Theorem tailfb 32372

Description: The collection of tails of a directed set is a filter base. (Contributed by Jeff Hankins, 25-Nov-2009.) (Revised by Mario Carneiro, 8-Aug-2015.)

Hypothesis

Ref	Expression
tailfb.1	⊢ 𝑋 = dom 𝐷

Assertion

Ref	Expression
tailfb	⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ∈ (fBas‘𝑋))

Proof of Theorem tailfb

Dummy variables 𝑣 𝑢 𝑤 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		tailfb.1	. . . . 5 ⊢ 𝑋 = dom 𝐷
2	1	tailf 32370	. . . 4 ⊢ (𝐷 ∈ DirRel → (tail‘𝐷):𝑋⟶𝒫 𝑋)
3		frn 6053	. . . 4 ⊢ ((tail‘𝐷):𝑋⟶𝒫 𝑋 → ran (tail‘𝐷) ⊆ 𝒫 𝑋)
4	2, 3	syl 17	. . 3 ⊢ (𝐷 ∈ DirRel → ran (tail‘𝐷) ⊆ 𝒫 𝑋)
5	4	adantr 481	. 2 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ⊆ 𝒫 𝑋)
6		n0 3931	. . . . 5 ⊢ (𝑋 ≠ ∅ ↔ ∃𝑥 𝑥 ∈ 𝑋)
7		ffn 6045	. . . . . . . 8 ⊢ ((tail‘𝐷):𝑋⟶𝒫 𝑋 → (tail‘𝐷) Fn 𝑋)
8		fnfvelrn 6356	. . . . . . . . 9 ⊢ (((tail‘𝐷) Fn 𝑋 ∧ 𝑥 ∈ 𝑋) → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷))
9	8	ex 450	. . . . . . . 8 ⊢ ((tail‘𝐷) Fn 𝑋 → (𝑥 ∈ 𝑋 → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷)))
10	2, 7, 9	3syl 18	. . . . . . 7 ⊢ (𝐷 ∈ DirRel → (𝑥 ∈ 𝑋 → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷)))
11		ne0i 3921	. . . . . . 7 ⊢ (((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷) → ran (tail‘𝐷) ≠ ∅)
12	10, 11	syl6 35	. . . . . 6 ⊢ (𝐷 ∈ DirRel → (𝑥 ∈ 𝑋 → ran (tail‘𝐷) ≠ ∅))
13	12	exlimdv 1861	. . . . 5 ⊢ (𝐷 ∈ DirRel → (∃𝑥 𝑥 ∈ 𝑋 → ran (tail‘𝐷) ≠ ∅))
14	6, 13	syl5bi 232	. . . 4 ⊢ (𝐷 ∈ DirRel → (𝑋 ≠ ∅ → ran (tail‘𝐷) ≠ ∅))
15	14	imp 445	. . 3 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ≠ ∅)
16	1	tailini 32371	. . . . . . . 8 ⊢ ((𝐷 ∈ DirRel ∧ 𝑥 ∈ 𝑋) → 𝑥 ∈ ((tail‘𝐷)‘𝑥))
17		n0i 3920	. . . . . . . 8 ⊢ (𝑥 ∈ ((tail‘𝐷)‘𝑥) → ¬ ((tail‘𝐷)‘𝑥) = ∅)
18	16, 17	syl 17	. . . . . . 7 ⊢ ((𝐷 ∈ DirRel ∧ 𝑥 ∈ 𝑋) → ¬ ((tail‘𝐷)‘𝑥) = ∅)
19	18	nrexdv 3001	. . . . . 6 ⊢ (𝐷 ∈ DirRel → ¬ ∃𝑥 ∈ 𝑋 ((tail‘𝐷)‘𝑥) = ∅)
20	19	adantr 481	. . . . 5 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ¬ ∃𝑥 ∈ 𝑋 ((tail‘𝐷)‘𝑥) = ∅)
21		fvelrnb 6243	. . . . . . 7 ⊢ ((tail‘𝐷) Fn 𝑋 → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥 ∈ 𝑋 ((tail‘𝐷)‘𝑥) = ∅))
22	2, 7, 21	3syl 18	. . . . . 6 ⊢ (𝐷 ∈ DirRel → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥 ∈ 𝑋 ((tail‘𝐷)‘𝑥) = ∅))
23	22	adantr 481	. . . . 5 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥 ∈ 𝑋 ((tail‘𝐷)‘𝑥) = ∅))
24	20, 23	mtbird 315	. . . 4 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ¬ ∅ ∈ ran (tail‘𝐷))
25		df-nel 2898	. . . 4 ⊢ (∅ ∉ ran (tail‘𝐷) ↔ ¬ ∅ ∈ ran (tail‘𝐷))
26	24, 25	sylibr 224	. . 3 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ∅ ∉ ran (tail‘𝐷))
27		fvelrnb 6243	. . . . . . . 8 ⊢ ((tail‘𝐷) Fn 𝑋 → (𝑥 ∈ ran (tail‘𝐷) ↔ ∃𝑢 ∈ 𝑋 ((tail‘𝐷)‘𝑢) = 𝑥))
28		fvelrnb 6243	. . . . . . . 8 ⊢ ((tail‘𝐷) Fn 𝑋 → (𝑦 ∈ ran (tail‘𝐷) ↔ ∃𝑣 ∈ 𝑋 ((tail‘𝐷)‘𝑣) = 𝑦))
29	27, 28	anbi12d 747	. . . . . . 7 ⊢ ((tail‘𝐷) Fn 𝑋 → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) ↔ (∃𝑢 ∈ 𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣 ∈ 𝑋 ((tail‘𝐷)‘𝑣) = 𝑦)))
30	2, 7, 29	3syl 18	. . . . . 6 ⊢ (𝐷 ∈ DirRel → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) ↔ (∃𝑢 ∈ 𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣 ∈ 𝑋 ((tail‘𝐷)‘𝑣) = 𝑦)))
31		reeanv 3107	. . . . . . 7 ⊢ (∃𝑢 ∈ 𝑋 ∃𝑣 ∈ 𝑋 (((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) ↔ (∃𝑢 ∈ 𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣 ∈ 𝑋 ((tail‘𝐷)‘𝑣) = 𝑦))
32	1	dirge 17237	. . . . . . . . . . 11 ⊢ ((𝐷 ∈ DirRel ∧ 𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋) → ∃𝑤 ∈ 𝑋 (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))
33	32	3expb 1266	. . . . . . . . . 10 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ∃𝑤 ∈ 𝑋 (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))
34	2, 7	syl 17	. . . . . . . . . . . . 13 ⊢ (𝐷 ∈ DirRel → (tail‘𝐷) Fn 𝑋)
35		fnfvelrn 6356	. . . . . . . . . . . . 13 ⊢ (((tail‘𝐷) Fn 𝑋 ∧ 𝑤 ∈ 𝑋) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
36	34, 35	sylan 488	. . . . . . . . . . . 12 ⊢ ((𝐷 ∈ DirRel ∧ 𝑤 ∈ 𝑋) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
37	36	ad2ant2r 783	. . . . . . . . . . 11 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
38		vex 3203	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ 𝑥 ∈ V
39		dirtr 17236	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) ∧ (𝑢𝐷𝑤 ∧ 𝑤𝐷𝑥)) → 𝑢𝐷𝑥)
40	39	exp32 631	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) → (𝑢𝐷𝑤 → (𝑤𝐷𝑥 → 𝑢𝐷𝑥)))
41	38, 40	mpan2 707	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝐷 ∈ DirRel → (𝑢𝐷𝑤 → (𝑤𝐷𝑥 → 𝑢𝐷𝑥)))
42	41	com23 86	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝐷 ∈ DirRel → (𝑤𝐷𝑥 → (𝑢𝐷𝑤 → 𝑢𝐷𝑥)))
43	42	imp 445	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝐷 ∈ DirRel ∧ 𝑤𝐷𝑥) → (𝑢𝐷𝑤 → 𝑢𝐷𝑥))
44	43	ad2ant2rl 785	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ 𝑤𝐷𝑥)) → (𝑢𝐷𝑤 → 𝑢𝐷𝑥))
45		dirtr 17236	. . . . . . . . . . . . . . . . . . . . . . 23 ⊢ (((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) ∧ (𝑣𝐷𝑤 ∧ 𝑤𝐷𝑥)) → 𝑣𝐷𝑥)
46	45	exp32 631	. . . . . . . . . . . . . . . . . . . . . 22 ⊢ ((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) → (𝑣𝐷𝑤 → (𝑤𝐷𝑥 → 𝑣𝐷𝑥)))
47	38, 46	mpan2 707	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝐷 ∈ DirRel → (𝑣𝐷𝑤 → (𝑤𝐷𝑥 → 𝑣𝐷𝑥)))
48	47	com23 86	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝐷 ∈ DirRel → (𝑤𝐷𝑥 → (𝑣𝐷𝑤 → 𝑣𝐷𝑥)))
49	48	imp 445	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝐷 ∈ DirRel ∧ 𝑤𝐷𝑥) → (𝑣𝐷𝑤 → 𝑣𝐷𝑥))
50	49	ad2ant2rl 785	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ 𝑤𝐷𝑥)) → (𝑣𝐷𝑤 → 𝑣𝐷𝑥))
51	44, 50	anim12d 586	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ 𝑤𝐷𝑥)) → ((𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤) → (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥)))
52	51	expr 643	. . . . . . . . . . . . . . . 16 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ 𝑤 ∈ 𝑋) → (𝑤𝐷𝑥 → ((𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤) → (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥))))
53	52	com23 86	. . . . . . . . . . . . . . 15 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ 𝑤 ∈ 𝑋) → ((𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤) → (𝑤𝐷𝑥 → (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥))))
54	53	impr 649	. . . . . . . . . . . . . 14 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → (𝑤𝐷𝑥 → (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥)))
55	1	eltail 32369	. . . . . . . . . . . . . . . 16 ⊢ ((𝐷 ∈ DirRel ∧ 𝑤 ∈ 𝑋 ∧ 𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
56	38, 55	mp3an3 1413	. . . . . . . . . . . . . . 15 ⊢ ((𝐷 ∈ DirRel ∧ 𝑤 ∈ 𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
57	56	ad2ant2r 783	. . . . . . . . . . . . . 14 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
58	1	eltail 32369	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝐷 ∈ DirRel ∧ 𝑢 ∈ 𝑋 ∧ 𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
59	38, 58	mp3an3 1413	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐷 ∈ DirRel ∧ 𝑢 ∈ 𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
60	59	adantrr 753	. . . . . . . . . . . . . . . 16 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
61	1	eltail 32369	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝐷 ∈ DirRel ∧ 𝑣 ∈ 𝑋 ∧ 𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
62	38, 61	mp3an3 1413	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐷 ∈ DirRel ∧ 𝑣 ∈ 𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
63	62	adantrl 752	. . . . . . . . . . . . . . . 16 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
64	60, 63	anbi12d 747	. . . . . . . . . . . . . . 15 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)) ↔ (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥)))
65	64	adantr 481	. . . . . . . . . . . . . 14 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → ((𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)) ↔ (𝑢𝐷𝑥 ∧ 𝑣𝐷𝑥)))
66	54, 57, 65	3imtr4d 283	. . . . . . . . . . . . 13 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣))))
67		elin 3796	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ (𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)))
68	66, 67	syl6ibr 242	. . . . . . . . . . . 12 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) → 𝑥 ∈ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣))))
69	68	ssrdv 3609	. . . . . . . . . . 11 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → ((tail‘𝐷)‘𝑤) ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
70		sseq1 3626	. . . . . . . . . . . 12 ⊢ (𝑧 = ((tail‘𝐷)‘𝑤) → (𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ ((tail‘𝐷)‘𝑤) ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣))))
71	70	rspcev 3309	. . . . . . . . . . 11 ⊢ ((((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷) ∧ ((tail‘𝐷)‘𝑤) ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣))) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
72	37, 69, 71	syl2anc 693	. . . . . . . . . 10 ⊢ (((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) ∧ (𝑤 ∈ 𝑋 ∧ (𝑢𝐷𝑤 ∧ 𝑣𝐷𝑤))) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
73	33, 72	rexlimddv 3035	. . . . . . . . 9 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
74		ineq1 3807	. . . . . . . . . . . 12 ⊢ (((tail‘𝐷)‘𝑢) = 𝑥 → (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) = (𝑥 ∩ ((tail‘𝐷)‘𝑣)))
75	74	sseq2d 3633	. . . . . . . . . . 11 ⊢ (((tail‘𝐷)‘𝑢) = 𝑥 → (𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ 𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣))))
76	75	rexbidv 3052	. . . . . . . . . 10 ⊢ (((tail‘𝐷)‘𝑢) = 𝑥 → (∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣))))
77		ineq2 3808	. . . . . . . . . . . 12 ⊢ (((tail‘𝐷)‘𝑣) = 𝑦 → (𝑥 ∩ ((tail‘𝐷)‘𝑣)) = (𝑥 ∩ 𝑦))
78	77	sseq2d 3633	. . . . . . . . . . 11 ⊢ (((tail‘𝐷)‘𝑣) = 𝑦 → (𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣)) ↔ 𝑧 ⊆ (𝑥 ∩ 𝑦)))
79	78	rexbidv 3052	. . . . . . . . . 10 ⊢ (((tail‘𝐷)‘𝑣) = 𝑦 → (∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣)) ↔ ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
80	76, 79	sylan9bb 736	. . . . . . . . 9 ⊢ ((((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) → (∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
81	73, 80	syl5ibcom 235	. . . . . . . 8 ⊢ ((𝐷 ∈ DirRel ∧ (𝑢 ∈ 𝑋 ∧ 𝑣 ∈ 𝑋)) → ((((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
82	81	rexlimdvva 3038	. . . . . . 7 ⊢ (𝐷 ∈ DirRel → (∃𝑢 ∈ 𝑋 ∃𝑣 ∈ 𝑋 (((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
83	31, 82	syl5bir 233	. . . . . 6 ⊢ (𝐷 ∈ DirRel → ((∃𝑢 ∈ 𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣 ∈ 𝑋 ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
84	30, 83	sylbid 230	. . . . 5 ⊢ (𝐷 ∈ DirRel → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
85	84	adantr 481	. . . 4 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
86	85	ralrimivv 2970	. . 3 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦))
87	15, 26, 86	3jca 1242	. 2 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → (ran (tail‘𝐷) ≠ ∅ ∧ ∅ ∉ ran (tail‘𝐷) ∧ ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))
88		dmexg 7097	. . . . 5 ⊢ (𝐷 ∈ DirRel → dom 𝐷 ∈ V)
89	1, 88	syl5eqel 2705	. . . 4 ⊢ (𝐷 ∈ DirRel → 𝑋 ∈ V)
90	89	adantr 481	. . 3 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → 𝑋 ∈ V)
91		isfbas2 21639	. . 3 ⊢ (𝑋 ∈ V → (ran (tail‘𝐷) ∈ (fBas‘𝑋) ↔ (ran (tail‘𝐷) ⊆ 𝒫 𝑋 ∧ (ran (tail‘𝐷) ≠ ∅ ∧ ∅ ∉ ran (tail‘𝐷) ∧ ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))))
92	90, 91	syl 17	. 2 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → (ran (tail‘𝐷) ∈ (fBas‘𝑋) ↔ (ran (tail‘𝐷) ⊆ 𝒫 𝑋 ∧ (ran (tail‘𝐷) ≠ ∅ ∧ ∅ ∉ ran (tail‘𝐷) ∧ ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ 𝑦)))))
93	5, 87, 92	mpbir2and 957	1 ⊢ ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ∈ (fBas‘𝑋))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 196   ∧ wa 384   ∧ w3a 1037   = wceq 1483  ∃wex 1704   ∈ wcel 1990   ≠ wne 2794   ∉ wnel 2897  ∀wral 2912  ∃wrex 2913  Vcvv 3200   ∩ cin 3573   ⊆ wss 3574  ∅c0 3915  𝒫 cpw 4158   class class class wbr 4653  dom cdm 5114  ran crn 5115   Fn wfn 5883  ⟶wf 5884  ‘cfv 5888  DirRelcdir 17228  tailctail 17229  fBascfbas 19734

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-rep 4771  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-nel 2898  df-ral 2917  df-rex 2918  df-reu 2919  df-rab 2921  df-v 3202  df-sbc 3436  df-csb 3534  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-iun 4522  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-f1 5893  df-fo 5894  df-f1o 5895  df-fv 5896  df-dir 17230  df-tail 17231  df-fbas 19743

This theorem is referenced by:  filnetlem4  32376