Proof of Theorem efeq1
| Step | Hyp | Ref
| Expression |
| 1 | | halfcl 12576 |
. . . 4
⊢ (𝐴 ∈ ℂ → (𝐴 / 2) ∈
ℂ) |
| 2 | | ax-icn 11263 |
. . . . 5
⊢ i ∈
ℂ |
| 3 | | ine0 11755 |
. . . . 5
⊢ i ≠
0 |
| 4 | | divcl 11984 |
. . . . 5
⊢ (((𝐴 / 2) ∈ ℂ ∧ i
∈ ℂ ∧ i ≠ 0) → ((𝐴 / 2) / i) ∈ ℂ) |
| 5 | 2, 3, 4 | mp3an23 1482 |
. . . 4
⊢ ((𝐴 / 2) ∈ ℂ →
((𝐴 / 2) / i) ∈
ℂ) |
| 6 | 1, 5 | syl 18 |
. . 3
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) / i) ∈
ℂ) |
| 7 | | sineq0 26858 |
. . 3
⊢ (((𝐴 / 2) / i) ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((𝐴 / 2) / i) /
π) ∈ ℤ)) |
| 8 | 6, 7 | syl 18 |
. 2
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((𝐴 / 2) / i) /
π) ∈ ℤ)) |
| 9 | | sinval 16296 |
. . . . . 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 18 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(sin‘((𝐴 / 2) / i)) =
(((exp‘(i · ((𝐴 / 2) / i))) − (exp‘( -i
· ((𝐴 / 2) / i)))) /
(2 · i))) |
| 11 | | divcan2 11986 |
. . . . . . . . . 10
⊢ (((𝐴 / 2) ∈ ℂ ∧ i
∈ ℂ ∧ i ≠ 0) → (i · ((𝐴 / 2) / i)) = (𝐴 / 2)) |
| 12 | 2, 3, 11 | mp3an23 1482 |
. . . . . . . . 9
⊢ ((𝐴 / 2) ∈ ℂ → (i
· ((𝐴 / 2) / i)) =
(𝐴 / 2)) |
| 13 | 1, 12 | syl 18 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ → (i
· ((𝐴 / 2) / i)) =
(𝐴 / 2)) |
| 14 | 13 | fveq2d 6890 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘(i · ((𝐴
/ 2) / i))) = (exp‘(𝐴
/ 2))) |
| 15 | | mulneg1 11756 |
. . . . . . . . . 10
⊢ ((i
∈ ℂ ∧ ((𝐴 /
2) / i) ∈ ℂ) → ( -i · ((𝐴 / 2) / i)) = -(i · ((𝐴 / 2) / i))) |
| 16 | 2, 6, 15 | sylancr 599 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → ( -i
· ((𝐴 / 2) / i)) =
-(i · ((𝐴 / 2) /
i))) |
| 17 | 13 | negeqd 11555 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → -(i
· ((𝐴 / 2) / i)) =
-(𝐴 / 2)) |
| 18 | 16, 17 | eqtrd 2795 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ → ( -i
· ((𝐴 / 2) / i)) =
-(𝐴 / 2)) |
| 19 | 18 | fveq2d 6890 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘( -i · ((𝐴 / 2) / i))) = (exp‘ -(𝐴 / 2))) |
| 20 | 14, 19 | oveq12d 7439 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
((exp‘(i · ((𝐴
/ 2) / i))) − (exp‘( -i · ((𝐴 / 2) / i)))) = ((exp‘(𝐴 / 2)) − (exp‘
-(𝐴 /
2)))) |
| 21 | 20 | oveq1d 7436 |
. . . . 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 2795 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(sin‘((𝐴 / 2) / i)) =
(((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (2 · i))) |
| 23 | 22 | eqeq1d 2762 |
. . 3
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (((exp‘(𝐴
/ 2)) − (exp‘ -(𝐴 / 2))) / (2 · i)) =
0)) |
| 24 | 1 | efcld 16255 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘(𝐴 / 2)) ∈
ℂ) |
| 25 | 1 | negcld 11660 |
. . . . . 6
⊢ (𝐴 ∈ ℂ → -(𝐴 / 2) ∈
ℂ) |
| 26 | 25 | efcld 16255 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘ -(𝐴 / 2))
∈ ℂ) |
| 27 | 24, 26 | subcld 11673 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) ∈ ℂ) |
| 28 | | 2mulicn 12574 |
. . . . 5
⊢ (2
· i) ∈ ℂ |
| 29 | | 2muline0 12575 |
. . . . 5
⊢ (2
· i) ≠ 0 |
| 30 | | diveq0 11988 |
. . . . 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)) |
| 31 | 28, 29, 30 | mp3an23 1482 |
. . . 4
⊢
(((exp‘(𝐴 /
2)) − (exp‘ -(𝐴
/ 2))) ∈ ℂ → ((((exp‘(𝐴 / 2)) − (exp‘ -(𝐴 / 2))) / (2 · i)) = 0
↔ ((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) = 0)) |
| 32 | 27, 31 | syl 18 |
. . 3
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (2 · i)) = 0 ↔ ((exp‘(𝐴 / 2)) − (exp‘ -(𝐴 / 2))) = 0)) |
| 33 | 25 | efne0d 16269 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
(exp‘ -(𝐴 / 2)) ≠
0) |
| 34 | 24, 26, 26, 33 | divsubdird 12136 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (exp‘ -(𝐴 /
2))) = (((exp‘(𝐴 /
2)) / (exp‘ -(𝐴 /
2))) − ((exp‘ -(𝐴 / 2)) / (exp‘ -(𝐴 / 2))))) |
| 35 | | efsub 16274 |
. . . . . . . . 9
⊢ (((𝐴 / 2) ∈ ℂ ∧
-(𝐴 / 2) ∈ ℂ)
→ (exp‘((𝐴 / 2)
− -(𝐴 / 2))) =
((exp‘(𝐴 / 2)) /
(exp‘ -(𝐴 /
2)))) |
| 36 | 1, 25, 35 | syl2anc 596 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(exp‘((𝐴 / 2) −
-(𝐴 / 2))) =
((exp‘(𝐴 / 2)) /
(exp‘ -(𝐴 /
2)))) |
| 37 | 1, 1 | subnegd 11680 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) − -(𝐴 / 2)) = ((𝐴 / 2) + (𝐴 / 2))) |
| 38 | | 2halves 12568 |
. . . . . . . . . 10
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) + (𝐴 / 2)) = 𝐴) |
| 39 | 37, 38 | eqtrd 2795 |
. . . . . . . . 9
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) − -(𝐴 / 2)) = 𝐴) |
| 40 | 39 | fveq2d 6890 |
. . . . . . . 8
⊢ (𝐴 ∈ ℂ →
(exp‘((𝐴 / 2) −
-(𝐴 / 2))) =
(exp‘𝐴)) |
| 41 | 36, 40 | eqtr3d 2797 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
((exp‘(𝐴 / 2)) /
(exp‘ -(𝐴 / 2))) =
(exp‘𝐴)) |
| 42 | 26, 33 | dividd 12095 |
. . . . . . 7
⊢ (𝐴 ∈ ℂ →
((exp‘ -(𝐴 / 2)) /
(exp‘ -(𝐴 / 2))) =
1) |
| 43 | 41, 42 | oveq12d 7439 |
. . . . . 6
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2)) /
(exp‘ -(𝐴 / 2)))
− ((exp‘ -(𝐴 /
2)) / (exp‘ -(𝐴 /
2)))) = ((exp‘𝐴)
− 1)) |
| 44 | 34, 43 | eqtrd 2795 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (exp‘ -(𝐴 /
2))) = ((exp‘𝐴)
− 1)) |
| 45 | 44 | eqeq1d 2762 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (exp‘ -(𝐴 /
2))) = 0 ↔ ((exp‘𝐴) − 1) = 0)) |
| 46 | 27, 26, 33 | diveq0ad 12107 |
. . . 4
⊢ (𝐴 ∈ ℂ →
((((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) / (exp‘ -(𝐴 /
2))) = 0 ↔ ((exp‘(𝐴 / 2)) − (exp‘ -(𝐴 / 2))) = 0)) |
| 47 | | efcl 16254 |
. . . . 5
⊢ (𝐴 ∈ ℂ →
(exp‘𝐴) ∈
ℂ) |
| 48 | | ax-1cn 11262 |
. . . . 5
⊢ 1 ∈
ℂ |
| 49 | | subeq0 11588 |
. . . . 5
⊢
(((exp‘𝐴)
∈ ℂ ∧ 1 ∈ ℂ) → (((exp‘𝐴) − 1) = 0 ↔ (exp‘𝐴) = 1)) |
| 50 | 47, 48, 49 | sylancl 598 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(((exp‘𝐴) − 1)
= 0 ↔ (exp‘𝐴) =
1)) |
| 51 | 45, 46, 50 | 3bitr3d 312 |
. . 3
⊢ (𝐴 ∈ ℂ →
(((exp‘(𝐴 / 2))
− (exp‘ -(𝐴 /
2))) = 0 ↔ (exp‘𝐴) = 1)) |
| 52 | 23, 32, 51 | 3bitrd 308 |
. 2
⊢ (𝐴 ∈ ℂ →
((sin‘((𝐴 / 2) / i))
= 0 ↔ (exp‘𝐴) =
1)) |
| 53 | | 2cnne0 12559 |
. . . . . 6
⊢ (2 ∈
ℂ ∧ 2 ≠ 0) |
| 54 | 2, 3 | pm3.2i 476 |
. . . . . 6
⊢ (i ∈
ℂ ∧ i ≠ 0) |
| 55 | | divdiv32 12029 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ (2 ∈
ℂ ∧ 2 ≠ 0) ∧ (i ∈ ℂ ∧ i ≠ 0)) → ((𝐴 / 2) / i) = ((𝐴 / i) / 2)) |
| 56 | 53, 54, 55 | mp3an23 1482 |
. . . . 5
⊢ (𝐴 ∈ ℂ → ((𝐴 / 2) / i) = ((𝐴 / i) / 2)) |
| 57 | 56 | oveq1d 7436 |
. . . 4
⊢ (𝐴 ∈ ℂ → (((𝐴 / 2) / i) / π) = (((𝐴 / i) / 2) /
π)) |
| 58 | | divcl 11984 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ i ∈
ℂ ∧ i ≠ 0) → (𝐴 / i) ∈ ℂ) |
| 59 | 2, 3, 58 | mp3an23 1482 |
. . . . . 6
⊢ (𝐴 ∈ ℂ → (𝐴 / i) ∈
ℂ) |
| 60 | | picn 26791 |
. . . . . . . 8
⊢ π
∈ ℂ |
| 61 | | pine0 26795 |
. . . . . . . 8
⊢ π ≠
0 |
| 62 | 60, 61 | pm3.2i 476 |
. . . . . . 7
⊢ (π
∈ ℂ ∧ π ≠ 0) |
| 63 | | divdiv1 12032 |
. . . . . . 7
⊢ (((𝐴 / i) ∈ ℂ ∧ (2
∈ ℂ ∧ 2 ≠ 0) ∧ (π ∈ ℂ ∧ π ≠ 0))
→ (((𝐴 / i) / 2) /
π) = ((𝐴 / i) / (2
· π))) |
| 64 | 53, 62, 63 | mp3an23 1482 |
. . . . . 6
⊢ ((𝐴 / i) ∈ ℂ →
(((𝐴 / i) / 2) / π) =
((𝐴 / i) / (2 ·
π))) |
| 65 | 59, 64 | syl 18 |
. . . . 5
⊢ (𝐴 ∈ ℂ → (((𝐴 / i) / 2) / π) = ((𝐴 / i) / (2 ·
π))) |
| 66 | | 2picn 26792 |
. . . . . . 7
⊢ (2
· π) ∈ ℂ |
| 67 | | 2cn 12422 |
. . . . . . . 8
⊢ 2 ∈
ℂ |
| 68 | | 2ne0 12453 |
. . . . . . . 8
⊢ 2 ≠
0 |
| 69 | 67, 60, 68, 61 | mulne0i 11963 |
. . . . . . 7
⊢ (2
· π) ≠ 0 |
| 70 | 66, 69 | pm3.2i 476 |
. . . . . 6
⊢ ((2
· π) ∈ ℂ ∧ (2 · π) ≠ 0) |
| 71 | | divdiv1 12032 |
. . . . . 6
⊢ ((𝐴 ∈ ℂ ∧ (i ∈
ℂ ∧ i ≠ 0) ∧ ((2 · π) ∈ ℂ ∧ (2
· π) ≠ 0)) → ((𝐴 / i) / (2 · π)) = (𝐴 / (i · (2 ·
π)))) |
| 72 | 54, 70, 71 | mp3an23 1482 |
. . . . 5
⊢ (𝐴 ∈ ℂ → ((𝐴 / i) / (2 · π)) =
(𝐴 / (i · (2
· π)))) |
| 73 | 65, 72 | eqtrd 2795 |
. . . 4
⊢ (𝐴 ∈ ℂ → (((𝐴 / i) / 2) / π) = (𝐴 / (i · (2 ·
π)))) |
| 74 | 57, 73 | eqtrd 2795 |
. . 3
⊢ (𝐴 ∈ ℂ → (((𝐴 / 2) / i) / π) = (𝐴 / (i · (2 ·
π)))) |
| 75 | 74 | eleq1d 2845 |
. 2
⊢ (𝐴 ∈ ℂ → ((((𝐴 / 2) / i) / π) ∈
ℤ ↔ (𝐴 / (i
· (2 · π))) ∈ ℤ)) |
| 76 | 8, 52, 75 | 3bitr3d 312 |
1
⊢ (𝐴 ∈ ℂ →
((exp‘𝐴) = 1 ↔
(𝐴 / (i · (2
· π))) ∈ ℤ)) |