Theorem disjunsn 28789

Description: Append an element to a disjoint collection. Similar to ralunsn 4360, gsumunsn 18182, etc. (Contributed by Thierry Arnoux, 28-Mar-2018.)

Hypothesis

Ref	Expression
disjunsn.s	⊢ (𝑥 = 𝑀 → 𝐵 = 𝐶)

Assertion

Ref	Expression
disjunsn	⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐶   𝑥,𝑀   𝑥,𝑉

Allowed substitution hint:   𝐵(𝑥)

Proof of Theorem disjunsn

Dummy variables 𝑖 𝑗 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		disjors 4568	. . . . . 6 ⊢ (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ ∀𝑖 ∈ (𝐴 ∪ {𝑀})∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
2		eqeq1 2614	. . . . . . . . 9 ⊢ (𝑖 = 𝑀 → (𝑖 = 𝑗 ↔ 𝑀 = 𝑗))
3		csbeq1 3502	. . . . . . . . . . 11 ⊢ (𝑖 = 𝑀 → ⦋𝑖 / 𝑥⦌𝐵 = ⦋𝑀 / 𝑥⦌𝐵)
4	3	ineq1d 3775	. . . . . . . . . 10 ⊢ (𝑖 = 𝑀 → (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵))
5	4	eqeq1d 2612	. . . . . . . . 9 ⊢ (𝑖 = 𝑀 → ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
6	2, 5	orbi12d 742	. . . . . . . 8 ⊢ (𝑖 = 𝑀 → ((𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
7	6	ralbidv 2969	. . . . . . 7 ⊢ (𝑖 = 𝑀 → (∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
8	7	ralunsn 4360	. . . . . 6 ⊢ (𝑀 ∈ 𝑉 → (∀𝑖 ∈ (𝐴 ∪ {𝑀})∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑖 ∈ 𝐴 ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
9	1, 8	syl5bb 271	. . . . 5 ⊢ (𝑀 ∈ 𝑉 → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ (∀𝑖 ∈ 𝐴 ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
10		eqeq2 2621	. . . . . . . . 9 ⊢ (𝑗 = 𝑀 → (𝑖 = 𝑗 ↔ 𝑖 = 𝑀))
11		csbeq1 3502	. . . . . . . . . . 11 ⊢ (𝑗 = 𝑀 → ⦋𝑗 / 𝑥⦌𝐵 = ⦋𝑀 / 𝑥⦌𝐵)
12	11	ineq2d 3776	. . . . . . . . . 10 ⊢ (𝑗 = 𝑀 → (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵))
13	12	eqeq1d 2612	. . . . . . . . 9 ⊢ (𝑗 = 𝑀 → ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
14	10, 13	orbi12d 742	. . . . . . . 8 ⊢ (𝑗 = 𝑀 → ((𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
15	14	ralunsn 4360	. . . . . . 7 ⊢ (𝑀 ∈ 𝑉 → (∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))))
16	15	ralbidv 2969	. . . . . 6 ⊢ (𝑀 ∈ 𝑉 → (∀𝑖 ∈ 𝐴 ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ ∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))))
17		eqeq2 2621	. . . . . . . . 9 ⊢ (𝑗 = 𝑀 → (𝑀 = 𝑗 ↔ 𝑀 = 𝑀))
18	11	ineq2d 3776	. . . . . . . . . 10 ⊢ (𝑗 = 𝑀 → (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵))
19	18	eqeq1d 2612	. . . . . . . . 9 ⊢ (𝑗 = 𝑀 → ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
20	17, 19	orbi12d 742	. . . . . . . 8 ⊢ (𝑗 = 𝑀 → ((𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (𝑀 = 𝑀 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
21	20	ralunsn 4360	. . . . . . 7 ⊢ (𝑀 ∈ 𝑉 → (∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑀 = 𝑀 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))))
22		eqid 2610	. . . . . . . . 9 ⊢ 𝑀 = 𝑀
23	22	orci 404	. . . . . . . 8 ⊢ (𝑀 = 𝑀 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)
24	23	biantru 525	. . . . . . 7 ⊢ (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑀 = 𝑀 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
25	21, 24	syl6bbr 277	. . . . . 6 ⊢ (𝑀 ∈ 𝑉 → (∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
26	16, 25	anbi12d 743	. . . . 5 ⊢ (𝑀 ∈ 𝑉 → ((∀𝑖 ∈ 𝐴 ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ ∀𝑗 ∈ (𝐴 ∪ {𝑀})(𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) ↔ (∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
27	9, 26	bitrd 267	. . . 4 ⊢ (𝑀 ∈ 𝑉 → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ (∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
28		r19.26 3046	. . . . . 6 ⊢ (∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ↔ (∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
29		disjors 4568	. . . . . . 7 ⊢ (Disj 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
30	29	anbi1i 727	. . . . . 6 ⊢ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ↔ (∀𝑖 ∈ 𝐴 ∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
31	28, 30	bitr4i 266	. . . . 5 ⊢ (∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
32	31	anbi1i 727	. . . 4 ⊢ ((∀𝑖 ∈ 𝐴 (∀𝑗 ∈ 𝐴 (𝑖 = 𝑗 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ∧ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) ↔ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
33	27, 32	syl6bb 275	. . 3 ⊢ (𝑀 ∈ 𝑉 → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
34	33	adantr 480	. 2 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))))
35		orcom 401	. . . . . . . . 9 ⊢ (((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ 𝑖 = 𝑀) ↔ (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
36	35	ralbii 2963	. . . . . . . 8 ⊢ (∀𝑖 ∈ 𝐴 ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ 𝑖 = 𝑀) ↔ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
37		r19.30 3063	. . . . . . . . 9 ⊢ (∀𝑖 ∈ 𝐴 ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ 𝑖 = 𝑀) → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑖 ∈ 𝐴 𝑖 = 𝑀))
38		risset 3044	. . . . . . . . . . . 12 ⊢ (𝑀 ∈ 𝐴 ↔ ∃𝑖 ∈ 𝐴 𝑖 = 𝑀)
39		biorf 419	. . . . . . . . . . . 12 ⊢ (¬ ∃𝑖 ∈ 𝐴 𝑖 = 𝑀 → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑖 ∈ 𝐴 𝑖 = 𝑀 ∨ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
40	38, 39	sylnbi 319	. . . . . . . . . . 11 ⊢ (¬ 𝑀 ∈ 𝐴 → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑖 ∈ 𝐴 𝑖 = 𝑀 ∨ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
41	40	adantl 481	. . . . . . . . . 10 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑖 ∈ 𝐴 𝑖 = 𝑀 ∨ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)))
42		orcom 401	. . . . . . . . . 10 ⊢ ((∃𝑖 ∈ 𝐴 𝑖 = 𝑀 ∨ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑖 ∈ 𝐴 𝑖 = 𝑀))
43	41, 42	syl6bb 275	. . . . . . . . 9 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑖 ∈ 𝐴 𝑖 = 𝑀)))
44	37, 43	syl5ibr 235	. . . . . . . 8 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ∨ 𝑖 = 𝑀) → ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
45	36, 44	syl5bir 232	. . . . . . 7 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅) → ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
46		olc 398	. . . . . . . 8 ⊢ ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ → (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
47	46	ralimi 2936	. . . . . . 7 ⊢ (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ → ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
48	45, 47	impbid1 214	. . . . . 6 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅) ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
49		nfv 1830	. . . . . . . . . 10 ⊢ Ⅎ𝑖(𝐵 ∩ 𝐶) = ∅
50		nfcsb1v 3515	. . . . . . . . . . . 12 ⊢ Ⅎ𝑥⦋𝑖 / 𝑥⦌𝐵
51		nfcv 2751	. . . . . . . . . . . 12 ⊢ Ⅎ𝑥𝐶
52	50, 51	nfin 3782	. . . . . . . . . . 11 ⊢ Ⅎ𝑥(⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶)
53	52	nfeq1 2764	. . . . . . . . . 10 ⊢ Ⅎ𝑥(⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅
54		csbeq1a 3508	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑖 → 𝐵 = ⦋𝑖 / 𝑥⦌𝐵)
55	54	ineq1d 3775	. . . . . . . . . . 11 ⊢ (𝑥 = 𝑖 → (𝐵 ∩ 𝐶) = (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶))
56	55	eqeq1d 2612	. . . . . . . . . 10 ⊢ (𝑥 = 𝑖 → ((𝐵 ∩ 𝐶) = ∅ ↔ (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
57	49, 53, 56	cbvral 3143	. . . . . . . . 9 ⊢ (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅)
58	57	a1i 11	. . . . . . . 8 ⊢ (𝑀 ∈ 𝑉 → (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
59		ss0b 3925	. . . . . . . . . . 11 ⊢ (∪ 𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) ⊆ ∅ ↔ ∪ 𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅)
60		iunss 4497	. . . . . . . . . . 11 ⊢ (∪ 𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) ⊆ ∅ ↔ ∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) ⊆ ∅)
61		iunin1 4521	. . . . . . . . . . . 12 ⊢ ∪ 𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶)
62	61	eqeq1i 2615	. . . . . . . . . . 11 ⊢ (∪ 𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)
63	59, 60, 62	3bitr3ri 290	. . . . . . . . . 10 ⊢ ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) ⊆ ∅)
64		ss0b 3925	. . . . . . . . . . 11 ⊢ ((𝐵 ∩ 𝐶) ⊆ ∅ ↔ (𝐵 ∩ 𝐶) = ∅)
65	64	ralbii 2963	. . . . . . . . . 10 ⊢ (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) ⊆ ∅ ↔ ∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅)
66	63, 65	bitri 263	. . . . . . . . 9 ⊢ ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅)
67	66	a1i 11	. . . . . . . 8 ⊢ (𝑀 ∈ 𝑉 → ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅))
68		nfcvd 2752	. . . . . . . . . . . 12 ⊢ (𝑀 ∈ 𝑉 → Ⅎ𝑥𝐶)
69		disjunsn.s	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑀 → 𝐵 = 𝐶)
70	68, 69	csbiegf 3523	. . . . . . . . . . 11 ⊢ (𝑀 ∈ 𝑉 → ⦋𝑀 / 𝑥⦌𝐵 = 𝐶)
71	70	ineq2d 3776	. . . . . . . . . 10 ⊢ (𝑀 ∈ 𝑉 → (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶))
72	71	eqeq1d 2612	. . . . . . . . 9 ⊢ (𝑀 ∈ 𝑉 → ((⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
73	72	ralbidv 2969	. . . . . . . 8 ⊢ (𝑀 ∈ 𝑉 → (∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅ ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
74	58, 67, 73	3bitr4d 299	. . . . . . 7 ⊢ (𝑀 ∈ 𝑉 → ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
75	74	adantr 480	. . . . . 6 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑖 ∈ 𝐴 (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅))
76	48, 75	bitr4d 270	. . . . 5 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅) ↔ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅))
77	76	anbi2d 736	. . . 4 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))
78		orcom 401	. . . . . . . 8 ⊢ (((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ 𝑀 = 𝑗) ↔ (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
79	78	ralbii 2963	. . . . . . 7 ⊢ (∀𝑗 ∈ 𝐴 ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ 𝑀 = 𝑗) ↔ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
80		r19.30 3063	. . . . . . . 8 ⊢ (∀𝑗 ∈ 𝐴 ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ 𝑀 = 𝑗) → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗))
81		risset 3044	. . . . . . . . . . . 12 ⊢ (𝑀 ∈ 𝐴 ↔ ∃𝑗 ∈ 𝐴 𝑗 = 𝑀)
82		eqcom 2617	. . . . . . . . . . . . 13 ⊢ (𝑗 = 𝑀 ↔ 𝑀 = 𝑗)
83	82	rexbii 3023	. . . . . . . . . . . 12 ⊢ (∃𝑗 ∈ 𝐴 𝑗 = 𝑀 ↔ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗)
84	81, 83	bitri 263	. . . . . . . . . . 11 ⊢ (𝑀 ∈ 𝐴 ↔ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗)
85		biorf 419	. . . . . . . . . . 11 ⊢ (¬ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗 → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑗 ∈ 𝐴 𝑀 = 𝑗 ∨ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
86	84, 85	sylnbi 319	. . . . . . . . . 10 ⊢ (¬ 𝑀 ∈ 𝐴 → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑗 ∈ 𝐴 𝑀 = 𝑗 ∨ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
87	86	adantl 481	. . . . . . . . 9 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (∃𝑗 ∈ 𝐴 𝑀 = 𝑗 ∨ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)))
88		orcom 401	. . . . . . . . 9 ⊢ ((∃𝑗 ∈ 𝐴 𝑀 = 𝑗 ∨ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗))
89	87, 88	syl6bb 275	. . . . . . . 8 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ ∃𝑗 ∈ 𝐴 𝑀 = 𝑗)))
90	80, 89	syl5ibr 235	. . . . . . 7 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ∨ 𝑀 = 𝑗) → ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
91	79, 90	syl5bir 232	. . . . . 6 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) → ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
92		olc 398	. . . . . . 7 ⊢ ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ → (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
93	92	ralimi 2936	. . . . . 6 ⊢ (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ → ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
94	91, 93	impbid1 214	. . . . 5 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
95		nfv 1830	. . . . . . . . . 10 ⊢ Ⅎ𝑗(𝐵 ∩ 𝐶) = ∅
96		nfcsb1v 3515	. . . . . . . . . . . 12 ⊢ Ⅎ𝑥⦋𝑗 / 𝑥⦌𝐵
97	96, 51	nfin 3782	. . . . . . . . . . 11 ⊢ Ⅎ𝑥(⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶)
98	97	nfeq1 2764	. . . . . . . . . 10 ⊢ Ⅎ𝑥(⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅
99		csbeq1a 3508	. . . . . . . . . . . 12 ⊢ (𝑥 = 𝑗 → 𝐵 = ⦋𝑗 / 𝑥⦌𝐵)
100	99	ineq1d 3775	. . . . . . . . . . 11 ⊢ (𝑥 = 𝑗 → (𝐵 ∩ 𝐶) = (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶))
101	100	eqeq1d 2612	. . . . . . . . . 10 ⊢ (𝑥 = 𝑗 → ((𝐵 ∩ 𝐶) = ∅ ↔ (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
102	95, 98, 101	cbvral 3143	. . . . . . . . 9 ⊢ (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅)
103	102	a1i 11	. . . . . . . 8 ⊢ (𝑀 ∈ 𝑉 → (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅))
104		incom 3767	. . . . . . . . . 10 ⊢ (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵)
105	104	eqeq1i 2615	. . . . . . . . 9 ⊢ ((⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅ ↔ (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)
106	105	ralbii 2963	. . . . . . . 8 ⊢ (∀𝑗 ∈ 𝐴 (⦋𝑗 / 𝑥⦌𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)
107	103, 106	syl6bb 275	. . . . . . 7 ⊢ (𝑀 ∈ 𝑉 → (∀𝑥 ∈ 𝐴 (𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
108	70	ineq1d 3775	. . . . . . . . 9 ⊢ (𝑀 ∈ 𝑉 → (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵))
109	108	eqeq1d 2612	. . . . . . . 8 ⊢ (𝑀 ∈ 𝑉 → ((⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
110	109	ralbidv 2969	. . . . . . 7 ⊢ (𝑀 ∈ 𝑉 → (∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅ ↔ ∀𝑗 ∈ 𝐴 (𝐶 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
111	107, 67, 110	3bitr4d 299	. . . . . 6 ⊢ (𝑀 ∈ 𝑉 → ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
112	111	adantr 480	. . . . 5 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ↔ ∀𝑗 ∈ 𝐴 (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅))
113	94, 112	bitr4d 270	. . . 4 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅) ↔ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅))
114	77, 113	anbi12d 743	. . 3 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) ↔ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))
115		anass 679	. . . 4 ⊢ (((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))
116		anidm 674	. . . . 5 ⊢ (((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ↔ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)
117	116	anbi2i 726	. . . 4 ⊢ ((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ((∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅ ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅))
118	115, 117	bitri 263	. . 3 ⊢ (((Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅))
119	114, 118	syl6bb 275	. 2 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (((Disj 𝑥 ∈ 𝐴 𝐵 ∧ ∀𝑖 ∈ 𝐴 (𝑖 = 𝑀 ∨ (⦋𝑖 / 𝑥⦌𝐵 ∩ ⦋𝑀 / 𝑥⦌𝐵) = ∅)) ∧ ∀𝑗 ∈ 𝐴 (𝑀 = 𝑗 ∨ (⦋𝑀 / 𝑥⦌𝐵 ∩ ⦋𝑗 / 𝑥⦌𝐵) = ∅)) ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))
120	34, 119	bitrd 267	1 ⊢ ((𝑀 ∈ 𝑉 ∧ ¬ 𝑀 ∈ 𝐴) → (Disj 𝑥 ∈ (𝐴 ∪ {𝑀})𝐵 ↔ (Disj 𝑥 ∈ 𝐴 𝐵 ∧ (∪ 𝑥 ∈ 𝐴 𝐵 ∩ 𝐶) = ∅)))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 195   ∨ wo 382   ∧ wa 383   = wceq 1475   ∈ wcel 1977  ∀wral 2896  ∃wrex 2897  ⦋csb 3499   ∪ cun 3538   ∩ cin 3539   ⊆ wss 3540  ∅c0 3874  {csn 4125  ∪ ciun 4455  Disj wdisj 4553

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3an 1033  df-tru 1478  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ral 2901  df-rex 2902  df-reu 2903  df-rmo 2904  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-nul 3875  df-sn 4126  df-iun 4457  df-disj 4554

This theorem is referenced by:  disjun0  28790  disjiunel  28791