| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | 1zzd 12650 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 1 ∈
ℤ) | 
| 2 |  | nnz 12636 | . . . 4
⊢ (𝑁 ∈ ℕ → 𝑁 ∈
ℤ) | 
| 3 | 2 | adantr 480 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 𝑁 ∈
ℤ) | 
| 4 |  | simplr 768 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → 𝐴 ∈ ℂ) | 
| 5 |  | 2nn 12340 | . . . . . 6
⊢ 2 ∈
ℕ | 
| 6 |  | elfznn 13594 | . . . . . . . 8
⊢ (𝑘 ∈ (1...𝑁) → 𝑘 ∈ ℕ) | 
| 7 | 6 | adantl 481 | . . . . . . 7
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → 𝑘 ∈ ℕ) | 
| 8 | 7 | nnnn0d 12589 | . . . . . 6
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → 𝑘 ∈ ℕ0) | 
| 9 |  | nnexpcl 14116 | . . . . . 6
⊢ ((2
∈ ℕ ∧ 𝑘
∈ ℕ0) → (2↑𝑘) ∈ ℕ) | 
| 10 | 5, 8, 9 | sylancr 587 | . . . . 5
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → (2↑𝑘) ∈ ℕ) | 
| 11 | 10 | nncnd 12283 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → (2↑𝑘) ∈ ℂ) | 
| 12 | 10 | nnne0d 12317 | . . . 4
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → (2↑𝑘) ≠ 0) | 
| 13 | 4, 11, 12 | divcld 12044 | . . 3
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑘 ∈ (1...𝑁)) → (𝐴 / (2↑𝑘)) ∈ ℂ) | 
| 14 |  | oveq2 7440 | . . . 4
⊢ (𝑘 = (𝑗 + 1) → (2↑𝑘) = (2↑(𝑗 + 1))) | 
| 15 | 14 | oveq2d 7448 | . . 3
⊢ (𝑘 = (𝑗 + 1) → (𝐴 / (2↑𝑘)) = (𝐴 / (2↑(𝑗 + 1)))) | 
| 16 | 1, 1, 3, 13, 15 | fsumshftm 15818 | . 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑘 ∈ (1...𝑁)(𝐴 / (2↑𝑘)) = Σ𝑗 ∈ ((1 − 1)...(𝑁 − 1))(𝐴 / (2↑(𝑗 + 1)))) | 
| 17 |  | 1m1e0 12339 | . . . . 5
⊢ (1
− 1) = 0 | 
| 18 | 17 | oveq1i 7442 | . . . 4
⊢ ((1
− 1)...(𝑁 − 1))
= (0...(𝑁 −
1)) | 
| 19 | 18 | sumeq1i 15734 | . . 3
⊢
Σ𝑗 ∈ ((1
− 1)...(𝑁 −
1))(𝐴 / (2↑(𝑗 + 1))) = Σ𝑗 ∈ (0...(𝑁 − 1))(𝐴 / (2↑(𝑗 + 1))) | 
| 20 |  | halfcn 12482 | . . . . . . . . . 10
⊢ (1 / 2)
∈ ℂ | 
| 21 |  | elfznn0 13661 | . . . . . . . . . . 11
⊢ (𝑗 ∈ (0...(𝑁 − 1)) → 𝑗 ∈ ℕ0) | 
| 22 | 21 | adantl 481 | . . . . . . . . . 10
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → 𝑗 ∈ ℕ0) | 
| 23 |  | expcl 14121 | . . . . . . . . . 10
⊢ (((1 / 2)
∈ ℂ ∧ 𝑗
∈ ℕ0) → ((1 / 2)↑𝑗) ∈ ℂ) | 
| 24 | 20, 22, 23 | sylancr 587 | . . . . . . . . 9
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → ((1 / 2)↑𝑗) ∈
ℂ) | 
| 25 |  | 2cnd 12345 | . . . . . . . . 9
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → 2 ∈
ℂ) | 
| 26 |  | 2ne0 12371 | . . . . . . . . . 10
⊢ 2 ≠
0 | 
| 27 | 26 | a1i 11 | . . . . . . . . 9
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → 2 ≠
0) | 
| 28 | 24, 25, 27 | divrecd 12047 | . . . . . . . 8
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (((1 / 2)↑𝑗) / 2) = (((1 / 2)↑𝑗) · (1 /
2))) | 
| 29 |  | expp1 14110 | . . . . . . . . 9
⊢ (((1 / 2)
∈ ℂ ∧ 𝑗
∈ ℕ0) → ((1 / 2)↑(𝑗 + 1)) = (((1 / 2)↑𝑗) · (1 / 2))) | 
| 30 | 20, 22, 29 | sylancr 587 | . . . . . . . 8
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → ((1 / 2)↑(𝑗 + 1)) = (((1 / 2)↑𝑗) · (1 /
2))) | 
| 31 |  | elfzelz 13565 | . . . . . . . . . . 11
⊢ (𝑗 ∈ (0...(𝑁 − 1)) → 𝑗 ∈ ℤ) | 
| 32 | 31 | peano2zd 12727 | . . . . . . . . . 10
⊢ (𝑗 ∈ (0...(𝑁 − 1)) → (𝑗 + 1) ∈ ℤ) | 
| 33 | 32 | adantl 481 | . . . . . . . . 9
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (𝑗 + 1) ∈ ℤ) | 
| 34 | 25, 27, 33 | exprecd 14195 | . . . . . . . 8
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → ((1 / 2)↑(𝑗 + 1)) = (1 / (2↑(𝑗 + 1)))) | 
| 35 | 28, 30, 34 | 3eqtr2rd 2783 | . . . . . . 7
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (1 / (2↑(𝑗 + 1))) = (((1 / 2)↑𝑗) / 2)) | 
| 36 | 35 | oveq2d 7448 | . . . . . 6
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (𝐴 · (1 / (2↑(𝑗 + 1)))) = (𝐴 · (((1 / 2)↑𝑗) / 2))) | 
| 37 |  | simplr 768 | . . . . . . 7
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → 𝐴 ∈ ℂ) | 
| 38 |  | peano2nn0 12568 | . . . . . . . . . 10
⊢ (𝑗 ∈ ℕ0
→ (𝑗 + 1) ∈
ℕ0) | 
| 39 | 22, 38 | syl 17 | . . . . . . . . 9
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (𝑗 + 1) ∈
ℕ0) | 
| 40 |  | nnexpcl 14116 | . . . . . . . . 9
⊢ ((2
∈ ℕ ∧ (𝑗 +
1) ∈ ℕ0) → (2↑(𝑗 + 1)) ∈ ℕ) | 
| 41 | 5, 39, 40 | sylancr 587 | . . . . . . . 8
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (2↑(𝑗 + 1)) ∈
ℕ) | 
| 42 | 41 | nncnd 12283 | . . . . . . 7
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (2↑(𝑗 + 1)) ∈
ℂ) | 
| 43 | 41 | nnne0d 12317 | . . . . . . 7
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (2↑(𝑗 + 1)) ≠ 0) | 
| 44 | 37, 42, 43 | divrecd 12047 | . . . . . 6
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (𝐴 / (2↑(𝑗 + 1))) = (𝐴 · (1 / (2↑(𝑗 + 1))))) | 
| 45 | 24, 37, 25, 27 | div12d 12080 | . . . . . 6
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (((1 / 2)↑𝑗) · (𝐴 / 2)) = (𝐴 · (((1 / 2)↑𝑗) / 2))) | 
| 46 | 36, 44, 45 | 3eqtr4d 2786 | . . . . 5
⊢ (((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) ∧ 𝑗 ∈ (0...(𝑁 − 1))) → (𝐴 / (2↑(𝑗 + 1))) = (((1 / 2)↑𝑗) · (𝐴 / 2))) | 
| 47 | 46 | sumeq2dv 15739 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑗 ∈ (0...(𝑁 − 1))(𝐴 / (2↑(𝑗 + 1))) = Σ𝑗 ∈ (0...(𝑁 − 1))(((1 / 2)↑𝑗) · (𝐴 / 2))) | 
| 48 |  | fzfid 14015 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(0...(𝑁 − 1)) ∈
Fin) | 
| 49 |  | halfcl 12494 | . . . . . 6
⊢ (𝐴 ∈ ℂ → (𝐴 / 2) ∈
ℂ) | 
| 50 | 49 | adantl 481 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (𝐴 / 2) ∈
ℂ) | 
| 51 | 48, 50, 24 | fsummulc1 15822 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(Σ𝑗 ∈
(0...(𝑁 − 1))((1 /
2)↑𝑗) · (𝐴 / 2)) = Σ𝑗 ∈ (0...(𝑁 − 1))(((1 / 2)↑𝑗) · (𝐴 / 2))) | 
| 52 | 47, 51 | eqtr4d 2779 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑗 ∈ (0...(𝑁 − 1))(𝐴 / (2↑(𝑗 + 1))) = (Σ𝑗 ∈ (0...(𝑁 − 1))((1 / 2)↑𝑗) · (𝐴 / 2))) | 
| 53 | 19, 52 | eqtrid 2788 | . 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑗 ∈ ((1 −
1)...(𝑁 − 1))(𝐴 / (2↑(𝑗 + 1))) = (Σ𝑗 ∈ (0...(𝑁 − 1))((1 / 2)↑𝑗) · (𝐴 / 2))) | 
| 54 |  | 2cnd 12345 | . . . . . . . 8
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 2 ∈
ℂ) | 
| 55 | 26 | a1i 11 | . . . . . . . 8
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 2 ≠
0) | 
| 56 | 54, 55, 3 | exprecd 14195 | . . . . . . 7
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((1 /
2)↑𝑁) = (1 /
(2↑𝑁))) | 
| 57 | 56 | oveq2d 7448 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1
− ((1 / 2)↑𝑁)) =
(1 − (1 / (2↑𝑁)))) | 
| 58 |  | 1mhlfehlf 12487 | . . . . . . 7
⊢ (1
− (1 / 2)) = (1 / 2) | 
| 59 | 58 | a1i 11 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1
− (1 / 2)) = (1 / 2)) | 
| 60 | 57, 59 | oveq12d 7450 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((1
− ((1 / 2)↑𝑁)) /
(1 − (1 / 2))) = ((1 − (1 / (2↑𝑁))) / (1 / 2))) | 
| 61 |  | simpr 484 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 𝐴 ∈
ℂ) | 
| 62 | 61, 54, 55 | divrec2d 12048 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (𝐴 / 2) = ((1 / 2) · 𝐴)) | 
| 63 | 60, 62 | oveq12d 7450 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (((1
− ((1 / 2)↑𝑁)) /
(1 − (1 / 2))) · (𝐴 / 2)) = (((1 − (1 / (2↑𝑁))) / (1 / 2)) · ((1 / 2)
· 𝐴))) | 
| 64 |  | ax-1cn 11214 | . . . . . . 7
⊢ 1 ∈
ℂ | 
| 65 |  | nnnn0 12535 | . . . . . . . . . . 11
⊢ (𝑁 ∈ ℕ → 𝑁 ∈
ℕ0) | 
| 66 | 65 | adantr 480 | . . . . . . . . . 10
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 𝑁 ∈
ℕ0) | 
| 67 |  | nnexpcl 14116 | . . . . . . . . . 10
⊢ ((2
∈ ℕ ∧ 𝑁
∈ ℕ0) → (2↑𝑁) ∈ ℕ) | 
| 68 | 5, 66, 67 | sylancr 587 | . . . . . . . . 9
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(2↑𝑁) ∈
ℕ) | 
| 69 | 68 | nnrecred 12318 | . . . . . . . 8
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1 /
(2↑𝑁)) ∈
ℝ) | 
| 70 | 69 | recnd 11290 | . . . . . . 7
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1 /
(2↑𝑁)) ∈
ℂ) | 
| 71 |  | subcl 11508 | . . . . . . 7
⊢ ((1
∈ ℂ ∧ (1 / (2↑𝑁)) ∈ ℂ) → (1 − (1 /
(2↑𝑁))) ∈
ℂ) | 
| 72 | 64, 70, 71 | sylancr 587 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1
− (1 / (2↑𝑁)))
∈ ℂ) | 
| 73 | 20 | a1i 11 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1 / 2)
∈ ℂ) | 
| 74 |  | 0re 11264 | . . . . . . . 8
⊢ 0 ∈
ℝ | 
| 75 |  | halfgt0 12483 | . . . . . . . 8
⊢ 0 < (1
/ 2) | 
| 76 | 74, 75 | gtneii 11374 | . . . . . . 7
⊢ (1 / 2)
≠ 0 | 
| 77 | 76 | a1i 11 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1 / 2)
≠ 0) | 
| 78 | 72, 73, 77 | divcld 12044 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((1
− (1 / (2↑𝑁))) /
(1 / 2)) ∈ ℂ) | 
| 79 | 78, 73, 61 | mulassd 11285 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((((1
− (1 / (2↑𝑁))) /
(1 / 2)) · (1 / 2)) · 𝐴) = (((1 − (1 / (2↑𝑁))) / (1 / 2)) · ((1 / 2)
· 𝐴))) | 
| 80 | 72, 73, 77 | divcan1d 12045 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (((1
− (1 / (2↑𝑁))) /
(1 / 2)) · (1 / 2)) = (1 − (1 / (2↑𝑁)))) | 
| 81 | 80 | oveq1d 7447 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((((1
− (1 / (2↑𝑁))) /
(1 / 2)) · (1 / 2)) · 𝐴) = ((1 − (1 / (2↑𝑁))) · 𝐴)) | 
| 82 | 63, 79, 81 | 3eqtr2d 2782 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (((1
− ((1 / 2)↑𝑁)) /
(1 − (1 / 2))) · (𝐴 / 2)) = ((1 − (1 / (2↑𝑁))) · 𝐴)) | 
| 83 |  | halfre 12481 | . . . . . . 7
⊢ (1 / 2)
∈ ℝ | 
| 84 |  | halflt1 12485 | . . . . . . 7
⊢ (1 / 2)
< 1 | 
| 85 | 83, 84 | ltneii 11375 | . . . . . 6
⊢ (1 / 2)
≠ 1 | 
| 86 | 85 | a1i 11 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1 / 2)
≠ 1) | 
| 87 | 73, 86, 66 | geoser 15904 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑗 ∈ (0...(𝑁 − 1))((1 / 2)↑𝑗) = ((1 − ((1 /
2)↑𝑁)) / (1 − (1
/ 2)))) | 
| 88 | 87 | oveq1d 7447 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(Σ𝑗 ∈
(0...(𝑁 − 1))((1 /
2)↑𝑗) · (𝐴 / 2)) = (((1 − ((1 /
2)↑𝑁)) / (1 − (1
/ 2))) · (𝐴 /
2))) | 
| 89 |  | mullid 11261 | . . . . . . 7
⊢ (𝐴 ∈ ℂ → (1
· 𝐴) = 𝐴) | 
| 90 | 89 | adantl 481 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (1
· 𝐴) = 𝐴) | 
| 91 | 90 | eqcomd 2742 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 𝐴 = (1 · 𝐴)) | 
| 92 | 68 | nncnd 12283 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(2↑𝑁) ∈
ℂ) | 
| 93 | 68 | nnne0d 12317 | . . . . . 6
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(2↑𝑁) ≠
0) | 
| 94 | 61, 92, 93 | divrec2d 12048 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (𝐴 / (2↑𝑁)) = ((1 / (2↑𝑁)) · 𝐴)) | 
| 95 | 91, 94 | oveq12d 7450 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (𝐴 − (𝐴 / (2↑𝑁))) = ((1 · 𝐴) − ((1 / (2↑𝑁)) · 𝐴))) | 
| 96 | 64 | a1i 11 | . . . . 5
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → 1 ∈
ℂ) | 
| 97 | 96, 70, 61 | subdird 11721 | . . . 4
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → ((1
− (1 / (2↑𝑁)))
· 𝐴) = ((1 ·
𝐴) − ((1 /
(2↑𝑁)) · 𝐴))) | 
| 98 | 95, 97 | eqtr4d 2779 | . . 3
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) → (𝐴 − (𝐴 / (2↑𝑁))) = ((1 − (1 / (2↑𝑁))) · 𝐴)) | 
| 99 | 82, 88, 98 | 3eqtr4d 2786 | . 2
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
(Σ𝑗 ∈
(0...(𝑁 − 1))((1 /
2)↑𝑗) · (𝐴 / 2)) = (𝐴 − (𝐴 / (2↑𝑁)))) | 
| 100 | 16, 53, 99 | 3eqtrd 2780 | 1
⊢ ((𝑁 ∈ ℕ ∧ 𝐴 ∈ ℂ) →
Σ𝑘 ∈ (1...𝑁)(𝐴 / (2↑𝑘)) = (𝐴 − (𝐴 / (2↑𝑁)))) |