Metamath Proof Explorer


Theorem lgamgulmlem6

Description: The series G is uniformly convergent on the compact region U , which describes a circle of radius R with holes of size 1 / R around the poles of the gamma function. (Contributed by Mario Carneiro, 9-Jul-2017)

Ref Expression
Hypotheses lgamgulm.r ( 𝜑𝑅 ∈ ℕ )
lgamgulm.u 𝑈 = { 𝑥 ∈ ℂ ∣ ( ( abs ‘ 𝑥 ) ≤ 𝑅 ∧ ∀ 𝑘 ∈ ℕ0 ( 1 / 𝑅 ) ≤ ( abs ‘ ( 𝑥 + 𝑘 ) ) ) }
lgamgulm.g 𝐺 = ( 𝑚 ∈ ℕ ↦ ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) )
lgamgulm.t 𝑇 = ( 𝑚 ∈ ℕ ↦ if ( ( 2 · 𝑅 ) ≤ 𝑚 , ( 𝑅 · ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ) , ( ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) + ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ) ) )
Assertion lgamgulmlem6 ( 𝜑 → ( seq 1 ( ∘f + , 𝐺 ) ∈ dom ( ⇝𝑢𝑈 ) ∧ ( seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) → ∃ 𝑟 ∈ ℝ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) ) )

Proof

Step Hyp Ref Expression
1 lgamgulm.r ( 𝜑𝑅 ∈ ℕ )
2 lgamgulm.u 𝑈 = { 𝑥 ∈ ℂ ∣ ( ( abs ‘ 𝑥 ) ≤ 𝑅 ∧ ∀ 𝑘 ∈ ℕ0 ( 1 / 𝑅 ) ≤ ( abs ‘ ( 𝑥 + 𝑘 ) ) ) }
3 lgamgulm.g 𝐺 = ( 𝑚 ∈ ℕ ↦ ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) )
4 lgamgulm.t 𝑇 = ( 𝑚 ∈ ℕ ↦ if ( ( 2 · 𝑅 ) ≤ 𝑚 , ( 𝑅 · ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ) , ( ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) + ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ) ) )
5 nnuz ℕ = ( ℤ ‘ 1 )
6 1zzd ( 𝜑 → 1 ∈ ℤ )
7 cnex ℂ ∈ V
8 2 7 rabex2 𝑈 ∈ V
9 8 a1i ( 𝜑𝑈 ∈ V )
10 1 2 lgamgulmlem1 ( 𝜑𝑈 ⊆ ( ℂ ∖ ( ℤ ∖ ℕ ) ) )
11 10 ad2antrr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑈 ⊆ ( ℂ ∖ ( ℤ ∖ ℕ ) ) )
12 simpr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑧𝑈 )
13 11 12 sseldd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑧 ∈ ( ℂ ∖ ( ℤ ∖ ℕ ) ) )
14 13 eldifad ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑧 ∈ ℂ )
15 simplr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑚 ∈ ℕ )
16 15 peano2nnd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( 𝑚 + 1 ) ∈ ℕ )
17 16 nnrpd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( 𝑚 + 1 ) ∈ ℝ+ )
18 15 nnrpd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑚 ∈ ℝ+ )
19 17 18 rpdivcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( ( 𝑚 + 1 ) / 𝑚 ) ∈ ℝ+ )
20 19 relogcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ∈ ℝ )
21 20 recnd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ∈ ℂ )
22 14 21 mulcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) ∈ ℂ )
23 15 nncnd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑚 ∈ ℂ )
24 15 nnne0d ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 𝑚 ≠ 0 )
25 14 23 24 divcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( 𝑧 / 𝑚 ) ∈ ℂ )
26 1cnd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → 1 ∈ ℂ )
27 25 26 addcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( ( 𝑧 / 𝑚 ) + 1 ) ∈ ℂ )
28 13 15 dmgmdivn0 ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( ( 𝑧 / 𝑚 ) + 1 ) ≠ 0 )
29 27 28 logcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ∈ ℂ )
30 22 29 subcld ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑧𝑈 ) → ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ∈ ℂ )
31 30 fmpttd ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) : 𝑈 ⟶ ℂ )
32 7 8 elmap ( ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) ∈ ( ℂ ↑m 𝑈 ) ↔ ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) : 𝑈 ⟶ ℂ )
33 31 32 sylibr ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑧𝑈 ↦ ( ( 𝑧 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) − ( log ‘ ( ( 𝑧 / 𝑚 ) + 1 ) ) ) ) ∈ ( ℂ ↑m 𝑈 ) )
34 33 3 fmptd ( 𝜑𝐺 : ℕ ⟶ ( ℂ ↑m 𝑈 ) )
35 nnex ℕ ∈ V
36 35 mptex ( 𝑚 ∈ ℕ ↦ if ( ( 2 · 𝑅 ) ≤ 𝑚 , ( 𝑅 · ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ) , ( ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) + ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ) ) ) ∈ V
37 4 36 eqeltri 𝑇 ∈ V
38 37 a1i ( 𝜑𝑇 ∈ V )
39 1 adantr ( ( 𝜑𝑚 ∈ ℕ ) → 𝑅 ∈ ℕ )
40 39 nnred ( ( 𝜑𝑚 ∈ ℕ ) → 𝑅 ∈ ℝ )
41 2re 2 ∈ ℝ
42 41 a1i ( ( 𝜑𝑚 ∈ ℕ ) → 2 ∈ ℝ )
43 1red ( ( 𝜑𝑚 ∈ ℕ ) → 1 ∈ ℝ )
44 40 43 readdcld ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑅 + 1 ) ∈ ℝ )
45 42 44 remulcld ( ( 𝜑𝑚 ∈ ℕ ) → ( 2 · ( 𝑅 + 1 ) ) ∈ ℝ )
46 simpr ( ( 𝜑𝑚 ∈ ℕ ) → 𝑚 ∈ ℕ )
47 46 nnsqcld ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑚 ↑ 2 ) ∈ ℕ )
48 45 47 nndivred ( ( 𝜑𝑚 ∈ ℕ ) → ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ∈ ℝ )
49 40 48 remulcld ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑅 · ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ) ∈ ℝ )
50 46 peano2nnd ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑚 + 1 ) ∈ ℕ )
51 50 nnrpd ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑚 + 1 ) ∈ ℝ+ )
52 46 nnrpd ( ( 𝜑𝑚 ∈ ℕ ) → 𝑚 ∈ ℝ+ )
53 51 52 rpdivcld ( ( 𝜑𝑚 ∈ ℕ ) → ( ( 𝑚 + 1 ) / 𝑚 ) ∈ ℝ+ )
54 53 relogcld ( ( 𝜑𝑚 ∈ ℕ ) → ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ∈ ℝ )
55 40 54 remulcld ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) ∈ ℝ )
56 39 peano2nnd ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑅 + 1 ) ∈ ℕ )
57 56 nnrpd ( ( 𝜑𝑚 ∈ ℕ ) → ( 𝑅 + 1 ) ∈ ℝ+ )
58 57 52 rpmulcld ( ( 𝜑𝑚 ∈ ℕ ) → ( ( 𝑅 + 1 ) · 𝑚 ) ∈ ℝ+ )
59 58 relogcld ( ( 𝜑𝑚 ∈ ℕ ) → ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) ∈ ℝ )
60 pire π ∈ ℝ
61 60 a1i ( ( 𝜑𝑚 ∈ ℕ ) → π ∈ ℝ )
62 59 61 readdcld ( ( 𝜑𝑚 ∈ ℕ ) → ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ∈ ℝ )
63 55 62 readdcld ( ( 𝜑𝑚 ∈ ℕ ) → ( ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) + ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ) ∈ ℝ )
64 49 63 ifcld ( ( 𝜑𝑚 ∈ ℕ ) → if ( ( 2 · 𝑅 ) ≤ 𝑚 , ( 𝑅 · ( ( 2 · ( 𝑅 + 1 ) ) / ( 𝑚 ↑ 2 ) ) ) , ( ( 𝑅 · ( log ‘ ( ( 𝑚 + 1 ) / 𝑚 ) ) ) + ( ( log ‘ ( ( 𝑅 + 1 ) · 𝑚 ) ) + π ) ) ) ∈ ℝ )
65 64 4 fmptd ( 𝜑𝑇 : ℕ ⟶ ℝ )
66 65 ffvelrnda ( ( 𝜑𝑛 ∈ ℕ ) → ( 𝑇𝑛 ) ∈ ℝ )
67 1 2 3 4 lgamgulmlem5 ( ( 𝜑 ∧ ( 𝑛 ∈ ℕ ∧ 𝑦𝑈 ) ) → ( abs ‘ ( ( 𝐺𝑛 ) ‘ 𝑦 ) ) ≤ ( 𝑇𝑛 ) )
68 1 2 3 4 lgamgulmlem4 ( 𝜑 → seq 1 ( + , 𝑇 ) ∈ dom ⇝ )
69 5 6 9 34 38 66 67 68 mtest ( 𝜑 → seq 1 ( ∘f + , 𝐺 ) ∈ dom ( ⇝𝑢𝑈 ) )
70 1zzd ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → 1 ∈ ℤ )
71 8 a1i ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → 𝑈 ∈ V )
72 34 adantr ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → 𝐺 : ℕ ⟶ ( ℂ ↑m 𝑈 ) )
73 37 a1i ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → 𝑇 ∈ V )
74 66 adantlr ( ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) ∧ 𝑛 ∈ ℕ ) → ( 𝑇𝑛 ) ∈ ℝ )
75 67 adantlr ( ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) ∧ ( 𝑛 ∈ ℕ ∧ 𝑦𝑈 ) ) → ( abs ‘ ( ( 𝐺𝑛 ) ‘ 𝑦 ) ) ≤ ( 𝑇𝑛 ) )
76 68 adantr ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → seq 1 ( + , 𝑇 ) ∈ dom ⇝ )
77 simpr ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) )
78 5 70 71 72 73 74 75 76 77 mtestbdd ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ∃ 𝑟 ∈ ℝ ∀ 𝑦𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟 )
79 nfcv 𝑧 abs
80 nffvmpt1 𝑧 ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 )
81 79 80 nffv 𝑧 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) )
82 nfcv 𝑧
83 nfcv 𝑧 𝑟
84 81 82 83 nfbr 𝑧 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟
85 nfv 𝑦 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟
86 2fveq3 ( 𝑦 = 𝑧 → ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) = ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) )
87 86 breq1d ( 𝑦 = 𝑧 → ( ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟 ↔ ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ) )
88 84 85 87 cbvralw ( ∀ 𝑦𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟 ↔ ∀ 𝑧𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 )
89 ulmcl ( seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) → ( 𝑧𝑈𝑂 ) : 𝑈 ⟶ ℂ )
90 89 adantl ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ( 𝑧𝑈𝑂 ) : 𝑈 ⟶ ℂ )
91 eqid ( 𝑧𝑈𝑂 ) = ( 𝑧𝑈𝑂 )
92 91 fmpt ( ∀ 𝑧𝑈 𝑂 ∈ ℂ ↔ ( 𝑧𝑈𝑂 ) : 𝑈 ⟶ ℂ )
93 90 92 sylibr ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ∀ 𝑧𝑈 𝑂 ∈ ℂ )
94 91 fvmpt2 ( ( 𝑧𝑈𝑂 ∈ ℂ ) → ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) = 𝑂 )
95 94 fveq2d ( ( 𝑧𝑈𝑂 ∈ ℂ ) → ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) = ( abs ‘ 𝑂 ) )
96 95 breq1d ( ( 𝑧𝑈𝑂 ∈ ℂ ) → ( ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ↔ ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
97 96 ralimiaa ( ∀ 𝑧𝑈 𝑂 ∈ ℂ → ∀ 𝑧𝑈 ( ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ↔ ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
98 ralbi ( ∀ 𝑧𝑈 ( ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ↔ ( abs ‘ 𝑂 ) ≤ 𝑟 ) → ( ∀ 𝑧𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ↔ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
99 93 97 98 3syl ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ( ∀ 𝑧𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑧 ) ) ≤ 𝑟 ↔ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
100 88 99 syl5bb ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ( ∀ 𝑦𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟 ↔ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
101 100 rexbidv ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ( ∃ 𝑟 ∈ ℝ ∀ 𝑦𝑈 ( abs ‘ ( ( 𝑧𝑈𝑂 ) ‘ 𝑦 ) ) ≤ 𝑟 ↔ ∃ 𝑟 ∈ ℝ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
102 78 101 mpbid ( ( 𝜑 ∧ seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) ) → ∃ 𝑟 ∈ ℝ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 )
103 102 ex ( 𝜑 → ( seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) → ∃ 𝑟 ∈ ℝ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) )
104 69 103 jca ( 𝜑 → ( seq 1 ( ∘f + , 𝐺 ) ∈ dom ( ⇝𝑢𝑈 ) ∧ ( seq 1 ( ∘f + , 𝐺 ) ( ⇝𝑢𝑈 ) ( 𝑧𝑈𝑂 ) → ∃ 𝑟 ∈ ℝ ∀ 𝑧𝑈 ( abs ‘ 𝑂 ) ≤ 𝑟 ) ) )