Theorem disjss3 5102

Description: Expand a disjoint collection with any number of empty sets. (Contributed by Mario Carneiro, 15-Nov-2016.)

Assertion

Ref	Expression
disjss3	⊢ ((𝐴 ⊆ 𝐵 ∧ ∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅) → (Disj 𝑥 ∈ 𝐴 𝐶 ↔ Disj 𝑥 ∈ 𝐵 𝐶))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵

Allowed substitution hint:   𝐶(𝑥)

Proof of Theorem disjss3

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-ral 3078	. . . . . . 7 ⊢ (∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅ ↔ ∀𝑥(𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅))
2		simprr 785	. . . . . . . . . . . 12 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → 𝑦 ∈ 𝐶)
3		n0i 4286	. . . . . . . . . . . 12 ⊢ (𝑦 ∈ 𝐶 → ¬ 𝐶 = ∅)
4	2, 3	syl 18	. . . . . . . . . . 11 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → ¬ 𝐶 = ∅)
5		simpl 488	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → 𝑥 ∈ 𝐵)
6	5	adantl 487	. . . . . . . . . . . 12 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → 𝑥 ∈ 𝐵)
7		eldif 3909	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ (𝐵 ∖ 𝐴) ↔ (𝑥 ∈ 𝐵 ∧ ¬ 𝑥 ∈ 𝐴))
8		simpl 488	. . . . . . . . . . . . 13 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → (𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅))
9	7, 8	biimtrrid 246	. . . . . . . . . . . 12 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → ((𝑥 ∈ 𝐵 ∧ ¬ 𝑥 ∈ 𝐴) → 𝐶 = ∅))
10	6, 9	mpand 708	. . . . . . . . . . 11 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → (¬ 𝑥 ∈ 𝐴 → 𝐶 = ∅))
11	4, 10	mt3d 149	. . . . . . . . . 10 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → 𝑥 ∈ 𝐴)
12	11, 2	jca 521	. . . . . . . . 9 ⊢ (((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) ∧ (𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)) → (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶))
13	12	ex 418	. . . . . . . 8 ⊢ ((𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) → ((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶)))
14	13	alimi 1844	. . . . . . 7 ⊢ (∀𝑥(𝑥 ∈ (𝐵 ∖ 𝐴) → 𝐶 = ∅) → ∀𝑥((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶)))
15	1, 14	sylbi 220	. . . . . 6 ⊢ (∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅ → ∀𝑥((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶)))
16		moim 2570	. . . . . 6 ⊢ (∀𝑥((𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶) → (𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶)) → (∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) → ∃*𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)))
17	15, 16	syl 18	. . . . 5 ⊢ (∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅ → (∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) → ∃*𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)))
18	17	alimdv 1949	. . . 4 ⊢ (∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅ → (∀𝑦∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶) → ∀𝑦∃*𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶)))
19		dfdisj2 5072	. . . 4 ⊢ (Disj 𝑥 ∈ 𝐴 𝐶 ↔ ∀𝑦∃*𝑥(𝑥 ∈ 𝐴 ∧ 𝑦 ∈ 𝐶))
20		dfdisj2 5072	. . . 4 ⊢ (Disj 𝑥 ∈ 𝐵 𝐶 ↔ ∀𝑦∃*𝑥(𝑥 ∈ 𝐵 ∧ 𝑦 ∈ 𝐶))
21	18, 19, 20	3imtr4g 299	. . 3 ⊢ (∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅ → (Disj 𝑥 ∈ 𝐴 𝐶 → Disj 𝑥 ∈ 𝐵 𝐶))
22	21	adantl 487	. 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ ∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅) → (Disj 𝑥 ∈ 𝐴 𝐶 → Disj 𝑥 ∈ 𝐵 𝐶))
23		disjss1 5076	. . 3 ⊢ (𝐴 ⊆ 𝐵 → (Disj 𝑥 ∈ 𝐵 𝐶 → Disj 𝑥 ∈ 𝐴 𝐶))
24	23	adantr 486	. 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ ∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅) → (Disj 𝑥 ∈ 𝐵 𝐶 → Disj 𝑥 ∈ 𝐴 𝐶))
25	22, 24	impbid 215	1 ⊢ ((𝐴 ⊆ 𝐵 ∧ ∀𝑥 ∈ (𝐵 ∖ 𝐴)𝐶 = ∅) → (Disj 𝑥 ∈ 𝐴 𝐶 ↔ Disj 𝑥 ∈ 𝐵 𝐶))

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 401  ∀wal 1568   = wceq 1570   ∈ wcel 2145  ∃*wmo 2563  ∀wral 3077   ∖ cdif 3896   ⊆ wss 3899  ∅c0 4279  Disj wdisj 5070

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-ext 2733

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-fal 1583  df-ex 1813  df-sb 2100  df-mo 2565  df-clab 2740  df-cleq 2753  df-clel 2836  df-ral 3078  df-rmo 3366  df-v 3453  df-dif 3902  df-ss 3916  df-nul 4280  df-disj 5071

This theorem is used by:  carsggect  34950