Mathbox for Jeff Hankins < Previous   Next > Nearby theorems Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  tailfb Structured version   Visualization version   GIF version

Theorem tailfb 33839
 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.
StepHypRef Expression
1 tailfb.1 . . . . 5 𝑋 = dom 𝐷
21tailf 33837 . . . 4 (𝐷 ∈ DirRel → (tail‘𝐷):𝑋⟶𝒫 𝑋)
32frnd 6498 . . 3 (𝐷 ∈ DirRel → ran (tail‘𝐷) ⊆ 𝒫 𝑋)
43adantr 484 . 2 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ⊆ 𝒫 𝑋)
5 n0 4263 . . . . 5 (𝑋 ≠ ∅ ↔ ∃𝑥 𝑥𝑋)
6 ffn 6491 . . . . . . . 8 ((tail‘𝐷):𝑋⟶𝒫 𝑋 → (tail‘𝐷) Fn 𝑋)
7 fnfvelrn 6829 . . . . . . . . 9 (((tail‘𝐷) Fn 𝑋𝑥𝑋) → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷))
87ex 416 . . . . . . . 8 ((tail‘𝐷) Fn 𝑋 → (𝑥𝑋 → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷)))
92, 6, 83syl 18 . . . . . . 7 (𝐷 ∈ DirRel → (𝑥𝑋 → ((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷)))
10 ne0i 4253 . . . . . . 7 (((tail‘𝐷)‘𝑥) ∈ ran (tail‘𝐷) → ran (tail‘𝐷) ≠ ∅)
119, 10syl6 35 . . . . . 6 (𝐷 ∈ DirRel → (𝑥𝑋 → ran (tail‘𝐷) ≠ ∅))
1211exlimdv 1934 . . . . 5 (𝐷 ∈ DirRel → (∃𝑥 𝑥𝑋 → ran (tail‘𝐷) ≠ ∅))
135, 12syl5bi 245 . . . 4 (𝐷 ∈ DirRel → (𝑋 ≠ ∅ → ran (tail‘𝐷) ≠ ∅))
1413imp 410 . . 3 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ≠ ∅)
151tailini 33838 . . . . . . . 8 ((𝐷 ∈ DirRel ∧ 𝑥𝑋) → 𝑥 ∈ ((tail‘𝐷)‘𝑥))
16 n0i 4252 . . . . . . . 8 (𝑥 ∈ ((tail‘𝐷)‘𝑥) → ¬ ((tail‘𝐷)‘𝑥) = ∅)
1715, 16syl 17 . . . . . . 7 ((𝐷 ∈ DirRel ∧ 𝑥𝑋) → ¬ ((tail‘𝐷)‘𝑥) = ∅)
1817nrexdv 3232 . . . . . 6 (𝐷 ∈ DirRel → ¬ ∃𝑥𝑋 ((tail‘𝐷)‘𝑥) = ∅)
1918adantr 484 . . . . 5 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ¬ ∃𝑥𝑋 ((tail‘𝐷)‘𝑥) = ∅)
20 fvelrnb 6705 . . . . . . 7 ((tail‘𝐷) Fn 𝑋 → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥𝑋 ((tail‘𝐷)‘𝑥) = ∅))
212, 6, 203syl 18 . . . . . 6 (𝐷 ∈ DirRel → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥𝑋 ((tail‘𝐷)‘𝑥) = ∅))
2221adantr 484 . . . . 5 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → (∅ ∈ ran (tail‘𝐷) ↔ ∃𝑥𝑋 ((tail‘𝐷)‘𝑥) = ∅))
2319, 22mtbird 328 . . . 4 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ¬ ∅ ∈ ran (tail‘𝐷))
24 df-nel 3095 . . . 4 (∅ ∉ ran (tail‘𝐷) ↔ ¬ ∅ ∈ ran (tail‘𝐷))
2523, 24sylibr 237 . . 3 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ∅ ∉ ran (tail‘𝐷))
26 fvelrnb 6705 . . . . . . . 8 ((tail‘𝐷) Fn 𝑋 → (𝑥 ∈ ran (tail‘𝐷) ↔ ∃𝑢𝑋 ((tail‘𝐷)‘𝑢) = 𝑥))
27 fvelrnb 6705 . . . . . . . 8 ((tail‘𝐷) Fn 𝑋 → (𝑦 ∈ ran (tail‘𝐷) ↔ ∃𝑣𝑋 ((tail‘𝐷)‘𝑣) = 𝑦))
2826, 27anbi12d 633 . . . . . . 7 ((tail‘𝐷) Fn 𝑋 → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) ↔ (∃𝑢𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣𝑋 ((tail‘𝐷)‘𝑣) = 𝑦)))
292, 6, 283syl 18 . . . . . 6 (𝐷 ∈ DirRel → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) ↔ (∃𝑢𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣𝑋 ((tail‘𝐷)‘𝑣) = 𝑦)))
30 reeanv 3323 . . . . . . 7 (∃𝑢𝑋𝑣𝑋 (((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) ↔ (∃𝑢𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣𝑋 ((tail‘𝐷)‘𝑣) = 𝑦))
311dirge 17843 . . . . . . . . . . 11 ((𝐷 ∈ DirRel ∧ 𝑢𝑋𝑣𝑋) → ∃𝑤𝑋 (𝑢𝐷𝑤𝑣𝐷𝑤))
32313expb 1117 . . . . . . . . . 10 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → ∃𝑤𝑋 (𝑢𝐷𝑤𝑣𝐷𝑤))
332, 6syl 17 . . . . . . . . . . . . 13 (𝐷 ∈ DirRel → (tail‘𝐷) Fn 𝑋)
34 fnfvelrn 6829 . . . . . . . . . . . . 13 (((tail‘𝐷) Fn 𝑋𝑤𝑋) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
3533, 34sylan 583 . . . . . . . . . . . 12 ((𝐷 ∈ DirRel ∧ 𝑤𝑋) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
3635ad2ant2r 746 . . . . . . . . . . 11 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → ((tail‘𝐷)‘𝑤) ∈ ran (tail‘𝐷))
37 dirtr 17842 . . . . . . . . . . . . . . . . . . . . . . 23 (((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) ∧ (𝑢𝐷𝑤𝑤𝐷𝑥)) → 𝑢𝐷𝑥)
3837exp32 424 . . . . . . . . . . . . . . . . . . . . . 22 ((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) → (𝑢𝐷𝑤 → (𝑤𝐷𝑥𝑢𝐷𝑥)))
3938elvd 3450 . . . . . . . . . . . . . . . . . . . . 21 (𝐷 ∈ DirRel → (𝑢𝐷𝑤 → (𝑤𝐷𝑥𝑢𝐷𝑥)))
4039com23 86 . . . . . . . . . . . . . . . . . . . 20 (𝐷 ∈ DirRel → (𝑤𝐷𝑥 → (𝑢𝐷𝑤𝑢𝐷𝑥)))
4140imp 410 . . . . . . . . . . . . . . . . . . 19 ((𝐷 ∈ DirRel ∧ 𝑤𝐷𝑥) → (𝑢𝐷𝑤𝑢𝐷𝑥))
4241ad2ant2rl 748 . . . . . . . . . . . . . . . . . 18 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋𝑤𝐷𝑥)) → (𝑢𝐷𝑤𝑢𝐷𝑥))
43 dirtr 17842 . . . . . . . . . . . . . . . . . . . . . . 23 (((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) ∧ (𝑣𝐷𝑤𝑤𝐷𝑥)) → 𝑣𝐷𝑥)
4443exp32 424 . . . . . . . . . . . . . . . . . . . . . 22 ((𝐷 ∈ DirRel ∧ 𝑥 ∈ V) → (𝑣𝐷𝑤 → (𝑤𝐷𝑥𝑣𝐷𝑥)))
4544elvd 3450 . . . . . . . . . . . . . . . . . . . . 21 (𝐷 ∈ DirRel → (𝑣𝐷𝑤 → (𝑤𝐷𝑥𝑣𝐷𝑥)))
4645com23 86 . . . . . . . . . . . . . . . . . . . 20 (𝐷 ∈ DirRel → (𝑤𝐷𝑥 → (𝑣𝐷𝑤𝑣𝐷𝑥)))
4746imp 410 . . . . . . . . . . . . . . . . . . 19 ((𝐷 ∈ DirRel ∧ 𝑤𝐷𝑥) → (𝑣𝐷𝑤𝑣𝐷𝑥))
4847ad2ant2rl 748 . . . . . . . . . . . . . . . . . 18 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋𝑤𝐷𝑥)) → (𝑣𝐷𝑤𝑣𝐷𝑥))
4942, 48anim12d 611 . . . . . . . . . . . . . . . . 17 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋𝑤𝐷𝑥)) → ((𝑢𝐷𝑤𝑣𝐷𝑤) → (𝑢𝐷𝑥𝑣𝐷𝑥)))
5049expr 460 . . . . . . . . . . . . . . . 16 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ 𝑤𝑋) → (𝑤𝐷𝑥 → ((𝑢𝐷𝑤𝑣𝐷𝑤) → (𝑢𝐷𝑥𝑣𝐷𝑥))))
5150com23 86 . . . . . . . . . . . . . . 15 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ 𝑤𝑋) → ((𝑢𝐷𝑤𝑣𝐷𝑤) → (𝑤𝐷𝑥 → (𝑢𝐷𝑥𝑣𝐷𝑥))))
5251impr 458 . . . . . . . . . . . . . 14 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → (𝑤𝐷𝑥 → (𝑢𝐷𝑥𝑣𝐷𝑥)))
53 vex 3447 . . . . . . . . . . . . . . . 16 𝑥 ∈ V
541eltail 33836 . . . . . . . . . . . . . . . 16 ((𝐷 ∈ DirRel ∧ 𝑤𝑋𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
5553, 54mp3an3 1447 . . . . . . . . . . . . . . 15 ((𝐷 ∈ DirRel ∧ 𝑤𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
5655ad2ant2r 746 . . . . . . . . . . . . . 14 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) ↔ 𝑤𝐷𝑥))
571eltail 33836 . . . . . . . . . . . . . . . . . 18 ((𝐷 ∈ DirRel ∧ 𝑢𝑋𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
5853, 57mp3an3 1447 . . . . . . . . . . . . . . . . 17 ((𝐷 ∈ DirRel ∧ 𝑢𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
5958adantrr 716 . . . . . . . . . . . . . . . 16 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ↔ 𝑢𝐷𝑥))
601eltail 33836 . . . . . . . . . . . . . . . . . 18 ((𝐷 ∈ DirRel ∧ 𝑣𝑋𝑥 ∈ V) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
6153, 60mp3an3 1447 . . . . . . . . . . . . . . . . 17 ((𝐷 ∈ DirRel ∧ 𝑣𝑋) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
6261adantrl 715 . . . . . . . . . . . . . . . 16 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → (𝑥 ∈ ((tail‘𝐷)‘𝑣) ↔ 𝑣𝐷𝑥))
6359, 62anbi12d 633 . . . . . . . . . . . . . . 15 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → ((𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)) ↔ (𝑢𝐷𝑥𝑣𝐷𝑥)))
6463adantr 484 . . . . . . . . . . . . . 14 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → ((𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)) ↔ (𝑢𝐷𝑥𝑣𝐷𝑥)))
6552, 56, 643imtr4d 297 . . . . . . . . . . . . 13 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) → (𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣))))
66 elin 3900 . . . . . . . . . . . . 13 (𝑥 ∈ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ (𝑥 ∈ ((tail‘𝐷)‘𝑢) ∧ 𝑥 ∈ ((tail‘𝐷)‘𝑣)))
6765, 66syl6ibr 255 . . . . . . . . . . . 12 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → (𝑥 ∈ ((tail‘𝐷)‘𝑤) → 𝑥 ∈ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣))))
6867ssrdv 3924 . . . . . . . . . . 11 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → ((tail‘𝐷)‘𝑤) ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
69 sseq1 3943 . . . . . . . . . . . 12 (𝑧 = ((tail‘𝐷)‘𝑤) → (𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ ((tail‘𝐷)‘𝑤) ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣))))
7069rspcev 3574 . . . . . . . . . . 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)))
7136, 68, 70syl2anc 587 . . . . . . . . . 10 (((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) ∧ (𝑤𝑋 ∧ (𝑢𝐷𝑤𝑣𝐷𝑤))) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
7232, 71rexlimddv 3253 . . . . . . . . 9 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)))
73 ineq1 4134 . . . . . . . . . . . 12 (((tail‘𝐷)‘𝑢) = 𝑥 → (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) = (𝑥 ∩ ((tail‘𝐷)‘𝑣)))
7473sseq2d 3950 . . . . . . . . . . 11 (((tail‘𝐷)‘𝑢) = 𝑥 → (𝑧 ⊆ (((tail‘𝐷)‘𝑢) ∩ ((tail‘𝐷)‘𝑣)) ↔ 𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣))))
7574rexbidv 3259 . . . . . . . . . 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))))
76 ineq2 4136 . . . . . . . . . . . 12 (((tail‘𝐷)‘𝑣) = 𝑦 → (𝑥 ∩ ((tail‘𝐷)‘𝑣)) = (𝑥𝑦))
7776sseq2d 3950 . . . . . . . . . . 11 (((tail‘𝐷)‘𝑣) = 𝑦 → (𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣)) ↔ 𝑧 ⊆ (𝑥𝑦)))
7877rexbidv 3259 . . . . . . . . . 10 (((tail‘𝐷)‘𝑣) = 𝑦 → (∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥 ∩ ((tail‘𝐷)‘𝑣)) ↔ ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
7975, 78sylan9bb 513 . . . . . . . . 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 ⊆ (𝑥𝑦)))
8072, 79syl5ibcom 248 . . . . . . . 8 ((𝐷 ∈ DirRel ∧ (𝑢𝑋𝑣𝑋)) → ((((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
8180rexlimdvva 3256 . . . . . . 7 (𝐷 ∈ DirRel → (∃𝑢𝑋𝑣𝑋 (((tail‘𝐷)‘𝑢) = 𝑥 ∧ ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
8230, 81syl5bir 246 . . . . . 6 (𝐷 ∈ DirRel → ((∃𝑢𝑋 ((tail‘𝐷)‘𝑢) = 𝑥 ∧ ∃𝑣𝑋 ((tail‘𝐷)‘𝑣) = 𝑦) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
8329, 82sylbid 243 . . . . 5 (𝐷 ∈ DirRel → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
8483adantr 484 . . . 4 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ((𝑥 ∈ ran (tail‘𝐷) ∧ 𝑦 ∈ ran (tail‘𝐷)) → ∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
8584ralrimivv 3158 . . 3 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦))
8614, 25, 853jca 1125 . 2 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → (ran (tail‘𝐷) ≠ ∅ ∧ ∅ ∉ ran (tail‘𝐷) ∧ ∀𝑥 ∈ ran (tail‘𝐷)∀𝑦 ∈ ran (tail‘𝐷)∃𝑧 ∈ ran (tail‘𝐷)𝑧 ⊆ (𝑥𝑦)))
87 dmexg 7598 . . . . 5 (𝐷 ∈ DirRel → dom 𝐷 ∈ V)
881, 87eqeltrid 2897 . . . 4 (𝐷 ∈ DirRel → 𝑋 ∈ V)
8988adantr 484 . . 3 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → 𝑋 ∈ V)
90 isfbas2 22444 . . 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 ⊆ (𝑥𝑦)))))
9189, 90syl 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 ⊆ (𝑥𝑦)))))
924, 86, 91mpbir2and 712 1 ((𝐷 ∈ DirRel ∧ 𝑋 ≠ ∅) → ran (tail‘𝐷) ∈ (fBas‘𝑋))
 Colors of variables: wff setvar class Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 399   ∧ w3a 1084   = wceq 1538  ∃wex 1781   ∈ wcel 2112   ≠ wne 2990   ∉ wnel 3094  ∀wral 3109  ∃wrex 3110  Vcvv 3444   ∩ cin 3883   ⊆ wss 3884  ∅c0 4246  𝒫 cpw 4500   class class class wbr 5033  dom cdm 5523  ran crn 5524   Fn wfn 6323  ⟶wf 6324  ‘cfv 6328  DirRelcdir 17834  tailctail 17835  fBascfbas 20083 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2114  ax-9 2122  ax-10 2143  ax-11 2159  ax-12 2176  ax-ext 2773  ax-rep 5157  ax-sep 5170  ax-nul 5177  ax-pow 5234  ax-pr 5298  ax-un 7445 This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-ex 1782  df-nf 1786  df-sb 2070  df-mo 2601  df-eu 2632  df-clab 2780  df-cleq 2794  df-clel 2873  df-nfc 2941  df-ne 2991  df-nel 3095  df-ral 3114  df-rex 3115  df-reu 3116  df-rab 3118  df-v 3446  df-sbc 3724  df-csb 3832  df-dif 3887  df-un 3889  df-in 3891  df-ss 3901  df-nul 4247  df-if 4429  df-pw 4502  df-sn 4529  df-pr 4531  df-op 4535  df-uni 4804  df-iun 4886  df-br 5034  df-opab 5096  df-mpt 5114  df-id 5428  df-xp 5529  df-rel 5530  df-cnv 5531  df-co 5532  df-dm 5533  df-rn 5534  df-res 5535  df-ima 5536  df-iota 6287  df-fun 6330  df-fn 6331  df-f 6332  df-f1 6333  df-fo 6334  df-f1o 6335  df-fv 6336  df-dir 17836  df-tail 17837  df-fbas 20092 This theorem is referenced by:  filnetlem4  33843
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