax-ext 2733

This theorem depends on definitions:  df-bi 210  df-an 401  df-or 861  df-tru 1571  df-ex 1808  df-sb 2095  df-clab 2740  df-cleq 2753  df-clel 2836  df-ral 3078  df-rex 3088  df-v 3455  df-ss 3921

This theorem is referenced by:  fiun  7939  f1iun  7940