Proof of Theorem efeq1
Step | Hyp | Ref
| Expression |
1 | | halfcl 12190 |
. . . 4
⊢ (𝐴 ∈ ℂ → (𝐴 / 2) ∈
ℂ) |
2 | | ax-icn 10923 |
. . . . 5
⊢ i ∈
ℂ |
3 | | ine0 11402 |
. . . . 5
⊢ i ≠
0 |
4 | | divcl 11631 |
. . . . 5
⊢ (((𝐴 / 2) ∈ ℂ ∧ i
∈ ℂ ∧ i ≠ 0) → ((𝐴 / 2) / i) ∈ ℂ) |
5 | 2, 3, 4 | mp3an23 1452 |
. . . 4
⊢ ((𝐴 / 2) ∈ ℂ →
((𝐴 / 2) / i) ∈
ℂ) |
6 | 1, 5 | syl 17 |
. . 3
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) / i) ∈
ℂ) |
7 | | sineq0 25670 |
. . 3
⊢ (((𝐴 / 2) / i) ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((𝐴 / 2) / i) /
π) ∈ ℤ)) |
8 | 6, 7 | syl 17 |
. 2
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((𝐴 / 2) / i) /
π) ∈ ℤ)) |
9 | | sinval 15821 |
. . . . . 6
⊢ (((𝐴 / 2) / i) ∈ ℂ →
(sin‘((𝐴 / 2) / i)) =
(((exp‘(i · ((𝐴 / 2) / i))) − (exp‘(-i ·
((𝐴 / 2) / i)))) / (2
· i))) |
10 | 6, 9 | syl 17 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(sin‘((𝐴 / 2) / i)) =
(((exp‘(i · ((𝐴 / 2) / i))) − (exp‘(-i ·
((𝐴 / 2) / i)))) / (2
· i))) |
11 | | divcan2 11633 |
. . . . . . . . . 10
⊢ (((𝐴 / 2) ∈ ℂ ∧ i
∈ ℂ ∧ i ≠ 0) → (i · ((𝐴 / 2) / i)) = (𝐴 / 2)) |
12 | 2, 3, 11 | mp3an23 1452 |
. . . . . . . . 9
⊢ ((𝐴 / 2) ∈ ℂ → (i
· ((𝐴 / 2) / i)) =
(𝐴 / 2)) |
13 | 1, 12 | syl 17 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ → (i
· ((𝐴 / 2) / i)) =
(𝐴 / 2)) |
14 | 13 | fveq2d 6773 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘(i · ((𝐴
/ 2) / i))) = (exp‘(𝐴
/ 2))) |
15 | | mulneg1 11403 |
. . . . . . . . . 10
⊢ ((i
∈ ℂ ∧ ((𝐴 /
2) / i) ∈ ℂ) → (-i · ((𝐴 / 2) / i)) = -(i · ((𝐴 / 2) / i))) |
16 | 2, 6, 15 | sylancr 587 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → (-i
· ((𝐴 / 2) / i)) =
-(i · ((𝐴 / 2) /
i))) |
17 | 13 | negeqd 11207 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → -(i
· ((𝐴 / 2) / i)) =
-(𝐴 / 2)) |
18 | 16, 17 | eqtrd 2780 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ → (-i
· ((𝐴 / 2) / i)) =
-(𝐴 / 2)) |
19 | 18 | fveq2d 6773 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘(-i · ((𝐴
/ 2) / i))) = (exp‘-(𝐴 / 2))) |
20 | 14, 19 | oveq12d 7287 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
((exp‘(i · ((𝐴
/ 2) / i))) − (exp‘(-i · ((𝐴 / 2) / i)))) = ((exp‘(𝐴 / 2)) −
(exp‘-(𝐴 /
2)))) |
21 | 20 | oveq1d 7284 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(((exp‘(i · ((𝐴 / 2) / i))) − (exp‘(-i ·
((𝐴 / 2) / i)))) / (2
· i)) = (((exp‘(𝐴 / 2)) − (exp‘-(𝐴 / 2))) / (2 ·
i))) |
22 | 10, 21 | eqtrd 2780 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(sin‘((𝐴 / 2) / i)) =
(((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (2 · i))) |
23 | 22 | eqeq1d 2742 |
. . 3
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((exp‘(𝐴
/ 2)) − (exp‘-(𝐴 / 2))) / (2 · i)) =
0)) |
24 | | efcl 15782 |
. . . . . 6
⊢ ((𝐴 / 2) ∈ ℂ →
(exp‘(𝐴 / 2)) ∈
ℂ) |
25 | 1, 24 | syl 17 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘(𝐴 / 2)) ∈
ℂ) |
26 | 1 | negcld 11311 |
. . . . . 6
⊢ (𝐴 ∈ ℂ → -(𝐴 / 2) ∈
ℂ) |
27 | | efcl 15782 |
. . . . . 6
⊢ (-(𝐴 / 2) ∈ ℂ →
(exp‘-(𝐴 / 2)) ∈
ℂ) |
28 | 26, 27 | syl 17 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘-(𝐴 / 2)) ∈
ℂ) |
29 | 25, 28 | subcld 11324 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) ∈ ℂ) |
30 | | 2cn 12040 |
. . . . . 6
⊢ 2 ∈
ℂ |
31 | 30, 2 | mulcli 10975 |
. . . . 5
⊢ (2
· i) ∈ ℂ |
32 | | 2ne0 12069 |
. . . . . 6
⊢ 2 ≠
0 |
33 | 30, 2, 32, 3 | mulne0i 11610 |
. . . . 5
⊢ (2
· i) ≠ 0 |
34 | | diveq0 11635 |
. . . . 5
⊢
((((exp‘(𝐴 /
2)) − (exp‘-(𝐴
/ 2))) ∈ ℂ ∧ (2 · i) ∈ ℂ ∧ (2 · i)
≠ 0) → ((((exp‘(𝐴 / 2)) − (exp‘-(𝐴 / 2))) / (2 · i)) = 0
↔ ((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) = 0)) |
35 | 31, 33, 34 | mp3an23 1452 |
. . . 4
⊢
(((exp‘(𝐴 /
2)) − (exp‘-(𝐴
/ 2))) ∈ ℂ → ((((exp‘(𝐴 / 2)) − (exp‘-(𝐴 / 2))) / (2 · i)) = 0
↔ ((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) = 0)) |
36 | 29, 35 | syl 17 |
. . 3
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (2 · i)) = 0 ↔ ((exp‘(𝐴 / 2)) − (exp‘-(𝐴 / 2))) = 0)) |
37 | | efne0 15796 |
. . . . . . . 8
⊢ (-(𝐴 / 2) ∈ ℂ →
(exp‘-(𝐴 / 2)) ≠
0) |
38 | 26, 37 | syl 17 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘-(𝐴 / 2)) ≠
0) |
39 | 25, 28, 28, 38 | divsubdird 11782 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (exp‘-(𝐴 /
2))) = (((exp‘(𝐴 /
2)) / (exp‘-(𝐴 / 2)))
− ((exp‘-(𝐴 /
2)) / (exp‘-(𝐴 /
2))))) |
40 | | efsub 15799 |
. . . . . . . . 9
⊢ (((𝐴 / 2) ∈ ℂ ∧
-(𝐴 / 2) ∈ ℂ)
→ (exp‘((𝐴 / 2)
− -(𝐴 / 2))) =
((exp‘(𝐴 / 2)) /
(exp‘-(𝐴 /
2)))) |
41 | 1, 26, 40 | syl2anc 584 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(exp‘((𝐴 / 2) −
-(𝐴 / 2))) =
((exp‘(𝐴 / 2)) /
(exp‘-(𝐴 /
2)))) |
42 | 1, 1 | subnegd 11331 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) − -(𝐴 / 2)) = ((𝐴 / 2) + (𝐴 / 2))) |
43 | | 2halves 12193 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) + (𝐴 / 2)) = 𝐴) |
44 | 42, 43 | eqtrd 2780 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) − -(𝐴 / 2)) = 𝐴) |
45 | 44 | fveq2d 6773 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(exp‘((𝐴 / 2) −
-(𝐴 / 2))) =
(exp‘𝐴)) |
46 | 41, 45 | eqtr3d 2782 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
((exp‘(𝐴 / 2)) /
(exp‘-(𝐴 / 2))) =
(exp‘𝐴)) |
47 | 28, 38 | dividd 11741 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
((exp‘-(𝐴 / 2)) /
(exp‘-(𝐴 / 2))) =
1) |
48 | 46, 47 | oveq12d 7287 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2)) /
(exp‘-(𝐴 / 2)))
− ((exp‘-(𝐴 /
2)) / (exp‘-(𝐴 /
2)))) = ((exp‘𝐴)
− 1)) |
49 | 39, 48 | eqtrd 2780 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (exp‘-(𝐴 /
2))) = ((exp‘𝐴)
− 1)) |
50 | 49 | eqeq1d 2742 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (exp‘-(𝐴 /
2))) = 0 ↔ ((exp‘𝐴) − 1) = 0)) |
51 | 29, 28, 38 | diveq0ad 11753 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) / (exp‘-(𝐴 /
2))) = 0 ↔ ((exp‘(𝐴 / 2)) − (exp‘-(𝐴 / 2))) = 0)) |
52 | | efcl 15782 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘𝐴) ∈
ℂ) |
53 | | ax-1cn 10922 |
. . . . 5
⊢ 1 ∈
ℂ |
54 | | subeq0 11239 |
. . . . 5
⊢
(((exp‘𝐴)
∈ ℂ ∧ 1 ∈ ℂ) → (((exp‘𝐴) − 1) = 0 ↔ (exp‘𝐴) = 1)) |
55 | 52, 53, 54 | sylancl 586 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(((exp‘𝐴) − 1)
= 0 ↔ (exp‘𝐴) =
1)) |
56 | 50, 51, 55 | 3bitr3d 309 |
. . 3
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘-(𝐴 /
2))) = 0 ↔ (exp‘𝐴) = 1)) |
57 | 23, 36, 56 | 3bitrd 305 |
. 2
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (exp‘𝐴) =
1)) |
58 | | 2cnne0 12175 |
. . . . . 6
⊢ (2 ∈
ℂ ∧ 2 ≠ 0) |
59 | 2, 3 | pm3.2i 471 |
. . . . . 6
⊢ (i ∈
ℂ ∧ i ≠ 0) |
60 | | divdiv32 11675 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ (2 ∈
ℂ ∧ 2 ≠ 0) ∧ (i ∈ ℂ ∧ i ≠ 0)) → ((𝐴 / 2) / i) = ((𝐴 / i) / 2)) |
61 | 58, 59, 60 | mp3an23 1452 |
. . . . 5
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) / i) = ((𝐴 / i) / 2)) |
62 | 61 | oveq1d 7284 |
. . . 4
⊢ (𝐴 ∈ ℂ → (((𝐴 / 2) / i) / π) = (((𝐴 / i) / 2) /
π)) |
63 | | divcl 11631 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ i ∈
ℂ ∧ i ≠ 0) → (𝐴 / i) ∈ ℂ) |
64 | 2, 3, 63 | mp3an23 1452 |
. . . . . 6
⊢ (𝐴 ∈ ℂ → (𝐴 / i) ∈
ℂ) |
65 | | picn 25606 |
. . . . . . . 8
⊢ π
∈ ℂ |
66 | | pire 25605 |
. . . . . . . . 9
⊢ π
∈ ℝ |
67 | | pipos 25607 |
. . . . . . . . 9
⊢ 0 <
π |
68 | 66, 67 | gt0ne0ii 11503 |
. . . . . . . 8
⊢ π ≠
0 |
69 | 65, 68 | pm3.2i 471 |
. . . . . . 7
⊢ (π
∈ ℂ ∧ π ≠ 0) |
70 | | divdiv1 11678 |
. . . . . . 7
⊢ (((𝐴 / i) ∈ ℂ ∧ (2
∈ ℂ ∧ 2 ≠ 0) ∧ (π ∈ ℂ ∧ π ≠ 0))
→ (((𝐴 / i) / 2) /
π) = ((𝐴 / i) / (2
· π))) |
71 | 58, 69, 70 | mp3an23 1452 |
. . . . . 6
⊢ ((𝐴 / i) ∈ ℂ →
(((𝐴 / i) / 2) / π) =
((𝐴 / i) / (2 ·
π))) |
72 | 64, 71 | syl 17 |
. . . . 5
⊢ (𝐴 ∈ ℂ → (((𝐴 / i) / 2) / π) = ((𝐴 / i) / (2 ·
π))) |
73 | 30, 65 | mulcli 10975 |
. . . . . . 7
⊢ (2
· π) ∈ ℂ |
74 | 30, 65, 32, 68 | mulne0i 11610 |
. . . . . . 7
⊢ (2
· π) ≠ 0 |
75 | 73, 74 | pm3.2i 471 |
. . . . . 6
⊢ ((2
· π) ∈ ℂ ∧ (2 · π) ≠ 0) |
76 | | divdiv1 11678 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ (i ∈
ℂ ∧ i ≠ 0) ∧ ((2 · π) ∈ ℂ ∧ (2
· π) ≠ 0)) → ((𝐴 / i) / (2 · π)) = (𝐴 / (i · (2 ·
π)))) |
77 | 59, 75, 76 | mp3an23 1452 |
. . . . 5
⊢ (𝐴 ∈ ℂ → ((𝐴 / i) / (2 · π)) =
(𝐴 / (i · (2
· π)))) |
78 | 72, 77 | eqtrd 2780 |
. . . 4
⊢ (𝐴 ∈ ℂ → (((𝐴 / i) / 2) / π) = (𝐴 / (i · (2 ·
π)))) |
79 | 62, 78 | eqtrd 2780 |
. . 3
⊢ (𝐴 ∈ ℂ → (((𝐴 / 2) / i) / π) = (𝐴 / (i · (2 ·
π)))) |
80 | 79 | eleq1d 2825 |
. 2
⊢ (𝐴 ∈ ℂ → ((((𝐴 / 2) / i) / π) ∈
ℤ ↔ (𝐴 / (i
· (2 · π))) ∈ ℤ)) |
81 | 8, 57, 80 | 3bitr3d 309 |
1
⊢ (𝐴 ∈ ℂ →
((exp‘𝐴) = 1 ↔
(𝐴 / (i · (2
· π))) ∈ ℤ)) |