Theorem fbunfip 21483

Description: A helpful lemma for showing that certain sets generate filters. (Contributed by Jeff Hankins, 3-Sep-2009.) (Revised by Stefan O'Rear, 2-Aug-2015.)

Assertion

Ref	Expression
fbunfip	⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∅ ∈ (fi‘(𝐹 ∪ 𝐺)) ↔ ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))

Distinct variable groups:   𝑥,𝑦,𝐺   𝑥,𝐹,𝑦   𝑥,𝑋,𝑦   𝑥,𝑌,𝑦

Proof of Theorem fbunfip

Dummy variables 𝑤 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		elfiun 8219	. . . 4 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (∅ ∈ (fi‘(𝐹 ∪ 𝐺)) ↔ (∅ ∈ (fi‘𝐹) ∨ ∅ ∈ (fi‘𝐺) ∨ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))))
2	1	notbid 307	. . 3 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∅ ∈ (fi‘(𝐹 ∪ 𝐺)) ↔ ¬ (∅ ∈ (fi‘𝐹) ∨ ∅ ∈ (fi‘𝐺) ∨ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))))
3		3ioran 1049	. . . 4 ⊢ (¬ (∅ ∈ (fi‘𝐹) ∨ ∅ ∈ (fi‘𝐺) ∨ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)) ↔ (¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)))
4		df-3an 1033	. . . 4 ⊢ ((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)) ↔ ((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)))
5	3, 4	bitr2i 264	. . 3 ⊢ (((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)) ↔ ¬ (∅ ∈ (fi‘𝐹) ∨ ∅ ∈ (fi‘𝐺) ∨ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)))
6	2, 5	syl6bbr 277	. 2 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∅ ∈ (fi‘(𝐹 ∪ 𝐺)) ↔ ((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))))
7		nesym 2838	. . . . . . 7 ⊢ ((𝑥 ∩ 𝑦) ≠ ∅ ↔ ¬ ∅ = (𝑥 ∩ 𝑦))
8	7	ralbii 2963	. . . . . 6 ⊢ (∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ ↔ ∀𝑦 ∈ (fi‘𝐺) ¬ ∅ = (𝑥 ∩ 𝑦))
9		ralnex 2975	. . . . . 6 ⊢ (∀𝑦 ∈ (fi‘𝐺) ¬ ∅ = (𝑥 ∩ 𝑦) ↔ ¬ ∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))
10	8, 9	bitri 263	. . . . 5 ⊢ (∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ ↔ ¬ ∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))
11	10	ralbii 2963	. . . 4 ⊢ (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ ↔ ∀𝑥 ∈ (fi‘𝐹) ¬ ∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))
12		ralnex 2975	. . . 4 ⊢ (∀𝑥 ∈ (fi‘𝐹) ¬ ∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦) ↔ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))
13	11, 12	bitri 263	. . 3 ⊢ (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ ↔ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))
14		fbasfip 21482	. . . . 5 ⊢ (𝐹 ∈ (fBas‘𝑋) → ¬ ∅ ∈ (fi‘𝐹))
15		fbasfip 21482	. . . . 5 ⊢ (𝐺 ∈ (fBas‘𝑌) → ¬ ∅ ∈ (fi‘𝐺))
16	14, 15	anim12i 588	. . . 4 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)))
17	16	biantrurd 528	. . 3 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦) ↔ ((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦))))
18	13, 17	syl5rbb 272	. 2 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (((¬ ∅ ∈ (fi‘𝐹) ∧ ¬ ∅ ∈ (fi‘𝐺)) ∧ ¬ ∃𝑥 ∈ (fi‘𝐹)∃𝑦 ∈ (fi‘𝐺)∅ = (𝑥 ∩ 𝑦)) ↔ ∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅))
19		ssfii 8208	. . . . 5 ⊢ (𝐹 ∈ (fBas‘𝑋) → 𝐹 ⊆ (fi‘𝐹))
20		ssralv 3629	. . . . 5 ⊢ (𝐹 ⊆ (fi‘𝐹) → (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅))
21	19, 20	syl 17	. . . 4 ⊢ (𝐹 ∈ (fBas‘𝑋) → (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅))
22		ssfii 8208	. . . . . 6 ⊢ (𝐺 ∈ (fBas‘𝑌) → 𝐺 ⊆ (fi‘𝐺))
23		ssralv 3629	. . . . . 6 ⊢ (𝐺 ⊆ (fi‘𝐺) → (∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))
24	22, 23	syl 17	. . . . 5 ⊢ (𝐺 ∈ (fBas‘𝑌) → (∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))
25	24	ralimdv 2946	. . . 4 ⊢ (𝐺 ∈ (fBas‘𝑌) → (∀𝑥 ∈ 𝐹 ∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))
26	21, 25	sylan9 687	. . 3 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))
27		ineq1 3769	. . . . . 6 ⊢ (𝑥 = 𝑧 → (𝑥 ∩ 𝑦) = (𝑧 ∩ 𝑦))
28	27	neeq1d 2841	. . . . 5 ⊢ (𝑥 = 𝑧 → ((𝑥 ∩ 𝑦) ≠ ∅ ↔ (𝑧 ∩ 𝑦) ≠ ∅))
29		ineq2 3770	. . . . . 6 ⊢ (𝑦 = 𝑤 → (𝑧 ∩ 𝑦) = (𝑧 ∩ 𝑤))
30	29	neeq1d 2841	. . . . 5 ⊢ (𝑦 = 𝑤 → ((𝑧 ∩ 𝑦) ≠ ∅ ↔ (𝑧 ∩ 𝑤) ≠ ∅))
31	28, 30	cbvral2v 3155	. . . 4 ⊢ (∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅ ↔ ∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅)
32		fbssfi 21451	. . . . . . 7 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝑥 ∈ (fi‘𝐹)) → ∃𝑧 ∈ 𝐹 𝑧 ⊆ 𝑥)
33		fbssfi 21451	. . . . . . 7 ⊢ ((𝐺 ∈ (fBas‘𝑌) ∧ 𝑦 ∈ (fi‘𝐺)) → ∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦)
34		r19.29 3054	. . . . . . . . . 10 ⊢ ((∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ ∃𝑧 ∈ 𝐹 𝑧 ⊆ 𝑥) → ∃𝑧 ∈ 𝐹 (∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑧 ⊆ 𝑥))
35		r19.29 3054	. . . . . . . . . . . . 13 ⊢ ((∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ ∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦) → ∃𝑤 ∈ 𝐺 ((𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑤 ⊆ 𝑦))
36		ss2in 3802	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝑧 ⊆ 𝑥 ∧ 𝑤 ⊆ 𝑦) → (𝑧 ∩ 𝑤) ⊆ (𝑥 ∩ 𝑦))
37		sseq2 3590	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((𝑥 ∩ 𝑦) = ∅ → ((𝑧 ∩ 𝑤) ⊆ (𝑥 ∩ 𝑦) ↔ (𝑧 ∩ 𝑤) ⊆ ∅))
38		ss0 3926	. . . . . . . . . . . . . . . . . . . 20 ⊢ ((𝑧 ∩ 𝑤) ⊆ ∅ → (𝑧 ∩ 𝑤) = ∅)
39	37, 38	syl6bi 242	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝑥 ∩ 𝑦) = ∅ → ((𝑧 ∩ 𝑤) ⊆ (𝑥 ∩ 𝑦) → (𝑧 ∩ 𝑤) = ∅))
40	36, 39	syl5com 31	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑧 ⊆ 𝑥 ∧ 𝑤 ⊆ 𝑦) → ((𝑥 ∩ 𝑦) = ∅ → (𝑧 ∩ 𝑤) = ∅))
41	40	necon3d 2803	. . . . . . . . . . . . . . . . 17 ⊢ ((𝑧 ⊆ 𝑥 ∧ 𝑤 ⊆ 𝑦) → ((𝑧 ∩ 𝑤) ≠ ∅ → (𝑥 ∩ 𝑦) ≠ ∅))
42	41	ex 449	. . . . . . . . . . . . . . . 16 ⊢ (𝑧 ⊆ 𝑥 → (𝑤 ⊆ 𝑦 → ((𝑧 ∩ 𝑤) ≠ ∅ → (𝑥 ∩ 𝑦) ≠ ∅)))
43	42	com13 86	. . . . . . . . . . . . . . 15 ⊢ ((𝑧 ∩ 𝑤) ≠ ∅ → (𝑤 ⊆ 𝑦 → (𝑧 ⊆ 𝑥 → (𝑥 ∩ 𝑦) ≠ ∅)))
44	43	imp 444	. . . . . . . . . . . . . 14 ⊢ (((𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑤 ⊆ 𝑦) → (𝑧 ⊆ 𝑥 → (𝑥 ∩ 𝑦) ≠ ∅))
45	44	rexlimivw 3011	. . . . . . . . . . . . 13 ⊢ (∃𝑤 ∈ 𝐺 ((𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑤 ⊆ 𝑦) → (𝑧 ⊆ 𝑥 → (𝑥 ∩ 𝑦) ≠ ∅))
46	35, 45	syl 17	. . . . . . . . . . . 12 ⊢ ((∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ ∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦) → (𝑧 ⊆ 𝑥 → (𝑥 ∩ 𝑦) ≠ ∅))
47	46	impancom 455	. . . . . . . . . . 11 ⊢ ((∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑧 ⊆ 𝑥) → (∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦 → (𝑥 ∩ 𝑦) ≠ ∅))
48	47	rexlimivw 3011	. . . . . . . . . 10 ⊢ (∃𝑧 ∈ 𝐹 (∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ 𝑧 ⊆ 𝑥) → (∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦 → (𝑥 ∩ 𝑦) ≠ ∅))
49	34, 48	syl 17	. . . . . . . . 9 ⊢ ((∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ ∧ ∃𝑧 ∈ 𝐹 𝑧 ⊆ 𝑥) → (∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦 → (𝑥 ∩ 𝑦) ≠ ∅))
50	49	expimpd 627	. . . . . . . 8 ⊢ (∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ → ((∃𝑧 ∈ 𝐹 𝑧 ⊆ 𝑥 ∧ ∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦) → (𝑥 ∩ 𝑦) ≠ ∅))
51	50	com12 32	. . . . . . 7 ⊢ ((∃𝑧 ∈ 𝐹 𝑧 ⊆ 𝑥 ∧ ∃𝑤 ∈ 𝐺 𝑤 ⊆ 𝑦) → (∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ → (𝑥 ∩ 𝑦) ≠ ∅))
52	32, 33, 51	syl2an 493	. . . . . 6 ⊢ (((𝐹 ∈ (fBas‘𝑋) ∧ 𝑥 ∈ (fi‘𝐹)) ∧ (𝐺 ∈ (fBas‘𝑌) ∧ 𝑦 ∈ (fi‘𝐺))) → (∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ → (𝑥 ∩ 𝑦) ≠ ∅))
53	52	an4s 865	. . . . 5 ⊢ (((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) ∧ (𝑥 ∈ (fi‘𝐹) ∧ 𝑦 ∈ (fi‘𝐺))) → (∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ → (𝑥 ∩ 𝑦) ≠ ∅))
54	53	ralrimdvva 2957	. . . 4 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (∀𝑧 ∈ 𝐹 ∀𝑤 ∈ 𝐺 (𝑧 ∩ 𝑤) ≠ ∅ → ∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅))
55	31, 54	syl5bi 231	. . 3 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅ → ∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅))
56	26, 55	impbid 201	. 2 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (∀𝑥 ∈ (fi‘𝐹)∀𝑦 ∈ (fi‘𝐺)(𝑥 ∩ 𝑦) ≠ ∅ ↔ ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))
57	6, 18, 56	3bitrd 293	1 ⊢ ((𝐹 ∈ (fBas‘𝑋) ∧ 𝐺 ∈ (fBas‘𝑌)) → (¬ ∅ ∈ (fi‘(𝐹 ∪ 𝐺)) ↔ ∀𝑥 ∈ 𝐹 ∀𝑦 ∈ 𝐺 (𝑥 ∩ 𝑦) ≠ ∅))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 195   ∧ wa 383   ∨ w3o 1030   ∧ w3a 1031   = wceq 1475   ∈ wcel 1977   ≠ wne 2780  ∀wral 2896  ∃wrex 2897   ∪ cun 3538   ∩ cin 3539   ⊆ wss 3540  ∅c0 3874  ‘cfv 5804  ficfi 8199  fBascfbas 19555

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-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847

This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  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-ne 2782  df-nel 2783  df-ral 2901  df-rex 2902  df-reu 2903  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-pss 3556  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-tp 4130  df-op 4132  df-uni 4373  df-int 4411  df-iun 4457  df-br 4584  df-opab 4644  df-mpt 4645  df-tr 4681  df-eprel 4949  df-id 4953  df-po 4959  df-so 4960  df-fr 4997  df-we 4999  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-pred 5597  df-ord 5643  df-on 5644  df-lim 5645  df-suc 5646  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-ov 6552  df-oprab 6553  df-mpt2 6554  df-om 6958  df-wrecs 7294  df-recs 7355  df-rdg 7393  df-1o 7447  df-oadd 7451  df-er 7629  df-en 7842  df-fin 7845  df-fi 8200  df-fbas 19564

This theorem is referenced by:  isufil2  21522  ufileu  21533  filufint  21534  fmfnfm  21572  hausflim  21595  flimclslem  21598  fclsfnflim  21641  flimfnfcls  21642