Proof of Theorem argregt0
Step | Hyp | Ref
| Expression |
1 | | recl 14821 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
(ℜ‘𝐴) ∈
ℝ) |
2 | | gt0ne0 11440 |
. . . . . 6
⊢
(((ℜ‘𝐴)
∈ ℝ ∧ 0 < (ℜ‘𝐴)) → (ℜ‘𝐴) ≠ 0) |
3 | 1, 2 | sylan 580 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℜ‘𝐴) ≠
0) |
4 | | fveq2 6774 |
. . . . . . 7
⊢ (𝐴 = 0 → (ℜ‘𝐴) =
(ℜ‘0)) |
5 | | re0 14863 |
. . . . . . 7
⊢
(ℜ‘0) = 0 |
6 | 4, 5 | eqtrdi 2794 |
. . . . . 6
⊢ (𝐴 = 0 → (ℜ‘𝐴) = 0) |
7 | 6 | necon3i 2976 |
. . . . 5
⊢
((ℜ‘𝐴)
≠ 0 → 𝐴 ≠
0) |
8 | 3, 7 | syl 17 |
. . . 4
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
𝐴 ≠ 0) |
9 | | logcl 25724 |
. . . 4
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (log‘𝐴) ∈
ℂ) |
10 | 8, 9 | syldan 591 |
. . 3
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(log‘𝐴) ∈
ℂ) |
11 | 10 | imcld 14906 |
. 2
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℑ‘(log‘𝐴)) ∈ ℝ) |
12 | | coshalfpi 25626 |
. . . . . 6
⊢
(cos‘(π / 2)) = 0 |
13 | | simpr 485 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
< (ℜ‘𝐴)) |
14 | | abscl 14990 |
. . . . . . . . . . . . . 14
⊢ (𝐴 ∈ ℂ →
(abs‘𝐴) ∈
ℝ) |
15 | 14 | adantr 481 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘𝐴) ∈
ℝ) |
16 | 15 | recnd 11003 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘𝐴) ∈
ℂ) |
17 | 16 | mul01d 11174 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘𝐴) · 0)
= 0) |
18 | | simpl 483 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
𝐴 ∈
ℂ) |
19 | | absrpcl 15000 |
. . . . . . . . . . . . . . . 16
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (abs‘𝐴) ∈
ℝ+) |
20 | 8, 19 | syldan 591 |
. . . . . . . . . . . . . . 15
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘𝐴) ∈
ℝ+) |
21 | 20 | rpne0d 12777 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘𝐴) ≠
0) |
22 | 18, 16, 21 | divcld 11751 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(𝐴 / (abs‘𝐴)) ∈
ℂ) |
23 | 15, 22 | remul2d 14938 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℜ‘((abs‘𝐴) · (𝐴 / (abs‘𝐴)))) = ((abs‘𝐴) · (ℜ‘(𝐴 / (abs‘𝐴))))) |
24 | 18, 16, 21 | divcan2d 11753 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘𝐴) ·
(𝐴 / (abs‘𝐴))) = 𝐴) |
25 | 24 | fveq2d 6778 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℜ‘((abs‘𝐴) · (𝐴 / (abs‘𝐴)))) = (ℜ‘𝐴)) |
26 | 23, 25 | eqtr3d 2780 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘𝐴) ·
(ℜ‘(𝐴 /
(abs‘𝐴)))) =
(ℜ‘𝐴)) |
27 | 13, 17, 26 | 3brtr4d 5106 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘𝐴) · 0)
< ((abs‘𝐴)
· (ℜ‘(𝐴 /
(abs‘𝐴))))) |
28 | | 0re 10977 |
. . . . . . . . . . . 12
⊢ 0 ∈
ℝ |
29 | 28 | a1i 11 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
∈ ℝ) |
30 | 22 | recld 14905 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℜ‘(𝐴 /
(abs‘𝐴))) ∈
ℝ) |
31 | 29, 30, 20 | ltmul2d 12814 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → (0
< (ℜ‘(𝐴 /
(abs‘𝐴))) ↔
((abs‘𝐴) · 0)
< ((abs‘𝐴)
· (ℜ‘(𝐴 /
(abs‘𝐴)))))) |
32 | 27, 31 | mpbird 256 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
< (ℜ‘(𝐴 /
(abs‘𝐴)))) |
33 | | efiarg 25762 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (exp‘(i
· (ℑ‘(log‘𝐴)))) = (𝐴 / (abs‘𝐴))) |
34 | 8, 33 | syldan 591 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(exp‘(i · (ℑ‘(log‘𝐴)))) = (𝐴 / (abs‘𝐴))) |
35 | 34 | fveq2d 6778 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℜ‘(exp‘(i · (ℑ‘(log‘𝐴))))) = (ℜ‘(𝐴 / (abs‘𝐴)))) |
36 | 32, 35 | breqtrrd 5102 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
< (ℜ‘(exp‘(i · (ℑ‘(log‘𝐴)))))) |
37 | | recosval 15845 |
. . . . . . . . 9
⊢
((ℑ‘(log‘𝐴)) ∈ ℝ →
(cos‘(ℑ‘(log‘𝐴))) = (ℜ‘(exp‘(i ·
(ℑ‘(log‘𝐴)))))) |
38 | 11, 37 | syl 17 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(cos‘(ℑ‘(log‘𝐴))) = (ℜ‘(exp‘(i ·
(ℑ‘(log‘𝐴)))))) |
39 | 36, 38 | breqtrrd 5102 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
< (cos‘(ℑ‘(log‘𝐴)))) |
40 | | fveq2 6774 |
. . . . . . . . 9
⊢
((abs‘(ℑ‘(log‘𝐴))) = (ℑ‘(log‘𝐴)) →
(cos‘(abs‘(ℑ‘(log‘𝐴)))) =
(cos‘(ℑ‘(log‘𝐴)))) |
41 | 40 | a1i 11 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) = (ℑ‘(log‘𝐴)) →
(cos‘(abs‘(ℑ‘(log‘𝐴)))) =
(cos‘(ℑ‘(log‘𝐴))))) |
42 | 11 | recnd 11003 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℑ‘(log‘𝐴)) ∈ ℂ) |
43 | | cosneg 15856 |
. . . . . . . . . 10
⊢
((ℑ‘(log‘𝐴)) ∈ ℂ →
(cos‘-(ℑ‘(log‘𝐴))) =
(cos‘(ℑ‘(log‘𝐴)))) |
44 | 42, 43 | syl 17 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(cos‘-(ℑ‘(log‘𝐴))) =
(cos‘(ℑ‘(log‘𝐴)))) |
45 | | fveqeq2 6783 |
. . . . . . . . 9
⊢
((abs‘(ℑ‘(log‘𝐴))) = -(ℑ‘(log‘𝐴)) →
((cos‘(abs‘(ℑ‘(log‘𝐴)))) =
(cos‘(ℑ‘(log‘𝐴))) ↔
(cos‘-(ℑ‘(log‘𝐴))) =
(cos‘(ℑ‘(log‘𝐴))))) |
46 | 44, 45 | syl5ibrcom 246 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) = -(ℑ‘(log‘𝐴)) →
(cos‘(abs‘(ℑ‘(log‘𝐴)))) =
(cos‘(ℑ‘(log‘𝐴))))) |
47 | 11 | absord 15127 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) = (ℑ‘(log‘𝐴)) ∨
(abs‘(ℑ‘(log‘𝐴))) = -(ℑ‘(log‘𝐴)))) |
48 | 41, 46, 47 | mpjaod 857 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(cos‘(abs‘(ℑ‘(log‘𝐴)))) =
(cos‘(ℑ‘(log‘𝐴)))) |
49 | 39, 48 | breqtrrd 5102 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
< (cos‘(abs‘(ℑ‘(log‘𝐴))))) |
50 | 12, 49 | eqbrtrid 5109 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(cos‘(π / 2)) <
(cos‘(abs‘(ℑ‘(log‘𝐴))))) |
51 | 42 | abscld 15148 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘(ℑ‘(log‘𝐴))) ∈ ℝ) |
52 | 42 | absge0d 15156 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) → 0
≤ (abs‘(ℑ‘(log‘𝐴)))) |
53 | | logimcl 25725 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (-π <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π)) |
54 | 8, 53 | syldan 591 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(-π < (ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π)) |
55 | 54 | simpld 495 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
-π < (ℑ‘(log‘𝐴))) |
56 | | pire 25615 |
. . . . . . . . . . 11
⊢ π
∈ ℝ |
57 | 56 | renegcli 11282 |
. . . . . . . . . 10
⊢ -π
∈ ℝ |
58 | | ltle 11063 |
. . . . . . . . . 10
⊢ ((-π
∈ ℝ ∧ (ℑ‘(log‘𝐴)) ∈ ℝ) → (-π <
(ℑ‘(log‘𝐴)) → -π ≤
(ℑ‘(log‘𝐴)))) |
59 | 57, 11, 58 | sylancr 587 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(-π < (ℑ‘(log‘𝐴)) → -π ≤
(ℑ‘(log‘𝐴)))) |
60 | 55, 59 | mpd 15 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
-π ≤ (ℑ‘(log‘𝐴))) |
61 | 54 | simprd 496 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℑ‘(log‘𝐴)) ≤ π) |
62 | | absle 15027 |
. . . . . . . . 9
⊢
(((ℑ‘(log‘𝐴)) ∈ ℝ ∧ π ∈ ℝ)
→ ((abs‘(ℑ‘(log‘𝐴))) ≤ π ↔ (-π ≤
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π))) |
63 | 11, 56, 62 | sylancl 586 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) ≤ π ↔ (-π ≤
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π))) |
64 | 60, 61, 63 | mpbir2and 710 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘(ℑ‘(log‘𝐴))) ≤ π) |
65 | 28, 56 | elicc2i 13145 |
. . . . . . 7
⊢
((abs‘(ℑ‘(log‘𝐴))) ∈ (0[,]π) ↔
((abs‘(ℑ‘(log‘𝐴))) ∈ ℝ ∧ 0 ≤
(abs‘(ℑ‘(log‘𝐴))) ∧
(abs‘(ℑ‘(log‘𝐴))) ≤ π)) |
66 | 51, 52, 64, 65 | syl3anbrc 1342 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘(ℑ‘(log‘𝐴))) ∈ (0[,]π)) |
67 | | halfpire 25621 |
. . . . . . 7
⊢ (π /
2) ∈ ℝ |
68 | | pirp 25618 |
. . . . . . . 8
⊢ π
∈ ℝ+ |
69 | | rphalfcl 12757 |
. . . . . . . 8
⊢ (π
∈ ℝ+ → (π / 2) ∈
ℝ+) |
70 | | rpge0 12743 |
. . . . . . . 8
⊢ ((π /
2) ∈ ℝ+ → 0 ≤ (π / 2)) |
71 | 68, 69, 70 | mp2b 10 |
. . . . . . 7
⊢ 0 ≤
(π / 2) |
72 | | rphalflt 12759 |
. . . . . . . . 9
⊢ (π
∈ ℝ+ → (π / 2) < π) |
73 | 68, 72 | ax-mp 5 |
. . . . . . . 8
⊢ (π /
2) < π |
74 | 67, 56, 73 | ltleii 11098 |
. . . . . . 7
⊢ (π /
2) ≤ π |
75 | 28, 56 | elicc2i 13145 |
. . . . . . 7
⊢ ((π /
2) ∈ (0[,]π) ↔ ((π / 2) ∈ ℝ ∧ 0 ≤ (π / 2)
∧ (π / 2) ≤ π)) |
76 | 67, 71, 74, 75 | mpbir3an 1340 |
. . . . . 6
⊢ (π /
2) ∈ (0[,]π) |
77 | | cosord 25687 |
. . . . . 6
⊢
(((abs‘(ℑ‘(log‘𝐴))) ∈ (0[,]π) ∧ (π / 2)
∈ (0[,]π)) → ((abs‘(ℑ‘(log‘𝐴))) < (π / 2) ↔
(cos‘(π / 2)) <
(cos‘(abs‘(ℑ‘(log‘𝐴)))))) |
78 | 66, 76, 77 | sylancl 586 |
. . . . 5
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) < (π / 2) ↔ (cos‘(π
/ 2)) < (cos‘(abs‘(ℑ‘(log‘𝐴)))))) |
79 | 50, 78 | mpbird 256 |
. . . 4
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(abs‘(ℑ‘(log‘𝐴))) < (π / 2)) |
80 | | abslt 15026 |
. . . . 5
⊢
(((ℑ‘(log‘𝐴)) ∈ ℝ ∧ (π / 2) ∈
ℝ) → ((abs‘(ℑ‘(log‘𝐴))) < (π / 2) ↔ (-(π / 2) <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) < (π /
2)))) |
81 | 11, 67, 80 | sylancl 586 |
. . . 4
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
((abs‘(ℑ‘(log‘𝐴))) < (π / 2) ↔ (-(π / 2) <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) < (π /
2)))) |
82 | 79, 81 | mpbid 231 |
. . 3
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(-(π / 2) < (ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) < (π /
2))) |
83 | 82 | simpld 495 |
. 2
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
-(π / 2) < (ℑ‘(log‘𝐴))) |
84 | 82 | simprd 496 |
. 2
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℑ‘(log‘𝐴)) < (π / 2)) |
85 | 67 | renegcli 11282 |
. . . 4
⊢ -(π /
2) ∈ ℝ |
86 | 85 | rexri 11033 |
. . 3
⊢ -(π /
2) ∈ ℝ* |
87 | 67 | rexri 11033 |
. . 3
⊢ (π /
2) ∈ ℝ* |
88 | | elioo2 13120 |
. . 3
⊢ ((-(π
/ 2) ∈ ℝ* ∧ (π / 2) ∈ ℝ*)
→ ((ℑ‘(log‘𝐴)) ∈ (-(π / 2)(,)(π / 2)) ↔
((ℑ‘(log‘𝐴)) ∈ ℝ ∧ -(π / 2) <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) < (π /
2)))) |
89 | 86, 87, 88 | mp2an 689 |
. 2
⊢
((ℑ‘(log‘𝐴)) ∈ (-(π / 2)(,)(π / 2)) ↔
((ℑ‘(log‘𝐴)) ∈ ℝ ∧ -(π / 2) <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) < (π /
2))) |
90 | 11, 83, 84, 89 | syl3anbrc 1342 |
1
⊢ ((𝐴 ∈ ℂ ∧ 0 <
(ℜ‘𝐴)) →
(ℑ‘(log‘𝐴)) ∈ (-(π / 2)(,)(π /
2))) |