Metamath Proof Explorer


Theorem nacsfix

Description: An increasing sequence of closed sets in a Noetherian-type closure system eventually fixates. (Contributed by Stefan O'Rear, 4-Apr-2015)

Ref Expression
Assertion nacsfix ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∃ y ∈ ℕ 0 ∀ z ∈ ℤ ≥ y F ⁡ z = F ⁡ y

Proof

Step Hyp Ref Expression
1 fvssunirn ⊢ F ⁡ z ⊆ ⋃ ran ⁡ F
2 simplrr ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → F ⁡ y = ⋃ ran ⁡ F
3 1 2 sseqtrrid ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → F ⁡ z ⊆ F ⁡ y
4 simpll3 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1
5 simplrl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → y ∈ ℕ 0
6 simpr ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → z ∈ ℤ ≥ y
7 incssnn0 ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ z ∈ ℤ ≥ y → F ⁡ y ⊆ F ⁡ z
8 4 5 6 7 syl3anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → F ⁡ y ⊆ F ⁡ z
9 3 8 eqssd ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F ∧ z ∈ ℤ ≥ y → F ⁡ z = F ⁡ y
10 9 ralrimiva ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ y ∈ ℕ 0 ∧ F ⁡ y = ⋃ ran ⁡ F → ∀ z ∈ ℤ ≥ y F ⁡ z = F ⁡ y
11 frn ⊢ F : ℕ 0 ⟶ C → ran ⁡ F ⊆ C
12 11 3ad2ant2 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ran ⁡ F ⊆ C
13 elpw2g ⊢ C ∈ NoeACS ⁡ X → ran ⁡ F ∈ 𝒫 C ↔ ran ⁡ F ⊆ C
14 13 3ad2ant1 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ran ⁡ F ∈ 𝒫 C ↔ ran ⁡ F ⊆ C
15 12 14 mpbird ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ran ⁡ F ∈ 𝒫 C
16 elex ⊢ ran ⁡ F ∈ 𝒫 C → ran ⁡ F ∈ V
17 15 16 syl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ran ⁡ F ∈ V
18 ffn ⊢ F : ℕ 0 ⟶ C → F Fn ℕ 0
19 18 3ad2ant2 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → F Fn ℕ 0
20 0nn0 ⊢ 0 ∈ ℕ 0
21 fnfvelrn ⊢ F Fn ℕ 0 ∧ 0 ∈ ℕ 0 → F ⁡ 0 ∈ ran ⁡ F
22 19 20 21 sylancl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → F ⁡ 0 ∈ ran ⁡ F
23 22 ne0d ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ran ⁡ F ≠ ∅
24 nn0re ⊢ a ∈ ℕ 0 → a ∈ ℝ
25 24 ad2antrl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 → a ∈ ℝ
26 nn0re ⊢ b ∈ ℕ 0 → b ∈ ℝ
27 26 ad2antll ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 → b ∈ ℝ
28 simplrr ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → b ∈ ℕ 0
29 simpll3 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1
30 simplrl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → a ∈ ℕ 0
31 nn0z ⊢ a ∈ ℕ 0 → a ∈ ℤ
32 nn0z ⊢ b ∈ ℕ 0 → b ∈ ℤ
33 eluz ⊢ a ∈ ℤ ∧ b ∈ ℤ → b ∈ ℤ ≥ a ↔ a ≤ b
34 31 32 33 syl2an ⊢ a ∈ ℕ 0 ∧ b ∈ ℕ 0 → b ∈ ℤ ≥ a ↔ a ≤ b
35 34 biimpar ⊢ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → b ∈ ℤ ≥ a
36 35 adantll ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → b ∈ ℤ ≥ a
37 incssnn0 ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℤ ≥ a → F ⁡ a ⊆ F ⁡ b
38 29 30 36 37 syl3anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → F ⁡ a ⊆ F ⁡ b
39 ssequn1 ⊢ F ⁡ a ⊆ F ⁡ b ↔ F ⁡ a ∪ F ⁡ b = F ⁡ b
40 38 39 sylib ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → F ⁡ a ∪ F ⁡ b = F ⁡ b
41 eqimss ⊢ F ⁡ a ∪ F ⁡ b = F ⁡ b → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ b
42 40 41 syl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ b
43 fveq2 ⊢ c = b → F ⁡ c = F ⁡ b
44 43 sseq2d ⊢ c = b → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c ↔ F ⁡ a ∪ F ⁡ b ⊆ F ⁡ b
45 44 rspcev ⊢ b ∈ ℕ 0 ∧ F ⁡ a ∪ F ⁡ b ⊆ F ⁡ b → ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
46 28 42 45 syl2anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ a ≤ b → ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
47 simplrl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → a ∈ ℕ 0
48 simpll3 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1
49 simplrr ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → b ∈ ℕ 0
50 eluz ⊢ b ∈ ℤ ∧ a ∈ ℤ → a ∈ ℤ ≥ b ↔ b ≤ a
51 32 31 50 syl2anr ⊢ a ∈ ℕ 0 ∧ b ∈ ℕ 0 → a ∈ ℤ ≥ b ↔ b ≤ a
52 51 biimpar ⊢ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → a ∈ ℤ ≥ b
53 52 adantll ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → a ∈ ℤ ≥ b
54 incssnn0 ⊢ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ b ∈ ℕ 0 ∧ a ∈ ℤ ≥ b → F ⁡ b ⊆ F ⁡ a
55 48 49 53 54 syl3anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → F ⁡ b ⊆ F ⁡ a
56 ssequn2 ⊢ F ⁡ b ⊆ F ⁡ a ↔ F ⁡ a ∪ F ⁡ b = F ⁡ a
57 55 56 sylib ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → F ⁡ a ∪ F ⁡ b = F ⁡ a
58 eqimss ⊢ F ⁡ a ∪ F ⁡ b = F ⁡ a → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ a
59 57 58 syl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ a
60 fveq2 ⊢ c = a → F ⁡ c = F ⁡ a
61 60 sseq2d ⊢ c = a → F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c ↔ F ⁡ a ∪ F ⁡ b ⊆ F ⁡ a
62 61 rspcev ⊢ a ∈ ℕ 0 ∧ F ⁡ a ∪ F ⁡ b ⊆ F ⁡ a → ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
63 47 59 62 syl2anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 ∧ b ≤ a → ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
64 25 27 46 63 lecasei ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 ∧ a ∈ ℕ 0 ∧ b ∈ ℕ 0 → ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
65 64 ralrimivva ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∀ a ∈ ℕ 0 ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
66 uneq1 ⊢ y = F ⁡ a → y ∪ z = F ⁡ a ∪ z
67 66 sseq1d ⊢ y = F ⁡ a → y ∪ z ⊆ w ↔ F ⁡ a ∪ z ⊆ w
68 67 rexbidv ⊢ y = F ⁡ a → ∃ w ∈ ran ⁡ F y ∪ z ⊆ w ↔ ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w
69 68 ralbidv ⊢ y = F ⁡ a → ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w ↔ ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w
70 69 ralrn ⊢ F Fn ℕ 0 → ∀ y ∈ ran ⁡ F ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w ↔ ∀ a ∈ ℕ 0 ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w
71 uneq2 ⊢ z = F ⁡ b → F ⁡ a ∪ z = F ⁡ a ∪ F ⁡ b
72 71 sseq1d ⊢ z = F ⁡ b → F ⁡ a ∪ z ⊆ w ↔ F ⁡ a ∪ F ⁡ b ⊆ w
73 72 rexbidv ⊢ z = F ⁡ b → ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w ↔ ∃ w ∈ ran ⁡ F F ⁡ a ∪ F ⁡ b ⊆ w
74 73 ralrn ⊢ F Fn ℕ 0 → ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w ↔ ∀ b ∈ ℕ 0 ∃ w ∈ ran ⁡ F F ⁡ a ∪ F ⁡ b ⊆ w
75 sseq2 ⊢ w = F ⁡ c → F ⁡ a ∪ F ⁡ b ⊆ w ↔ F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
76 75 rexrn ⊢ F Fn ℕ 0 → ∃ w ∈ ran ⁡ F F ⁡ a ∪ F ⁡ b ⊆ w ↔ ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
77 76 ralbidv ⊢ F Fn ℕ 0 → ∀ b ∈ ℕ 0 ∃ w ∈ ran ⁡ F F ⁡ a ∪ F ⁡ b ⊆ w ↔ ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
78 74 77 bitrd ⊢ F Fn ℕ 0 → ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w ↔ ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
79 78 ralbidv ⊢ F Fn ℕ 0 → ∀ a ∈ ℕ 0 ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F F ⁡ a ∪ z ⊆ w ↔ ∀ a ∈ ℕ 0 ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
80 70 79 bitrd ⊢ F Fn ℕ 0 → ∀ y ∈ ran ⁡ F ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w ↔ ∀ a ∈ ℕ 0 ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
81 19 80 syl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∀ y ∈ ran ⁡ F ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w ↔ ∀ a ∈ ℕ 0 ∀ b ∈ ℕ 0 ∃ c ∈ ℕ 0 F ⁡ a ∪ F ⁡ b ⊆ F ⁡ c
82 65 81 mpbird ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∀ y ∈ ran ⁡ F ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w
83 isipodrs ⊢ toInc ⁡ ran ⁡ F ∈ Dirset ↔ ran ⁡ F ∈ V ∧ ran ⁡ F ≠ ∅ ∧ ∀ y ∈ ran ⁡ F ∀ z ∈ ran ⁡ F ∃ w ∈ ran ⁡ F y ∪ z ⊆ w
84 17 23 82 83 syl3anbrc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → toInc ⁡ ran ⁡ F ∈ Dirset
85 isnacs3 ⊢ C ∈ NoeACS ⁡ X ↔ C ∈ Moore ⁡ X ∧ ∀ y ∈ 𝒫 C toInc ⁡ y ∈ Dirset → ⋃ y ∈ y
86 85 simprbi ⊢ C ∈ NoeACS ⁡ X → ∀ y ∈ 𝒫 C toInc ⁡ y ∈ Dirset → ⋃ y ∈ y
87 86 3ad2ant1 ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∀ y ∈ 𝒫 C toInc ⁡ y ∈ Dirset → ⋃ y ∈ y
88 fveq2 ⊢ y = ran ⁡ F → toInc ⁡ y = toInc ⁡ ran ⁡ F
89 88 eleq1d ⊢ y = ran ⁡ F → toInc ⁡ y ∈ Dirset ↔ toInc ⁡ ran ⁡ F ∈ Dirset
90 unieq ⊢ y = ran ⁡ F → ⋃ y = ⋃ ran ⁡ F
91 id ⊢ y = ran ⁡ F → y = ran ⁡ F
92 90 91 eleq12d ⊢ y = ran ⁡ F → ⋃ y ∈ y ↔ ⋃ ran ⁡ F ∈ ran ⁡ F
93 89 92 imbi12d ⊢ y = ran ⁡ F → toInc ⁡ y ∈ Dirset → ⋃ y ∈ y ↔ toInc ⁡ ran ⁡ F ∈ Dirset → ⋃ ran ⁡ F ∈ ran ⁡ F
94 93 rspcva ⊢ ran ⁡ F ∈ 𝒫 C ∧ ∀ y ∈ 𝒫 C toInc ⁡ y ∈ Dirset → ⋃ y ∈ y → toInc ⁡ ran ⁡ F ∈ Dirset → ⋃ ran ⁡ F ∈ ran ⁡ F
95 15 87 94 syl2anc ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → toInc ⁡ ran ⁡ F ∈ Dirset → ⋃ ran ⁡ F ∈ ran ⁡ F
96 84 95 mpd ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ⋃ ran ⁡ F ∈ ran ⁡ F
97 fvelrnb ⊢ F Fn ℕ 0 → ⋃ ran ⁡ F ∈ ran ⁡ F ↔ ∃ y ∈ ℕ 0 F ⁡ y = ⋃ ran ⁡ F
98 19 97 syl ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ⋃ ran ⁡ F ∈ ran ⁡ F ↔ ∃ y ∈ ℕ 0 F ⁡ y = ⋃ ran ⁡ F
99 96 98 mpbid ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∃ y ∈ ℕ 0 F ⁡ y = ⋃ ran ⁡ F
100 10 99 reximddv ⊢ C ∈ NoeACS ⁡ X ∧ F : ℕ 0 ⟶ C ∧ ∀ x ∈ ℕ 0 F ⁡ x ⊆ F ⁡ x + 1 → ∃ y ∈ ℕ 0 ∀ z ∈ ℤ ≥ y F ⁡ z = F ⁡ y